In a major step towards its renewable energy goals, the Los Angeles Department of Water & Power on Tuesday signed an agreement with Mexico’s federal power utility to immediately buy up to 100 megawatts of geothermal energy.

The agreement between the DWP and Mexico’s Comision Federal de Electricidad enables the DWP to make wholesale purchases of up to 100 megawatts of electricity generated by CFE’s Prieto Geothermal facility in Mexicali in Baja California. A megawatt is enough energy to power between 700 and 1,000 single-family homes.

With the geothermal power from this agreement, the DWP is now slated to have renewable power make up 10 percent of its total power portfolio. Los Angeles Mayor Antonio Villaraigosa has set a goal of 20 percent renewable power by 2010.

“With this agreement, LADWP and CFE are affirming that climate change is a global problem and that reversing the effects of greenhouse gases will require a global effort,” said DWP Chief Executive David Nahai.

Tuesday’s signing ceremony among Villaraigosa, Nahai, Mexican Consul General Juan Marcos Gutierrez Gonzales and CFE General Director Alfredo Elias Ayub formalized an agreement reached late last year. The DWP purchased 25 megawatts of continuous geothermal power from CFE in December 2008 and an additional 50 megwatts last month.