California’s Renewable Portfolio Standard, which requires 60 percent of electricity retail sales to be served by renewable resources by 2030, is ambitious and attainable. It is an undertaking, however, with its share of challenges, many of which can be summarized as maintaining the reliability of the transmission and distribution network in a costeffective manner. The UniGen Smart System for Renewable Integration (UniGen) represents an approach, considerably different from those being currently pursued in the industry, for integrating large amounts of renewable energy into the daily operation of the California Independent System Operator grid without sacrificing reliability.
UniGen is primarily a tool that allows variable energy resources to use the day-ahead market. This is attractive to resource owners because negative prices are increasingly present in the real-time market but not in the day-ahead market. It is attractive to the California Independent System Operator because day-ahead schedules make the markets operate more efficiently and contribute to grid reliability.
However, variable energy resource owners are primarily scheduling in the real-time market, where they are not charged balancing costs in the event that the schedule is not met. Variable energy resource owners could use UniGen to schedule all forecasted generation into the day-ahead market and be assured that the schedule is met, thus creating financial incentives for variable energy resource owners to transition from the real-time market to the day-ahead market.
The use of UniGen by market participants to serve their own financial interests would support California ISO’s efforts to maintain grid reliability.
Author(s)
John Redding, James Detmers, Dr. Mahyar Zarghami, Ali Rahimi, Bo Stauffer-Olsen
