Google has increased its commitment to clean and sustainable energy with a sizable investment in two wind farms. The company will put $38.3 million into two NextEra Energy Resources wind farms to speed the process of serving consumers with renewable energy.

The wind farms currently generate 169.5 megawatts of power; that’s enough to power more than 55,000 homes, according to Google’s blog post on the investment.

Energy conservation and renewable energy have been key initiatives for Google for the past several years. Last year, Google.org (the company’s philanthropic arm) rolled out PowerMeter, a service to help consumers monitor and optimize their energy usage. It’s been bringing the service to more users and more “smart” devices and appliances throughout the 2009 with the PowerMeter API.

And in February 2010, Google was granted an order by the Federal Energy Regulatory Commission to buy and sell energy at market rates, mostly to make energy management for its data centers more efficient, but also in case Google Energy ever becomes a power utility.

So why did Google choose NextEra for its wind farm investment? Google’s Green Business Operations Manager Rick Needham wrote today that this company “uses some of the latest wind turbine technology and control systems to provide one of the lowest-cost sources of renewable energy to the local grid. The turbines can continuously adjust the individual blade pitch angles to achieve optimal efficiency and use larger blades with 15 percent more swept area than earlier generations, allowing capture of even more wind energy for each turbine. The control systems for these wind farms are also advanced and dynamic, allowing for remote 24/7 monitoring and operation to ensure maximum turbine up-time and power production.”