This is a repost from one of our sister publications, Windermere Sun, below:
Perovskite solar cells (Attribution: Stanford ENERGY, video by Mark Shwartz, https://creativecommons.org/licenses/by/2.5/, Presented at: WindermereSun.com)
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Back in 2015, I interviewed the Chief Technology Officer Dr. Christopher Case of Oxford PV during the InterSolar North America in San Francisco, CA. Dr. Case introduced me to a potentially game-changing solar technology, the perovskite solar cell technology, that holds much promise for lowering the cost and boosting the performance of solar power by increasing photovoltaic efficiency of any solar photovoltaic thin film material to 30+% in a perovskite tandem layer (which is more than the maximum efficiency achieved in traditional mono-and poly-crystalline silicon cells). In laboratories, perovskite cells are manufactured by spin-coating, spraying, or “painting” them onto a substrate (material that provides the surface for the chemicals to crystalize on). Perovskites are only about half a micron thick while silicon layer is roughly 200 microns. The main hurdle for perovskite is durability. Perovskites are very sensitive to oxygen, moisture, and heat, therefore, requiring heavy encapsulation to protect the cell, leading to increased cost and weight of solar cell. Oxford PV’s tandem cell conversion efficiency is 29.52%. More research and development and data are needed for testing its efficiency, stability, as well as increasing lifespan and replacing toxic materials with safer ones. Company such as Saule Technologies has some very interesting perovskite products in the works: 1. they have a perovskite photovoltaic glass ( a semi-transparent perovskite solar cell printed onto flexible foils and overlayed with layers of glass), making it a window that generates electricity. 2. Saule is also producing energy-harvesting sun-blinds that can block intense summer sunlight, and allowing sunlight to enter the building in mornings and evenings to provide natural light and passive heating. These blinds can be adjusted manually or automatically. 3. In May of 2021, Saule launched the world’s first industrial production line of perovskite solar panels in Poland. Jinko Solaris also working on rolling out perovskite technology. The perovskite solar cell could be the future of energy, in the video published on Sep. 14, 2021, “Perovskite Solar Cells Could Be the Future of Energy“, below:
Perovskite mineral was discovered over 150 years ago, but it’s only recently that scientists have been able to synthesize the properties of the material in laboratories using commonly available chemicals. And what they’re finding is that it can give a big boost to the performance of existing solar cell technology. This week we take at look at how it works, in the video published on Aug. 9, 2020, “Perovskite Solar Cells: Game changer?“, below:
In the video published on March 26, 2021, “Perovskite solar out-benches rivals-2021| perovskite solar cells shines a little brighter“, below:
Perovskite, a calcium titanium oxide mineral discovered in the Ural Mountains of Russia in 1839. This new old material is generating quite an explosive buzz because scientists have found, in recent years, that it is a great material to be used in solar absorption applications. It can be made simply and inexpensively by using common wet chemistry lab methods and low cost equipment instead of the expensive deposition equipment common in the semiconductor industry. To take a look at how this process is made cheap and accessible, I’m sharing the video below:
These solar (photovoltaic) cells are made in tandem (layer by layer) fashion on a specially coated glass support. In the video above:
the glass is coated with a dense layer of titanium dioxide, by robotic arm, to prevent electrical charge generated by sunlight from leaking out of the cell.
a less dense porous oxide layer covers the dense oxide layer (usually titanium dioxide, other oxides may also be used).
a simple high speed spin coater deposits this layer from solution and spreads this coating evenly across the device.
heating this glass/device in an oven conditions it for solar cell use.
prepare the Perovskite material (which absorbs in the broad range of solar spectrum) by combining 2 precursor materials: PbI2 (lead iodide) & CH6IN (methylammonium iodide)
drip the liquid phase mixture (from 5.) onto the oxide coated device (from 4.)
spin the resulting device in 6 to assure even coating
applying halide solution
heating the device resulting from 8 on a hot plate–>spontaneously crystallizes precursors in freshly deposited liquid
color changes also result from crystallization process resulting from 9.
Such tandem product has the advantage of being able to be introduced into existing infrastructure of current silicon module manufacturing process, boosting its efficiency. With added few steps toward the end of the production line, the coating (equivalent to second solar cell) takes advantage of the blue portion of the solar spectrum and may improve the solar cell efficiency by 20-25% above the underlying silicon. The fact that Perovskite-based solar cell technology is of earth abundant material also insures its availability and low cost. Its high absorption in solar spectrum enables it to have comparable characteristics to that of gallium arsenide. Its ability to change its sensitivity to different band gaps in solar spectrum allows it to make different architectures in tandem solar cells. It can truly be considered as the Custom Solar Absorber! In short term, Perovskite-based solar cell may boost the efficiency level of existing technology and in the long term. It may be a stand-alone technology with closer efficiency level to that of gallium arsenide but at a much lower cost. It may potentially be sprayed, ink-jet printed, dip-coated, etc. It is no wonder that Dr. Case commented, “the perovskite in solar application is the fastest increasing photovoltaic efficiency of any solar photovoltaic thin film material ever! In just a few years, it went from a lab efficiency of about 6% to well over 17%…the material is a very good solar absorber….bringing the material to 25% efficiency in a monolithic layer and 30%+ in a perovskite tandem layer….potentially the future replacement for silicon.” The perovskite thin-film solar cells, is currently being developed by Oxford PV (a spin-out from the University of Oxford in 2009-2010 to commercialize this technology, which has exclusively licensed the intellectual property developed by Professor Henry Snaith and his team of 20 scientists). Below, Professor Henry Snaith will embellish upon the development of this solar technology, in the video published on Jan. 10, 2014, “Perovskites: The Emergence of a New Era for Low-Cost, High-Efficiency Solar Cells“, below :
Henry J. Snaith is Professor of Physics in the Clarendon Laboratory at the University of Oxford and Fellow of the Royal Society. He has pioneered the field of perovskite solar cells and published hundreds of papers. He is founder and CSO of Oxford PV, which holds the largest perovskite patent portfolio worldwide and focuses on developing and commercializing perovskite PV technology. In this interview, he discusses the present status and future prospects of perovskite PV, in the video published on Nov. 11, 2018, “The Path to Perovskite on Silicon PV | Prof. Henry Snaith“, below:
Oxford PVplans on continuing to optimize this technology’s cell efficiency and accelerate the transfer of the technology into production. Furthermore, it aims to develop the range of substrates to which the cells can be applied. With its promising future, we, the solar enthusiasts and investors alike, should keep our eyes on Oxford PV in the coming years. In the next few years, we anticipate that Dr. Henry Snaith and his team of scientists will continue to tackle challenges in trap densities, doping densities, mobility, mechanisms for free carrier generations, etc., to further improve device performance. You will find that many in the solar industry share the optimism of Professor Henry Snaith and Dr. Christopher Case. In the video published on June 9, 2021, “Henry Snaith – The advent of Perovskite solar cells“, below: For those of you interested in more details about Perovskite-based solar cell technology, please refer to the two videos below:
1. Introducing Perovskite Solar Cells to Undergraduates:
2. In the video published on Nov. 17, 2017, “Everything you ever wanted to know about perovskite“, below:
Keep in mind that Shockley-Queisser limit applies to silicon solar cell and not to perovskite solar cell. The Shockley-Queisser limit is calculated by examining the amount of electrical energy that is extracted per photon of incoming sunlight.For better understanding of Shockley-Queisser limit, please refer to the excerpt from wikipedia, in italics, below:In a traditional solid-statesemiconductorsuch as silicon, a solar cell is made from two doped crystals, one an n-type semiconductor, which has extra free electrons, and the other a p-type semiconductor, which is lacking free electrons, referred to as “holes.” When initially placed in contact with each other, some of the electrons in the n-type portion will flow into the p-type to “fill in” the missing electrons. Eventually enough will flow across the boundary to equalize the Fermi levels of the two materials. The result is a region at the interface, thep-n junction, where charge carriers are depleted on each side of the interface. In silicon, this transfer of electrons produces a potential barrier of about 0.6 V to 0.7 V.[6]When the material is placed in the sun, photons from the sunlight can be absorbed in the p-type side of the semiconductor, causing electrons in the valence band to be promoted in energy to the conduction band. This process is known asphotoexcitation. As the name implies, electrons in the conduction band are free to move about the semiconductor. When a load is placed across the cell as a whole, these electrons will flow from the p-type side into the n-type side, lose energy while moving through the external circuit, and then go back into the p-type material where they can re-combine with the valence-band holes they left behind. In this way, sunlight creates an electric current.[6]In physics, the Shockley–Queisser limit (also known as the detailed balance limit, Shockley Queisser Efficiency Limit or SQ Limit, or in physical terms the radiative efficiency limit) is the maximum theoretical efficiency of a solar cell using a single p-n junction to collect power from the cell where the only loss mechanism is radiative recombination in the solar cell. It was first calculated by William Shockley and Hans-Joachim Queisser at Shockley Semiconductor in 1961, giving a maximum efficiency of 30% at 1.1 eV.[1] This first calculation used the 6000K black-body spectrum as an approximation to the solar spectrum. Subsequent calculations have used measured global solar spectra (AM1.5G) and included a back surface mirror which increases the maximum efficiency to 33.7% for a solar cell with a bandgap of 1.34 eV.[2] The limit is one of the most fundamental to solar energy production with photovoltaic cells, and is considered to be one of the most important contributions in the field.[3]The limit is that the maximumsolar conversion efficiency is around 33.7% for a single p-n junction photovoltaic cell, assuming typical sunlight conditions (unconcentrated, AM 1.5 solar spectrum), and subject to other caveats and assumptions discussed below. This maximum occurs at a band gap of 1.34 eV.[2] That is, of all the power contained in sunlight (about 1000 W/m2) falling on an ideal solar cell, only 33.7% of that could ever be turned into electricity (337 W/m2). The most popular solar cell material, silicon, has a less favorable band gap of 1.1 eV, resulting in a maximum efficiency of about 32%. Modern commercial mono-crystalline solar cells produce about 24% conversion efficiency, the losses due largely to practical concerns like reflection off the front of the cell and light blockage from the thin wires on the cell surface.The Shockley–Queisser limit only applies to conventional solar cells with a single p-n junction; solar cells with multiple layers can (and do) outperform this limit, and so can solar thermal and certain other solar energy systems. In the extreme limit, for a multi-junction solar cell with an infinite number of layers, the corresponding limit is 68.7% for normal sunlight,[4]or 86.8% using concentrated sunlight.[5] (See Solar cell efficiency.) Gathered, written, and posted by Windermere Sun-Susan Sun Nunamaker More about the community at www.WindermereSun.com
Below is a repost from our sister publication, Windermere Sun.
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Tesla Dual Motor design (credit: Tesla/Screen shot)
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After all that’s been going on with Trump Administration this week, I seriously need to report/share on some topics that would make me feel good. Last night, as I came across an article about Tesla’s dual-engine or dual motor design, I realized that I never did report, in detail, about this intriguing design in the past. I’ve known about Tesla’s self-driving or autopilot optional feature in Tesla Model S/X/3, but did not mention much about its dual motor design until last night. It is very impressive both in its efficiency and optimized outcome in speed and acceleration. It can go from 0 to 60 mph in 3.20 seconds, with top speed at 155 mph. Any of the Tesla cars that comes with dual motor/engine would come with “D” in its model name. In the video below, one can see the front drive unit and rear drive unit of Model S. Its uniqueness is in its ability to be able to shift its dynamic power from front to rear in a matter of millilseconds. So its torque can be quickly adjusted, much better and quicker than the historical mechanically linked system (linked with the shaft). So, this is a design equivalent to the digital system, replacing the old analog system. Its constant optimal efficiency level is actually able to compensate for the increased mass of a dual motor design. Every thing is improved with this design. In Elon Musk’s words, “it’s like having your own roller coaster.” It is actually coming with the option of having 3 settings: Normal, Sport, and Insane. Elon Musk also assured us that future designs of Tesla will continue to improve. The more affordable Tesla’s Model 3 (costing about $35,000) should be arriving by the end of 2017. Model 3 of 2017 currently comes with single motor, and Model 3 dual motor design can be ordered in 2018.
I was also very happy to find out about Elon Musk’s presentation in December of 2016 for Tesla Solar Roof. So, hopefully one day, soon in the future, we will be able to order an autopilot, dual motor, solar powered car from Tesla. In the mean time, apparently Tesla is also planning on bringing a new compact SUV to the market. This vehicle will be the crossover version of the Model 3 and will be called Model Y, expected to be rolled out by 2020.
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Some wonderful solar news closer to home, in Florida: the Swedish company and the world’s largest furniture retailer, IKEA, had completed the installation of South Florida’s largest solar array in June of this year. This solar array will be atop the future Miami-Dade IKEA store opening this summer in Sweetwater, FL. Combined with rooftop arrays in Orlando, Tampa, and Sunrise, this fourth solar project will keep IKEA as Florida’s largest non-utility solar owner. The 416,000 square-feet future IKEA Miami, with 1,500 parking spaces, is being built on 14.6 acres adjacent to the Dolphin Mall, at the intersection of the Dolphin Expressway (SR 836) and Florida’s turnpike, in the city of Sweetwater, FL.
The 178,000 square foot solar array at Sweetwater consists of a 1,178 kW system, built with 4,620 panels, and will produce about 1,738,876 kWh of electricity annually for the store, equivalent to reducing 1,227 tons of carbon dioxide (CO2)-equal to the emissions of 256 cars or providing electricity for 169 homes annually (calculation for clean energy equivalents). IKEA contracted with REC Solar (a national leader in solar electric system design with installations of more than 350 systems across U.S.). Let’s take a look at the video about IKEA’s Clean Energy/Solar Installations, below:
This installation will represent the 40th solar project for IKEA in the U.S., contributing to the IKEA solar presence atop nearly 92% (35 out of 38) of its locations in U.S. and a total generation of 38 MW (translating to powering 90,000 homes). IKEA owns and operates these solar PV systems, rather than through solar lease or PPA (power purchase agreement), and has allocated $1.8 billion to invest in renewable energy through 2015 globally. This investment demonstrates IKEA’s long term commitment to sustainability and confidence in PV technology and industry. Due to IKEA’s goal of becoming completely energy independent by 2020 (“We want to get to 70% by 2015, and by 2020, we actually want to produce more energy from renewable sources than we/IKEA consume in the total operation“, commented the President of IKEA USA, Mike Ward), IKEA has installed more than 550,000 solar panels on buildings across the world and owns/operated about 157 wind turbines in Europe and Canada, with 49 more being build in the U.S.
IKEA evaluates locations regularly for conservation opportunities, integrates innovative materials into product design, works to maintain sustainable resources, and flat-packs goods for efficient distribution. Specific U.S. sustainable efforts include: recycling waste material;incorporating energy-efficient HVAC and lighting systems, recycled construction materials, skylights in warehouse areas, and water-conserving restrooms. IKEA has also eliminated plastic bags from the check-out process, phased out the sale of incandescent bulbs, facilitates recycling of customers’ compact fluorescent bulbs, and by 2016 will sell only LED. IKEA has also installed EV charging stations at 13 stores, with plans for more locations in the future.
Besides helping to improve our environment, these conservation efforts and solar investments have enabled IKEA to spend less on energy. This would also mean lower cost and lower prices that will be passed down to consumers. IKEA’s Swedish heritage and respect of nature is not only good for the environment, but also great for business. Bravo! IKEA! We hope more businesses will try to emulate what IKEA has done.
~have a bright and sunny day~
Gathered and posted by sunisthefuture-Susan Sun Nunamaker
Any of your questions/comments/suggestions will be welcomed at sunisthefuture@gmail.com
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At InterSolar North America 2014 in San Francisco, CA, I came across a potentially game-changing technology that holds much promise for low cost solar power in the future. This technology, the perovskite thin-film solar cells, is currently being developed by Oxford PV (a spin-out from the University of Oxford in 2009-2010 to commercialize this technology, which has exclusively licensed the intellectual property developed by Professor Henry Snaith and his team of 20 scientists). The perovskite thin-film solar cells can be directly printed/sprayed onto glass to produce a semi-transparent colored coating. Below is an interview with the Chief Technology Officer, Dr. Christopher Case, of Oxford PV:
The apparent enthusiasm of Dr. Case is seen in his discussion of the perovskite cell technology. One can understand the source of Dr. Case’s enthusiasm. According to Dr. Case, “the perovskite in solar application is the fastest increasing photovoltaic efficiency of any solar photovoltaic thin film material ever! In just a few years, it went from a lab efficiency of about 6% to well over 17%…the material is a very good solar absorber….bringing the material to 25% efficiency in a monolithic layer and 30%+ in a perovskite tandem layer….potentially the future replacement for silicon.” This perovskite solar cell technology is optimized to drive a paradigm shift in the aesthetics, performance, and cost of BIPV (Building Integrated Photovoltaic) systems, potentially bringing low cost electricity to the solar market much sooner than predicted. It is no wonder the highly respected international journal, Nature, has named Dr. Henry Snaith of University of Oxford as one of the ten people who have made the most difference in science during 2013 in recognition of his work on this next generation solar power technology. Let’s also take a look at the comparison between Convetional PV vs. Oxford PV, below (provided by www.oxfordpv.com):
Conventional PV Oxford PV_________________
Opaque Range of transparency options
Blue or Black Palette of colors and tints
Contains scarce elements and rare earths Sustainable, abundant, organic ingredients
Complex, high temperature and high vacuum manufacturing Simple screen printing manufacturing processes
High capital cost of manufacturing Low capital cost of manufacturing
Heavy panels physically attached to building Aesthetically attractive glazing panels integrated into the building envelope
Without using the titanium dioxide as a semiconductor, this technology results in higher levels of efficiency, much lower processing temperature, and improved cell stability. Oxford PV plans on continuing to optimize this technology’s cell efficiency and accelerate the transfer of the technology into production. Furthermore, it aims to develop the range of substrates to which the cells can be applied.
Oxford PV has a strong supporting team (such as Kevin Arthur, Dr. David Fyfe, Paul Vickery, etc.) With its promising future, we, the solar enthusiasts and investors alike, should keep our eyes on Oxford PV in the coming years.
~have a bright and sunny day~
Gathered, written, and posted by sunisthefuture-Susan Sun Nunamaker
Any of your questions/comments/suggestions will be welcomed at sunisthefuture@gmail.com
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Dear Friends, Visitors/Viewers/Readers, (Please click on red links below)
Great News, one of our viewers/visitors has a fantastic piece of news to share about his company, press release below:
A 1934 series $1,000 United States banknote featuring the portrait of Grover Cleveland, now probably worth over $5,000 (credit: public domain bank notes + "savings"=>sunisthefuture-Susan Sun Nunamaker)
Businesses and Municipalities Look to Save Money Through Smart Grid Technologies
Silicon Valley Startup Green Charge Networks Signs 1 MW of Intelligent Energy Storage
SANTA CLARA, Calif. (Feb. 4, 2014) – Green Charge Networks, a leader in intelligent energy storage, has signed agreements for 1 MW of energy storage with retail chain customers and city municipalities that are seeking to reduce their electricity bills through smart grid technologies. Many businesses in California and New York City pay 40% or more of their monthly electric bill in “demand charges” based on their peak electricity use. Green Charge Network’s (GCN) proven GreenStationTM technology uses utility and weather data to predict peak use and store energy accordingly. This reduces these demand charges and saves businesses thousands of dollars. 7-Eleven stores have been using GCN’s GreenStationTM successfully for the past two years. One 7-Eleven GreenStationTM in New York endured Hurricane Sandy and then went on to save the business 56% on their electricity bills during the 2013 summer heat wave. Green Charge Networks is adding to its list of customers including 7-Eleven, Walgreens, office buildings, community colleges, and municipalities, adding up to 1 MW as listed on the DOE’s Global Energy Storage Database.“It is a big accomplishment to our company to help businesses and local governments use power more efficiently,” said Vic Shao, CEO at Green Charge Networks. “1 MW marks a very significant milestone for Green Charge Networks as we continue to diversify our customer base and increase our penetration in the rapidly growing intelligent energy storage market. Energy efficiency initiatives can only take us so far. The era of power efficiency using advanced software is the next frontier in energy savings.” America’s aging grid is in need of an update. Not only can smart grid technologies like GreenStationTM save businesses thousands of dollars on their electricity bills, they are also an important tool in both climate change adaptation and mitigation. GreenStationTM is designed to withstand storms as fierce as Hurricane Sandy or temperatures as extreme as the recent polar vortex. The combination of an aging utility grid and increasing storms due to climate change is a deadly mix. Between 2003-2012, the US experienced 679 major weather related outages, including 7 of the 10 costliest storms in US history (White House Report). GCN’s GreenStation TM energy storage technology helps businesses regulate their energy use so that even during extreme weather events they don’t pay special “demand” charges for peak energy use. If smart grid technologies like GreenStation TM were implemented nationally they could save the energy equivalent of 4,000 coal plants per year (Energy Manager Today).
About Green Charge NetworksFounded in 2009, Green Charge Networks is a leader in intelligent customer-sited energy storage. The company gives commercial and industrial customers control of rising demand rates on their monthly electric bills. Green Charge Networks’ product complements solar PV, electric vehicle charging, and energy efficiency. The GreenStationTM was developed in partnership with leading utilities around the country, the U.S. Department of Energy, and Fortune 500 customers. GCN is headquartered in Santa Clara, CA with office in Brooklyn, N.Y. For more information, visit www.GreenChargeNet.com.
CONTACT:Tram Tran Green Charge Networks: 408-638-0072, tram@GreenChargeNet.com
~have a bright and sunny day~
Gathered and posted by sunisthefuture-Susan Sun Nunamaker
Any of your comments/suggestions/questions will be welcomed at sunisthefuture@gmail.com
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If you are in favor of renewable/CLEAN energy, please sign the petition page showing support for FIT/CLEAN Program at http://sunisthefuture.net/?page_id=1065 Thank you.
I came across an interesting graph on the evolution of solar power/technology today in an article by Sebastian Anthony in ExtremeTech,
History of Solar Power/Technology
started from the lucky finding by Alexandre Becquerel in 1839, a current was generated when an electrode in a conductive solution was hit by sunlight . Then came the first solar cell, at 1% efficiency, produced by Charles Fritts in 1883. It was in 1904, Albert Einstein published a paper on the discovery of the photoelectric effect, followed by a flurry of photoelectirc advances until AT & T Bell Lab created the first modern silicon solar cell in 1954. Between 1950s and 70s cost (about $250 per watt) and efficiency (10%) were two important factors preventing solar power to be the major power player. But today, the solar power industry has brought the cost/price per watt down to around $3 and at-home installations are becoming more common. In 2010, even President Obama ordered the installation of solar panels and a solar hot water heater at the White House. It will simply be a matter of few years when solar power will overtake coal in terms of cost and efficiency. As storage battery technology advances and the fact that solar power is the much cleaner technology (therefore, at a much lower environmental cost) and the technology least likely to generate warfare among nations, solar power/technology does appear to be the best choice for the future of planet earth.
Posted by sunisthefuture-Susan Sun Nunamaker, sunisthefuture@gmail.com
