Arizona PublicService Co. is now actively using inverters connected to customersolar panels to turn those solar arrays into miniature power plants controlledby APS, the state's largest utility.
The deployment of the advanced inverters makes APS the firstutility in the country to be able to remotely use this technology, thePinnacle West Capital Corp.subsidiary said in an April 7 statement. The inverters recently gained acertification that allows the utility to begin using the devices to ramp up orcurtail power from the residential rooftop panels in real time, serving theneeds of the grid as a power plant would.
APS installed the inverters as part of a program that iscontroversial among some solar advocates in the state. The utility has enlisted1,500 customers to host rooftop solar panels that APS rents for $360 a year.
In a statement, APS said the inverters will help the utilitymake electricity service more reliable. As rooftop solar panels have grown inpopularity, the grid has become more difficult to manage due to the two-wayflow of power where not only the utility but also the customer can producepower, as well as the fact that solar panels only intermittently generateelectricity.
"The small power plants found on customer rooftopsacross the state present interesting challenges to service quality andreliability, and advanced inverters are a technology APS believes can helpavoid service disruptions and power quality issues," APS Director ofTechnology Innovation Scott Bordenkircher said in a .
But residential solar provider has APS's ventures into control ofthe rooftop solar market "anticompetitive." The Alliance for SolarChoice, of which Sunrun is a member, argues that vertically integratedutilities have monopolistic advantages that can muscle non-utility solarproviders out.
While APS may be the first to deploy the technology in theU.S., Canadian municipal energy company PowerStream Inc. has combined residential solar with lithium-ion batteries tostore energy in order to create what it calls a "virtual power plant."