This summer, utility Arizona Public Service (APS) reached a major solar milestone, surpassing 1 GW of solar energy capacity. When generating at full power, this capacity meets the partial daytime needs of 250,000 Arizona homes, and the company says its total investment in solar energy is approximately $2 billion.
APS’ solar portfolio is almost an even split between rooftop systems and grid-scale projects, with 551 MW coming from rooftop systems and 499 MW coming from grid-scale projects.
“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’ system is carbon-free,” said Tammy McLeod, APS vice president of resource management. “A cleaner energy mix is a top priority for us, with solar playing an important role.”
The utility says it receives its grid-scale solar generation from a combination of APS-owned systems and power purchase agreements. Through its AZ Sun Program, APS owns and operates nine solar plants across Arizona. These plants were designed and constructed by independent solar developers, contractors and equipment providers and provide 170 MW of capacity. The rest of APS’ grid-scale solar comes from independently owned power plants across Arizona with long-term agreements to sell power to APS.
Most of the power from rooftop solar comes from systems owned by homeowners or leasing companies. APS owns 10 MW. The utility says the APS-owned systems are strategically placed on customer homes in a way that allows the company to engage in research and development activities on how solar and other advanced technologies, such as smart inverters and battery storage, impact the ability of the utility to provide reliable and safe energy for customers.
Notably, APS came under fire from some solar advocates earlier this year after the utility proposed changes to net energy metering rules and other solar policies. However, APS CEO Don Brandt contended at the time, “Our proposal is pro-solar and pro-customer. We want to continue Arizona’s solar leadership the right way – with more solar, for more customers, without driving up the energy bills paid by non-solar customers.”