Flexible Spectrum Splitting Holographic Concentrators

The Department of Energy is beginning a new Solar America Initiative (SAI) to accelerate the development of photovoltaic systems. The goal is to make solar energy, based on photovoltaics, cost-competitive with other forms of renewable electricity by the year 2015. This project will develop a low-cost, flexible, Spectrum Splitting Holographic Concentrator (SSHOC) based on four thin film holographic optical elements. This concentrator will focus light onto the appropriate spectral response solar cells with high efficiency, flexible chromatic dispersion-compensated splitting of the light spectrum, thereby increasing the output of existing photovoltaic (PV) systems. The key SSHOC components are dispersion- and aberration-corrected visible and near IR broadband holographic optical elements, which are easily manufactured, have 99% diffraction efficiency, are lightweight, and are low-cost. The flexible SSHOC film can be laminated to any PV system solar cell. Phase I will demonstrate the feasibility of SSHOC and its ability to focus light onto the appropriate spectral response solar cells in a laboratory environment. A demonstration SSHOC module will be fabricated, and its performance will be measured in a series of bench tests. Phase II will build an engineering SSHOC as a compact portable system for field testing. Commercial Applications and other Benefits as described by the awardee: A scalable SSHOC could be adapted to a variety of applications, from large solar collectors in space to solar tiles for residential homes. A broader use of photovoltaics should reduce the nation¿s dependence on environmentally unfriendly sources, such as fossil fuels and nuclear fusion, and reduce reliance on non-renewable energy sources, especially foreign oil.