A key component of a callable load market characterization is identifying the extent to which customers are currently enrolled in programs and participating in demand response events when called upon. This section describes current enrollment by customer category as well as the portion of that enrollment estimated to be “available” for demand response events when program overlap and actual participation history during events are taken into account.
Demand response participation values for Con Edison’s DLRP and EDRP programs and for NYISO’s ICAP program were assigned to the appropriate customer segment. Additionally, participation in Con Edison’s Direct Load Control (DLC) program was estimated44. Figure 4-76 summarizes the demand response enrollment data by customer segment, which indicates a total demand response enrollment of 783 MW.
41 The details of the different scenarios considered when estimating achievable potential are described in Chapter 5.
42 The study team is aware that legislation is currently being considered that could significantly reduce the ability of distributed generation to contribute to demand response (see New York State Department of Environmental
Conservation, proposed rule modifying 6 NYCRR Part 222 Distributed Generation Sources, October 25, 2007). The ultimate ramifications of pending legislation are still largely uncertain, however, and therefore were not explicitly included as part of the scenario analysis.
43 The normal distribution is truncated to be less than 1.
44 The DLC program uses communicating thermostats to control air-conditioning load in residential homes and small businesses during summer peak hours. The 2006 DLC evaluation report was used to estimate the demand response participation for the Residential segment. A total of 16,056 thermostats each contributed 1.13 kW of load reduction during system peak. An additional 5,737 thermostats in small businesses contributed 1.24 kW each. Since the segment identification was not known for each of the small business customers, it was assumed that the
reduction was spread proportionately across all of the other segments. SC4 Offices, Government Offices, and nonresidential Multi-Family Housing were excluded from this proportional allocation because it is unlikely they participated in the small business thermostat program.
Figure 4-6. Current Demand Response Program Enrollment45
Note: Residential enrollment data reflect 2006 values. Enrollment in 2007 was 19.7 MW.
The above figure illustrates that office buildings (when the four office sub-segments are combined), government facilities, multi-family housing (SC8/12/13), and industrial facilities are the top participants in demand response programs. These four segments collectively represent 593 MW of the 783 MW of enrollment, or 73% of the total.
While enrollment values present the actual registered commitments in DR programs, they fail to provide a complete picture of available demand response resources for three reasons.
1. Facilities are permitted to enroll in multiple programs (e.g., DLRP and ICAP), but overlap between program enrollments results in lower available resources than enrollment numbers alone would indicate.
2. Actual load curtailment during demand response events varies considerably with program type and is lower than the committed values, on average, for every program type (with voluntary programs expectedly having the lowest participation rates during events). For instance, analysis of events called in 2005 and 2006 reveals that actual load reductions as a percentage of committed load reduction were 97%, 63%, and 35% for the ICAP, DLRP Voluntary, and EDRP programs, respectively.
3. Unlike the potential curtailments estimated for this study, the currently available reductions are not necessarily available at the time of system peak demand and therefore may over-estimate reductions that can be provided when needed most.
The first two factors cited above (program overlap and actual curtailments during called events) can be quantified from available data and—when both are taken into consideration—the estimated MW of
45 Including enrollment in ICAP, DLRP, EDRP, and DLC programs.
available demand response drops from 783 MW to an estimated 569 MW.46 A comparison by customer segment of the available vs. enrolled MW in demand response programs is provided in Figure 4-7.
Figure 4-7. Enrolled MW vs. Available MW in DR Programs
Note: Residential enrollment data reflect 2006 values. Enrollment in 2007 was 19.7 MW.
To better understand how the values above compare with the total peak demand for each customer
segment, the percentage of peak demand that is currently available by customer segment is also illustrated below in Figure 4-8.
46 As noted previously, the estimate of 569 MW of achievable callable load reductions from current enrollments assumes that the Average Peak Monthly Demand (APMD) is a reliable method of estimating actual load curtailments. Many states use a customer baseline load (CBL) method based on recent similar-day loads, with a same-day adjustment that can account for changes in baseline loads due to weather. Regardless of the baseline calculation method, it is important that metering equipment and procedures allow for adequate verification of meter data.
Figure 4-8. Currently Available DR as a % of 2007 Coincident Peak
As can be seen above, hospitals currently have available for a demand response event the greatest percentage of their total segment’s peak demand, due in large part to their abundant emergency generation. Industrial facilities are also able to contribute a substantial portion of the entire industrial segment’s peak demand, at roughly 25%.
The above discussed values for available demand response will be compared in Section 5.1.4 with the estimated achievable potential for each customer segment to better understand the remaining
opportunities for demand response that exist by customer segment.