US solar developer SunPower has designed and installed a 7.5MW PV system at the Lake Pleasant water treatment plant in the US city of Phoenix, Arizona.
The system is composed of a 6MW ground-mounted array and a 1.5MW rooftop system. The 6MW array utilises the SunPower T0 Tracker system which the company claims helps the modules to capture up to 25% more sunlight compared with conventional fixed tilt systems. The 1.5MW array is located atop a reservoir and utilises the SunPower T10 Solar Roof Tile system. In total, 22,936 PV modules were utilised.
The system will generate around 15 million kWh of electricity a year. This will meet around 70% of the water treatment plant’s electricity demand and will help the plant to save approximately US$4.2 million over the next 20 years.
The city of Phoenix is financing the system through a solar services agreement with SunPower. As part of the agreement, Wells Fargo owns the system whilst SunPower will operate and maintain it. The city will buy the electricity at rates that are competitive with retail electricity, minimising the effect of rising electricity costs with no capital investment.
According to SunPower, the installation represents the largest solar installation on the city’s property. The company has several additional PV installations located in the city including a 5.4MW system at Sky Harbor and two 100kW systems at the Phoenix Convention Center and the Burton Barr Central Library.
“With more than 300 days of sunshine each year, Phoenix is a natural for using solar power,” said Phoenix Mayor Greg Stanton. “The Lake Pleasant Water Treatment Plant project is the latest in a series of solar initiatives utilized at various city locations to increase the city's commitment to sustainable energy development.”
Councilman Bill Gates, chairman of the city's Finance, Efficiency, Innovation and Sustainability Subcommittee added: “This is another great example of the progressive thinking that enables Phoenix to keep customer costs as low as possible. City solar projects are currently generating 13 megawatts of electricity through solar energy, or enough to power about 2,600 homes annually.”