Solar energy

RESOURCES • SOLAR RECOURCES •

Solar Energy Conversion Toward 1 Terawatt
David Ginley (National Renewable Energy Laboratory, USA) Martin A. Green (University of New South Wales, Australia) Reuben Collins (Colorado School of Mines, USA) Abstract
The direct conversion of solar energy to electricity by photovoltaic cells or thermal energy in concentrated solar power systems is emerging as a leading contender for next-generation green power production. The photovoltaics (PV) area is rapidly evolving based on new materials and deposition approaches. At present, PV is predominately based on crystalline and polycrystalline Si and is growing at >40% per year with production rapidly approaching 3 gigawatts/year with PV installations supplying 5%, respectively. Many of these devices can be fabricated with of technologies. low-cost, solution-based, low-temperature, atmospheric-pressure As we look to the future of solar energy, it is clear that materials science plays a critical role in this arena—in the near term for the improvement of Si, thin-film, and concentrator technologies and in the next 20–30 years for the development of thirdgeneration technologies. Although the focus here is on cell- and

Figure 4. Historical and projected costs for wafer and film c-Si photovoltaic modules versus their cumulative production (in megawatts). Extrapolations for future technologies are also shown (from References 5 and 6). The 70%, 80%, and 90% curves represent learning curves for the technology; the lower the percentage, the more rapid the learning, and the more rapid the price decrease with increasing production.

Figure 5. Cost-efficiency analysis for first- (I), second- (II), and third(III) generation PV technologies (from Reference 9).

MRS BULLETIN

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VOLUME 33 • APRIL 2008

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www.mrs.org/bulletin • Harnessing Materials for Energy

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device-level materials science, it is important to keep in mind the broad range of materials