AriSEIA Submits First Brief in APS Rate Case

READ THE BRIEF

AriSEIA filed its Initial Brief in Arizona Public Service’s current rate case, urging the Arizona Corporation Commission to eliminate the Grid Access Charge and Legacy Solar Rate Increase imposed on residential solar customers. AriSEIA argues that APS has again failed to demonstrate that customers with rooftop solar impose unique costs on the electric system that justify solar-specific charges. APS’s own cost-of-service witness acknowledged that the Company did not identify specific costs attributable to solar customers, while AriSEIA’s analysis shows that correcting flaws in APS’s methodology eliminates the alleged cost shift. Eliminating both charges would have an estimated impact of only $0.34 per month on other residential customers.
​
The brief also asks the Commission to strengthen opportunities for customers to participate in distributed energy resources. AriSEIA recommends expanding APS’s virtual power plant program to commercial and industrial customers, allowing broader participation by third-party-owned systems, and improving program marketing and enrollment. AriSEIA also urges the Commission to retain and improve the E-32L Storage Pilot rather than eliminate it, and supports Microsoft’s Bring Your Own Power proposal, including recognition that aggregated distributed energy resources and virtual power plants can participate.
​
On broader rate case issues, AriSEIA opposes APS’s proposed Formula Rate Adjustment Mechanism and requested 10.7% return on equity, arguing that the proposals would reduce regulatory oversight and unnecessarily increase costs for customers. AriSEIA also opposes Kroger’s proposed commercial rate design changes, which would reduce the economic value of on-site solar, while supporting recovery of APS’s Agave Battery Energy Storage System. The brief asks the Commission to adopt a rate structure that protects customers, supports clean energy investment, and expands the ability of distributed resources to provide value to APS’s system.