Two new Exchange Traded Funds, filed within days of each other with the U.S. Securities and Exchange Commission, will focus on companies that provide products and services to the wind-energy industry, such as turbine makers and utilities with wind farms.

Wind energy reduces carbon dioxide emissions and cuts natural gas and water use. Of particular interest to investors, wind power is unaffected by price swings in natural gas, coal and uranium — all of which soared this year.

The new filings reflect the deepening role of wind in the battle against climate change.

U.S. wind-power capacity increased by 46% in 2007, with $9 billion invested in 2007 alone, making the U.S. the fastest-growing wind power market in the world for the third consecutive year. Energy generated by wind could supply 20% of U.S. energy needs by 2030, according to the U.S. Department of Energy.

The global wind-power market, meanwhile, grew 27% to 94 gigawatts installed capacity, according to the Global Wind Energy Council. Total global capacity is projected to increase by 155% to 240.3 gigawatts by 2012 with China leading the growth.