Technology Advances in Delivering Cost-Competitive Solar Energy
The prevalent approach for generating solar electricity is through photovoltaic (PV) systems that use semiconductor PV material to convert sunlight directly into electricity. The market is currently dominated by silicon-based flat-plate PV, which produces electricity by having sunlight directly strike panels tiled with sheets or wafers of expensive PV cell material. Flat-plate PV has defined the solar electricity market since its emergence 30 years ago, and drove the market’s recent rapid growth to $7 billion in 2005. However, recent silicon feedstock shortages and rising wafer prices have highlighted the need for technologies which can advance the market beyond current flat-plate PV and its underlying cost limitations.
Concentrator photovoltaic (CPV) approaches enable lower total system cost by reducing the amount of PV material used. They use mirrors or lenses to focus sunlight collected from a given receiver area onto a much smaller area of PV material, and in some cases use higher efficiency, non-silicon PV material. This paper describes a particular high-performance CPV solution which compared to average flat-plate PV, uses 1/500th as much PV material and produces nearly twice as much electricity for a given collection area. The proposed solution is also smaller, cheaper, and easier to manufacture. These improvements enable generating electricity at less than half the cost possible with existing flat-plate technologies, potentially opening large new markets for clean solar energy.