Some time ago, we started a series on solar energy innovation that proved quite popular (part 1, part 2, part 3). While there is steady and gradual progress in conversion efficiencies (the part of sunlight converted into electricity) and cost, there are companies and labs all around the world working on more radical concepts.
Radical concepts that could offer existing solar players (almost all of them already deeply plagued by market circumstances) a run for their money, but at the same time offer a critical break through to a future without subsidies and mass adoption.
We feel that investors in existing solar companies (or any company) tend to be insufficiently aware of industry characteristics. For instance, many investors were focusing on the growth in demand and steady cost reduction, while having insufficient appreciation for the lack of pricing power, due to the fact that solar cells are a near commodity. This often turned out to be a costly mistake.
Also, insufficient weight is often given to the lack of a dominant design and the fact that literally hundreds of labs and relatively unknown, often non-public companies are trying new approaches, any one of which might lead to a more radical break-through in price and/or efficiency.
For existing players (and investors in these companies), all this innovation from so many different corners presents a clear risk, the risk that some other company will eat their cheese, but for society as a whole, this is a giant trial and error race towards affordable clean energy, enlisting some of the best and the brightest.
So here is the fourth installment of our survey of promising new technologies and concepts on the horizon.
One approach to get solar cells to convert more sunlight into electricity is to build cells that react to a wider gamut of frequencies. This is what researchers at MIT are doing, creating an all carbon solar cell that captures much of the near infrared spectrum (40% of the sunlight's energy hitting earth) which normal solar cells don't convert.
The idea is to uses these cells in combination with normal cells capturing the visible light:
The carbon-based cell is most effective at capturing sunlight in the near-infrared region. Because the material is transparent to visible light, such cells could be overlaid on conventional solar cells, creating a tandem device that could harness most of the energy of sunlight. [MIT]
Before you'll get overly enthusiastic, the very much experimental cells at present offer only a 0.1% conversion efficiency, which is terribly low. But there are good hopes this can be significantly improved in the near future.
New Jersey institute of Technology (NJIT)
The NJIT is working on a concept that will ultimately enable consumers to
print sheets of these solar cells with inexpensive home-based inkjet printers... Imagine someday driving in your hybrid car with a solar panel painted on the roof, which is producing electricity to drive the engine. The opportunities are endless [Dailytech]
The concept is based on solar cells made of polymers, a material that is way cheaper than the purified silicon (the same material used for making microprocessors), and is much easier to handle.
North Carolina State University
Researchers from North Carolina State University have developed a method to sandwich the active layers of cells between a 'nano sandwich.' This allows the active material to be way thinner (amorphous silicon can be 70nm, in stead of the usual 300-500nm thin), without compromising their conversion efficiency.
This method can be applied to a wide range of active materials, not only amorphous silicon, but also cadmium telluride, copper indium gallium selenide and organic materials.
Fraunhover and Dow Chemical
The US research institute and chemical giant have together developed an 'elixer' to shield solar panels from all kinds of environmental influences that could lead to a degradation in performance. This is rather important, as the economics of panels are such (almost all up-front cost) that it depends critically on durability. Panels have to be able to keep working with little performance degradation for periods up to 25 years.
Instead of laminating panels with ethylene-vinyl acetate (EVA), the scientists used liquid silicone. After this hardened, they subjected it to rigorous tests, which showed that these were more durable.
Advanced Solar Phontonics
While not from the lab as such (this is a company with commercial operations, here is a brochure with their product lines), the US company also addresses the durability of panels. They have done that through encapsulating solar modules two sided by glass. This dual sided glass modules provide dual sided protection from extreme weather conditions and are expected to have a usable lifetime of 50 years.
They have other tricks up their sleeve though, like a cheaper optical tracking system or:
To further increase efficiency, ASP modules feature a holographic material sandwiched between the silicon and EVA layers maximizing the time per day they can generate electricity from the sun. [sacbee]
Berkeley National Laboratory, the University of California, and the DOE
Researchers from these institutes have arrived at a method to use virtually any semiconductor material for solar cells, opening the door to low-cost, high efficiency cells. At present, expensive semiconductor materials are used, such as large crystals of silicon, or thin films of cadmium telluride (CaTd) or copper indium gallium selenide (CGIS).
Previously, cheaper semiconductor material like metal oxides, sulfides and phosphides have been difficult because it was expensive to taylor their properties by chemical means (called 'doping'). What the researchers did was to tailor these materials simply by applying an electric field:
Our technology reduces the cost and complexity of fabricating solar cells and thereby provides what could be an important cost-effective and environmentally friendly alternative that would accelerate the usage of solar energy [greenbuildingelements]
Despite very tough market circumstances, particularly for start-up thin film producers, there is still plenty of activity and innovation in this sector. This sector faces two sets of problems. First is that more traditional silicon based technologies, which are generally more efficient, have come way down in price, negating much of the cost advantage of most thin film based manufacturers.
Second, since there is so much overcapacity in the market, clients are very hesitant to go with new companies, these might not be around in 5 or 10 years time, and it's also more difficult to get project financing.
The American producer of thin film panels is already commercially active, with plants in California and Mississippi. It is backed by famous venture capitalist Vinod Khosla, but also a host of others (AVACO, a private Korean equity fund, Taiwan Semiconductor, Lightspeed Venture Partners, Braemar Energy Ventures and General Catalyst Partners).
The company didn't start production before it was ready and was very frugal with capital. The company has achieved a 13.4% conversion efficiency for it's CIGA based modules, which is a record for commercial panels. It is presently offering panels for $0.75 per watt, which is very competitive if you realize that market leader First Solar's production cost (first quarter figures) are 73 cents per watt.
Flexible cells from Stanford University
One of the problems with solar panels is that because of the plunging price of cells and panels, the cost of installation is often higher than the panels themselves, and these costs are less susceptible to efficiency improvements or cost cuts.
One way to deal with that is to make solar panels light and flexible. The active material in thin film technologies is thin enough to be just that, but the substrate isn't, as that's usually rigid material like glass. Now, there are thin-film panels that are flexible, but these have drawbacks, like having complex manufacturing processes or expensive flexible substrates with extremely uniform surfaces.
Here comes Xiaolin Zheng, from Stanford University who can transfer the active materials of thin film cells to other surfaces, such as a sheet of paper(!) or plastic, the roof of a car, or the back of a smartphone. His trick is to use a layer of nickel between the fixed substrate and the active layer.
Using water which reacts with the nickel, the substrate becomes loose and can be peeled away and deposited onto another material, not affecting the efficiency of the cells. Very much a work in progress, but any commercial success could make cells ubiquitous.
Researchers at UCLA are using polymer solar cells to arrive at much the same end result: flexible (70%) transparent cells that can be integrated in windows, buildings, and electrical devices. The transparency is achieved by absorbing infrared light, not visible light and using a transparent conductor made of a mixture of silver nanowire and titanium dioxide nanoparticles, which was able to replace the opaque metal electrode used in the past. At just 4%, it's electricity conversion efficiency leaves something to be desired though.
Here we have a company already producing lightweight, flexible panels. It uses the same thin film CIGS (copper, indium, gallium, and selenide) technology as Solyndra (of rather famed bankruptcy), but it's targeting rooftops of industrial and commercial buildings that can't support heavy panels. This is a niche market, but nevertheless an interesting one in countries, like Japan and Italy, where electricity prices are high, government subsidies help, and there is a lot of demand or rooftop panels.
The lightweight nature of the panels command a premium price. One problem is relatively low efficiencies though. They hope to increase these to 13% by the end of the year, 13% conversion efficiency is good for CGIS technology, but it still trails other CGIS producers (like MiaSolé and Stion), let alone other technologies, like Suntech (STP) Pluto cells (20.3% efficiency).
It remains to be seen whether the company can succeed where other thin-film start-ups (Abound Solar, MiaSole, Unisolar, Global Solar)) have failed or suspended plans for commercialization (GE). Market circumstances are very tough indeed, and much of thin-film's cost advantage has been eroded by the relentless decline of the more traditional silicon based technologies.
Magnolia Solar is developing a nanostructured antireflection (AR) coating that can be used to increase the efficiency of existing solar technologies as it allows for much more of the light spectrum to be converted into electricity. That is:
the complete solar spectrum covering UV, Visible and Infrared part of the solar energy. This approach allows for better than 95 percent of the sun energy absorption and minimizes the reflection losses to less than approximately 5 percent. We believe this is a significant improvement over what is commercially available today. [Marketwatch]
Apart from using a much broader part of the solar spectrum, these reflection losses can be significant, especially in the morning and late afternoon when the sun is lower in the horizon:
At normal sunlight incidence during peak sunlight hours, the reflection losses at the glass-air interface have been reduced from approximately 4% to less than 1%. At large angles of incidence during morning and late afternoon hours, the reflection losses have been reduced from over 25% to less than 5%.
It's also pleasant that this is a public company, its shares trade on the OTCBB with ticker (OTC:MGLT)
But, Magnolia are hardly the only ones pursuing improved coatings. They're up against one of the chemical behemoths, in the form of Dow Chemical (DOW). Not only are they're working with Fraunhofer to develop silicon coatings, they have already developed the ENLIGHT(TM) encapsulant film that:
- Help extend the service life of modules because the films have significantly better electrical properties and improved moisture resistance.
- Allow panel manufacturers to potentially increase yield and capacity by reducing lamination cycle times by up to 30 percent. [Marketwatch]
This isn't stuff that's in the lab, Dow already has two plants (one in the US, the other in Thailand) producing the stuff and a third one (in Germany) under construction.
New Energy Technologies SolarWindow Technology
The US start-up company has developed what must be the ultimate in flexible, lightweight solar cells, 'spray-on' photovoltaic windows, materials that can be sprayed on windows which:
is so effective as to harvest light even from northern exposure, and indeed even from indoor fluorescent lighting... It puts energy harvesting everywhere. [Technology Review]
The spray dramatically simplify the thin film manufacturing process
Solar cells that are currently available are largely made of silicon wafers, an expensive and brittle material that can limit their commercial usability. Other newer generation, lower-cost, flexible thin film solar materials such as amorphous silicon, copper-indium-gallium-selenide, and cadmium telluride, often require high-vacuum and high-temperature production techniques, and are many times thicker than New Energy's ultra-small solar cells. This generally limits the application of such thin films primarily to stainless steel, an expensive substrate material with limited prospects of delivering transparency. [New Energy Technologies]
There are more advantages as the spray is transparent so it's prime use is intended for windows (hence "SolarWindow"). The technology is subject to 11 patent filings. What's also interesting for us is that this is a listed company (ticker: NENE). The potential savings are significant:
In December 2010, our power production modeling calculations were validated by Steven Hegedus, Ph.D., a renowned scientist and authority in photovoltaics. His lab confirmed our important estimate that a 40-story glass building fitted with SolarWindow™ could see from $40,000 to $70,000 in savings per year. In comparison, common rooftop modules only produce $20,000 in savings. Dr. Hegedus was so impressed with the science of SolarWindow™ and the potential of our company, in fact, that he subsequently joined our Board of Advisors. [New Energy Technologies]
The goal is to put SolarWindows in approximately 85 million commercial buildings and homes in the US, which constitutes a rather large market opportunity. Although promising, it's early days yet, so stay tuned.
However, New Energy Technologies doesn't have the field all for itself, there are other companies working on similar technologies. One is UK based Oxford Photovoltaics, a spin-off from Oxford University. These companies hope to take advantage of the fact that 60% of the exterior of modern office buildings is glass.
Oxford Photovoltaics doesn't produce completely transparent windows though, their windows are tainted, and can be had in a variety of colors, or opaque. As of yet, they only have a small 10cm by 10cm prototype, but they're planning to move to a full scale pilot production line that can make panes that are two meters by three meters.
So it's early days here as well, but they hope to have a commercial product in the second half of this year, and are envisioning a cost break-through:
Because you are basically screen printing, production costs are much lower than for conventional solar cells and the cost of the materials is also falling... While the technology certainly isn't there yet, "modelling done by the company suggested the system could produce solar power at a cost of just 35 cents per watt," [Business Green]
Cell conversion efficiency stand at 6% today, but they hope to raise that to 20%, but one could argue that with glass being a much bigger part of commercial buildings than roof, cell efficiency isn't quite as important as for rooftop solutions. The model showed that a 700 foot skyscraper in Texas could generate up to 5.3MWh a day, enough to power 52,000 iPads.
Again, this is promising, but they're not there yet, one go keep an eye on though.
Long a bit of a mystery, this US company finally came out of 'stealth' mode to unveil its plans:
Solexel is looking to mass produce 35 micron-thick, high-performance, low-cost mono-crystalline solar cells using a lift-off technology based on a reusable template and a porous silicon substrate. [Greentechmedia]
It claims that it will be able to produce 20% efficient modules at $0.42 per watt in 2014, which would be a remarkable breakthrough, but as a matter of fact, they have been able to produce a cell with 20.62% conversion efficiency recently. This is slightly better even than the 20.3% efficiency achieved by Suntech's Pluto cells.
One of the ways it is supposed to do this is dispensing with the need for expensive silver, using aluminum instead in it's p-type cells. Another mayor savings comes from using just one-tenth (that is, 0.5 grams per watt) of the silicon compared to conventional cells.
The cells are also flexible and therefore dispenses with the need for a frame, considerably reducing installation costs. They have a host of backers, notable venture capitalists like Kleiner Perkins and Technology Partners, but perhaps most significantly fellow solar cell producer SunPower (SPWR). We have a feeling we're going to hear a lot more about this company pretty soon.
We already mentioned above that because of plunging panel prices, installation cost are an ever bigger part, as these have remained relatively stable. Although there are wide variety in installation cost in the world (US installation costs are roughly twice those in Germany, for instance), reducing these installation cost will make solar energy more competitive with other forms of energy.
Trina Solar (TSL) has made significant progress, cutting installation time (and labor) by two-thirds. They do away with the traditional anchoring long metal racks on rooftops (to create the framework that will angle the panels towards the sun and hold them together). Instead, the Trina solution uses the frame of the solar panel itself to provide the framework.
Savings in materials and labor costs can add up to a 10-cent-per-watt reduction in costs for solar power, a significant drop considering that solar panels now sell for less than $1 per watt. [Technologyreview]
Hard to believe, but these first four parts on solar innovation barely scratch the surface of the amount of innovation and experimentation going on in this industry. For existing players, the big solar companies which already face dire market circumstances, this clearly poses an additional risk.
The problem they are facing is a difficult one. At present, solar panels are a near commodity, and because there is so much oversupply, prices have been falling steeply. This has put many solar players out of business, and the industry is clearly consolidating. In time, the industry will balance out, through bankruptcies, consolidation, postponement of additional capacity building and an increase in demand as a result of the falling prices.
The companies that survive are the ones with the best balance sheets and the most efficient production, the likes of First Solar (FSLR), SunPower (, we wrote an article about that company) and a number of Chinese solar companies like Trina Solar (, we also wrote about that company).
However, apart from trying to be a cost leader, there is another escape from a commodity industry like the solar industry, which is differentiation through innovation, building better, more efficient products. As you can see from these series of articles, this is being tried in many corners in the world. The dilemma for existing solar players is how much should they spend on their already ravished balance sheets on innovation? For many, that is very difficult indeed.