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.
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.
“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.
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.
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.
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.
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.
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.
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.
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.
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 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.
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.
In 2020, renewable energy sources such as wind and solar grew at their fastest rate since 1999 — and will continue expanding at a faster rate than before the pandemic, according to a report by the International Energy Agency (IEA). While China’s growth will stabilize, a large expansion is expected in the US and Europe.
Moving towards renewable sources is one of the key ways to reduce global emissions and achieve carbon neutrality. But as clean energy expanded, so did coal, the most polluting energy source. Coal demand is expected to grow 4.5% this year, approaching its all-time peak from 2014.
The amount of renewable electricity capacity added in 2020 rose by 45% in 2020 to 280 gigawatts (GW), the largest year-on-year increase in the past two decades, IEA showed. This significant increase is set to continue, surpassing previous IEA estimates by 25%.
“Wind and solar power are giving us more reasons to be optimistic about our climate goals as they break record after record. Last year, the increase in renewable capacity accounted for 90% of the entire global power sector’s expansion,” Fatih Birol, IEA’s executive director, said in a statement.
Global wind capacity additions almost doubled last year to 114 GW. While the increase won’t be as significant over the next few years, it will still be 50% larger than the expansion seen between 2017 and 2019, the IEA said. Meanwhile, solar energy projects are expected to continue expanding, with up to 160GW forecasted for 2022.
Although China has accounted for 40% of global renewable capacity growth for several years already, for the first time in 2020 it was responsible for 50% – a record level resulting from the unprecedented peak in new installations. This is expected to decline as the government phases out subsidies for new projects. But other places are lining up to compensate.
In Europe, annual capacity additions are forecast to increase 11% to 44 GW in 2021 and 49 GW in 2022. With this expansion, this year the region will break the record for annual additions for the first time since 2011 and become the second largest market after China – with Germany as the main producer of the bloc.
Meanwhile, in the US, renewable capacity growth this year and next is mainly encouraged by the extension of federal tax credits. IEA’s report didn’t consider Biden’s new climate pledge or the country’s recently announced infrastructure bill. If they are met, both would drive a strong acceleration in the deployment of renewables.
“Governments need to build on this promising momentum through policies that encourage greater investment in solar and wind, in the additional grid infrastructure they will require, and in other key renewable technologies such as hydropower, bioenergy and geothermal,” Birol said in a statement.
In a report earlier this year, IEA said global energy-related CO2 emissions are on course to surge by 1.5 billion tons this year. This would be the second-largest increase in history, reversing the decline caused by the pandemic. The key driver is coal demand, which countries are still relying on in addition to renewable energy sources. Hopefully, that will soon change — installing renewable energy is only one part of the challenge, keeping fossils fuels in the ground is what’s going to make or break our climate efforts.
Solar panels make for very good real estate — if you’re a flower. A new paper reports that the partial shade these panels generate can increase the abundance of flowers and create a delay in their blooming time, which could help improve our agricultural output. The authors explain that extending bloom times is important for pollinators, as it provides them food later in the season.
New research at the Oregon State University could have important implications for managers of land under solar panels, farmers, and those concerned with the plight of pollinators such as bees. According to the findings, these devices do impact the plants living in their shade, but that’s not to say they have a negative impact. In fact, the shady areas beneath solar panels increase flower density.
“The understudy of solar panels is typically managed to limit the growth of plants,” said Maggie Graham, a faculty research assistant at Oregon State and lead author of the paper. “My thought coming into this research was can we flip that? Why not plant under solar arrays with something beneficial to the surrounding ecosystem, like flowers that attract pollinators? Would insects even use it? This study demonstrates that the answer is yes.”
The team says their study is the first to look at how solar panels impact flowering plants and insects. The findings come just after some states, including Minnesota, North Carolina, Maryland, Vermont, and Virginia, have implemented statewide guidelines and incentives meant to support pollinator-focused solar installations.
Pollinators are an essential lynchpin of virtually every ecosystem on Earth. They’re directly involved in the reproduction of 75% of flowering plant species and 35% of crop species globally, and their services are valued at an estimated 14 billion USD annually. Which is a lot!
That being said, they’re also struggling. One of the most pressing issues they’re facing is a global decline in habitat due to urbanization, agriculture, and other types of land use. Climate change is also having a negative impact on these insects and further impacting their available habitat.
But solar panels — of which there are increasing numbers in the US — could help. Agrivoltaics is the approach of installing solar energy production on agricultural land, such as cropfields or grazing areas. The authors have previously studied agrivoltaics and its potential, finding that it could provide 20% of total electricity generation in the United States with an investment of less than 1% of the annual U.S. budget. It would also slash around 330,000 tons of carbon dioxide emissions per year, create jobs, and have a minimal impact on crop yields.
Those findings spurred the current research. The team wanted to better understand how these panels impact plant life around them, so they collected data on pollinators and plant populations in the US from seven, two-day sampling events from June through September 2019. These samplings corresponded with the post-peak bloom times for flowers. The collected data pertained to 48 species of plants and 65 different insect species. The study sites were broken into three categories: full shade plots under solar panels, partial shade plots under solar panels, and full sun plots (not under panels).
Among the most important findings, the team reports that flowers were most abundant in partial shade, where 4% more blooms were found compared to full sun and full shade plots — but there was no difference in the number of (flower) species between the plots. Plots with partial shade had 3% more pollinating insects on average than full-shade or full-sun plots. Partial-shade plots had more insects, and more insect diversity, than full-sun or full-shade spots. Finally, the team didn’t find any difference in the number of insects per flower among the plots.
“Unused or underutilized lands below solar panels represent an opportunity to augment the expected decline of pollinator habitat,” Graham said. “Near agricultural lands, this also has the potential to benefit the surrounding agricultural community and presents an avenue for future study.”
“Solar developers, policymakers, agricultural communities and pollinator health advocates looking to maximize land-use efficiency, biodiversity and pollination services might want to consider pollinator habitat at solar photovoltaic sites as an option.”
The paper “Partial shading by solar panels delays bloom, increases floral abundance during the late-season for pollinators in a dryland, agrivoltaic ecosystem” has been published in the journal Scientific Reports.
Installing solar panels in your home doesn’t just reduce your own electricity costs but also the ones of your entire neighborhood, a new study showed. Researchers have found that solar photovoltaic (PV) owners are actually subsidizing their non-PV neighbors’ thanks to the lower costs of solar compared to fossil fuel power generation.
PV technologies have had a rapid industrial learning curve, which has resulted in continuous cost reductions and improved economics. This constant cost reduction pressure has resulted in Chinese-manufactured PV modules only costing now US$0.18 per watt, for example. Technology is constantly improving and bringing down costs.
The International Renewable Energy Agency (IRENA) has confidently predicted that PV prices will fall by another 60% in the next decade. IRENA expects between 80 to 90 GW of new solar capacity will be added globally each year over the next five to six years, consolidating China as the biggest and fastest-growing solar market in the world.
A group of researchers at Michigan Technological University wanted to look at whether solar panels were driving up electricity costs for people without panels. It’s a common argument been used over the years by utility companies, governments, and regulators to slow down the progress of PV, especially among homeowners and small businesses.
But the researchers found that the opposite was actually true, with PV owners subsidizing their non-PV neighbors. This is due to the avoided costs for new grid, reserve, and generation capacity, as well as for avoided operation and maintenance and environmental and health liabilities due to fossil fuel power generation. So in other words, solar panel owners were reducing the costs of their neighbors instead of increasing them.
“Anyone who puts up solar is being a great citizen for their neighbors and for their local utility,” research co-author Joshua Pearce said in a statement. “Customers with solar distributed generation are making it so utility companies don’t have to make as many infrastructure investments while, at the same time, solar shaves down peak demands when electricity is the most expensive.”
Of course, solar panel owners also get direct benefits. When you use solar energy, you rely less on utilities to give you electricity. Consequently, your monthly bills go down, and you can even earn a credit on your statement. Electricity companies also pay customers for using panels for the extra energy they don’t use in a month, so you make money (in some countries, at least). However, we might not be supporting solar panels enough. The study suggests more measures need to be taken to ensure that PV owners aren’t “unjustly” subsidizing electric companies across the US.
A crystal known to science for more than a century has only in recent years become recognized for its use in harvesting solar power. Since the first successful usage of perovskite in solar cells in 2009, the advances in the field have grown exponentially. In just a few years of development, rated efficiency in the lab for perovskite solar cells soared from 3.8% to nearly 20%. Now, scientists at Helmholtz-Zentrum Berlin (HZB) have paired perovskite with silicon in a hybrid solar cell that harvested photons with an impressive 29.15% efficiency — a new world record that may propel the industry to new heights.
Solar cells convert incoming photons into electricity by exploiting the electron-hole pair generation and recombination. When photons come in contact with the semiconducting material, and if their energy falls into the semiconductor bandgap, then an electron is offset, leaving a gap in the atom. The electron travels from atom to atom within the material, each time leaving behind a hole and occupying holes downstream until it eventually reaches an electrode and has its charge transferred to a circuit. This is when electricity is finally generated.
The key is to have electrons moving for as long as possible, and thanks to its diffusing capabilities, perovskite can theoretically generate more electricity. Perovskite solar cells have many distinct advantages over traditional silicon cells. Firstly, the fabrication of perovskite photovoltaics is much cheaper and simpler than silicon photovoltaic cell production. Additionally, perovskite cells have a higher bandgap than traditional silicon or thin-film cells.
Because perovskite thin films are transparent, they can be placed on top of lower bandgap cells like silicon. The result is a hybrid or “tandem” photovoltaic system. Stacking two solar cells one on top of the other in this manner allows a larger portion of solar energy to be converted into electricity.
More than 50 years ago, William Shockley and Hans-Joachim Queisser discovered the Shockley-Queisser limit, which is the efficiency ceiling of solar cells with only one single layer. For both silicon and perovskite, the theoretical limit is around 30%. For tandem cells the theoretical limit is about 35%.
However, in the real world single-layer silicon or perovskite solar cells usually don’t convert more than 20% of the solar energy they receive. This is why the new tandem cell developed in Germany — which uses a perovskite composition with a 1.68-eV band gap — is so impressive, clocking in nearly 30% efficiency, just 5% shy of the absolute theoretical limit.
The solar cell developed by the researchers led by Steve Albrecht and Bernd Stannowski was tested in the lab on a sample measuring only 0.2 cm by 0.2 cm (1 cm2 ), but it should be quite easy to scale up the size. Next, the HZB team wants to break the 30% efficiency barrier. Albrecht says that initial ideas for this are already under discussion.
Aptera Motors, an American startup company based in San Diego, California, recently announced a new three-wheeled electric car with a range of up to 1,000 miles. If you have at least one eyebrow raised in skepticism, you’re not alone. That’s because no other auto company, not even market leader Tesla, has come up with a vehicle close to this range. The catch? You can charge the car’s 100 kWh battery from an electrical outlet, but also while driving or parked thanks to its solar harvesting roof.
A solar batmobile
Electric vehicles have been bashed by skeptics for a number of reasons since they rose to prominence in the past decade. Two arguments usually come to mind. One is their limited range compared to a conventional petrol car on a full tank of gas, the other is environmental, with many critics highlighting the irony of buying a car to “go green” while charging using electricity from a coal-powered plant.
But with dramatic improvements in battery technology and rapid developments in charging infrastructure, as well as phenomenal deployments of wind and solar energy (The solar PV annual market could reach about 150 GW – an increase of almost 40% in just three years), these arguments are becoming obsolete.
Sales of electric cars topped 2.1 million globally in 2019, surpassing 2018 – already a record year – to boost the stock to 7.2 million electric cars and marking a 40% year-to-year increase.
Clearly, a lot of people love EVs, whose market is an increasing expansion. But those who are still not happy with their range or about the source of their charging electricity may find Aptera’s concept appealing. Previously, Aptera folded in 2011 after failing to secure a $150 million loan to produce its Aptera 2e vehicle.
Instead of a sedan or SUV, Aptera Motors designed a three-wheeled electric vehicle that is all about efficiency. The composite materials and the streamlined shape makes the three-wheeled vehicle light, compact, and fast.
According to the company, Aptera’s curvy vehicle has a drag coefficient of just 0.13, compared to 0.23 for Tesla’s Model 3 or 0.28 for Volkswagen’s ID 4. This highly efficient use of energy enables the car to travel up to 1,000 miles on a single charge.
What’s more, the vehicle is covered in solar panels which would offer an additional 40 miles of range per day, depending on where in the world you park or drive it.
Preorders for Aptera’s Paradigm and Paradigm Plus models are open now for a price tag ranging between $25,900 and $46,000. The company expects to deliver them by the end of 2021. So far, the company has raised nearly $1.5 million from small private investors.
Over 75% of the energy to be installed in the US in 2020 will be wind or solar, a new report by the Energy Information Association (EIA) shows.
EIA expects the addition of 42 gigawatts (GW) of new capacity in the US in 2020. Solar and wind represent almost 32 GW of these (76%). Wind accounts for the lion’s share of this (44%), followed by solar at 32%. Natural gas will only account for 22% of this new energy.
However, it’s important to note that this represents capacity — not actual electricity generated. This means that there will be ups and downs in renewable energy, which is not the case for something like nuclear or natural gas, which are generally more stable.
Nevertheless, this is a telling story: despite interventions from the current administration, attempting to artificially support the fossil fuel industry, new energy is predominantly renewable — and coal no longer really has a seat at the table when it comes to novelty.
The expected prediction of retired energy production is also telling. Of the 11 GW set to be retired in 2020, more than half of it (5.8 GW) will be coal, much of which comes from Kentucky and Ohio. Another 3.8 set-to-be-retired GWs come from older natural gas units that came online in the 1950s or 1960s. So the bulk of the decommissioned energy will be from fossil fuels.
However, two nuclear plants totaling 1.6 GW are currently scheduled to retire in 2020.
The impact of these shifts indicate a longer trend for the foreseeable future. Most of the new energy is renewable, and most of the decommissioned energy is fossil fuel. This is also making an impact in the country’s greenhouse gas emissions. After decreasing by 2.1% in 2019, EIA forecasts that energy-related carbon dioxide (CO2) emissions will decrease by 2.0% in 2020 and by 1.5% in 2021 (under normal weather conditions).
However, while significant, this shift is not ambitious enough to set the US on a trajectory to reduce its emissions enough to avoid catastrophic climate change.
Much of the change involves renewables replacing coal — and while that’s certainly a step in the right direction, natural gas remains almost untouched. EIA projects that the share of U.S. total utility-scale electricity generation from natural gas-fired power plants will remain relatively steady, it was 37% in 2019, and we forecast it will be 38% in 2020 and 37% in 2021.
Heavy industries such as cement, glass and steel manufacturing could soon be saying goodbye to their reliance on fossil fuels and welcoming renewable energy – all thanks to a breakthrough in solar technology by a startup supported by Bill Gates.
The company, called Heliogen, announced it found a way to use mirrors and artificial intelligence to reflect sunlight and reach a temperature of more than 1,000 degrees Celsius – the temperature needed to manufacture cement, glass, steel and other materials.
“The world has a limited window to dramatically reduce greenhouse gas emissions,” says Bill Gross, CEO and founder of Heliogen. “We’ve made great strides in deploying clean energy in our electricity system. But electricity accounts for less than a quarter of global energy demand.
The industries that could benefit from the new invention represent around 20% of the global greenhouse gas emissions, according to Gross, who said that up until now not many options had been developed to lower the carbon footprint of the sector.
Heliogen took this a step further a technology through which hundreds of mirrors located in a field aligned to direct sunlight to a steam turbine located in a tower. The heat then turns liquid to steam, giving power to the turbine. New software can now align the mirrors and obtain better results.
“Heliogen represents a technological leap forward in addressing the other 75 percent of energy demand: the use of fossil fuels for industrial processes and transportation. With low-cost, ultra-high temperature process heat, we have an opportunity to make meaningful contributions to solving the climate crisis,” said Gross.
In the past, the technology used by Heliogen, called concentrating solar power (CSP), was able to generate heat of up to 560 degrees Celsius. Now, thanks to Heliogen’s research, the temperature could reach up to 1,500 degrees Celsius – enough to split hydrogen atoms from water and create a fossil-fuel-free gas.
But that’s further down the line. So far, Heliogen has been able to reach a temperature of 1,000 degrees, which is also helpful heavy industries. For example, cement represents the third most important source of greenhouse gas emissions after oil and coal – with a growing production that threatens the pledges of the Paris Agreement.
“Today, industrial processes like those used to make cement, steel, and other materials are responsible for more than a fifth of all emissions,” Bill Gates told The Guardian. “These materials are everywhere in our lives, but we don’t have any proven breakthroughs that will give us affordable, zero-carbon versions of them.”
Bolstered by government support and falling costs, global renewable energy capacity is set to rise by 50% in five years’ time, according to a new report, which especially highlighted the expansion of solar photovoltaic installations on homes, buildings and industry.
The International Energy Agency (IEA) found that solar, wind and hydropower projects are rolling out at their fastest rate in four years. It predicts that by 2024, a new dawn for cheap solar power could see the world’s solar capacity grow by 600GW — almost double the installed total electricity capacity of Japan.
This means that the total renewable-based power capacity will rise by 1.2 terawatts (TW) by 2024 from 2.5 TW last year, equivalent to the total installed current power capacity of the United States.
“This is a pivotal time for renewable energy,” said the IEA’s executive director, Fatih Birol. “Technologies such as solar photovoltaics and wind are at the heart of transformations taking place across the global energy system. Their increasing deployment is crucial for efforts to tackle greenhouse gas emissions, reduce air pollution, and expand energy access.”
The EIA estimated that the share of renewables in global power generation will rise to 30% in 2024 (up from the current 26%) as China, Europe and the U.S. increase deployment of wind turbines and solar panels. Most of the gains, about 60%, will be due to solar.
Costs of both utility-scale and distributed solar PV generation are expected to decline as much as 35% by 2024. That will help make costs of utility-scale solar plants equal to or cheaper than new fossil fuel plants in some countries. Distributed solar, the panels that are placed on homes, offices and factories, is set to boom as costs come down.
The number of home solar panels is also expected to more than double to reach around 100m rooftops by 2024, with the strongest per capita growth in Australia, Belgium, and California. Even after that growth expected for solar, panels will cover only 6% of the world’s available rooftops, leaving room for further growth.
Renewables are also making gains in providing heat to buildings. Heating and cooling demand from buildings and industry account for roughly half of global energy consumption and is responsible for 40% of global carbon dioxide emissions.
Heating from renewable energy is set to increase by 22% by 2024, according to the IEA, with China, the EU, India, and the US contributing most of that growth. Even so, renewables will only support 12% of global heat consumption by 2024 compared with 10% now.
“Renewables are already the world’s second largest source of electricity, but their deployment still needs to accelerate if we are to achieve long-term climate, air quality and energy access goals,” Birol said.
The race against fossil fuels
Earlier this year, a report by Bloomberg showed that not only was renewable energy cheaper than building a new gas or coal plant, but that it would soon be cheaper than using existing thermal plants too.
This economic tipping point means it would save money to shut existing coal-fired power plants down and build new renewable energy projects from scratch. Abundant clean electricity could help remove the emissions from the world’s transport and heating systems too.
By 2030, Bloomberg expects demand for road fuels to peak, and coal is also expected to peak by 2026. DNV GL, a global energy advisory, believes that by the same year oil will no longer be the world’s biggest energy source, and by the end of the 2020s, the world’s demand for crude oil will begin to fall. Is this in time to avoid catastrophic climate damage? That matter is still not clear. But there are some reasons to be optimistic.
“It provides a lot of hope,” said Seb Henbest, the lead author of the Bloomberg report. “It provides a counterbalance to the doom and gloom we face, partly because it includes up-to-date data which tells a slightly different story.”
The greatest benefit of solar energy is how green it is. Once you make and deploy the solar panels, you have clean energy, meaning there is no carbon dioxide produced during their operation. However, there are a number of reasons to adopt solar and go green, and they go well beyond protecting the environment.
For people living off the grid, it is a clean source of energy that also saves them from having to buy kerosene for light and gasoline to run a generator — they save money without sacrificing quality of life.
Solar equipment manufacturing is high tech but long-lasting. By buying solar power, you’re encouraging long-term investment in solar power plants. There are some logistical and infrastructure requirements such as wiring the solar panels and maintaining the electrical equipment, but there’s no need to constantly supply gasoline or mine coal to generate power. This helps close the foreign trade gap since we can make power ourselves.
If you’ve put solar panels on the roof, they’ll generally improve the resale value of the home. They’re seen as a cost-savings just like extra insulation in the roof. This is in sharp contrast to a complex organic garden or geothermal system, since the maintenance requirements scare many potential home buyers away. And if you select a renewable energy provider for your home, you don’t have to worry about what potential home buyers might think. Conversely, you don’t have to own a home to take advantage of renewable energy delivered by your electric company.
The Social Benefits
Supporting solar power has a number of social benefits. You’re getting energy without paying for oil that ends up subsidizing oppressive Islamic regimes or wars for oil. Instead, you’re encouraging local power production through solar panels put up on rooftops and solar farms. You’re creating local high-tech, good-paying jobs, too.
These jobs are often distributed throughout the area, whereas oil field jobs are typically far from civilization. By supporting solar power, you aren’t asking people to trek to Alaska or Saudi Arabia to fuel your modern lifestyle. They’re not exposed to toxic chemicals working in a refinery or trying to sail oil tankers past pirate-infested Somalia.
The Long-Term Benefits
There are long-term benefits to adopting solar energy. Once we have solar panels, we can reuse the silicone and other metals as required. We can store the energy for future use via batteries; that has to be done anyway since the sun and solar power production both go down at night.
A side benefit of setting up batteries and other energy storage devices across the power grid is that it increases the grid’s overall resilience. If local power lines went down, a facility could rely on power produced by solar panels on the roof or pull from their batteries. They may run for several hours before things go down, and service is likely to be restored by then. If power transmission lines went down for a given community, it may not be able to send excess power to its neighbors but may meet part of its local energy needs via solar power and stored energy reserves. Some power producers rely on a mix of solar, wind and other renewable energy sources to provide a steady stream of power, all of it green.
Use an energy comparison site to shop for green energy suppliers and sign up for a plan today. You could find a renewable energy company that matches or beats your current energy provider on service and price, and you’re supporting renewable energy development with every electric bill. You’re also encouraging energy providers to invest in renewable energy through the free market. That you may save on your energy bill by putting solar panels on the roof or lead the energy provider to save money through tax credits is an added bonus.
The Impact on Quality of Life
We’ll set aside the doom and gloom projections of global warming, climate change, climate catastrophes and every other name that’s been applied to everything from hurricanes to flooding. Shifting to solar power has a direct impact on everyone’s quality of life.
By moving to solar power and other renewable sources of energy, you reduce the production of particulate pollution through the burning of coal and natural gas, thereby improving air quality for everyone. This reduces problems from asthma attacks in children to emphysema deaths in adults.
Solar has had a fantastic track record so far, having achieved a 90% reduction in cost over the last decade — and it doesn’t show any sign of stopping
A new report released by researchers at the Lappeenranta University of Technology in Finland found that solar energy is cheaper than spot wholesale electricity prices in many European cities and nations. What’s more, even when adding up to two hours of storage, solar is still competitive with the average wholesale electricity spot market (WESM) price.
WESM is a venue for trading electricity as a commodity, serving as a clearinghouse to reflect the economic value of electricity for a particular period, as indicated by the “spot price”.
The researchers led by Christian Breyer, a professor of solar economy at Lappeenranta, analyzed the levelized cost of electricity (LCOE) of solar energy — meaning the average cost of electricity when taking into account capital expenditure, operations, storage, and other factors — and compared it to wholesale electricity prices in various European markets.
The findings were astonishing, suggesting that the LCOE of photovoltaic (PV) solar energy is already cheaper than most average spot market prices, ranging from only €24/MWh ($26/MWh) in sunny locations like Malaga (Spain) to €42/MWh ($46/MWh) even in cloudy Helsinki (Finland).
In the graph below, you can see how the LCOE of solar beats the average spot market price in many European countries — and by quite a considerable margin in places like Italy and Spain which are generously bathed in sunlight.
Solar remains competitive even when factoring storage costs of up to two hours, ranging from €54/MWh ($60/MWh) in Malaga to €95/MWh ($105/MWh) in Helsinki — and the cost is projected to plunge even deeper.
The report estimates an LCOE of solar ranging from €14-24/MWh ($15.5-$27/MWh) in 2030 and €9-15/MWh ($10-16.5/MWh) in 2050 — that’s peanuts compared to the current average wholesale electricity price.
If solar is so advantageous, why aren’t we investing more in it? The authors of the report state that the rate of advances in PV and storage technologies is so fast that policymakers haven’t kept up — they’re simply working with outdated figures, the researchers argue.
“This proves that it is of utmost importance for the solar PV industry to convince the financial community that utility‐scale PV is a safe and profitable investment. Policy makers need to be informed that PV is the cheapest form of electricity, especially if its inherent low economic, technical, and environmental risks are taken into account. In addition, it has to be highlighted that the high dynamics in the solar PV industry has led to PV CAPEX and PV LCOE levels not yet well reflected in literature and major reports typically taken into account for decision making. PV plus batteries are the cornerstones of the future energy system if we wish to tackle the climate crisis in a fast and cost‐neutral way,” the authors concluded.
Researchers from the University of Cambridge look to plants for a new energy revolution.
Oxygen, hydrogen (left) and water molecules (right). Image credits Luis Romero / Flickr.
Looking for new and more efficient ways of harvesting solar energy, a team of researchers from St John’s College has turned plants to the job. The team has successfully split water molecules into hydrogen and oxygen by altering and improving on natural photosynthetic processes. Photosynthesis is the process plants use to convert sunlight into energy.
Lettuce make fuel
Photosynthesis is arguably the most important process for life on Earth. The process — which uses energy in sunlight to break down water and carbon dioxide — provides the energy and building blocks that plants need to grow. In turn, plants act as primary producers: they form the first link of virtually every trophic network on the planet, essentially feeding the rest of the planet. Moreover, photosynthesis is the source of nearly all the oxygen in the atmosphere today. In its absence, oxygen (a very reactive gas) would bind with chemical compounds or would be used up in biological respiration pretty quickly, and we’d all choke to death. Which would be sad.
Not content to let the process drive just our biology, the team — led by St John’s College PhD student Katarzyna Sokół — worked on turning it into a power source.
Hydrogen has long been considered a viable — and powerful — alternative to fossil fuels. In fact, the first internal combustion engine ever built used a mixture of hydrogen and oxygen, not fossil fuels, to generate energy. It was designed by Francois Isaac de Rivaz, a Swiss inventor, all the way back in 1806. However, it never really caught on, as we didn’t know of any fast and cheap way of mass-producing the gas.
Artificial photosynthesis has yet to reach a point where it can supply enough hydrogen for wide-scale use, mostly because it relies on the use of catalysts, which are often expensive and toxic. On the other hand:
“Natural photosynthesis is not efficient because it has evolved merely to survive so it makes the bare minimum amount of energy needed — around 1-2 per cent of what it could potentially convert and store,” says Katarzyna Sokół, who is also the paper’s first author.
This means that neither can support an industrial-level economy based on hydrogen.
Experimental two-electrode setup showing the photoelectrochemical cell illuminated with simulated solar light. Image credits Katarzyna Sokół.
The team’s new paper details their efforts to change this state of affairs. Using a combination of biological components and manmade technologies, they managed to convert water into hydrogen and oxygen at high efficiency using only sunlight — a process known as semi-artificial photosynthesis. As part of their research, the team had to remove genetic limitations on photosynthesis that had been imposed millennia ago.
“Hydrogenase is an enzyme present in algae that is capable of reducing protons into hydrogen. During evolution this process has been deactivated because it wasn’t necessary for survival,” Sokół explains, “but we successfully managed to bypass the inactivity to achieve the reaction we wanted — splitting water into hydrogen and oxygen.”
The team is the first to successfully create semi-artificial photosynthesis driven solely by sunlight. Their method was over 80% more efficient than natural photosynthesis.
The groundwork they laid down in integrating organic and inorganic materials into semi-artificial devices also provides new avenues of research into other systems for solar energy capture, they add.
“It’s exciting that we can selectively choose the processes we want, and achieve the reaction we want which is inaccessible in nature,” Sokół explains.
“This could be a great platform for developing solar technologies. The approach could be used to couple other reactions together to see what can be done, learn from these reactions and then build synthetic, more robust pieces of solar energy technology.”
The paper has been published in the journal Nature.
Renewable energy are set to power the future in 2050. Credit: Pixabay.
The annual energy report by Bloomberg NEF (BNEF) concluded that wind and solar are set to surge to a “50 by 50” future, meaning they’ll account for 50% of the world’s energy production by the year 2050. The main driver for this tremendous growth is falling battery cost.
The 150-page report, called New Energy Outlook (NEO) 2018, was authored by more than 65 analysts from around the world. This year’s outlook concluded that the impact of falling lithium-ion battery costs will drive huge growth for new renewable energy power capacity between 2018 and 2050.
During this timeframe, the authors predict investments of $8.4 trillion in wind and solar energy, with an additional $1.5 trillion into hydro and nuclear energy.
Since 2010, the cost of lithium-ion batteries per megawatt-hour has dropped by 80 percent.
“We see $548 billion being invested in battery capacity by 2050, two thirds of that at the grid level and one third installed behind-the-meter by households and businesses,” said Seb Henbest, head of Europe, Middle East and Africa for BNEF and lead author of NEO 2018, in a statement.
These investments should produce a 17-fold increase in solar power capacity worldwide and a six-fold increase in wind power capacity. Falling power generation costs will translate to far lower electricity bills than consumers, business or residential, see today. According to the report, the levelized cost of electricity (LCOE) from new photovoltaic plants should fall by 71 percent by 2050 and 58 percent for onshore wind. Between 2009 and 2018, the LCOE for solar and wind has dropped by 77 percent and 41 percent respectively.
Today, gas-fired power plants and other fossil fuel-based energy generators provide round-the-clock electricity — the so-called baseload. However, BNEF envisions a 2050 future where gas-fired plants are responsible for backup energy rather than baseload. Gas-fired generation is expected to rise by 15 percent between 2017 and 2050, but its share in the overall global electricity is set to decline.
The report doesn’t forecast a bright future for coal, which is expected to continue in its downward spiral. BNEF predicts the amount of coal burned in power stations will fall from 56 percent between 2017 and 2050.
Since renewable energy will occupy the top slot in the energy generation mix, BNEF predicts global emissions will fall, rather than rise, past an inflection point. The report estimates emissions from the global electricity sector rising by 2 percent between 2017 and 2027, after which it will fall by 38 percent in 2050.
The New Energy Outlook based its conclusions on the modeling of power generation country-by-country, and on the evolving cost dynamics of different technologies. It assumes that existing energy policy settings around the world will remain in place until their scheduled expiry dates. It doesn’t assume additional government measures, meaning the evolution of renewable energy might actually be more aggressive if policy steps up its game in favor of more sustainable measures.
If you told the average person only thirty years ago that black panels left in the sun would generate copious amounts of electricity for homes and businesses, the likeliest reaction would have been a condescending grin. Luckily the technology to capture energy from the sun — which shines enough light on Earth’s surface in an hour to power the whole world’s energy for an entire year — has improved immensely, to the point that for many homeowners it’s cheaper to install solar panels on their rooftop than to use the grid.
The first solar cell was constructed by Charles Fritts in the 1880s and had a conversion efficiency of just 1% — hardly enough to be useful. Today, however, the most efficient commercially available solar panels on the market have efficiency ratings as high as22.5%, while the majority of panels range from 12% to 16% efficiency rating. However, solar efficiency can climb to rated efficiencies as high as 46%, in the case of multi-junction photovoltaic (PV) cells that pick up energy from multiple different spectra.
If all this sounds somewhat familiar, it’s because plants have been harnessing energy from the sun for hundreds of millions of years — there’s nothing new about how solar energy works, we are just using it in a different way. Plants convert the sun’s energy into chemical energy, whereas solar cells produce electricity. This leads us to an important question: how do solar panels work?
Solar panels ABC
Solar panels generate electricity when photons knock electrons off from the material. In fact, a solar panel is comprised of an array of smaller units called photovoltaic cells, which are the things that actually convert solar energy into electricity. The typical solar panel is additionally comprised of a metal frame, a glass casing, and various wiring to allow current to flow from the silicon cells. Because solar panels generate direct current, an inverter is also required to allow you to use the electricity in your home.
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Physics-wise, solar power is predicated on the photovoltaic effect (photo meaning “light” and voltaic meaning “electricity”), in which two dissimilar materials in close contact produce an electrical voltage when struck by light or other radiant energy. In solar energy, the materials belong to a class called semiconductors — neither conductors nor electrical insulators that allow electrons to flow under certain conditions. The most common semiconductor used in the solar industry is silicon.
Semiconductors can be one of two types: P and N. Every solar cell sandwiches two of these semiconductors, one layer of P-type and one layer of N-type (which looks a lot like a battery).
P-type semiconductors tend to pick up a small positive charge while N-type ones have a negative charge. Typically, the semiconducting material is riddled with impurities that make them more susceptible to donating or accepting electrons because crystals such as silicon or germanium do not usually allow electrons to move freely from atom to atom. It’s all very similar to how one of the battery’s electrodes has a negative voltage with respect to the other, but applied in a different context.
It’s the P-N junction where electrons are free to cross from one side to the other, but not in the opposite direction. Imagine a hill — electrons can easily go down the hill (to the N side), but can’t climb it (to the P side).
Each photon with enough energy will normally free exactly one electron, causing a ‘hole’ to form. The electric field will then cause the electron to migrate to the N side and the hole to the P side.
This happens when an electron is lifted up to an excited state by consuming energy received from the incoming light. Were it not for a junction-forming material, the free electrons would have eventually fallen back to the ground state. And because the electrons are only allowed to flow in a single direction — from N-type to P-type — the photovoltaic effect produces a direct current. This current, together with the cell’s voltage, defines the power (or wattage) that the solar cell can produce.
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According to the International Energy Association (IEA), photovoltaic solar power grew faster than any other energy source in 2016. The organization estimates that more solar capacity will be added in the next four years than any other type of renewable energy, including wind and hydropower.
Much of this demand comes from China, which is expected to add 40% of the world’s new solar panels between now and 2022, despite having already surpassed its solar power target for 2020. Along with developments in other countries, such as India, Japan, and the US, the IEA estimates that by 2022 the world will triple its PV cumulative capacity to 880 GW. This is equivalent to half the global capacity in coal power, which has taken 80 years to build. This also means that in the next five years, about 70,000 new solar panels will be installed every hour – enough to cover 1,000 soccer pitches every day.
Chernobyl, the worst nuclear accident in human history, is about to get a complete makeover. A new, almost completed project, will provide the local grid with one megawatt of renewable solar power.
The nearby city of Pripyat has become a ghost town. Over 100,000 people were evacuated in 1986 when Chernobyl exploded. Image via Pixabay.
The Chernobyl Disaster was one of mankind’s worst fears. Nuclear power, this tremendous tool, backfired — ironically, not because of a scientific or technological failure, but due to an operating failure. Contamination from the Chernobyl accident was scattered irregularly depending on weather conditions, affecting virtually all of Eastern Europe and going as far as Switzerland or Greece. As for Pripyat, the nearby town which had a population of about 50,000 people, it was completely evacuated, becoming a ghost town. Chernobyl was sealed and the area around it became a black hole in the middle of Ukraine.
Now, all that might change.
Engineers have installed 3,800 photovoltaic panels across an area the size of two football pitches, just 100 meters from the containment zone — the giant concrete sarcophagus which covered the nuclear reactor.
That’s enough to fulfill the needs of a small town of about 2,000 homes, and eventually, Rodina (the company behind this project) says the area could generate 100 times more energy.
The reasoning is fairly simple: first of all, the land is cheap, for obvious reasons — it’s literally a radioactive wasteland. Secondly, Ukraine is offering “relatively high feed-in tariffs,” which makes investing in the area much more attractive. Also, the area is already connected to the grid, thanks to the previously existing infrastructure from the nuclear power plant. It’s still extremely challenging to build anything there, but at the end of the day, it’s not impossible. The new containment dome, completed in 2016, helps greatly by preventing further contamination from the nuclear plant.
For the Ukrainian authorities, it also makes a lot of sense. It’s not like you can use the area for anything else — the area is still radioactive, and the soil is greatly contaminated, making agriculture impossible for thousands of years in the future.
Unlike other projects, Rodina’s $1.2 million investment is nearing completion. It hasn’t started producing electricity yet, but we can probably expect to see it kick off sometime this year. There’s some poetic justice in having Chernobyl once again produce energy — but this time, from the Sun.
All biological processes on Earth rely on the sun for energy. It’s the sun’s rays that allow plants or cyanobacteria to grow. They become lunch for different creatures which in turn are preyed on higher up the food chain. Plants use the energy from incoming photons in a biological process known as photosynthesis, and for all intents and purposes, this is an elegant solution. However, it’s not all that efficient and researchers at the University of California, Berkeley, think they can come up with something better — or at least something different that might work well for some applications.
Artist’s rendering of bioreactor (left) loaded with bacteria decorated with cadmium sulfide, light-absorbing nanocrystals (middle) to convert light, water and carbon dioxide into useful chemicals (right). Credit: Kelsey K. Sakimoto.
At the 254th National Meeting & Exposition of the American Chemical Society (ACS), Kelsey K. Sakimoto and colleagues showed off their latest attempt at harvesting energy with a hybrid system comprised of bacteria and what can only be described as tiny solar panels. Essentially, when the Moorella thermoacetica bacteria, which is nonphotosynthetic, was fed cadmium and the amino acid cysteine, it synthesized the food into cadmium sulfide (CdS) nanoparticles. These are the semiconducting materials many solar panels employ on their surface to collect photons and create electron-hole pairs.
They then showed that the hybrid system comprised of M. thermoacetica-CdS could make acetic acid from CO2, water, and light. “Once covered with these tiny solar panels, the bacteria can synthesize food, fuels, and plastics, all using solar energy,” Sakimoto said in a statement.
Plants turn CO2, water, and light into oxygen and sugars mainly through chlorophyll, which are the green pigments plants use to harvest sunlight. They’re quite similar to semiconductors employed in solar energy only photovoltaic cells turn all of that sunlight into flowing electrons whereas photosynthetic plant cells turn it into plant food. The problem is photosynthesis doesn’t seem all that efficient. Typically, most plants have a sunlight to biomass conversion of only 0.1%-0.2% whereas some crops see 1-2% efficiency.
The hybrid system, however, operates at an efficiency of more than 80 percent, all in a self-replicating and self-generating environment. “These bacteria outperform natural photosynthesis,” Sakimoto said.
Of course, none of this makes trees and plants obsolete. Given our urgent need to phase off fossil fuels, however, any alternative technology that can generate clean energy or products is more than welcome. Acetic acid, for instance, is a very versatile chemical. It’s widely used in the chemical manufacturing industry to make polymers, pharmaceuticals, even liquid fuels. In fact, you have a 5-20% acetic acid-water solution in your kitchen right now — vinegar. Even among alternative energy systems, such as artificial photosynthesis devices, this bacterial-semiconductor system offers long-standing benefits.
“Many current systems in artificial photosynthesis require solid electrodes, which is a huge cost. Our algal biofuels are much more attractive, as the whole CO2-to-chemical apparatus is self-contained and only requires a big vat out in the sun,” Sakimoto points out.
For now, he and colleagues are working on making the semiconductor and bacteria interact better. They’re also looking at other matches that might render different chemicals or foods.