WHAT IS DEMAND RESPONSE? | RDR-1 RENEWABLE ENERGY INTEGRATION & DEMAND RESPONSE
JOULE.SYSTEM 10 KW BATTERY STORAGE DEVICE | POWER SHIFT DEMAND RESPONSE

A customer or utility's "demand" is the total amount of kilowatts (kW) their load is drawing at any given time. Demand response tools help utilities level out the spikes of energy consumption during times of peak use, such as in the morning when people wake up and turn on lights and appliances; when water heaters recharge after morning showers; in the winter, when heaters kick on to bring the temperature of a home up to a comfortable level. All of these appliances are requesting (demanding) resources at the same time which results in a peak of energy being pulled off the system all at once.

Demand response uses technology and incentives to change electricity consumption by end-use customers. It can result in a reduction in energy consumption at times of peak use and at times of high wholesale market prices. Demand response offers benefits to both utilities and consumers in the form of increased electric system reliability and reduced price volatility. It uses a wide range of technologies offering a variety of options for both peaking and energy capacities across the electrical system.

In the Pacific Northwest, demand response also has the potential to help utilities integrate increasing amounts of wind power and renewable energy. Stronger wind often occurs at night, when there isn't a large demand for its energy on the grid; water heaters are charged after the evening bathing sessions; most homes have maintained a lower, more comfortable sleeping temperature throughout the night; and appliances and lights are turned off. Demand response can potentially help harness the power of wind by intelligently controlling storage devices. For example, water heaters can be equipped with a device so they can automatically turn on when a wind generator is producing power. This power is then stored as thermal energy (hot water) in the tank of the water heater until it is needed.

Mason County PUD No. 3 acquired a ten kW demand shifter as part of the Running with the Wind pilot project. PUD 3 worked closely with Demand Energy Network out of Liberty Lake, Washington to bring the “Joule.System” (Grid.Controller software + Grid.Balancer hardware) unit to the PUD 3 Johns Prairie Operations Center. The ten kW Grid.Balancer takes four to six hours to fully charge and can then generate energy for up to four hours. The unit can be programmed to do this on a regular schedule or manually controlled at any time through the web-based demand energy management software, Grid.Controller.

PUD 3’s ten kW Grid.Balancer was programmed to charge its battery bank during less-expensive light load hours from 1:00 a.m – 5:00 a.m. and to generate during more-expensive heavy load hours in two shifts 7:00 a.m. – 9:00 a.m. and 6:00 p.m. – 8:00 p.m. PUD 3 analyzed the efficiencies of the unit when the pilot project was completed.

Pictured is a ten kW Grid.Balancer which optimizes existing generation resources by creating load during off-peak times, stores the energy, and dispatches it on command back to the grid during periods of peak demand. Also pictured, is a 45KVa pad mount transformer required for the Grid.Balancer unit installation at this location.

Inside the Grid.Balancer, the re-generation subsystem powers a rotating motor assembly that transforms into an induction generator. The generator mechanism is a specialized DC motor with auxiliaries.

The storage technology found in the Grid.Balancer is chemical battery media; typically an advanced form of lead-acid battery technology or lithium ion.

Over a six-month trial period, with several specific timed scenarios, Mason County PUD No. 3 found the 10 kW Joule.System (Grid.Balancer + Grid.Controller) by Demand Energy to be a less efficient and more costly way to shift energy and shave peak demand than anticipated. To learn more about the tests and pilot project analysis, please view the Joule.System final report.