What do small wind turbines, photovoltaics (PV), fuel cells, microturbines, reciprocating engines, combustion turbines, cogeneration (combined heat and power, CHP) and energy storage systems (batteries) have in common? They are all distributed energy resources (DER).

Distributed generation may serve a single structure, such as a home or business. It may be part of a microgrid (a smaller grid that is also tied into the larger electricity delivery system), such as at a major industrial facility, a military base or a large college campus. When connected to the electric utility’s lower voltage distribution lines, distributed generation can help support delivery of clean, reliable power to additional customers and reduce electricity losses along transmission and distribution lines.

Distributed energy resources are small, modular, energy generation and storage technologies that provide electric capacity or energy where needed. Because they produce less than 10 megawatts (MW) of power, DER systems can usually be sized to meet particular needs and installed on site. DER systems may be either connected to the local electric power grid or isolated from the grid in stand-alone applications. 

DERs can help meet electric grid goals, deliver energy savings and provide environmental benefits. Resilience, an emerging application for distributed renewable energy, storage and CHP, means providing power in the event that a site loses grid electricity. When integrated into a  microgrid, distributed energy technologies can also increase survival time during a grid outage when fuel supplies are limited.