Distributed energy resources represent a small but growing part of the electric energy resource mix. Electric utilities and RTOs are working alongside others in the electricity industry to explore how to optimally integrate DERs into markets and operations to help maintain system reliability.
- DER are small electric generation or energy storage units connected to the local electric distribution system.
- Most DER are installed on the customer’s side of the electric meter. RTOs are learning about DERs and what information is necessary to maintain reliability including size, location and when they were installed.
- Some DER participate in wholesale energy markets, and when they do, MISO and PJM gain visibility into their operation and how to coordinate with them.
- The more DER in an area, the greater potential impact on the high-voltage transmission system.
- DER can be powered by a wide variety of fuel sources and can range in capacity from a few-kilowatt residential unit, to a few-hundred-kilowatt commercial unit, to a generator as large as 20 megawatts. One megawatt powers about 800 homes
Utility-scale solar, smart homes and communities, rooftop solar, electric vehicles (EVs) all represent rapidly changing and emerging technologies. This growth of DERs poses a host of new opportunities and challenges electric system operators.
According to MISO, DERs can be organized into three technology categories:
- Demand-side management, which may include energy efficiency measures, load-modifying resources and demand response (e.g., smart thermostats, large water pumps, variable-speed motors) or ways to control electric vehicle charging. This usually includes incentives to help shape the consumption of energy from the grid to provide value to the end user and/or to the grid.
- Distributed generation, which is generation connected to the distribution grid. It may be in front-of or behind the meter, and may be used to reduce customer net load or to provide energy or services sold into the grid.
- Distributed storage, which is customer or utility/third-party-owned resources, located on the distribution system or behind the customer meter that can withdraw energy for later use or injection onto the grid.
For more information about DERs, please visit https://www.misoenergy.org/stakeholder-engagement/issue-tracking/distributed-energy-resources/