Distrubuted Energy Res...

Introducing DERA

This post is part of the continuing Paths to Transactive Energy series. You can find them all listed by clicking on the matching metatag at the bottom of each post.

Demand response (DR) is the capability of systems that consume or supply power to respond to messages from the power grid. While DR can include using more or less power, or supplying more or less power, for most practical purposes it refers to nodes on the grid reducing the power they are using when they receive a request from a grid operator who anticipates a looming shortage of electrical power.

Many DR programs originally relied on phone calls and other manual processes. Automated Demand Response (ADR) has long been a request of the utilities. A decade ago, the California Energy Commission (CEC) and others funded a project to develop OpenADR 1.0. This work was contributed to the OASIS Energy Interoperation Technical Committee for incorporation into the Energy Interoperation specification. Energy Interoperation specification also defined the common transactive services for transactive energy. The OpenADR Alliance is a trade association that developed OpenADR 2.0 based on the OASIS specification, as well as maintaining interoperability and conformance requirements to insure interoperability of systems that use OpenADR.

The common transactive services (CTS) were designed to offer sufficient communication to operate the North American bulk power markets. Because CTS concerns effects on the market (services) rather than the mechanisms of operation, systems built around CTS can incorporate any technology. Components of CTS-based systems can evolve rapidly, can have their own security, and can support their own internal purposes. At the May 2016 Transactive Energy Conference, representatives of the open-source European initiative PowerMatcher acknowledged that their published services are fundamentally compatible with CTS.

In the fall of 2016, FERC proposed a ruling granting Distributed Energy Resource Aggregates full and unprejudiced access to wholesale power markets. The Federal Energy Regulatory Commission (FERC) is the US agency charged with the safety and reliability of the grid, encouraging energy markets between the states free of manipulation, promoting safe, reliable, secure, and efficient infrastructure. Distributed Energy Resources (DER) names decentralized systems that supply or store energy, as compared to centrally owned and operated generators. Practically, DER refers to systems attached to the distribution network, that is, the power grid that works within neighborhoods.  Many DERs are too small to draw much attention, although their cumulative effect is large and growing. DER Aggregates (DERA) refer to groups of DER the can be marshalled by a common entity. This proposed FERC ruling directs the utilities commission of each state to develop rules that permit DERAs to buy and sell power.

CTS is sufficient for DERAs to communicate with grid operators and with each other to operate a power grid. Energy Interoperation specifies communications sufficient to operate DR and CTS. Power interactions are abstracted to nine (9) services with a half dozen methods apiece. These services can be used to operate resource markets, where resources are commodities whose value is determined by time of delivery. Electric Power, the grid Ancillary Services, as well as the carrying capacity of the distribution network are each resources under this definition.