III. Demand Response Program Performance
in July 2006
A. PG&E
PG&E called on several demand response programs in July 2006, among them, the Business Energy Coalition (BEC), Demand Reserves Partnership (DRP), Critical Peak Pricing Program (CPP), Demand Bidding Program (DBP), BIP and the Non-Firm Program. The sum of the average load drops attributable to each of PG&E's programs was about 478 megawatts (MW) in July. The DRP and the Non-Firm program provided the largest share of energy reductions, with DRP providing 211 MW of load drop and the Non-Firm program providing about 197 MW of load drop.
B. SCE
SCE's demand response programs contributed to load reductions during the July heat wave. On July 24, 2006 after the CAISO called a Stage 2 Emergency, SCE called a total of eight demand response programs with an aggregate maximum load reduction of 809 MW. During July 2006, "day-of" programs contributed 755 MWs of load reduction and "day-ahead" programs contributed 54 MW. The vast majority of load reductions - more than 590 MW - are attributed to SCE's I-6 tariff.2 On July 24, SCE experienced 97% compliance with the requirement for its 464 I-6 customers to drop load. SCE also reports that by the time SCE notified these customers to drop load, some had already voluntarily reduced demand by about 100 MW. SCE also reports that its BIP customers reduced load on July 24 by as much as 75 MW during a 15-minute period. The BIP is very similar to the I-6 tariff except that it is offered to customers with demand of 200-499 MW. Not all BIP customers reduced demand in every time interval. On average, BIP customer demand exceeded available service by 13 MW.
C. SDG&E
SDG&E reports reasonably good participation by demand response customers during several July 2006 events. Demand response customers subscribing to day-ahead programs reduced load by an hourly average of 28 MW, with high levels of participation by CPP and DRP subscribers. Its day-of subscribers reduced load by an hourly average of 18 MW, most of which came from its AC Cycling program and smaller amounts from several other programs.
2 I-6 is a rate discount program open to bundled and Direct Access Customers able to provide a minimum demand reduction of 500 kW with 30 minutes notice during an CAISO Stage 2 emergency or a localized system emergency.
