Arizona Public Service (APS) became the first non-California utility to surpass 1 GW of solar capacity this summer.
APS’ solar portfolio is almost equally divided between rooftop and grid-scale solar installations, with 551 MW of rooftop and 499 MW of grid-scale solar farms.
APS says it has invested a total of about $2 billion in solar power.
APS has had a contentious relationship with solar power, battling net metering, while the state itself is in an ongoing battle over the value of solar power and how rates should be structured to balance the competing interests of consumers, solar advocates and utilities.
Against that backdrop, it appears slightly incongruous that an Arizona utility is the first outside of California to surpass 1 GW of solar capacity.
APS’ grid-scale solar capacity comes from a combination of solar farms owned by APS and power purchase agreements.Through its AZ Sun Program, APS owns and operates nine solar plants with a combined capacity of 170 MW. The plants were designed and built by independent solar developers, contractors and equipment providers.The rest of APS’ 329 MW of grid-scale solar comes from independently owned solar farms that sell their output to APS.
APS also owns 10 MW of rooftop solar installations, with the remaining 541 MW coming from systems owned by homeowners or leasing companies.
APS is using the rooftop panels it owns to conduct in research and development on how solar power and other technologies, such as smart inverters and battery storage, affect its ability to serve its customers.
“APS customers benefit from the fact that when you include energy from APS’ other renewable energy sources — wind, geothermal, biomass and biogas – and the Palo Verde Nuclear Generating Station, nearly half of all the power on APS’s system is carbon-free,” Tammy McLeod, APS vice president of resource management, said in a statement.