According to the Wall Street Journal, solar and wind power enjoyed substantial growth in 2007, spurred by federal and state energy policies and incentives that support green energy sources.

The solar industry added more than 300 megawatts (MW) of capacity last year, according to the Solar Energy Industries Association (SEIA), with additions expected to roughly double in 2008. Large commercial solar installations now exceed home installations in California, reversing a long-term pattern. This is likely a bellwether for other states.

The growth of the solar industry will become more pronounced as utility-scale projects get built. More than 3,000 MW of giant concentrating solar projects have been announced for large parts of the Desert Southwest, to be completed between 2009 and 2014, with utilities buying the electric output.

According to the American Wind Energy Association (AWEA), the U.S. wind energy industry now represents just over 1 percent of the nation’s electrical supply with enough installed capacity to power the equivalent of 1.5 million American households. It reached this milestone after shattering all of its own previous records for annual growth in 2007, even beating the AWEA’s expectations for the year.

The total U.S. wind power capacity now stands at 16,818 MW. Growth for 2007 in installed capacity represented a 45 percent increase. The 5,244 MW of wind power capacity installed exceeded the industry’s own projections of 4,000 MW for the year by more than 25 percent.

Also of note, last year, Texas cemented its place as the nation’s leader in wind power capacity, with 4,356 MW, almost double the 2,439 MW in second-place California. AWEA expects the trend in growth to continue. It points out that at least 14 new manufacturing facilities opened or were announced in 2007. The industry group projects installed wind power capacity in 2008 to equal last year’s development.

Federal policies are assisting the solar and wind industries by encouraging clean energy sources. State and federal tax credits and other incentives also back the alternative energies. In half of the states, utilities are required to increase their purchases of renewable energy to lessen dependence on fossil fuels that contribute to climate change. One concern for the sector is the expiration, at the end of 2008, of certain federal tax credits that have spurred development.

—Rick Laezman/Information Inc.