Salt River Project works with university on battery storage development

Feb. 17, 2015

SRP is working with Arizona State University on a project that will help SRP and its customers maximize the benefit of solar photovoltaic (PV) systems utilizing battery storage technology.

SRP delivers reliable energy to about 1 million customers 24 hours a day, seven days a week. During the summer, demand for electricity generally reaches its peak between 3 and 6 p.m. on weekdays. That’s the hottest part of the day, and also around the time when SRP’s customers are arriving home from work and turning up their air conditioners and turning on appliances.

While the Phoenix area has abundant sunshine and the potential for significant solar PV generation, solar generation generally peaks in the early afternoon, often hours before SRP summer load peaks, which means solar customers rely on the grid for their energy needs during the utility’s peak hours. Customers on time-of-day plans pay more for electricity in those hours, which translates to higher monthly bills.

ASU graduate students and faculty in the School of Computer, Electrical and Energy Engineering are looking for ways to better align the solar generation to match customers energy use by storing the PV energy and then using the stored energy to reduce the residential late afternoon peak load. In essence, the battery would “shift” the PV energy generation later in the day to match the system load peak.

SRP builds its power system to meet peak demand. As a result, reducing the demand for electricity during those peak hours will also save customers money by allowing SRP to defer building new power plants and infrastructure.

A PV/Battery storage system has been installed on the roof of the Engineering Research Center on ASU’s Tempe Campus to test it against the Arizona heat. The system contains an array of PV panels, a bank of lithium ion batteries, a control system and a device that simulates SRP’s load.

Researchers also hope to determine the optimal capacity of the battery that could help shave the peak load, while saving SRP’s time-of-use customers the most amount of money.

“As batteries become more economically viable, they can help customers save money by reducing energy consumption during peak pricing hours and through this research, we hope to learn how residential solar systems in our service territory impact our system, and determine how battery delivery can assist in peak shaving, frequency regulation and voltage support to further enhance grid reliability,” said SRP Lori Singleton, director of SRP Emerging Customer Programs for Solar, Sustainability and Telecom.

They hope to have their findings available by July 2015.

SRP has been engaged in research related to solar technology for nearly 30 years. SRP’s research has included demonstration projects at various locations throughout the Valley, small installations for educational purposes at various schools, and studies to better understand the long-term performance of solar to help educate our customers.

In collaboration with the Electric Power Research Institute (EPRI), the National Renewable Energy Laboratory (NREL), and several other utilities, SRP is participating in a project to demonstrate and test a variety of flat-plate and concentrating solar power systems at EPRI’s Solar Technology Acceleration Center (SolarTAC). SRP is also partnering with EPRI to evaluate “smart” solar inverters with advanced grid-friendly behavior.

SRP is a community-based, nonprofit utility serving approximately 1 million customers in the greater Phoenix metropolitan area.