Demand Response: Commitment to Curtailing Energy
Part 2: Demand Response: How to Coordinate Peak-Load Reductions
Demand Response: How to Coordinate Peak-Load Reductions
By James Piper, P.E. - August 2011 - Energy Efficiency
After determining whether a facility is a viable candidate for demand response, managers need to consider the way they will coordinate the reduction of peak loads.
A key factor to consider is response time. When a utility notifies a facility of a demand-response event, the customer typically has 30 minutes to two hours to reduce electrical demand. The facility must keep electrical demand at that level until a pre-established period passes.
Building-automation systems (BAS) allow managers to reduce loads well within the required time frame. But if the facility does not have a central automation system or other means of remotely curtailing loads, managers must depend on technicians to manually switch off pre-identified equipment at the start of the event and turn the equipment back on once the event concludes. If the facility does not have enough personnel to respond within the predefined timeframe, it is not a candidate for participation.
Demand-response programs also affect building occupants. If technicians can ensure that load curtailments rotate among building systems and that individual pieces of equipment shut down for a very limited period, occupants might be willing to put up with the impact on comfort and operations. But if load curtailments are too long and interfere with operations, customers might not buy into the program.
Before enrolling, managers also should review the risks and benefits a demand-response program carries. While participation can produce savings and rebates, failure to achieve pre-established levels in use reductions can result in significant penalties. Before committing to a particular program, managers must understand and quantify the financial benefits, as well as the penalties for failing to meet predetermined reductions.
Finally, consider the facility's electricity use. Does the building use enough electricity and are there sufficient controllable loads to warrant participation? For smaller facilities — particularly those with relatively small electrical bills — the risks might exceed cost benefits. Similarly, if the facility's electrical demand is relatively flat — meaning most electrical equipment operates throughout the day — managers might not be able to identify enough loads to curtail to meet demand-reduction targets.