Growth in renewable energy has occasionally led to excess power and negative pricing. Utilities are finding creative ways to help balance the system while lowering costs.
Arizona Public Service recently proposed a slate of efficiency and demand-side measures that include many of the usual suspects, along with new takes on traditional resources. The utility’s plan includes incentives for smart thermostats, electric vehicle charging infrastructure, energy storage and water heater timers — along with a new “reverse demand response” product that aims to balance system load with excess renewable generation.
The utility is a member of the California ISO’s Energy Imbalance Market, a real-time marketplace that helps several balancing areas voluntarily trade energy. The market sends 5- and 15-minute price signals, which on mild sunny days can show up as negative pricing: renewable generation that customers get paid to take, in order to avoid curtailment.