Beating Silicon on all Fronts
Posted 30 September 2015 11:00 AM by Raffi Garabedian
Our updated utility-scale solar power plant design software shows First Solar's modules´ superior performance over polycrystalline silicon
Thin-film PV is still erroneously considered by some in the solar sector to be synonymous with low-efficiency. This view is outdated. We recently announced our 18.2 percent full-area Cadmium-Telluride (CdTe) module efficiency record. We're proud to say that First Solar CdTe thin film technology is now more efficient than multicrystalline Si, the most widely installed PV technology around the globe.
The power rating (efficiency) or nominal capacity of a solar module is just the beginning. More important in the real world is the energy density in field conditions, which can vary quite a bit depending on various technology-dependent factors such as climate, system design and application.
One of the first steps that we take when we develop a solar power plant is to use software to simulate energy output and cost for a project. To simplify the initial stages of system design, we developed the Energy Capacity Assessment Tool
- a free online application that makes it easy for solar developers to evaluate potential project sites and see how much energy their site can produce using First Solar technology. We recently released a new version that offers the ability to download basic design documents for easy utility-scale solar designs. The update comes with more accurate weather data models, at 8km resolution based on industry-standard weather data software Meteonorm 7.1, and includes flexibility for advanced systems designers to plug in their own weather data. And now you can compare our CdTe modules with multicrystalline silicon panels, both at module efficiencies available today, and for projects that begin construction in the future based on our technology roadmap and the industry projected silicon efficiency roadmap.*
When choosing sites on four different continents and modeling them using the Energy Capacity Assessment Tool, our technology outperformed c-Si in both revenue and energy yield. In India, you’ll see energy yield was more than 9 percent; in the United Arab Emirates it was 8.8 percent; in the southeastern part of the U.S., there is a 5 percent advantage; in South Africa, over 4 percent; in Germany, 2 percent. Why is that?
Hot Climate Advantage
One of our technology's better-known advantages is a lower temperature coefficient compared to silicon modules. PV modules rely on semiconductors to convert light into electricity. When they get hot, performance is compromised. All types of commercial PV modules suffer from lower performance in high heat, but our modules' performance is impacted to a much lesser degree than multicrystalline Si.
More Energy in Humid Conditions
It is less well-known that our modules also perform better in humid conditions. PV technologies respond differently to different light wavelengths. Our modules' semiconductors are less sensitive than c-Si to certain wavelengths of light that are most affected by high atmospheric water content. It's no surprise that First Solar modules strongly outperform c-Si in the hot & dry climate of the Arabian Peninsula (where they were recently selected for the largest solar plant in the region). Our modules' superior spectral response explains why our technology also outperforms solar systems built on c-Si modules in the cool and humid Central European climate.
Better Shading Response
First Solar modules minimize power loss from shading because of their monolithically integrated thin-film architecture. When a First Solar module is shaded, only the shaded portion is impacted, while the rest of the module continues to produce power. Contrast this to a typical c-Si modules that turn off disproportionately large portions of the module when shading occurs to protect cells from damage. In an environment with 10 percent row-to-row shading, a standard c-Si module will lose 30 percent of its power, while a First Solar module only experiences a 10 percent loss of power under the same conditions.
And there is more good news to come. Our module efficiencies have been improving at a rate greater than 4x that of multicrystalline Si. We intend to keep this pace of improvement going for years to come, further separating us from the pack.
To see how much energy and revenue your utility-scale solar project can produce, visit firstsolar.com/energycapacity
*International Technology Roadmap for Photovoltaics (ITRPV) Edition 2015_Revision 1