AriSEIA Files Final Brief in TEP Rate Case

READ THE BRIEF

The Arizona Solar Energy Industries Association (AriSEIA) filed its Responsive Brief in Tucson Electric Power’s (TEP) pending rate case, urging the Arizona Corporation Commission to adopt rate designs that provide customers with clear price signals, protect customers from poorly designed demand rates, and expand access to energy storage and virtual power plants. AriSEIA argues that TEP has not justified key elements of its proposed rates and has failed to address evidence showing significant problems with its existing rate designs.
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AriSEIA highlighted new customer-level analysis showing that 52% of the more than 10,000 non-solar customers enrolled in TEP’s Residential Demand Time-of-Use rate would pay less on the standard Time-of-Use rate. Those customers are overpaying by an average of 21%, or approximately $215 per year. AriSEIA is asking the Commission to close the demand-based rate to new customers, notify existing customers who could save by switching rates, and require TEP to redesign its time-of-use rates so customers receive simpler and more actionable signals to reduce usage during periods of peak demand.
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The brief also urges the Commission to preserve and improve opportunities for commercial and industrial customers to use battery storage rather than allowing TEP to eliminate its existing commercial storage tariff. AriSEIA recommends expanding storage-specific tariffs, opening TEP’s virtual power plant program to non-residential customers, allowing third-party-owned systems to participate directly, and expanding the non-residential storage tariff pilot to 50 MW. These changes would allow more customers to use private investment in storage to reduce peak demand and provide benefits to TEP’s grid.