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)
(Please click on red links & note magenta)
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
Sonnenbatterie Complete System (credit: Sonnenbatterie)
(Please click on red links & note magenta)
Those of us who have been following the solar industry for quite a few years/decades realize that reliable Energy Storage holds the key to Solar Energy Future. Therefore, it is not surprising that Intersolar North America 2015 placed a great deal of emphasis on the topic of Energy Storage-Battery Technology. The simple fact that the sun does not shine 24/7/365 necessitates reliable energy storage before solar energy can truly become mainstream. Important factors when choosing the energy storage system are: reliability, capacity, durability, and safety. With Tesla’s Powerwall and Powerpack being in the news much lately, I was curious about the energy storage systems being introduced by Sonnenbatterie,
a German company that has been a leader for energy storage in Europe for many years.
Sonnenbatterie Manufacturing storage system (credit: Sonnenbatterie)
For the first time, Sonnenbatterie is entering the North American market and is the winner of Bloomberg Pioneers Award 2015. I had the opportunity to chat with US management/CEO of Sonnenbatterie, Boris Von Bormann, about features that distinguish Sonnenbatterie’s units from Tesla’s Powerwall or Powerpack: Sonnenbatterie has a fully integrated (battery+inverter) system and can be taken apart whereas Tesla’s Powerwall or Powerpack contains only the battery system. In the age of collaboration, it would be great if Sonnenbatterie would also develop an inverter system that will work with Tesla’s battery technology. Sonnenbatterie’s system can also be integrated with the utility so to be more efficiently managed. The intelligent storage solution has a built-in smart meter
that enables the management of local energy production and consumption. By using a mobile app the houseowner decides whether to feed-in or directly consume the homemade electricity. Without further ado, let’s hear what Boris Von Bormann has in store for us, below:
I’d also like to share with you, another video, with Sonnenbatterie’s Christoph Ostermann, at Ecosummit 2013, below. Sonnenbatterie is a true pioneer for Sonnenbatterie started selling their system prior to the existence of either supply or demand for the market/system. Within two years of its inception, Sonnenbatterie was able to sell 1500 systems. The growth continued, with about 8,000 systems sold in Germany by Spring of 2015 and production running at about 100-150 systems per week. At ECO13, Sonnenbatterie won the Ecosummit Award Jury Bronze medal in recognition of their outstanding business potential.
With the anticipated upcoming Solar Tsunami, it will be well worth the effort for investors and consumers in the solar energy market to keep an eye on Sonnenbatterie, for it has a fully integrated system and it can fill consumers’ order this year.
Recently, Sonnenbatterie has partnered with Outback Power to integrate their smart energy storage solutions with a trusted inverter for residential solar customers across North America. Historically, Outback Power has been a leading designer and manufacturer of advanced power electronics for renewable energy, backup power, and mobile applications. “OutBackPower’s Radian inverter/charger was a natural choice to integrate into Sonnenbatterie’s eco residential smart storage system,” said Boris von Bormann, CEO of Sonnenbatterie USA. “Working with OutBack, we are confident we can provide American home owners with the peace of mind our European customers have come to expect from Sonnenbatterie — that their home energy storage system will operate reliably in any environment and applications.” For a look of Outback Power’s Radian Series, in the video below:
~have a bright and sunny day~
Gathered, written, and posted by sunisthefuture-Susan Sun Nunamaker
Any comments and suggestions are welcomed at sunisthefuture@gmail.com
Please also get into the habit of checking at these sites below for more on solar energy topics:
Allow me to share with you some of the golden nuggets (above) during opening ceremony of Intersolar North America 2015: It is both heart warming and energizing to hear the opening speech by Prof./Dr. Eicke R. Weber, the Intersolar North America Conference Chairman and Director of Fraunhofer Institute for Solar Energy Systems (ISE)at Intersolar North America 2015, in Intercontinental Hotel. Prof. Weber’s speech is full of good news. Besides mentioning the necessity of renewable energy source, its cost trending downward toward 2-4 cents per kWh and much more improved energy storages becoming commercially available on the market, Prof. Weber also reminds us that PV is currently at its infancy, equivalent to the automotive sector back in 1920’s, with much exciting growth to come in the coming decade. Chief Technology Officer and Co-Founder of Tesla Motors, J.B. Straubel, further supports this view, adding the synergy between PV, renewables, and cars, and achieving sustainability with transportation. In order to achieve this, it is important not just to make electric vehicles but to make sure that these electric vehicles are linked back to renewable energy sources.There is much similarity between the PV and e-vehicle markets, both have dropped in cost and will eventually be dominating its respective markets (PV in the energy market and e-vehicle in transportation market). It is truly exciting to be at the beginning of the cost-decline curve, for PV to be within grasping distance of the goal of being cheaper than fossil energy. Such a tipping point is anticipated to occur within the coming decade. Yes, sensation of excitement is palpable in the room. I felt as though surrounded by a room full of soldiers, rearing to go.
At this point, I’d like to present two charts: 1. Global Annual PV Market Until 2017 (Sourc: EPIA) 2. Global Revenues of PV Energy Storage, in Billion US$ (Source: IHS Inc.), below:
Continuing on, the Executive Director of CALSEIA (California Solar Energy Industries Association) Bernadette Del Chiaro, points out that the 3 gigawatts of solar installations within the past 3 months in CA is largely responsible for combating the shortfall of hydroelecric output resulting from CA draught (recall 25% of the CA energy/power comes from hydroelectric power, currently down 25-50% due to CA draught). So, definitely applause is in order for the unsung hero of solar PV! It is terrific to hear the statistics on “every 3 minutes, some one in CA is going Solar“. Director Del Chiaro also reminded the audience the importance of SAVE The ITC (Investmnet Tax Credit) campaign. Then we come to New York Senator Kevin S. Parker, citing more exponential growth data of solar installations and the New York -Sun Initiative, with ambitious goal of 3 gigawatts of solar installations in the coming decade. He further states that he is looking for opportunities of partnerships with various groups for large scale renewables as the state of New York continues to walk toward the Sun. More on Intersolar North America 2015 and storing the sun, below, with Kilian Reichert:
Also, it is important for the world to learn from CA, to encourage the right kind of policy to be instituted so to encourage the growth of solar and renewable energy. During Intersolar North America 2015, we’d like to share some thoughts from the Champion of Change Award winner, former state assemblywoman Nancy Skinner, who was instrumental in introducing the mandate of 33% of the electricity generated from CA to be coming from renewable sources such as solar. She is in support of policy that would encourage renewable sources for both distributed as well as utility scale generation. Our hats off to Nancy Skinner! I believe such mandate would benefit all states of USA. More, below….
~have a bright and sunny day~
Gathered, written, and posted by sunisthefuture-Susan Sun Nunamaker
Any comments and suggestions are welcomed at sunisthefuture@gmail.com
Please also get into the habit of checking at these sites below for more on solar energy topics:
Intersolar North America 2015 (Exhibition: July 14-16, 2015, Conference: July 13-15, 2015, https://www.intersolar.us/en/home.html)
(Please click on red links & note magenta)
Just a quick note to remind you all that Intersolar North America 2015 will take place in San Francisco, Moscone Center, Exhibition between July 14-16, 2015 and Conference between July 13-15, 2015. This is the most attended Solar Event/Exhibition in the United States. 27,000 trade visitors are expected. There will be high caliber conference with renowned speakers and multitude of workshops. It also provides great international marketing opportunity.
I really need to share this “Standing Ovation at the InterSolar North America Open Ceremony” with you all, taking place in July of 2014, at Moscone Center of San Francisco, CA.:
California Gov. Edmund G. Brown Jr. was met with a standing ovation as he delivered the keynote remarks at Intersolar North America’s Opening Ceremony 2014. Following the Governor’s remarks, San Francisco’s Mayor Edwin M. Lee took the stage. New York State Senator Kevin S. Parker similarly championed local policies that have grown the solar energy industry significantly in New York. Franz Untersteller, minister of the environment, climate protection and the energy sector, Germany, discussed the major policy incentives implemented in Germany that have played a key role boosting the solar industry. Finally, CALSEIA’s executive director Bernadette Del Chiaro concluded the session with a discussion of California’s solar policies and an inspirational call to action, asking the audience to help quadruple the solar industry in the next six years.
It is important to point out/remind ourselves that:
1. There is much more solar that needs to be installed in the decades to come!
2. There is much more needing to be done. We’ve not yet met the turning point to Sustainability.
3. The cost of PV modules has dropped 80% in the last five years.
4. Solar Industry employs more than 142,000 people in USA (more than 50,000 in CA).
5. We can look to and utilize much of the lessons learned from Germany.
6. Solar is desperately NEEDED now, especially in light of climate change.
7. 16.5% of the electricity supply of CA on any given day is from Solar (without including the 2 GW on rooftops).
8. CA Solar Industry now employs more people than the three investor-owned utility companies combined.
So, let those of us in the rest of the 49 states also align ourselves with this tremendous task of transitioning into the Renewable/Solar Energy Future!
~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
Please also get into the habit of checking at these sites below for more on solar energy topics:
This is an interview with the team (Sr. Vice President/General Manager Dr. Venkatesan Murali, Sr. Director of Marketing Jeff Nestel-Patt, and Vice President of Sales Andrew Barta) from GT Advanced Technologies (GTAT) at San Francisco, CA, during InterSolar North America 2014, on July 9, 2014,overlooking the Yerba Buena Gardens on top of Moscone North. Video below:
As the global demand for solar energy continues to grow while the industry is facing downward pricing pressure, reduced subsidies, and solar trade tensions, it becomes increasingly important for PV manufacturers to achieve further cost reductions and improved cell efficiency. GTAT accomplishes this by introducing the innovative metallization & cell interconnect technology (Merlin Advanced Metallization Technology) that transforms the solar module into a less expensive, more efficient panel that is easier to install.
The Merlin Advanced Metallization Technology enables greater performance than the traditional modules by:
Eliminating up to 80% of the expensive silver paste used in the traditional cells and modules, leading to cost reduction.
The same screen printing equipment installed in cell line can be used to print the segmented fingers onto the cell
Flexible grid that eliminates silver bus bars: a plated copper grid is attached to the segmented fingers on the top of the solar cell. The combination of segmented fingers and flexible grid makes it easier to move current off the cell. The flexible grid provides 20 paths/highways for the current to travel along rather than the three bus bars found on the traditional solar cells.
Reducing shading by bus bars and increasing electrical connections on the surface of the cell lead to increased cell efficiency and increased power output (by 3-5% compared to standard module).
Improving the interconnection between cells by eliminating the need for stringing and tabbing of the old technology, providing highly flexible and durable way to connect cells while eliminating the bus bar tabs of traditional cells. Cells can therefore be connected closer together, allowing a smaller and more flexible module than the conventional module.
The flexible tabs at the end of each grid solve the problem generally associated with breakage of modules during transport resulting from metal fatigue when ribbons break due to dynamic loading conditions during shipping.
GTAT is almost 50% lighter than the conventional modules.
Easier installation results in lower balance of system costs
GTAT is already working with select customers to implement Merlin, involving custom-made copper meshes soldered on to PV cells instead of bus bars. GTAT will produce and sell customized copper meshes to customers, and expects to reach a production capacity of 100 MW annually by the end of 2014. In early 2015, it will begin to offer a wire attachment tool to customers, which will replace the tabbing stringer. Orders may be taken in last quarter of 2014, so in 2015, solar PV module makers will be able to work with this new technology to replace silver bus bars with a customizable copper mesh, reducing silver usage, increasing power output, and allowing lighter modules to be transported and installed.
GT Advanced Technologies Inc. is a global provider of polysilicon production technology and sapphire and silicon crystalline growth systems and materials for the global solar, LED, and other electronics industries and specialty markets. The company’s products and services accelerate the adoption of new advanced materials that improve performance and lower the cost of manufacturing. For additional information about GT Advanced Technologies, please visit www.gtat.com.
~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
Please also get into the habit of checking at these sites below for more on solar energy topics:
Solar enthusiasts, there are quite a few fantastic upcoming events that you might be interested in attending. We’re starting with the upcoming InterSolar North America Conference of 2014, in July:
InterSolar North America Conference of 2014 will take place between July 7-9, 2014 (Exhibition from July 8-10, 2014), in San Francisco, CA (USA). Conference will be located at InterContinental Hotel San Francisco, 888 Howard Street, San Francisco, CA 94103 Conference Area at Level 3-5. Exhibition will take place at Moscone Center, 747 Howard Street, San Francisco, CA 94103. This is the most attended solar exhibition in North America. To get a view of what took place last year in InterSolar North America 2013, video below:
~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
Please also get into the habit of checking at these sites below for more on solar energy topics:
