These distributed energy resources (DER) can reduce the amount of large-scale renewable generation needed, reduce the amount of transmission and distribution network build, provide Frequency Control Ancillary Services (FCAS), emergency power supplies (individually and through the Reliability and Emergency Reserve Trader (RERT) scheme), as well as flexible demand, including demand response. Offering such an array of possibilities, DER can be seen as the Swiss Army knife of the electricity system. DER is the Swiss army knife of the electricity system
