Since the beginning of 2010, we’ve watched Google turn into an increasingly regular investor in renewable energy technologies. This month alone, the search giant has had three major announcements that will lead to more clean megawatts on the grid.

We regularly evaluate the renewable energy investments of Google and other IT brands on the Cool IT Leaderboard. Google was a leader in this scoring area at the time of our last assessment (December 2010), and it looks like the company is putting forward plenty of examples to keep up the lead in 2011.

Google may be the most consistent of its IT peers, but it is not the only company to invest directly in clean energy. Microsoft announced a contract in February to buy wind power for a 22.2 megawatt capacity data center in Dublin, and Intel scored points on our last Leaderboard for its investments in cleantech firms, such as solar manufacturing. A few cloud hosting companies have also partnered with renewable energy providers or a utility to purchase clean energy directly for their operations.

Here’s a quick look at Google’s investments of the past two years, starting with the most recent:

April 18, 2011: The World’s Largest Wind Farm

Location: Shepherds Flat, Oregon

Investment: $100 million

Size: 845 MW

Google’s statement:

This will be the first commercial wind farm in the U.S. to deploy, at scale, turbines that use permanent magnet generators—tech-speak for evolutionary turbine technology that will improve efficiency, reliability and grid connection capabilities.

April 11, 2011: Brightsource’s Ivanpah Solar Electric Generating System

Location: Mojave Desert, California

Investment: $168 million

Size: 392 MW

Google’s statement:

We need smart capital to transform our energy sector and build a clean energy future. This is our largest investment to date, and we’ve now invested over $250 million in the clean energy sector. We’re excited about Ivanpah because our investment will help deploy a compelling solar energy technology that provides reliable clean energy, with the potential to significantly reduce costs on future projects.

April 7, 2011: German Solar Farm

Investment: $5 million

Size: 18.7 MW solar farm

Where: Brandenburg an der Havel, Germany

Google’s statement:

This facility will provide clean energy to more than 5,000 households in the area surrounding Brandenburg. Until the early 90’s, the site was used as a training ground by the Russian military.

October 2010: Offshore wind cable

Investment: Tens of millions (with co-investors, Good Energies and Marubeni)

Size: 6 GW (or 6,000 MW) is the wind capacity that could be generated by offshore farms that would be built next to the wind power transmission backbone

Where: 350-mile cable extending from New Jersey to Virginia

Google’s statement:

We believe in investing in projects that make good business sense and further the development of renewable energy. We’re willing to take calculated risks on early stage ideas and projects that can have dramatic impacts while offering attractive returns.

July 2010: 20-year contract to buy NextEnergy wind

Investment: unknown

Size: 114 MW

Google’s statement:

Buying renewable energy directly from the developer impacts the development of renewable energy projects in ways that are more meaningful than the purchase of Renewable Energy Certificates (RECs) from third parties.

May 2010: NextEnergy Resources wind project

Investment: $38.8 million

Size: 169.5 MW

Google’s statement:

To reach a clean energy future, we need three things: effective policy, innovative technology and smart capital... Smart capital includes not only these early-stage company investments, but also dedicated funding for utility-scale projects. To tackle this need, we’ve been looking at investments in renewable energy projects, like the one we just signed, that can accelerate the deployment of the latest clean energy technology while providing attractive returns to Google and more capital for developers to build additional projects.

Google is not using renewable energy generated through these investments to directly power its infrastructure, but the company has hinted that the creation of Google Energy, its wholesale electricity purchasing subsidiary, makes it more feasible to procure clean energy for its own operations. We would still like to see Google increase its overall transparency, particularly regarding the company’s carbon footprint and energy demands.

Tomorrow at the Green:Net conference in San Francisco we will release a new report evaluating the good and bad energy choices that Google and its peers are making as cloud computing demands more and more electricity. Google is providing the rest of the sector with a number of good examples.

Check back tomorrow to download the full report.

Update: Our report, "How Dirty Is Your Data?," is now available here.