Load as a Resource

Demand Response Spinning Reserve Demonstration Project

In summer 2006, CERTS will conduct the first-ever demonstration of the use of aggregated demand-side resources to provide the electric system reliability resource known as spinning reserve. Providing spinning reserve with demand-side resources will arm grid operators at California Independent System Operator (CAISO) and Southern California Edison (SCE) with a powerful new tool to help to prevent rolling blackouts and improve system reliability.

Rolling blackouts are called when system operators run short of operating reserves. The most important operating reserve is spinning reserve which is the first line of defense relied on by operators when they respond to system emergencies, such as the unplanned loss of a large generator or major inter-tie. Using controllable demand to provide spinning reserve will increase the total amount of operating reserves available to the operator and thereby circumvent situations when they would otherwise run short and have to call for rolling blackouts.

Customers in a specially-metered geographic region of SCE's air conditioning load-cycling program, called the Summer Discount Program, will be able to join the demonstration voluntarily. During the demonstration, the Southern California Edison will order short-duration load curtailments on the customers who sign up for the tests at pre-scheduled times during summer weekday afternoons. The curtailments will last between five to 20 minutes each between 2 and 6 p.m.

California ISO staff and other participants will observe load curtailments on a secure, external website that can read and broadcast the specially metered data in real time. CERTS researchers will also install high time-resolution data monitoring devices to record loads (and indoor temperatures) on a statistical sample of individual air conditioning cycling units for further analysis of the AC usage patterns and of the effectiveness of the pre-scheduled interruptions.

This demonstration is being funded by the California Energy Commission Public Interest Energy Research Program.

Figure 1. Demonstration of Spinning Reserve Supplied by Aggregated Load

Step 1 — At a pre-determined time, the curtailment signal is triggered from a client machine at the substation.
Step 2 — Signal is transmitted over a 154MHz SCE owned, one-directional, private radio network.
Step 3 — AC cycling switch receives signal and starts shedding load.
Step 4 — Curtailment signal is simultaneously received by a substation installed switch that records the time of receipt.
Step 5 — Substation SCADA continuously records aggregated circuit load and monitored temperature, humidity and switch.
Step 6 — eDNA server extracts relevant test data from SCADA system in 8 second intervals.
Step 7 — eDNA databridge service is used to replicate data from SCE to Connected Energy's data center.
Step 8 — eDNA servers located in Connected Energy's archive SCADA data.
Step 9 — Connected Energy's COMSYS system performs realtime data aggregation and calculations.
Step 10 — Real-time test monitoring is made available via Connected Energy's EnerVIEW application.
Step 11 — Power Meter collects real time power data from the AC unit and sends to Connected Energy via wireless Internet
Step 12 — Real-time & forecasted weather data is provided by the National Weather Service.
Step 13 — The CentryWCC collects real-time and forecasted weather data from the National Weather Service feeds.

Contact:

Joseph Eto
Lawrence Berkeley National Laboratory
(510) 486-7284