Wind & Solar Mutual Funds

Solar funds typically invest in a blend of companies that are involved in generating solar power. Many of them are global in nature, investing in solar companies throughout the world. The Guggenheim Solar ETF has only 42.3 percent of its investments in the United States, with an almost equal percentage spread between Hong Kong and China.

The First Trust ISE Global Wind Energy Index Fund invests in global wind energy companies. While two-thirds of its holdings are directly related to the wind energy industry, the balance is in companies that are indirectly related. Roughly 55 percent of its holdings were concentrated in three European countries as of October 2013.

Alternative energy funds blend multiple types of green energy together, although many have a heavy focus on wind and solar. For example, the global Guinness Atkinson Alternative Energy Fund had slightly over 79 percent of its holdings in wind and solar as of Sept. 30, 2013. The five largest holdings of the PowerShares WilderHill Clean Energy Portfolio ETF are also wind and solar companies.

Broader green funds give you exposure to wind and solar power as well as to other companies with environmentally friendly credentials. These funds might hold shares of a company that makes high-efficiency water heaters, a maker of transmission power lines, a high-tech company with a commitment to be greener in its operations or a natural food store chain -- in addition to solar and wind companies. The additional diversification may give them better performance in varying markets while still giving them solid environmental bona fides.