Silicon solar cells have been around since the 1940s, but their application to mainstream electricity generation has been limited by the cost of photovoltaic (PV)-cell fabrication and poor cell efficiency. Today though, high oil prices, growing environmental concerns, and our likely increasing dependence on renewable energy are changing the solar equation and creating a huge new economic opportunity.
Although “grid parity” (when solar power becomes cost-competitive with conventional electricity) is still only a goal, both Europe and the U.S. have programs in place aimed at reaching grid parity by 2015. This is no small undertaking and requires successful alignment of several diverse elements-from better PV cell efficiency to advances in manufacturing. And while the long term may ultimately include novel PV technologies, the current outlook suggests no momentous PV breakthroughs. In fact, the European Photovoltaic Technology Platform’s current Strategic Research Agenda foresees no major changes in PV technology, instead relying on investment in existing PV technology (see page 65).
In the U.S., the Department of Energy (DOE), as part of its Solar America Initiative, has increased R&D investment and created technology roadmaps for ten different solar technologies (see www1.eere.energy.gov/solar). DOE-supported R&D has led to more efficient PV cells (see page 73 and cover). But raising overall PV-cell efficiency is not only a function of the materials or their fabrication. It can depend drastically on the optics around the cell. Researchers in Israel have designed a microconcentrator that increases the amount of light (collection efficiency) actually reaching the active surface of a PV cell by as much as 15% (see page 26).
In terms of the economic opportunity, global revenues for the PV industry today exceed $12 billion and it’s one of the fastest growing high-tech sectors in the world. The World Bank has predicted that the global market for solar electricity will reach $4 trillion in about 30 years (see page 132). Certainly, an opportunity not to be missed-and one you’ll be reading much more about in future pages of Laser Focus World.