A Swedish startup is introducing a new approach to making next-gen thin film solar panels, using techniques from optical disc manufacturing. However, the solar manufacturing sector is facing a brutal year in 2013 and as solar manufacturers continue to suffer losses, it could be a difficult time to launch a new production technique.
Midsummer, based in Jarfalla, Sweden, has developed equipment and processes to make thin film solar panels, using the material copper indium gallium (di)selenide, or CIGS. If the term CIGS rings a bell, that’s because the ashes of CIGS firms have burned brightly — and burned their investors’ cash – in recent years.
Silicon Valley’s MiaSolé, which had originally impressed investors with its high conversion efficiencies, was sold at a bargain-basement price to Chinese renewable energy firm Hanergy earlier this year. Reports are that the firm was snapped up for 10 percent of the price tag the board was after. There was also Solyndra, Nanosolar, Heliovolt, and others that have struggled.
But beyond just CIGS, the entire solar panel market is laboring under the weight of oversupply, and manufacturers have production capacities for about twice as many solar panels than the market needs. Even the big manufacturers are struggling and one of the biggest, China’s Suntech, has been unable to pay bondholders, with the subsidiary responsible for much of its manufacturing slipping into insolvency.
So it shouldn’t come as a surprise that it’ll be difficult to sell new equipment to prospective manufacturers. But that hasn’t stopped Sweden’s Midsummer. It believes its new approach to CIGS deposition offers major advantages.
Optical disk approach to solar panels
Midsummer’s approach is to produce individual CIGS thin film cells on a stainless steel substrate. The cells are “punched out” of the stainless roll before deposition. “We wanted to produce many small thin film solar cells and then later on put them together in a module,” says CEO Sven Lindström.
This approach draws on optical disc manufacturing techniques, treating each individual CIGS cells in much the same was a CD or DVD would be created. It certainly marks a departure from current thin film semiconductor deposition, which tends to be employed in a continuous process, either onto a glass substrate or a roll of stainless steel. The closest relative to the Midsummer process in PV would be MiaSolé, which uses a stainless steel substrate cut into cells. But even MiaSolé uses a continuous deposition process with the cells being sorted into efficiencies batches afterwards.
What’s the advantages of the CIGS semiconductor deposition onto individual cells? Lindström believes that it allows R&D improvements to be made more quickly and incrementally, one cell at a time. The company is aiming to produce 200 to 400 cells per hour on its equipment, and says it can change the process parameters a little for each individual cell. Midsummer employs its 2D bar coding system for the substrate, so individual cells can be logged on a database and efficiencies assessed.
Midsummer claims that other advantages include that its cells can be employed in a flexible module, which is a market segment that has been largely left open after Global Solar and Uni-Solar ceased production. The difference between Midsummer’s approach and those companies’ technologies is that Midsummer’s cells are significantly more efficient. Midsummer can produce modules with an efficiency of 14 to 15 percent, while Global Solar and Unisolar were producing modules for closer to 8 to 10 percent.
In addition, Lindstöm says the weight per square meter of Midsummer’s modules is below three kilograms per square meter, which is more lightweight than competitors. Flexible modules have been touted as a solution for commercial rooftop panels or membrane roofing, where weight load is an issue. Light weight, flexible panels could also open up other more unusual markets, like on the roofs of trains.
In terms of costs, the Midsummer claims its flexible module can be made for $1.10/W and with glass for $0.70. It has a roadmap for $0.50/W by the end of 2014, which is slightly ahead of competitors. It also believes that such costs can be achieved at a relatively small scale, tens of megawatts instead of hundreds or gigawatts.
It should be noted that while Midsummer has a line up and running in its labs in Sweden, but that the efficiency and cost results have not yet been tested in scale production. And with very few solar panel manufacturers looking to add capacity, there’s a chance that won’t happen soon.
“Nobody is buying”
While all of these advantages and this new approach appears promising, it could be incredibly hard to find buyers willing to invest in new solar panel equipment. “Nobody is adding new capacity,” at least for the next 12 to 18 months, says Finlay Colville, VP at NPD Solarbuzz. “This makes it a really big problem for anybody who is introducing a new tool,” particularly turnkey thin film lines.
But that doesn’t mean all is lost for Midsummer. It reports that an unnamed Chinese customer has one of the Midsummer lines currently installed for testing. The solar market’s geographical shift away from traditional European markets and to new ones in the Middle East and East Asia may also provide opportunities.
A GTM Research report released recently predicted that the Middle East and Africa will provide 1 GW of demand for solar panels in 2013, an increase of over 600 percent on 2012. The strong performance of thin film panels and CIGS’ in hotter temperatures could also give that technology an advantage. GTM Research’s Shyam Mehta thinks that if some of the CIGS cells that have reached 19 percent efficiency in a lab setting, could be applied to commercial production, there could be good prospects for the technology.
Even with a PV manufacturing market under considerable stress, innovation is still required to drive efficiencies up and costs down and Midsummer may allow for iterative improvements, cell by cell, for the first time in thin film. CEO Lindstöm reports that the company is well funded at present, but for its approach to make an impression it will have to start selling equipment sooner rather than later.