The latest McKinsey Quarterly has an interesting look at the economics and growth rates of solar PV production - The economics of solar power. Note the excellent graphic showing when PV will reach grid parity in different regions.
A new era for solar power is approaching. Long derided as uneconomic, it is gaining ground as technologies improve and the cost of traditional energy sources rises. Within three to seven years, unsubsidized solar power could cost no more to end customers in many markets, such as California and Italy, than electricity generated by fossil fuels or by renewable alternatives to solar. By 2020, global installed solar capacity could be 20 to 40 times its level today.
But make no mistake, the sector is still in its infancy. Even if all of the forecast growth occurs, solar energy will represent only about 3 to 6 percent of installed electricity generation capacity, or 1.5 to 3 percent of output in 2020. While solar power can certainly help to satisfy the desire for more electricity and lower carbon emissions, it is just one piece of the puzzle. ...
Even in the most favorable regions, solar power is still a few years away from true “grid parity”—the point when the price of solar electricity is on par with that of conventional sources of electricity on the power grid. The time frame is considerably longer in countries such as China and India, whose electricity needs will require large amounts of new generating capacity in the years ahead and whose cheap power from coal makes grid parity a more elusive goal. ...
Government subsidies have played a prominent role in the growth of solar power. Producers of renewable energy in the United States receive tax credits, for example, and Germany requires electricity distributors to pay above-market rates for electricity generated from renewable sources. Without such policies, the high cost of generating solar power would prevent it from competing with electricity from traditional fossil-fuel sources in most regions.
But the sector’s economics are changing. Over the last two decades, the cost of manufacturing and installing a photovoltaic solar-power system has decreased by about 20 percent with every doubling of installed capacity. The cost of generating electricity from conventional sources, by contrast, has been rising along with the price of natural gas, which heavily influences electricity prices in regions that have large numbers of gas-fired power plants. These regions include California, the Northeast, and Texas (in the United States), as well as Italy, Japan, and Spain.
As a result, solar power has been creeping toward cost competitiveness in some areas. California, for example, combines abundant sunshine with retail electricity prices that, partly as a result of the state’s policies, are among the highest in the United States—up to 36 cents per kilowatt-hour for residential users. Unsubsidized solar power costs 36 cents per kilowatt-hour. Support from the California Solar Initiative2 cuts the price customers pay to 27 cents. Rising natural-gas prices, state regulations aiming to limit greenhouse gas emissions, and the need to build more power plants to keep up with growing demand could push the cost of conventional electricity higher.
During the next three to seven years, solar energy’s unsubsidized cost to end customers should equal the cost of conventional electricity in parts of the United States (California and the Southwest) and in Italy, Japan, and Spain. These markets have in common relatively strong solar radiation (or insolation), high electricity prices, and supportive regulatory regimes that stimulate the solar-capacity growth needed to drive further cost reductions. These conditions set in motion a virtuous cycle: growing demand for solar power creates more opportunities for companies to reduce production costs by improving solar-cell designs and manufacturing processes, to introduce new solar technologies, and to enjoy lower prices from raw-material and component suppliers competing for market share.