Google says that it plans to be carbon neutral by 2008, Reuters reports.

To reach the goal, Google is investing in energy efficiency, renewable energy like solar, and will purchase carbon offsets.

In April, Yahoo announced its goal of reaching carbon neutrality by 2008.

Google says it plans to create an additional 50 MWs of renewable energy generating capacity by 2012 -? above the solar power system it turned on earlier this week – enough to power 50,000 homes. The company will also apply a shadow price for carbon when buying power for its data centers to encourage the use of cleaner energy.

For its offset purchases, Google said it would invest in projects like capturing and burning methane from animal waste at Mexican and Brazilian farms.

“When considering an offset project, we carefully examine the project’s environmental integrity, its ability to be monitored and verified, and the impact that our investment will have in furthering that project’s goals,” Urs Hoelzle, Senior Vice President, Operations, wrote in a blog post. “In other words, we want to make sure that our offset funding directly enables the project, and that the carbon savings of the project are real.”

Nonprofit emissions advisors The Climate Group said they will partner with Google to support its offset plans.

Google did not reveal the actual size of the footprint it has to neutralize. The company, according to a recent article, closely guards the exact size of its carbon footprint, worrying that competitors could reverse engineer its greenhouse gas data to figure out how many servers and data centers it operates.

Google says it took into account emissions from purchased electricity, employee commuting, business travel, construction, and server manufacturing. In a partnership with the Environmental Resources Trust, the company said it independently verified this assessment.

Google has launched a new site to track its energy initiatives

Google last week launched a program with Intel to introduce more energy-efficient personal computers and server systems.