Distributed Energy Resource Technologies Overview
Typically, centralized power plants generate electricity and distribute it to end-users through the electric grid. Distributed Energy Resources (DERs) are localized sources of electric generation or storage used to reduce demand or provide supply. DERs systems can usually be sized to meet customers’ particular needs and installed on site. DERs systems may be either connected to the local electric power grid or isolated from the grid in stand-alone applications. DER is a term applied to a wide variety of technologies and consumer products, including fuel cells, microturbines, reciprocating engines, combustion turbines, cogeneration, photovoltaics (PV), and energy storage systems.
- Power Plants
- Distributed Generation/Behind-the-meter Microgrids
- Residential End-users
- Commercial & Industrial (C&I) End-users
- Switch - Connect or Disconnect to Utility grid
Benefits of Distributed Energy Resources
Reduce Energy Cost
In comparison to paying for power at the rate offered by the electric utilities, customers could reduce their monthly energy bills with the on-site power generation option using DER technologies. Customers can save even more by using the heat associated with the generation of power that is ordinarily wasted, thus avoiding the purchase of the natural gas that would have provided the heat.
DER technologies have the opportunity to provide environmental benefit by lowering emissions. For example, natural gas generators emit 18% less carbon, 39% less smog-forming (NOx) emissions and 93% less particulate matter (PM) 10 than diesel generators. Natural gas fuel cells emit 50-69% less carbon, nearly 100% less NOx emissions and 100% less PM 10 than diesel generators. Additionally, DERs utilizing renewable fuel can have zero greenhouse gas emissions, therefore offsetting what would be emissions generated from the electric grid.
Increase Energy Resiliency and Power Quality
As the world is experiencing extreme weather events such as heat waves, wildfires, droughts, and storms, relying on only one source for energy from the power grid could be insufficient to meet the customers' needs for energy resiliency. DER technologies can help customers keep their lights on during the rolling blackouts and Public Safety Power Shutoff that could last longer than 24 hours. Additionally, DERs in concert with small power storage systems, can offer improved power quality. Harmonics, voltage sag, and momentary outages (enough to trip expensive computers) can all be mitigated through the use of such systems.
Distributed Energy Resources can be used as a physical hedge to lock in the cost of power, rather than expose your business to the fluctuations of the electric energy market.
Microgrid Installations in California
As of October 31, 2021, there are 84 microgrid installation sites in California with a capacity of 485MW. 90% of the microgrids installed in California utilize more than one type of distributed energy resource. The technology mix includes either combining various types of generation technologies or integrating storage technology with one or more generation technologies.
Source: U.S. Department of Energy
Microgrids Capacity Percentages by Technology
Microgrids Capacity by Technology and Year (kW)
- Natural Gas
- Wind, Fuel Cell, Hydro
- Storage Capacity