The Kingdom of Thailand wants to seal its commitment to green energy with its new hybrid solar-hydropower generation facility that covers a water reservoir in the northeast of the country.
The installation covers an immense 720,000 square meters of the reservoir’s surface and produces clean electricity around the clock: solar power during the day, hydropower at night. Christened the Sirindhorn dam farm, this is the “world’s largest floating hydro-solar farm”, and the first of 15 such farms planned to be built by Thailand by 2037. They are a linchpin in the kingdom’s pledge for carbon neutrality by 2050.
Floating towards the future
“We can claim that through 45 megawatts combined with hydropower and energy management system for solar and hydro powers, this is the first and biggest project in the world,” Electricity Generating Authority of Thailand (EGAT) deputy governor Prasertsak Cherngchawano told AFP.
At the 2021 United Nations Climate Change Conference (COP26) last year, Thailand’s Prime Minister Prayut Chan-O-Cha officially announced his country’s goal of reaching carbon neutrality by 2050, and a net-zero greenhouse emissions target by 2065. Thailand also aims to produce 30% of its energy from renewables by 2037 as an interim goal.
The Sirindhorn dam farm project, which went into operation last October, is the cornerstone of that pledge. The farm contains over 144,000 solar cells and can output 45 MW of electricity. This is enough to reduce Thailand’s carbon dioxide emissions by an estimated 47,000 tons per year.
Thailand’s energy grids continue to rely heavily on fossil fuel; some 55% of the country’s power generation as of October last year was derived from such fuels, while only 11% came from renewable sources such as solar or hydropower, according to Thailand’s Energy Policy and Planning Office, a department of the ministry of energy. Still, projects such as Sirindhorn show that progress is being made.
The $35 million project took two years to build, with repeated delays caused by the pandemic, which saw technicians falling sick and deliveries of solar panels being repeatedly delayed. EGAT plans to install floating hydro-solar farms in 15 more dams across Thailand by 2037, which would total an estimated 2,725 MW of power.
Currently, power generated at Sirindhorn is being distributed mainly to domestic and commercial users in the lower northeastern region of the country.
Thailand is also betting that its floating solar farms will be of interest to tourists, as well. Sirindhorn comes with a 415-meter (1,360-foot) long “Nature Walkway” which will give a breathtaking view of the reservoir and the solar cells floating across its surface. Locals are already flocking to see the solar farm, and time will tell if international travelers will be drawn here as well.
Local communities report that with the solar floats installed, catches of fish in the reservoir have decreased — but they seem to be positive about it. State authorities say that the project will not affect agriculture, fishing, or other community activities in the long term, and are committed to taking any steps necessary towards this goal.
“The number of fish caught has reduced, so we have less income,” village headman Thongphon Mobmai, 64, told AFP. “But locals have to accept this mandate for community development envisioned by the state.”
“We’ve used only 0.2 to 0.3 percent of the dam’s surface area. People can make use of lands for agriculture, residency, and other purposes,” said EGAT’s Prasertsak.
A groundbreaking technology has been used to improve another, as researchers have demonstrated how AI could be used to control the superheated plasma inside a tokamak-type fusion reactor.
“This is one of the most challenging applications of reinforcement learning to a real-world system,” says Martin Riedmiller, a researcher at DeepMind.
DeepMind produced a range of shapes whose properties are under study by plasma physicists. Image credits: DeepMind & SPC/EPFL.
Current nuclear plants use nuclear fission to harness energy, forcing larger atoms to split into two smaller atoms. Fusion, on the other hand, is the opposite process. In nuclear fusion, two or more atomic nuclei combine to form one or more larger atoms. It’s the process that powers stars, but harnessing this power and using it on Earth is extremely challenging.
If you’re essentially building a miniature star (hotter than the surface of the Sun) and then using it to harness its power, you need to be absolutely certain you can control it. Researchers use a lot of tricks to achieve this, like magnets, lasers, and clever designs, but it’s still proven to be a gargantuan challenge.
This is where AI could enter the stage.
Researchers use several designs to try and contain this superheated plasma — one of these designs is called a tokamak. A tokamak uses magnetic fields in a donut-shaped containment area to keep the superheated atoms (as plasma) under control long enough that we can extract energy from it. The main idea is to use this magnetic cage to keep the plasma from touching the reactor walls, which would damage the reactor and cool the plasma.
Controlling this plasma requires constant shifts in the magnetic field, and the researchers at DeepMind (the Google-owned company that built the AlphaGo and AlphaZero AIs that dominated Go and chess) felt like this would be a good task for an algorithm.
They trained an unnamed AI to control and change the shape of the plasma by changing the magnetic field using a technique called reinforcement learning. Reinforcement learning is one of the three main machine learning approaches (alongside supervised learning and unsupervised learning). In reinforcement learning, the AI takes certain actions to maximize the chance of earning a predefined reward.
After the algorithm was trained on a virtual reactor, it was given control of the magnets inside the Variable Configuration Tokamak (TCV), an experimental tokamak reactor in Lausanne, Switzerland.
The AI-controlled the plasma for only two seconds, but this is as much as the TCV can go without overheating — and it was a long enough period to assess the AI’s performance.
Every 0.0001 seconds, the AI took 90 different measurements describing the shape and location of the plasma, adjusting the magnetic field accordingly. To speed the process up, the AI was split into two different networks — a large network that learned via trial and error in the virtual stage, and a faster, smaller network that runs on the reactor itself.
“Our controller first shapes the plasma according to the requested shape, then shifts the plasma downward and detaches it from the walls, suspending it in the middle of the vessel on two legs. The plasma is held stationary, as would be needed to measure plasma properties. Then, finally the plasma is steered back to the top of the vessel and safely destroyed,” DeepMind explains in a blog post.
“We then created a range of plasma shapes being studied by plasma physicists for their usefulness in generating energy. For example, we made a “snowflake” shape with many “legs” that could help reduce the cost of cooling by spreading the exhaust energy to different contact points on the vessel walls. We also demonstrated a shape close to the proposal for ITER, the next-generation tokamak under construction, as EPFL was conducting experiments to predict the behaviorr of plasmas in ITER. We even did something that had never been done in TCV before by stabilizing a “droplet” where there are two plasmas inside the vessel simultaneously. Our single system was able to find controllers for all of these different conditions. We simply changed the goal we requested, and our algorithm autonomously found an appropriate controller.”
The controller trained with deep reinforcement learning steers the plasma through multiple phases of an experiment. On the left, there is an inside view in the tokamak during the experiment. On the right, the reconstructed plasma shape and the target points the researchers wanted to hit. Image credits: DeepMind & SPC/EPFL.
While this is still in its early stages, it’s a very promising achievement. DeepMind’s AIs seem ready to move on from complex games into the real world, and make a real difference — as they previously did with protein structure.
This doesn’t mean that we’ll have nuclear fusion tomorrow. Although we’ve seen spectacular breakthroughs in the past couple of years, and although AI seems to be a promising tool, we’re still a few steps away from realistic fusion energy. But the prospect of virtually limitless fusion energy, once thought to be technically impossible, now seems within our reach.
Even Australia, where over half of the energy comes from coal, is starting to wave goodbye to the polluting fossil fuel. The country’s largest coal plant will now close seven years earlier than planned, as its operator claims it can’t compete with the expansion and lower costs of renewable energy sources — mainly solar and wind.
Image credit: Wikipedia Commons.
The massive 2.8 GW Eraring plant is located north of Sidney and is operated by Origin Energy. It will now close in 2025, after functioning for over 35 years. Eraring is the largest of the 16 coal-fired power plants in Australia, with seven scheduled to close by 2035 and the last one by 2051 as part of a transition to lower the country’s emissions.
Last year, Eraring alone was responsible for about 2% of Australia’s greenhouse gas emissions, based on emissions data and calculations from the energy market. This makes the early closure of the plant a particularly big deal in the ongoing climate crisis, especially considering the recent early closure of other coal plants such as Bayswater and Yallourn.
New South Wales Energy Minister Matt Kean told reporters the decision to closer Eraring was months in the making, creating a plan to make it happen.
“That plan will involve making sure that we focus on keeping the reliability of the system and that we put downward pressure on prices,” he added, dismissing any energy security risks.
Frank Calabria, Origin’s CEO, said the energy market is now very different from when Eraring opened up decades ago. The economics of coal-fired power stations are “under increasing, unsustainable pressure” by non-conventional renewable sources, such as wind and solar, which are cleaner and cheaper, Calabria said in a press statement.
The company now plans to build a massive battery of up to 700MW at the power station site, which it aims to have mostly done before the plant shuts. At the same time, the state government of NSW said it’s working on a complementary project to build a second 700MW battery to free up capacity on the state transmission system.
Australia’s climate challenges
An analysis of the electricity market from last year found that Eraring was the coal plant most exposed to the growth of renewables and likely to lose money by 2025. Last year, the market share of renewable energy increased to over 30%, according to official data. In particular, rooftop solar and solar farms have expanded in Australia.
When international climate negotiations come up, Australia is usually labeled as a “laggard” on climate change, although it’s one of the countries that also suffer most due to climate change. Prime Minister Scott Morrison is a prime example of the country’s love affair with coal — especially considering that in 2017. he brought a lump of coal to the parliament and said: “This is coal, don’t be afraid, don’t be scared, it won’t hurt you.” But the story goes beyond that specific anecdote.
The country’s climate target and policies are classified as “highly insufficient” by Climate Action Tracker (CAT), a think-tank that reviews countries’ commitments. If all countries would follow Australia’s climate action, the world would be on track for global warming of 4ºC, with no hint at the country’s emissions going down any time soon.
At the recent COP26 climate summit in the UK, the Australian government pledged to achieve net-zero carbon emissions by 2050. Nevertheless, the plan didn’t set more ambitious targets for 2030 and didn’t include a phase-out for the country’s fossil fuels. This led to wide criticism, with NGOs saying the plan had the strength of a wet paper bag.
Coupled with renewable sources of energy like wind and solar, nuclear power can help us transition to a zero-emission future, a new study reports. Especially in countries with geographies less suited to these renewable sources, nuclear energy could play a key role in helping us finally get rid of our polluting fossil fuel industry.
Nuclear power could hasten energy decarbonization, the researchers conclude. Image credits: Lukáš Lehotský.
We’re all excited about renewable energy — well, fossil fuel companies are understandably less happy about it, but in general, it’s excellent news. But renewable energy isn’t perfect; it has gaps where it doesn’t provide energy, and the infrastructure isn’t quite here yet.
“Renewable energy sources like wind and solar are great for reducing carbon-emissions,” says Lei Duan, from Carnegie’s Department of Global Ecology, and author of a new study analyzing this. “However, the wind and sun have natural variation in their availability from day to day, as well as across geographic regions, and this creates complications for total emissions reduction.”
So we need something to help fill in the gaps, at least until renewables have matured enough to take over. In today’s world, this unfortunately means either coal, gas, or oil. But there’s another way, the authors of a new study argue: by using nuclear.
Nuclear energy has a very bad rep, and many fear it based on what happened at Chernobyl and Fukushima — but this reputation is very undeserved. Study after study has shown that nuclear energy is one of the most reliable and safe sources of energy. In fact, nuclear energy is responsible for 99.8% fewer deaths than brown coal; 99.7% fewer than coal; 99.6% fewer than oil; and 97.5% fewer than gas. Most of these fossil fuel deaths come from pollution.
In terms of both safety and emissions, nuclear energy is on par with renewables, and it would be a good complement to renewables as well. Previous estimates have suggested that in many parts of the world, renewables could account for 80% of energy production within the decade — the new study suggests that the remaining 20% should come from nuclear.
“To nail down that last 10 or 20 percent of decarbonization, we need to have more tools in our toolbox, and not just wind and solar,” explained Ken Caldeira, also one of the study authors.
To assess the potential of nuclear power to address this need, Duan, Caldera, and other colleagues looked at the wind and solar potential for energy in 42 countries. They found that some countries, like the US, have great potential of implementing new sources of solar and wind energy. For these countries, nuclear power would only be needed as a complement to get over the last remaining hurdles of decarbonization. But in countries with less potential (like Brazil, for instance), nuclear power could play a more important role, accelerating the energy system’s decarbonization.
Furthermore, the team notes, nuclear energy can be cost-competitive with other types of energy, and can even promote wind and solar by storing energy.
“In our model, in moderate decarbonization scenarios, solar and wind can provide less costly electricity when competing against nuclear at near-current US Energy Information Administration cost levels,” the study reads. “In contrast, in deeply decarbonized systems (for example, beyond ~80% emissions reduction) and in the absence of low-cost grid-flexibility mechanisms, nuclear can be competitive with solar and wind. High-quality wind resources can make it difficult for nuclear to compete. Thermal heat storage coupled to nuclear power can, in some cases, promote wind and solar.”
All in all, nuclear energy seems to be the missing puzzle piece in our plans to decarbonize energy production. While often feared, nuclear energy is a safe and reliable alternative and a great complement to renewable energy.
“Our analysis looked at the cheapest way to eliminate carbon dioxide emissions assuming today’s prices. We found that at today’s price, nuclear is the cheapest way to eliminate all electricity-system carbon emissions nearly everywhere,” Caldeira concludes. “However, if energy storage technologies became very cheap, then wind and solar could potentially be the least-cost path to a zero-emission electricity system.”
The possibility of developing practical nuclear fusion, the energy process that powers the stars, is now a step closer to reality. UK scientists at the Joint European Torus (JET) have reached a new record on the amount of energy released in a sustained fusion reaction, generating 59 megajoules of heat – equivalent to about 14 kilograms of TNT. This more than doubles the previous record of 21.7 megajoules achieved in 1997 at the same research facility.
While it’s still not a lot of energy, enough to boil 60 kettles of water, the achievement is widely being described as a “major milestone” on the path to eventually make fusion a viable and sustainable low-carbon energy source.
“These landmark results have taken us a huge step closer to conquering one of the biggest scientific and engineering challenges of them all,” Ian Chapman, head of the UK Atomic Energy Authority, said in a statement. “It’s clear we must make significant changes to address the effects of climate change, and fusion offers so much potential.”
A major source of energy
Fusion occurs in the heart of starts and grants the energy that powers the universe. It’s the process through which two light atom nuclei combine to form a single heavier one, releasing bursts of energy as a consequence. It’s the opposite of nuclear fission, used in nuclear power stations, in which a large nucleus splits apart to form smaller ones.
The benefits of fusion power make it a very attractive option, especially in the context of climate change and diminishing limited fossil fuel supplies. It produces no carbon emissions, with its only by-products being small amounts of helium, an inert gas that could also be useful. It’s also very efficient, less radioactive than fission, and saf — as the amount of fuel used in fusion devices is very small.
The JET laboratory in central England uses a machine called tokamak for its studies. It’s the largest of its type in the world. Inside the machine, a small amount of fuel containing tritium and deuterium (isotopes of hydrogen) is heated to create plasma. This is kept in place using magnets as it spins around, fuses, and releases energy.
Experiments at the lab have focused on whether fusion is feasible with a fuel based on deuterium and tritium, which seems to be the case based on the latest results. This is good news for Iter, a massive fusion project being built in France by a coalition of several governments. It will still take some time, though: if all goes well, Iter should start burning fuel by 2035.
Countries have been working closely on fusion energy for years as, unlike nuclear fission used in the existing atomic power plants, the technology doesn’t produce radioactive material that can be then used for weapons. China, the EU, the US, India, Japan, and Russia have so far been involved in the mega project of Iter in France.
If researchers manage to carry out nuclear fusion, it promises to supply a near-limitless source of clean energy. But so far no experiment has created more energy out than it puts in. The new results at JET don’t change that, but they indicate that a fusion reacts project that uses the same tech and fuel mix, Iter, could eventually achieve that goal.
French President Emmanuel Macron is set to announce a massive building effort by the French state energy company, EDF. The goal is to construct at least six new nuclear reactors by 2050, which will ensure the country’s continued supply of low-cost energy.
Image credits Markus Distelrath.
Nuclear energy gets a lot of bad rep these days, due to past (and admittedly, very damaging) accidental meltdowns. France, however, generates a lot of its energy requirements using nuclear power. It has been one of the largest producers of such energy since the 1970s. And it’s a safe bet to say that it will keep splitting the atom to keep the lights on: French President Emmanuel Macron is set to announce the construction of at least six new reactors over the next five decades.
French-made
“It (nuclear) is ecological, it enables us to produce carbon-free electricity, it helps give us energy independence, and it produces electricity that is very competitive,” a French presidential aide told reporters on Wednesday.
The initiative is not without its detractors, however. France has a bit of a history of spectacularly exceeding its budgets and timelines when building nuclear reactors. The state-run company EDF is already massively indebted from building efforts in France, Britain, and Finland. As an example, its flagship program — in the northern French province of Flamanville — is expected to cost over four times its initial budget (of 3.3 billion euros / 3.8 billion dollars) and will at best become operational next year, some 11 years later than expected. Yannick Jadot, one of the contenders for the French presidency, criticized Macron’s decision on these grounds.
Still, as part of this initiative, Macron will be visiting a turbine manufacturing site in eastern France on a pre-election visit in which he will detail his energy policy and stance on nuclear energy. Currently, the atomic industry covers around 70% of the energy requirements of the country.
According to presidential aides, Macron will be announcing the construction of at least six new reactors by EDF. He will also set out his vision “of our future energy mix, for nuclear but also renewables and energy efficiencies,” according to the aide.
Despite this, its reactors are aging, and France should be looking to replace them if nuclear energy is to remain a mainstay of its power grids.
The final outcome of this initiative depends entirely on the outcome of the French presidential elections in April. Most candidates have announced their intention to continue investing in the industry, although two candidates — hard-left candidate Jean-Luc Melenchon and the Greens’ Yannick Jadot — oppose the continued use of nuclear power due to environmental concerns.
All in all, however, France seems to have thrown its hat squarely in the ring of nuclear power. Last month, it successfully lobbied for it to be labeled as “green” by the European Commission, which means it can now attract funding as a climate-friendly power source.
Europe as a whole is still divided on the future of atomic energy. Germany, for example, decided to phase it out entirely by 2022 following the Fukushima disaster of 2011.
Nuclear energy is one of the cleanest forms of energy, but it still has a very bad reputation — which is somewhat understandable. Throughout the history of nuclear energy, there have been few (but very severe) problems. But a new generation of reactors could virtually eliminate the risk of nuclear accidents.
Nuclear energy has a bad rep
What comes to mind when you think of “nuclear power?” I carried out a small survey with my friends and family, and the results were telling. People thought of reactors, bombs, radiation, or even Homer Simpson. It was generally a pretty bleak picture, but a pattern stood out: people are associating nuclear energy with the old-fashioned light water reactors (LWRs) that caused the Three Mile Island, Chernobyl, and Fukushima disasters. However, since then, the safety of nuclear energy production has been improved with the creation of new reactors.
I’m talking about molten salt reactors. To see why this sort of reactor is much safer, let’s first see how nuclear energy is generated.
Results from my family and friends survey.
In modern nuclear reactors, power is the result of nuclear fission. Fission is the process in which the nucleus of an atom splits into two or more smaller nuclei. In reactors, it’s a chain reaction that starts when a uranium atom is struck by a neutron. The impact releases energy in the form of heat and radiation, which results in more neutrons flying off the uranium atom, restarting the cycle.
“Classic” nuclear reactors have their uranium stored in solid fuel rods. To moderate the heat and speed of the reaction, sea or lake water is typically used to keep the rods cool. Without a coolant, the fuel rods begin to melt. If they melt the reactor core and containment storage area, they can release radiation into the environment – this is what a nuclear meltdown is in a nutshell. But there’s another type of nuclear reactor that isn’t prone to melting: Molten Salt Reactors (MSRs).
While a lot of people associate the word molten with lava, this molten salt looks more like green-tinted water. The molten salt is not table salt, but rather a mixture of lithium and beryllium fluoride with the nuclear fuel melted into it. This fuel can be uranium like the older generation of reactors, or it can be plutonium and thorium from the old nuclear waste from the spent fuel rods that we already have from our LWRs, thus eliminating our need to deal with the long term safety issues regarding storage.
A lithium salt.
The reason why MSRs can’t have meltdowns is surprisingly simple: You can’t melt what has already been melted. However, this can be difficult to understand without the proper context. Therefore, to understand just how safe MSRs are, we must contrast them with the LWR disasters of the past.
When old reactors fail
When people think about nuclear disasters, they generally refer to the three following events.
Three Mile Island
On March 28th, 1979, there was a partial meltdown in a nuclear reactor near Middletown, Pennsylvania. The root cause of the accident was that (either for mechanical or electrical reasons) the main feedwater pumps failed to send water to the steam generators. Since the water was meant to be the coolant, the reactor automatically shut down.
The pressure in the primary system began to increase, so an emergency valve opened. Once the pressure had returned to normal, instruments in the control room indicated that it had closed, when in fact, it was still open. As a result, the cooling water was escaping through the valve as steam, which made the pressurizer vibrate, so the crew turned it off. Without the pumps operating, the emergency cooling water threatened to flood the pressurizer, so crews decreased the water supply, and this caused the reactor to overheat.
In this case, there was a mechanical failure (in the valve) and without adequate system diagnostics, the crew couldn’t stop the meltdown.
The results of my brief survey showed mixed opinions.
Chernobyl
On April 26th, 1986, in what is now Ukraine and was then a part of the USSR, there was an explosion in the Chernobyl nuclear power plant. The day before, the crew was preparing to test how long the turbines would spin and supply power to the circulating pumps in the case of an electrical outage. The operators disabled the automatic shutdown mechanisms and then attempted the test the next day. By the time they started the test, the reactor was already unstable.
The design peculiarities combined with incorrect operating procedures resulted in an uncontrollable power surge. This power surge resulted in a rapid increase in heat, which ruptured the pressure tubes. The fuel inside the tubes spilled into the water, and the reaction resulted in two steam explosions releasing radioactive material into the environment.
Fukushima
On March 11th, 2011, there was a magnitude 9.0 earthquake off the east coast of Japan. The reactors in the Fukushima Daiichi Nuclear Power Plant were automatically shut down, but the earthquake took out all six external power supply sources. To make up for the loss of power, emergency power generators in the basements started up. Two tsunamis hit less than an hour later, and took out the generators and the seawater pumps. After the power outage, the reactors continued to produce some heat from fission product decay. Without the pumps, the heat wasn’t being removed, so this resulted in a buildup of steam in the reactors.
There were six reactor units at the time, but only units 1-3 were active.
In unit 1, there were attempts made to vent the steam, but without the power, steam built up on the service floor, resulting in a hydrogen explosion. This nuclear meltdown occurred as a result of the loss of the cooling system. Units 2 and 3 also experienced their own meltdowns, but to a lesser extent than unit 1. Unit 2 had a leak and released the most radioactive material. Unit 3 had a similar build-up in steam as unit 1, which resulted in a hydrogen explosion. Some of the steam from unit 3 made its way into the defueled unit 4 through the shared ventilation system. So, this caused another explosion in unit 4 despite the fact that it wasn’t even active at the time.
Unlike the Three Mile Island and Chernobyl disasters, Fukushima’s disaster involved multiple reactors. But, every explosion and leakage in Fukushima was caused by a power outage and sea pumps.
Why Molten Salt Reactors won’t fail
The key shared issue between these three disasters was the failure of the cooling systems. In every case, the coolant (water) wasn’t adequately cooling the fuel rods. Safety features either malfunctioned or were tampered with, and it often ended with an abundance of steam that would either leak out of a valve or blow up its container.
The biggest difference between LWRs and MSRs is that, while LWRs use water as a coolant, MSRs don’t need water to moderate the temperature of the reaction. The fuel acts as its own coolant. Essentially, MSRs can’t meltdown. Furthermore, in an emergency situation, the fuel can be quickly drained out of a reactor and passively dumped.
First, it’s important to know that thorium, which is present in the fuel, absorbs neutrons as well. But, unlike uranium, it doesn’t release more neutrons to perpetuate the chain reaction. The hotter it gets, the more neutrons the thorium will absorb. By reducing the quantity of neutrons in the fuel, the thorium limits how fast the reaction can be.
Thermal expansion also plays a role in the natural cooling of the fuel. When molecules in any substance are heated up, they move faster and expand. In the case of the molten salt, this process pushes out the active core region, making it so that the neutrons have to travel farther to continue the cycle. Just like the thorium, thermal expansion also limits the speed of the nuclear reaction.
Because the fuel passively moderates its own temperature with both thorium and thermal expansion, the odds of it overheating are low. But in the case of an emergency, there is a backup plan: A plug of frozen salt at the bottom of the reactor. It’s kept cool by a fan, but if the fuel surpasses a critical temperature, it melts the salt plug. Once the plug has melted, the fuel is drained out of the reactor and into a catch basin, where it can cool down and solidify, thereby reducing the pressure. The process is similar to that of a sink with a drain: Removing the plug will allow for the fluid to drain out of the sink.
Unlike LWRs, MSRs operate under low pressure conditions. Because of these conditions, and because there isn’t any water in the system, there can’t be any buildup of steam or hydrogen. Furthermore, as a result of the natural temperature limitations of the fuel, the salt can’t boil. There is a chemical system within the MSR that is continuously removing the vapors produced by nuclear fission. Therefore, there is no possibility of a buildup of any form of vapor, which eliminates the possibility of an explosion.
Why should we care?
All nuclear energy is zero-carbon green energy. However, molten salt nuclear reactors aren’t just limited to new uranium: we can use our old nuclear waste to power them. By reusing nuclear waste, we will be using it to its maximum potential, and will not have to store it for thousands of years.
While they are both classified as nuclear reactors, LWRs and MSRs are very different. They operate under different conditions, have different cooling systems, and use different fuels. MSRs are safer because, since the fuel is liquid, they can’t have devastating meltdowns similar to those in Chernobyl, Fukushima, and Three Mile Island. The safety concerns of LWRs simply do not apply to MSRs. We can’t let our fear of nuclear meltdowns get in the way of the development of meltdown-proof reactors.
Now more than ever, it’s important to invest in nuclear energy. Our dependence on fossil fuels has already plunged the planet into a sixth mass extinction, and on August 9th 2021, the IPCC released a code red for humanity. We need to act fast if we want to preserve our planet.
Molten salt reactors can play a huge role in this effort.
North America’s largest roofing and waterproofing company just stepped into the 21st century. This week, GAF revealed the world’s first nailable solar shingle, which integrates solar energy into existing roofing materials and installations.
Some homeowners, although keen to play their part in solving the climate crisis, loathe the aesthetics of conventional rooftop solar panels. With them in mind, Tesla launched the Solar Roof in 2016, consisting of an array of glass tiles that harvest solar energy all while looking beautiful. Since then, we’ve seen other companies come to the market with similar solutions. But GAF Energy has thought of a simpler, cheaper solution to installing rooftop solar.
Having a solar shingle, one that can be nailed down like everyday shingles, is easier to integrate with existing roofs. It’s also easier to replace or repair thanks to its coplanar design that integrates electrical components on the front rather than the back for easy servicing.
Credit: GAF Energy.
Conventional rooftop solar panels require rails so the modules can be screwed down. The new shingles, known as Timberline Solar Shingles, are nailed through a three-inch nailing strip. It’s just a matter of overlapping one shingle on top of the bottom one until you’re done scaling the entire roof.
According to GAF Energy president Martin DeBono, the shingle design has a number of advantages over conventional solar rooftops. Thanks to its design, it takes days rather than weeks to install a solar roof, for instance. “We’ve installed them already in two days, including ripping off the old roof and putting on the new roof,” he told The Verge.
Timberline Solar Shingles are the first products that have been certified as both solar panels and construction materials. They’re fire-resistant and walkable like any plank but just transparent enough to let light hit photovoltaic cells sandwiched between glass and a polymer. The polysilicon solar cells embedded in the shingles have a rated efficiency of 22.6%, which is just a few points shy of the commercially available state-of-the-art.
Credit: GAF Energy.
“Solar roofs are the future of clean energy, and Timberline Solar is the game-changing innovation that will get us there,” said DeBono in a statement.“At GAF Energy, we have the capacity to scale this technology like no one else through GAF, bringing an integrated solar product that is weatherproof, affordable, and design-minded to homeowners across the country. We’re excited to lead the next generation of clean energy adoption.”
You do have to install a lot of them to complete a roof since they’re much narrower than conventional solar ‘blue’ panels. It takes around 130 of them to assemble a typical 6kW solar array.
Credit: GAF Energy.
Although we don’t have exact price specs yet, you can expect that covering your roof in these shingles will cost more than installing conventional solar roofing. However, DeBono claims that “it will cost the same as if you were to get a new roof and put solar on it.”
Considering over five million new roofs are installed in the United States annually, with one out of every four of these roofs using GAF materials and contractors, these solar shingles sound like a game-changer – at least on paper.
Unfortunately, the golden days of residential rooftop solar seem behind us. California and Nevada, the country’s prime solar market, have either phased out incentives or are planning to charge solar panel owners a flat fee for every kW they hook up to the grid. Considering the government is pouring billions into fossil fuel subsidies every year, one can only ironically wonder if our priorities are set straight.
Denmark aims to make its domestic flights fossil fuel-free by the end of the decade, according to its Prime Minister.
Denmark’s Prime Minister Mette Fredriksen, 2019. Image via Wikimedia.
In her New Year’s address, Denmark’s Prime Minister Mette Fredriksen announced that she aims to “make flying green” inside the country. Although she acknowledges that the solutions are not yet in place in order to reach this goal, the announcement marks a strong — if not fully official — embracing of this goal.
On a larger scale, Denmark aims to slash its overall carbon emissions by 70% compared to 1990 levels by 2030. Fredriksen’s aim to de-couple internal flights from fossil fuel use would help push the country closer to that goal.
Flying green
“To travel is to live and therefore we fly,” said Ms Frederiksen (link in Danish), announcing her plan.”When other countries in the world are too slow, then Denmark must take the lead and raise the bar even more”.
She admits that making domestic flights fully green is no small feat, adding that researchers, as well as transport companies, are working to find solutions.
For example Airbus, a European airplane manufacturer, has announced plans to have hydrogen-fueled planes operational by 2035. If that hydrogen is generated using renewable energy, it could be one avenue through which Denmark could make good on its goal.
However, it’s not yet clear whether said tech will be ready to use on planes, in a cost-efficient manner, by 2030.
That being said, there is growing international interest in this regard — Sweden has also announced plans to make domestic flight fossil fuel-free by 2030, and international flights by 2045. France is also moving to ban domestic flights on routes where trains would take under two-and-a-half hours to make the same journey.
Researchers and manufactures will surely take this interest into account, and it will help to spur development on. For example, there has been some encouraging progress in the field of electric planes, although for now, it remains confined to smaller aircraft.
The air transport sector is a major polluter worldwide. Although domestic flights account for only a small part of its emissions, the smaller distances involved make it a prime area for innovation and development. In time, progress here could make their way on vehicles serving international routes.
FedEx is set to start delivering US parcels with its brand-new electric delivery vans from General Motors’s EV subsidiary BirghtDrop. The transportation company has already received five of the 500 vans it purchased, which will be first rolled out in the state of California and then expand to other locations across the country.
FedEx’s ground fleet consists of over 100,000 trucks, cars, and vans, and replacing them with electric cars could make a significant difference in reducing the company’s greenhouse gas emissions. Image credit: FedEx.
Electrifying deliveries
The delivery vans are powered by Ultium batteries, with an estimated range of up to 250 miles (400 kilometers) on a full charge. The vans are designed for the delivery of goods and services, with a cargo area of 600 cubic feet. FedEx is now building charging infrastructure in its facilities, having already installed 500 charging stations across California.
“The delivery of the first EV600s is a historic moment, born out of a spirit of collaboration between two leading American companies,” Mitch Jackson, Chief Sustainability Officer at FedEx, said in a statement. “Transforming our pickup and delivery fleet to electric vehicles is integral to achieving our ambitious sustainability goals.”
Last year, FedEx set out the goal to have a zero-emission, all-electric global pickup and delivery (PUD) fleet by 2040. As part of that plan, FedEx Express, its subsidiary, wants to make 50% of its global vehicle purchases to be electric by 2025 – rising to 100% by 2030. The collaboration with General Motors will now help to achieve those targets, FedEx said. But it’s a long and winding road to electrifying the company’s fleet.
A long-search for EVs
Before partnering up with General Motors, FedEx had long been searching for a reliable EV supplier around the world. The company first reached a deal with the startup Chanje to buy 1,000 electric delivery vans. But then Chanje shut down and failed to make good on its promise, prompting FedEx to start a legal battle with the startup that is still ongoing. This also forced FedEx to find a different supplier, further delaying the transition to electric vehicles. But that transition seems to start taking place now, thanks to a partnership with General Motors.
General Motors unveiled in June its new delivery and logistics business, BrightDrop. The announcement came as GM is undergoing a massive pivot to the business of manufacturing electric vehicles. The company will increase its investment in EVs and autonomous vehicles to $35 billion through 2025 – a 75% hike from pre-pandemic levels. All in all, it’s a perfect option for FedEx.
“BrightDrop is thrilled to partner with FedEx in our mission to dramatically reduce vehicle emissions from delivery and deliver a brighter future for all of us. FedEx has ambitious sustainability goals, and the speed with which we brought the first BrightDrop electric vehicles to market shows how the private sector can innovate,” Travis Katz, CEO of BrightDrop, said in a statement.
FedEx was the first delivery company to use hybrid vehicles for pickup and delivery back in 2003. A few years before, in 1994, the company used its first electric vehicle, powered by an acid battery, in California. FedEx currently has more than 200,000 operational motorized vehicles, of which almost 3,000 are either electric or hybrid. Now, the company hopes to raise the bar once more and raise the bar in the transportation sector and electrify its fleet as quickly as possible.
Few things scream ‘privilege’ the way playing golf does. Golfing has become a symbol of sorts, reserved only for those rich enough to afford it. The courses themselves have become a symbol: lavish, well-maintained, and large areas where people go about hitting the balls.
But the courses also pose a number of environmental problems. Despite being “green”, they don’t typically contribute to biodiversity, and often actually pose serious problems for local biodiversity, as they’re covered in short grass and frequented by humans. To make matters even worse, golf courses consume a lot of water. In the US alone, golf courses require over 2 billion gallons of water (7.5 billion liters) per day, averaging about 130,000 gallons (492,000 liters per day). However, some see an opportunity here — an opportunity to turn golf courses from an environmental problem into an environmental asset. How? By filling them with solar panels.
Image in Creative Commons.
In New York, a 27-acre that started out as a landfill and then became a golf driving range in the 1980s was transformed into a solar farm in 2019.
“This solar farm is what hope and optimism look like for our future,” Adrienne Esposito, executive director of the nonprofit Citizens Campaign for the Environment, said in a statement. The non-profit had campaigned for the transformation of the golf course. “We know over the next 20 years, the sun will shine, the power will be produced and we will have clean power. We don’t know, and we may not want to know, the cost of fossil fuels.”
The move not only ensured electricity for around 1,000 houses in Long Island but it will also eliminate some of the pesticides and pollutants in the area — pollutants that the golf course used for maintenance. Overall, the move is estimated to generate $800,000 for local authorities.
This type of project is possible because of recent developments in solar panel technology. It seems like almost overnight, solar panels have become incredibly cheap, and it’s not just the panels themselves — a multitude of solar farm components are becoming cheaper, allowing solar energy to compete, even as the fossil fuel industry remains heavily subsidized.
“I think New York is at a critical time in its history,” NextEra spokesman Bryan Garner said. NextEra is the company behind the solar farm. “The state has had really ambitious renewable energy goals, and this is clearly a step in the right direction.”
Next Era itself is not entirely a renewable energy company but drawn in by falling prices, it’s focusing more and more on solar energy.
This is not the only project to turn golf into solar energy, and New York is not the only place where this is happening. Rockwood Golf Course in Independence, Missouri, has also gone through a similar transformation. In Cape Cod, Massachusetts, solar panels were chosen as the “lesser of two evils”, with the alternative being turning the golf course into housing, which would have caused more traffic and more pollution in the area.
“We like the fact that it will be used for solar,” said Chairman Patricia Kerfoot at A meeting ON THE PROJECT. “That is a policy of the town to increase solar as much as possible, that it will keep it open space, which is part of our local comprehensive plan, as much as possible.”
It’s a perfect fit if you think about it — golf courses cover large areas of open land, which is exactly what solar farms also need. At the same time, the dropping prices of renewable energy make it a more attractive proposition.
These aren’t just isolated examples, a trend seems to be emerging, driven not just by decreasing prices of solar energy, but also by a decrease in the interest in golf. Between 2003 and 2018, golf saw a decline of almost 7 million players, and any hopes of turning the golf industry around were shattered during the COVID-19 pandemic. Halfway through 2021, the National Golf Foundation reported the closure of 60 18-hole courses, several of which have been replaced by solar farms.
But perhaps nowhere in the world is this trend as prevalent as in Japan.
Japan is turning its abandoned golf courses into solar farms
Image in Creative Commons.
Japan even has a national plan to replace some of its golf courses with large solar plants.
This is remarkable because, despite declining costs of solar energy, Japan’s solar power is still far more expensive than the global average — and even so, the country feels like adding more and more solar farms. Renewable energy initiatives are welcome and heavily subsidized in Japan, particularly as the country is looking for alternatives to nuclear energy after the 2011 Fukushima plant disaster.
Japan’s golf courses were built during the country’s inflated-asset boom in the 1980s but interest continued declining as years passed. This is where solar energy enters the stage.
Solar energy has become a national priority for Japan, and the country has become a leader in photovoltaics. In addition to being a leading manufacturer of photovoltaics (PV), Japan is also a large installer of domestic PV systems with most of them grid-connected.
Naturally, the country also set its sights on golf courses, repurposing several of them for solar installations. The most recent of these, a 100 MW solar plant has begun operation in the Kagoshima Prefecture, becoming one of the largest photovoltaic facilities in the area.
In particular, rural golf courses in Japan were deemed as ideal places or new solar installations. A perfect example is up a mountainous road in Kamigori, in the Hyogo prefecture, where a new solar farm is installed in a former golf course link — generating enough power to meet the needs of 29,000 local households.
Another reason why golf courses are so attractive for solar investments is that the ground has already been leveled, and flood-control and landslide prevention measures are already in place. Essentially, golf courses check all the boxes for what you’d want in a solar farm.
All in all, a tide seems to be turning against some golf courses, and towards solar energy. Innovations on the technical side have made solar plants a cheap and competitive source of energy. The price of electricity generated by utility-scale solar photovoltaic systems is continuously decreasing, but solar plants do more than just offer cheap electricity — as the golf course showed, they have emerged as a space for sustainable innovation.
Back in 2017, Portugal pledged to give up on coal, the most polluting energy source of all fossil fuels, by 2030. With nine years to go, the government just shut down the last remaining coal plant (Pego) which had been the country’s second-largest emitter of carbon dioxide. Now, it’s time to expand renewable energy, campaigners argue.
Image credit: Flickr / Rich.
Portugal is now the fourth country in the European Union to stop using coal for power generation — the three others being Belgium, Austria, and Sweden. This year, the EU adopted ambitious climate targets to tackle climate change, hoping to cut greenhouse gas emissions by at least 55% by 2030 — and leaving coal is essential to deliver on that pledge.
The last coal plant to close in Portugal, Pego, is located 150 kilometers (90 miles) northeast of the capital Lisbon. Now, the country doesn’t have any coal mines left, and it also doesn’t have any oil or gas resources (so they’re all imported). Seeking to replace them, the government has been investing heavily in renewables in recent decades, which now account for about 70% of its energy matrix, but there’s still a way to go.
While environmentalists welcomed the news, Portugal is now considering the continued use of Pego with other types of energy, including biomass (burning wood pellets), and many see this as counterproductive. Francisco Ferreira, head of the Portuguese environmental association ZERO, said in a statement Portugal shouldn’t repurpose Pego and instead expand renewables even further.
“Portugal is the perfect example of how once a country commits to quitting coal, the pace of the phase out inevitably accelerates. The benefits of transitioning to renewables are so great, once started, it only makes sense to get out of coal as fast as possible,” said Kathrin Gutmann, Europe Beyond Coal campaign director, in a statement.
Considering that the Portuguese government is now being sued by the European Commission (EC) for poor air quality, moving away from coal is a step in the right direction. Portugal has very high levels of nitrogen dioxide (NOX) in the atmosphere and the EC is questioning the government for “continually and persistently” exceeding the NOX limit in several cities.
Phasing out coal
A group of 28 countries recently joined forces at the COP26 climate summit a global alliance to phase out coal, which has already been agreed by a total of 48 governments. The Powering Past Coal Alliance (PPCA) includes members such as Poland, one of the main consumers of coal in Europe, as well as Singapore, Chile, Estonia, South Korea, and Canada.
China hasn’t signed the pledge yet, which is very significant as China is the world’s largest coal consumer. Coal accounted for 56% of energy consumption in China last year and the government is currently building new coal plants. Still, there have been some positive signs, as China agreed to stop funding new coal plants in foreign countries.
Coal currently accounts for over one-third of global electricity generation, according to the International Energy Agency (IEA). Still, there seems to be a light at the end of the tunnel. Since 2015, a total of 1,175GW of planned coal-fired power projects were canceled after pressure from civil society, market trends, and government policies. However, if we want to truly give up on fossil fuel energy, there’s much more we still need to do.
No matter how sustainable, eco-friendly, and clean sources of energy they are, conventional solar panels require a large setup area and heavy initial investment. Due to these limitations, it’s hard to introduce them in urban areas (especially neighborhoods with lots of apartment blocks or shops). But thanks to the work of ingenious engineers at the University of Michigan, that may soon no longer be the case.
The researchers have created transparent solar panels which they claim could be used as power generating windows in our homes, buildings, and even rented apartments.
If these transparent panels are indeed capable of generating electricity cost-efficiently, the days of regular windows may be passing as we speak. Soon, we could have access to cheap solar energy regardless of where we live — and to make it even better, we could be rid of those horrific power cuts that happen every once in a while because, with transparent glass-like solar panels, every house and every tall skyscraper will be able to generate its own power independently.
An overview of the transparent solar panels
In order to generate power from sunlight, solar cells embedded on a solar panel are required to absorb radiation from the sun. Therefore, they cannot allow sunlight to completely pass through them (in the way that a glass window can). So at first, the idea of transparent solar panels might seem preposterous and completely illogical because a transparent panel should be unable to absorb radiation.
But that’s not necessarily the case, researchers have found. In fact, that’s not the case at all.
Professor R. Lunt at MSU showing the transparent luminescent solar concentrator. Image credits: Michigan State University
The solar panels created by engineers at the University of Michigan consist of transparent luminescent solar concentrators (TLSC). Composed of cyanine, the TLSC is capable of selectively absorbing invisible solar radiation including infrared and UV lights, and letting the rest of the visible rays pass through them. So in other words, these devices are transparent to the human eye (very much like a window) but still absorb a fraction of the solar light which they can then convert into electricity. It’s a relatively new technology, only first developed in 2013, but it’s already seeing some impressive developments.
Panels equipped with TLSC can be molded in the form of thin transparent sheets that can be used further to create windows, smartphone screens, car roofs, etc. Unlike, traditional panels, transparent solar panels do not use silicone; instead they consist of a zinc oxide layer covered with a carbon-based IC-SAM layer and a fullerene layer. The IC-SAM and fullerene layers not only increase the efficiency of the panel but also prevent the radiation-absorbing regions of the solar cells from breaking down.
Surprisingly, the researchers at Michigan State University (MSU) also claim that their transparent solar panels can last for 30 years, making them more durable than most regular solar panels. Basically, you could fit your windows with these transparent solar cells and get free electricity without much hassle for decades. Unsurprisingly, this prospect has a lot of people excited.
According to Professor Richard Lunt (who headed the transparent solar cell experiment at MSU), “highly transparent solar cells represent the wave of the future for new solar applications”. He further adds that these devices in the future can provide a similar electricity-generation potential as rooftop solar systems plus, they can also equip our buildings, automobiles, and gadgets with self-charging abilities.
“That is what we are working towards,” he said. “Traditional solar applications have been actively researched for over five decades, yet we have only been working on these highly transparent solar cells for about five years. Ultimately, this technology offers a promising route to inexpensive, widespread solar adoption on small and large surfaces that were previously inaccessible.”
Recent developments in the field of transparent solar cell technology
Apart from the research work conducted by Professor Richard Lunt and his team at MSU, there are some other research groups and companies working on developing advanced solar-powered glass windows. Earlier this year, a team from ITMO University in Russia developed a cheaper method of producing transparent solar cells. The researchers found a way to produce transparent solar panels much cheaper than ever before.
“Regular thin-film solar cells have a non-transparent metal back contact that allows them to trap more light. Transparent solar cells use a light-permeating back electrode. In that case, some of the photons are inevitably lost when passing through, thus reducing the devices’ performance. Besides, producing a back electrode with the right properties can be quite expensive,” says Pavel Voroshilov, a researcher at ITMO University’s Faculty of Physics and Engineering.
“For our experiments, we took a solar cell based on small molecules and attached nanotubes to it. Next, we doped nanotubes using an ion gate. We also processed the transport layer, which is responsible for allowing a charge from the active layer to successfully reach the electrode. We were able to do this without vacuum chambers and working in ambient conditions. All we had to do was dribble some ionic liquid and apply a slight voltage in order to create the necessary properties,” adds co-author Pavel Voroshilov.
PHYSEE, a technology company from the Netherlands has successfully installed their solar energy-based “PowerWindow” in a 300 square feet area of a bank building in The Netherlands. Though at present, the transparent PowerWindows are not efficient enough to meet the energy demands of the whole building, PHYSEE claims that with some more effort, soon they will be able to increase the feasibility and power generation capacity of their solar windows.
California-based Ubiquitous Energy is also working on a “ClearView Power” system that aims to create a solar coating that can turn the glass used in windows into transparent solar panels. This solar coating will allow transparent glass windows to absorb high-energy infrared radiations, the company claims to have achieved an efficiency of 9.8% with ClearView solar cells during their initial tests.
In September 2021, the Nippon Sheet Glass (NSG) Corporation facility located in Chiba City became Japan’s first solar window-equipped building. The transparent solar panels installed by NSG in their facility are developed by Ubiquitous Energy. Recently, as a part of their association with Morgan Creek Ventures, Ubiquitous Energy has also installed transparent solar windows on Boulder Commons II, an under-construction commercial building in Colorado.
All these exciting developments indicate that sooner or later, we also might be able to install transparent power-generating solar windows in our homes. Such a small change in the way we produce energy, on a global scale could turn out to be a great step towards living in a more energy-efficient world.
Not there just yet
If this almost sounds too good to be true, well sort of is. The efficiency of these fully transparent solar panels is around 1%, though the technology has the potential to reach around 10% efficiency — this is compared to the 15% we already have for conventional solar panels (some efficient ones can reach 22% or even a bit higher).
So the efficiency isn’t quite there yet to make transparent solar cells efficient yet, but it may get there in the not-too-distant future. Furthermore, the appeal of this system is that it can be deployed on a small scale, in areas where regular solar panels are not possible. They don’t have to replace regular solar panels, they just have to complement them.
When you think about it, solar energy wasn’t regarded as competitive up to about a decade ago — and a recent report found that now, it’s the cheapest form of electricity available so far in human history. Although transparent solar cells haven’t been truly used yet, we’ve seen how fast this type of technology can develop, and the prospects are there for great results.
The mere idea that we may soon be able to power our buildings through our windows shows how far we’ve come. An energy revolution is in sight, and we’d be wise to take it seriously.
Fully-integrating solar panels into buildings could make cities almost self-sustaining, according to new research.
Image credits Ulrike Leone.
Solar panels get a lot of bad press for having a low energy output; individually, that may be so. A small, single panel will not be able to keep your home lit, warmed, and all the appliances running. But the secret with solar energy is to think at scale, a new paper suggests, and to make the most of every bit of free space. According to the findings, the City of Melbourne could generate 74% of its electricity needs if solar technology was to be integrated into the roofs, walls, and windows of every building.
This study is the first to estimate the viability and impact of integrating several types of solar technology including window-integrated and rooftop-mounted photovoltaics on a city-wide scale. The results are promising, suggesting that the City of Melbourne could greatly reduce its reliance on energy produced through the burning of fossil fuels.
Lighting the way
“By using photovoltaic technology commercially available today and incorporating the expected advances in wall and window-integrated solar technology over the next ten years, we could potentially see our CBD (central business district) on its way to net zero in the coming decades,” said lead author Professor Jacek Jasieniak.
“We began importing coal-fired power from the LaTrobe Valley in the 1920s to stop the practice of burning smog-inducing coal briquettes onsite to power our CBD buildings, and it’s now feasible that over one hundred years later, we could see a full circle moment of Melbourne’s buildings returning to local power generation within the CBD, but using clean, climate-safe technologies that help us meet Australia’s Net Zero 2050 target.”
The authors report that existing rooftop photovoltaic technology alone could dramatically reduce Melbourne’s carbon footprint. If technologies that are still being developed, such as high-efficiency solar windows or facade-integrated panels, are also taken into account, solar energy can become the leading source of energy in the city. These estimates hinge on the assumption that such technologies are integrated on a wide scale across the city.
For the study, the team compared the electrical energy consumption in Melbourne in 2018 to an estimate of the energy that could be produced through wide use of building-integrated solar systems. Consumption figures were obtained from Jemena and CitiPower & Powercor distribution companies through the Centre for New Energy Technologies (C4NET), an independent research body in Victoria, Australia. The production estimates were based on city-wide mathematical modelling.
Out of the total potential energy that solar power could provide, rooftop-mounted solar panels could generate 88%, with wall-integrated and window-integrated solar delivering 8% and 4% respectively. However, wall- and window-mounted solar technologies lost a lot less of their efficiency during the winter months relative to rooftop-mounted panels, the models showed. In other words, although they have a lower total output potential, these two types of technology deliver power more reliably and at more constant levels throughout the year.
Building height had a particular impact only on window-integrated solar technologies; in highrise neighborhoods, its potential rose to around 18% of the total generated energy. In areas with low average building height, the total wall and window areas available are small, reducing their overall potential to generate power. The window-to-wall surface ratio also tends to be greater in commercial buildings compared to residential buildings.
The modeling took into account the impact of shadows cast in the city by elements such as buildings, shading systems, or balconies, and natural factors such as sun incidence angle and total solar potential of different areas across Melbourne. The technologies used as part of the simulations were selected based on their technical characteristics, limitations, and costs of installation and operation.
All in all, the study worked with the 37.4 km2 area of central Melbourne, which consists mainly of residential and commercial buildings. In 2019, a total of 35.1 km2 of the studied perimeter was built floor area. This area was selected because it offered one the greatest potential for window-integrated solar in Melbourne, the team explains.
“Although there’s plenty of policies supporting energy-efficiency standards for new buildings, we’re yet to see a substantial response to ensuring our existing buildings are retrofitted to meet the challenges of climate change,” says co-author Dr. Jenny Zhou. “Our research provides a framework that can help decision-makers move forward with implementing photovoltaic technologies that will reduce our cities’ reliance on damaging fossil fuels.”
“In the near future, market penetration and deployment of high-efficient solar windows can make a substantive contribution towards the carbon footprint mitigation of high-rise developments,” adds first author Dr. Maria Panagiotidou. “As the world transitions towards a net-zero future, these local energy solutions would play a critical role in increasing the propensity of PVs within urban environments.”
The paper “Prospects of photovoltaic rooftops, walls and windows at a city to building scale” has been published in the journal Solar Energy.
Solar concentrators mounted on the university’s rooftop raise the temperature inside reaction chambers to thousands of degrees to turn CO2 into syngas, and later into kerosene or methanol. Credit: ETH Zurich.
Researchers from Switzerland have devised a method that simultaneously captures CO2 from the atmosphere and turns it into synthetic fuel, which can later be refined into methanol or kerosene. The entire process is powered by solar energy and, since the input carbon is extracted from the air, the fuel is essentially net-zero carbon neutral.
Although solving our climate emergency requires transitioning away from fossil fuel towards a 100% renewable energy system, this transition cannot happen overnight. The challenge is to minimize carbon emissions as much as possible during this critical transition period because the effects of CO2 buildup today will keep having an effect long into the future. Even if we miraculously stop burning all fossil fuels tomorrow, the damage done so far cannot be undue as greenhouse gases can remain stable in the atmosphere for decades, perhaps even centuries.
It’s likely we’ll be using fossil fuels for decades to come, especially in transportation. So, researchers at ETH Zurich have devised a single coherent system that addresses this need for sustainable liquid fuels.
In one box, the system first captures carbon dioxide and water vapor from the air at ambient temperature. The two ingredients are then sent to a second reactor where they’re converted into carbon monoxide and hydrogen using a similar heating/cooling cycle to that employed in the first step. The mix of carbon monoxide and molecular hydrogen is known as “syngas”. Finally, this syngas is introduced to another reaction chamber where it reacts in the presence of a copper-based catalyst, changing phase from gas to liquid and forming methanol or kerosene, depending on the concentration of each reactant.
Throughout the entire time, these reactions are powered by electricity and heat generated by solar panels and solar concentrators, respectively.
During a day of operation, the experimental setup produced 100 liters of syngas, which was processed into about half a decilitre (0.05 liters) of pure methanol. That may sound like a disappointingly low yield, however, this is merely a proof of concept rig and the researchers are confident they can considerably improve the efficiency from 5.6% currently to over 20%.
“The energy efficiency is still too low. To date, the highest efficiency value that we measured for the solar reactor is 5.6 percent. Although this value is a world record for solar thermochemical splitting, it is not good enough. Substantial process optimization is still required,” said Aldo Steinfeld, first author of the new study and Professor of Renewable Energy Carriers at ETH Zurich.
The resulting liquid fuel is carbon neutral because solar energy is used in its production and it releases only as much CO2 as was previously extracted from the air during combustion.
“The solar fuel production chain’s life-cycle assessment indicates 80 percent avoidance of greenhouse gas emissions with respect to fossil jet fuel and approaching 100 percent, or zero emissions, when construction materials (e.g. steel, glass) are manufactured using renewable energy,” Steinfeld added.
The number of wind turbines across the world has grown exponentially thanks to plummeting costs. By now, people have grown accustomed to huge wind turbine farms that dot some landscapes, either onshore or offshore. But unlike solar panels, residential wind turbines are less affordable and accessible, being seen as too cumbersome and wind-dependent, and this is most evident in urban areas. You’ll be hard-pressed to find wind turbines in Manhattan, whereas rooftop solar installations abound.
It’s this predicament that inspired designer and entrepreneur Joe Doucet to fill the gap in our renewable energy generation toolkit with an out-of-the-box solution: rather than harnessing the wind with huge blades suspended on tall towers, Doucet invented a flat wind turbine that can be incorporated into walls.
The turbine wall is made up of a grid of square panes that spin along 25 axes. The first prototype consists of 25 wind turbine generators that are already commercially available, which are attached to 25 corresponding vertical rods with square panels attached alongside them to capture wind pressure.
The prototype wall measures 25 feet (7.5 meters) in length and 8 feet (2.5 meters) in height but can be scaled to virtually any dimension. For instance, one such modular panel could be interconnected with others like it, the same way we now use individual solar panels to cover a rooftop.
And although it may look like a fancy kinetic art installation, Doucet claimed in an interview with Fast Company that an average American home with one side covered by a turbine wall could meet its yearly energy needs (10,000 kilowatt-hours/year). That’s based on simulations that are obviously subject to great fluctuations depending on how much wind hits the turbines. These results have not been verified or peer-reviewed by independent sources, so one should take these claims with a grain of salt. In urban settings, turbulent winds are dampened by tall buildings and other obstructions and real-life applications may render very different results from these simulations.
Where Doucet imagines his invention flourishing is in large-scale commercial buildings, such as malls, office buildings, and supermarkets — even inside busy and crammed cities. Conventional wind turbines take up a lot of real estate, can be noisy, and are seen as eyesores and obstructions to the visual landscape, which have made them unappealing in urban settings. Wall turbines may prove to be an acceptable compromise — that’s if they don’t hypnotize people with their revolving panels.
What’s more, the turbine walls, whose turbines are made of aluminum, could also dot roads and highways, taking advantage of the air pressure generated by traffic.
“Instead of the typical retaining walls along roads and freeways, you’d have an array of these,” Doucet told Fast Company. “With the added wind boost from trucks, our highways could take care of all our energy needs.”
Doucet is currently hammering out deals with several manufacturers to bring his prototype to the market. In combination with solar panels, these turbine walls could greatly lower our urban carbon footprint.
Rooftop solar panels are up to 79% cheaper than they were in 2010. These plummeting costs have made rooftop solar photovoltaics even more attractive to households and businesses who want to reduce their reliance on electricity grids while reducing their carbon footprints.
But are there enough rooftop surfaces for this technology to generate affordable, low-carbon energy for everyone who needs it? After all, it’s not just people who own their own houses and want to cut their bills who are in need of solutions like this. Around 800 million people globally go without proper access to electricity.
Our new paper in Nature Communications presents a global assessment of how many rooftop solar panels we’d need to generate enough renewable energy for the whole world – and where we’d need to put them. Our study is the first to provide such a detailed map of global rooftop solar potential, assessing rooftop area and sunlight cover at scales all the way from cities to continents.
We found that we would only need 50% of the world’s rooftops to be covered with solar panels in order to deliver enough electricity to meet the world’s yearly needs.
Method
We designed a programme that incorporated data from over 300 million buildings and analysed 130 million km² of land – almost the entire land surface area of the planet. This estimated how much energy could be produced from the 0.2 million km² of rooftops present on that land, an area roughly the same size as the UK.
We then calculated electricity generation potentials from these rooftops by looking at their location. Generally, rooftops located in higher latitudes such as in northern Europe or Canada can vary by as much as 40% in their generation potential across the year, due to big differences in sunshine between winter and summer. Rooftops near the equator, however, usually only vary in generation potential by around 1% across the seasons, as sunshine is much more consistent.
This is important because these large variations in monthly potential can have a significant impact on the reliability of solar-powered electricity in that region. That means places where sunlight is more irregular require energy storage solutions – increasing electricity costs.
Hotspots
Our results highlighted three potential hotspots for rooftop solar energy generation: Asia, Europe and North America.
Of these, Asia looks like the cheapest location to install panels, where – in countries like India and China – one kilowatt hour (kWh) of electricity, or approximately 48 hours of using your laptop, can be produced for just 0.05p. This is thanks to cheap panel manufacturing costs, as well as sunnier climates.
Meanwhile, the costliest countries for implementing rooftop solar are USA, Japan and the UK. Europe holds the middle ground, with average costs across the continent of around 0.096p per kWh.
Rooftop solar panels look like they’d be equally useful in areas with low population as they would be in urban centres. For those living in remote areas, panels help top up or even replace supply from potentially unreliable local grids. And for those in cities, panels can significantly reduce air pollution caused by burning fossil fuels for energy.
It’s vital to point out that global electricity supply cannot rely on a single source of generation to meet the requirements of billions of people. And, thanks to changeable weather and our planet’s day and night cycle, a mismatch between solar energy demand and supply is unavoidable.
The equipment required to store solar power for when it’s needed is still extremely expensive. Additionally, solar panels won’t be able to deliver enough power for some industries. Heavy manufacturing and metal processing, for example, require very large currents and specialised electricity delivery, which solar power won’t yet be able to provide.
Despite this, rooftop solar has huge potential to alleviate energy poverty and put clean, pollution-free power back in the hands of consumers worldwide. If the costs of solar power continue to decrease, rooftop panels could be one of the best tools yet to decarbonise our electricity supply.
A move that would have been hailed as an environmental victory almost anywhere in the world will likely achieve little in Norway — because the country is already doing so well on this front. Norway has set the earliest target in the world for the phaseout of new petrol cars, in 2025. But if trends continue, there’ll be next to no petrol cars by April.
Image credits: Michael Fousert.
Normally, the announcement would be good news. But there’s even better news. According to an analysis published in the Norwegian Automobile Federation’s magazine, Motor, the decision may not even be needed.
The analysis, which builds on data from Norway’s Road Traffic Information Council (OFV) shows that the demand for gas cars is already decreasing in Norway, and the trendline could reach zero in April 2022.
In the first 8 months of 2017, petrol and diesel cars accounted for 25% of new car sales. Meanwhile, over the same period in 2021, this accounted for 4.93% and 4.73% respectively (for a comparable number of overall sales). If this trend keeps up, there could be virtually no demand for non-electric cars.
New fossil fuel car sales in Norway.
The fine print
This is good news no matter how you look at it. But there are a few details that should be worth mentioning. For starters, the statistics count hybrid cars as “electrified” — which is a rather misleading way of looking at it, because hybrid cars just make better use of the energy they derive from fossil fuels, but it’s still fossil fuel energy. However, hybrid cars make up less than 10% of new car sales, so it’s not a major concern.
Furthermore, Norway didn’t technically draft a law to outright ban non-EV cars starting 2025, it’s more a soft commitment than anything else. But maybe this is why this trend is so important.
Already, 14 out of the top 15 best-sold cars in Norway are all EVs — with just one hybrid in the top 15 list. The most popular petrol car is only on 38th place.
The fact that public opinion is shifting towards EVs faster than governments can only be encouraging. We’re witnessing a general trend in many parts of the world, with more and more people embracing electric cars. But there’s another side to this story: money.
While the upfront cost of an EV may be higher, the long-term maintenance costs are already significantly lower. But what really made a difference in Norway is tax incentives. Gas vehicles are subjected to a hefty tax, while EVs are exempt.
To make the switch from cars that run on electricity, we probably need a bit of all of the above: a cultural shift in perspective favoring electric cars, financial incentives, and in time, bans. For now, Norway is leading the pack. Hopefully, others will catch up.
Could car exhaust be captured and used to grow crops? Researchers at Texas A&M University are saying yes. A new white paper published by three faculty members is proposing that CO2 and water from car exhaust can be captured for this purpose, and outlines a general approach on how to do so. Although such an idea might seem quite exotic, it’s not the first time it’s been proposed, the authors argue.
Image credits Andreas Lischka.
The current paper doesn’t intend to offer an exact solution to such an approach, or the exact way through which it is to be implemented. Rather, it is a white paper — it outlines the basic issue and the authors’ initial analysis and thoughts on how to best address it. The team hopes that this paper will help to attract the funding needed to perform in-depth, formal research on the topic.
From tailpipe to table
“I started reading the related literature and did simulations of what was possible,” says Maria Barrufet, professor and Baker Hughes Endowed Chair in the Harold Vance Department of Petroleum Engineering at Texas A&M. “This is entirely realistic.”
“Several proposals have already been written for large trucks and marine vehicle applications, but nothing has been implemented yet. And we are the first to think of a passenger car engine.”
Such an approach would help massively reduce humanity’s overall environmental impact by reducing our output of carbon dioxide (CO2), a greenhouse gas, into the atmosphere. At the same time, it would help us increase agricultural productivity without placing any extra strain on natural processes and the ecosystems that provide them.
In broad lines, what the authors propose is to integrate a device into car engines that would capture and compress these waste products. The device in question would operate on the organic Rankine cycle (ORC) system and would be powered by waste heat given off by the engine. Organic Rankine cycle systems operate very similarly to steam engines on a smaller scale, using an organic fluid in lieu of water. This fluid has a lower boiling point than water, meaning that the device requires much lower temperatures to produce physical work than a traditional steam engine.
In turn, this ORC system will power components such as a heat exchange and pumps which will cool down and compress CO2 from a gas into a liquid, to enable storage.
The team explains that the CO2 and water captured from exhaust engines could prove to be very useful for agriculture, especially in high-intensity urban greenhouses. Such greenhouses employ artificial atmospheres that are highly enriched in CO2, generally containing around three times as much of it as the air we breathe. In combination with other systems supplying vital nutrients, this higher concentration of CO2 helps foster plant growth and leads to increased yields, as plants primarily grow using carbon from the air. Farms like these already spend money purchasing CO2, but making the gas widely available for cheap from traffic — maybe even for free — could go a long way towards promoting intensive urban agriculture. The team explains that on average, urban farms purchase roughly 5 pounds (2 kg) of CO2 and nearly six gallons (22 liters) of water for every two pounds (1 kg) of produce they grow.
Another argument in favor of such a scheme is that growing produce locally further reduces costs and environmental impact related to storing, handling, transporting, and refrigerating produce from farms to groceries. It would also help reduce traffic.
Beyond the benefits to agriculture, the sheer environmental benefits such a scheme can produce would be immense. In 2019, there were 1.4 billion private vehicles in operation globally, producing an average of 4.6 tons of CO2 per year each — which adds up to a lot.
“Years ago, we didn’t think we could have air conditioning in a car,” Barrufet said. “This is a similar concept to the air conditioning that we now have. In a simple way, it’s like that device, it will fit in tight spaces.”
For us driving the cars, the ORC system wouldn’t make any noticeable impact. Since it operates using waste heat, the authors are confident that it will not lead to any significant loss of engine power, increase in fuel use, or maintenance needs (although special coatings will be needed to prevent corrosion in the heat exchange systems). As far as emptying the system, the team envisions drivers simply turning in cartridges of water and CO2 in specialized centers, or even at gas stations, in exchange for empty ones. There’s nothing preventing them from using the products in their own greenhouses, however, but the authors stress that this process should be done responsibly to ensure that the CO2 is fully absorbed by plants and does not escape into the atmosphere — which would defeat the purpose of this whole exercise in the first place.
Not everything is settled, however. There is still work to be done determining how large these cartridges should be, how the water produced by the system should be handled (water cannot be compressed like a gas), and technical details, such as determining how the weight of these cartridges would affect the car’s performance and handling across all possible levels of weight.
Realistically, we’re probably looking at roughly 10 years or so of development before such systems are ready to be implemented commercially. We already have all the individual components needed, but we still need to figure out how to put them all together in the most efficient way.
“All of these independent ideas and technologies have no value if they cannot connect,” Barrufet said. “We need people concerned about the future to make this happen soon, energized students in petroleum, mechanical, civil, agricultural and other engineering disciplines who can cross boundaries and work in sync.”
The paper “Capture of CO2 and Water While Driving for Use in the Food and Agricultural Systems” has been published in the journal Circular Economy and Sustainability.
Londoners might already be familiar with the giant Whipsnade White Lion, an iconic landmark overlooking Britain’s huge Whipsnade zoo. But this chalk landmark is now getting a modern counterpart that will help the zoo get closer to its sustainability goals.
The planned ‘solar lion’. Image credits ZSL Whipsnade Zoo.
Lion-powered
The new lion will cover an area of two acres (87.100 sq ft, or 8.090 sq meters) and will be made out of solar panels, estimated to provide one-third of the power requirements of the Zoo — around 1MWs of power (enough to power some 700 houses). Although its sheer size will mean that someone at ground level won’t be able to see the lion’s shape but Whipsnade is confident that it will “create a spectacle to be seen from the skies”.
“We are really excited about our plans for a Solar Lion to join our Whipsnade White Lion on the beautiful Chiltern hills and even more excited about the difference she could make to the planet” said Owen Craft, ZSL Whipsnade Zoo’s Chief Operating Officer, in a press kit. “I hope that our Whipsnade Solar Lion, when she is in place, will be a beacon of light reminding people that change is not only necessary, but possible.”
The Whipsnade White Lion is a chalk figure that has been overlooking the Dunstable Downs escarpment since 1933. Since then, it’s become an iconic sight for the area, attracting tourist attention and not just a little local pride. The lion has been restored in September 2017, with special care being taken to protect both it and the “special scientific interest area” around it.
Now, it’s getting a modern counterpart. Essentially, what the zoo is planning to do is to create a massive solar farm in the shape that harkens back to the iconic chalk lion.
Whipsnade Zoo hill figure photographed from Ivinghoe Beacon
According to the press kit from ZSL Whipsnade Zoo, this ‘solar lion’ is part of the zoo’s commitment to becoming carbon neutral by 2035. Other initiatives that will accompany the lion include reducing their emissions from The ‘solar lion’ is part of ZSL Whipsnade Zoo’s mission to make itself net zero carbon by 2035. Other plans to achieve this include reducing emissions caused by electricity and fossil fuel use for heating by 50% by 2030, and taking steps towards reducing their indirect emissions generated by the zoo’s supply chains.
Other initiatives include halving the zoo’s water consumption, helping to foster local wildlife, and arranging transport schemes with local services to encourage the use of public transport with visitors.
The announcement comes in the wake of the zoo celebrating its 90th birthday (on 23 May 2021). Whipsnade is not simply a zoo, however; part of the Zoological Society of London (ZSL), it has a long heritage of conservation and breeding efforts and has taken an active role in the reintroduction of species that had gone extinct in the wild, including Przewalski’s horse (Equus ferus przewalskii) native to Mongolia and the Scimitar Horned Oryx (Oryx dammah), native to North Africa.
“As a global conservation charity, we know only too well the devasting effect climate change is having on the world’s wildlife, as well as on the survival of our own species. As we approach the United Nations climate change conference COP26 in Glasgow, we’re calling on world leaders to put nature at the heart of global decision making, and we’re committed to that ourselves,” Craft adds. “We must invest our time, energy and resources into reducing our carbon emissions to be as low as they can be, as quickly as we can, with innovations like the Solar Lion.”
The full details on ZSL Whipsnade Zoo’s environmental policy and initiatives can be found here.
