Duke Energy (NYSE:DUK) announced today that it has acquired a 4.5 MW San Francisco solar project, the largest in the city, and one of the largest urban solar farms in California.

The company's Duke Energy Renewables subsidiary purchased the plant from developer Recurrent Energy, and will sell electricity to the San Francisco Public Utilities Commission for at least the next 25 years.

"With the addition of this project, we continue to grow our solar footprint in California," said Duke Energy Renewables President Greg Wolf in a statement today. "As this asset continues to contribute to the state and city's renewable energy goals for years to come, we look forward to being a positive presence in this community."

For San Francisco's part, the city seems more than happy to purchase more solar power. "The Sunset Reservoir solar project more than tripled San Francisco's municipal solar generating capacity," said Public Utilities Commission General Manager Harlan Kelly in a statement. "The renewable, greenhouse gas-free energy from Sunset Reservoir and all of our other facilities help power public buses, the San Francisco International Airport, health clinics, and other vital city services."

Duke Energy Renewables currently has over 100 MW of solar generating capacity spread across 16 different farms. In April, the company acquired 21 MW of solar projects in Twentynine Palms, California, and has invested over $3 billion in solar and wind power since 2007.