Vinod Khosla, Co-founder of Sun Micro Systems, Khosla Ventures
In terms of the technology, the increased power production comes from a number of factors, but two in particular. Stion’s CIGS technology has an industry best temperature coefficient of -0.26%, which means production decreases less in hot climates relative to crystalline silicon. This is particularly useful in hotter climates such as the Southeastern United States, but also in other solar markets that are developing in India, the Caribbean, and Africa. And, while traditional silicon panels degrade about one-half a percent each year, Stion’s thin film panels do not degrade due to the stable chemistry
Over the past year the company has focused on a frameless line of panels specifically for the utility scale market. The frameless line has a number of benefits including lower manufacturing costs and increased performance.
of CIGS materials. There is no Potential Induced Degredation (PID) nor Light Induced Degradation (LID). Nor is there any moisture ingress. Due to the combination of a lower temperature coefficient and zero degradation, Stion’s thin film panels will produce at least 3% more than a traditional silicon panel installed in the same location in the first year, and closer to 8% more each year after year one. Proprietary cell and circuit design minimizes impact of shade and debris as well. Whereas with a traditional silicon panel if a leave shades 5% part of the panel, the production can drop by more than 50%, CIGS panels shaded by a leaf that covers 5% of the panel will only lose 5% production. Over the past year the company has focused on a frameless line of panels specifically for the utility scale market. The frameless line has a number of benefits including lower manufacturing costs and increased performance. The frameless panel costs less to manufacture, and costs less to ship due to its increased packaging den-
solar thin films sity. The frameless panel also cuts down on installation costs, as it does not require grounding and can be installed without clips by adhering the panels directly to the rack. It also is lighter weight which saves time and money on installation and on shipping. The lack of a frame also increases production by reducing soiling. Framed panels will have dirt and dust buildup along the bottom of the panel, where it gets trapped, but debris on frameless panels washes right off the panel.Stion’s frameless line has been proven on smaller utility scale products in Georgia, and four and ten Megawatt products are currently in development using the frameless panel. Due to the higher production factor of Stions CIGS technology, developers can actually use fewer kilowatts and henceforth fewer panels to achieve the same production as a traditional silicon panel. The benefits of the “power boost” increase the hotter the climate gets. “We expect to see increased returns over the lifetime of projects,” says Jim McGrath, VP of Sales for Stion, “whereas traditional panels with traditional degradation cut into the return on investment, the zero degradation factor of Stion panels combined with the low temperature coefficient will keep returns constant for the 25 year lifetime of the system.” CIGS modules are becoming more popular due their low manufacturing costs and increased power production. We have seen Japan’s solar frontier readily adopted in Japanese markets, which are known for high quality, and we are already seeing early development using CIGS in Africa, India, and Asia. First Solar’sCdTe technology was used for three of the largest solar projects in the US, for a total of 1,390MW spread over three projects in the Southwest. The island of Mauritius, just off the coast of Madagascar, is about to break ground on a 4MW solar farm using Stion’s frameless CIGS modules. With an average temperature of 24-27 degrees Fahrenheit, the superior performance of Stion’s panels in high temperatures is a feature that India and other emerging markets with hot climates all over the world can take advantage of. Thin film installations are becoming more popular all over the world. Performance data from projects in not only Georgia, but Florida and other hot environments have demonstrated the higher production. As states with hotter climates continue to develop larger and larger projects, CIGS technologies higher performance will prove to be the go-to technology.