Solar Power Inc. said Thursday it signed a partnership to develop 50 megawatts of floating solar photovoltaic projects in California, three other states and Mexico.

Floating photovoltaic arrays are relatively new technology for irrigation ponds, reservoirs and water treatment plants. They are getting notice because they don’t take up valuable farmland or expensive real estate.

There are existing floating solar projects in Napa County, Japan and India, and many more are planned.

“Large-scale floating PV systems have increasingly shown their effectiveness in various settings, and this platform gives SPI a strong competitive advantage in this growing market segment,” Xiaofeng Peng, chairman of SPI, said in a news release. “This technology not only generates clean solar power energy, but also serves to conserve water in critically dry regions like the Southwestern U.S. and California in particular.”