Demand Response

This credit awards two points to projects that create a “real-time, fully automated” demand response (DR) plan, install controls and meters to allow the plan to be implemented, and also participate in a local utility demand response program. If there is no local utility DR program, the project can earn one point for installing the controls and meters needed if a program becomes available in the future.

A demand response plan is triggered when the building control system receives a signal from the utility to reduce a building’s electric demand during periods of peak load on
the utility infrastructure. When the signal is received, the building control system will automatically reduce electric demand by at least 10% by implementing energy savings measures. The control system needs to have the capability for automatic implementation and operation, but a “semi-automated” plan, where the automated controls are initiated by manual action in response to notification from the utility is also acceptable.

Under LEED, the building must enroll in a program for at least one year. LEED is looking for a minimum 10% demand reduction based on the peak demand (as calculated by the project’s energy model). The DR plan control sequence must be included in the Commissioning Agent’s scope of work, and it must include at least one full test of the DR plan. This will be needed for LEED documentation, and should also be furnished to the utility company to show compliance with the program. There is usually an upfront payment from the utility to a building that participates in a DR program, along with payments on an ongoing basis or on an as-needed occurrence basis.

It is important to note that, unlike normal electric utility demand response plans, which focus on reducing the demand on the grid, LEED is looking for a reduction in peak energy used in the building; utility grid load shed measures like wind power, solar PV, or onsite generators, which would reduce the amount of energy taken from the grid but don’t reduce the energy used by the building, are not acceptable for this credit. Peak demand reduction measures can include:

Reducing lighting levels
Adjusting space temperature setpoints
Adjusting HVAC system operating parameter setpoints (chilled water temperatures, air handler or AC unit discharge temperature, static pressure, etc.)
Turning down or turning off non-essential loads, such as fountains, decorative features, or video displays
Postponing energy-intensive activities, such as running dishwashers or laundry machines, until later, low-demand periods.

The utility infrastructure peak load typically occurs on a hot, summer, weekday afternoon when there is a high cooling demand. That means that daylighting controls at perimeter spaces with windows are usually an effective DR strategy because they can be applied
to reduce both lighting power and cooling load. Summer peak loads also sometimes coincide with a high percentage of staff being gone for vacation, making the building sparsely occupied. This might present an opportunity to temporarily relocate staff within the building, allowing HVAC and lighting to be shut down in entire sections or floors of buildings.

This credit requires a direct digital control (DDC) control building management system (BMS) that can perform a pre-programmed response while allowing onsite building management to make adjustments at the time of implementation and then restore to normal operation when the need has passed. This usually requires the BMS to control everything in the HVAC systems, from central plant down to the zone units, including air handlers, AC units, chillers, boilers, pumps, cooling towers, VAV boxes and fan-powered VAV boxes, fan coils, cabinet and unit heaters, exhaust fans, and the like.

Specialty HVAC systems, like data center cooling, kitchen cooking and dishwasher exhaust and make-up air, and process HVAC should also be included. The BMS should also be able to control, or at least interface with, lighting controls, domestic hot water generation, water booster pumps, and any other building system that uses energy.

Costs and benefits of this program will vary widely, based on location, utility, building type, and systems installed, not to mention actual energy reduction. Some utility providers have programs and some do not; depending on the region, the program may be implemented by the grid manager or ISO rather than the local utility.

In a 100,000 SF office building, we would expect a BMS to cost about $1/SF. Most of this goes to purchasing the control devices, installing the devices and running network cable. About 20%–25% is allocated for programming the control sequences needed into the system, downloading the sequences to each piece of equipment, and then debugging the system operation. Finally, a small portion of this cost will also be allocated towards working with the Commissioning Agent during commissioning.

A LEED office building will typically include a BMS to manage energy efficiency sequences, to enable ventilation measurement and control sequences, and also to enable individual control sequences needed for thermal comfort and interior lighting requirements.

The added cost for this credit would go toward additional programming to create the demand response sequences in the BMS.

This additional programming is likely to be 10%–15% of the control system cost, or $0.10–$0.15 per square foot. No additional devices, network cabling, or control installation should be needed. However, there is an added cost of employee and staff education and preparation for implementing the demand response plan. This education cost will depend on the number of people affected by the plan, but is likely to be less than $10,000.