What is Demand Response?
Demand Response is the act of responding to the needs of current electricity demand by actively adjusting how electricity is being consumed. Changing consumption is done instead of changing production, for example turning off some lights instead of turning on another power plant. Demand Response does not happen every day; in fact Demand Response events occur only a handful of days per year.
Demand Response is usually only needed on the hottest weekdays of the year because that is when energy demand reaches its peak, due mainly to the electricity consumption of air conditioners on top of normal energy use. When electricity demand peaks in the hot afternoons, the price of electricity can become very high or demand for electricity can become greater than the available supply of electricity. When this happens it puts stress on the electrical distribution grid and can cause power interruptions. Demand Response enables the utility companies to respond to the peak demands without having to purchase very expensive electricity or build new power plants that would only be needed a few days per year.
Manual Demand Response VS Automated Demand Response
There are two main types of DR programs: Manual and Automated. For a Manual Demand Response program, the actual light switch is flipped or the decision to turn off the lights is made by the building operator or occupants. In an Automated Demand Response program, the decision to flip the light switch is made by the energy management system of the building. For both programs advanced notice of the Demand Response event is given.
The utilities communicate a Demand Response event to their customers by sending them a special signal. An Automated Demand Response system uses an electronic controller to receive and interpret the Demand Response signals. The signals are then sent to the building’s energy management system (EMS) which is preprogrammed to take actions to prepare for the Demand Response event. These preparations could include precooling a building, so that during the Demand Response event the air conditioner can be used less or turned off.
When the time of the event occurs, the signal sent by the utilities changes and the EMS is notified that the event is starting. Because this is an Automated Demand Response system there is no need to manually turn off or adjust any lights or systems manually. The EMS is preprogrammed to do all of those things for you. When the event is over the signal to the EMS will change and the EMS will adjust to resume normal building operations.
Automated Demand Response Benefits
There are many benefits to an Automated Demand Response program:
- Balanced Supply and Demand – Because the EMS is preprogrammed, the energy savings can be known in advance which helps the utilities balance the supply and demand of electricity during a Demand Response event.
- Decreased Manual Operation – The building operator does not have to manually adjust any systems or turn any lights off.
- Utility Support – The utilities encourage Demand Response programs by incentivizing them. Not only will the utilities help with the costs of the equipment needed to participate in a Demand Response event, but they will also pay for electricity conserved during a Demand Response event.
- Protected Power Grid – Participation in Demand Response events helps protect the electrical grid and prevent power interruptions.