5.3 BEHIND THE METER Today’s electricity grid is no longer the exclusive domain of traditional electricity utilities supplying electricity to customers in the conventional fashion. Introduction to the Open-Access System The electrical grid is becoming a more open-access system that includes new generation, storage, and energy-management options that are situated “behind the electricity meter.” These systems are located within a customer’s home, facility, or property—but are nevertheless integrated within the grid as a whole.
Distributed Energy Resources (DERs) The meter used to be a firm and one-way demarcation point. The customer was charged for the electricity that flowed through the meter, and nothing flowed back in the other direction. The utility was not concerned with how the electricity was used. Today, that is changing, mainly because of the growth in distributed energy resources. DERs Distributed Energy Resources, or DERs for short, are sources of electricity connected to a local distribution system that can store or generate electricity or adjust consumption. DERs consist of the array of small-scale energy technologies that are increasingly commonly owned by consumers. They can include the following: •
Rooftop solar panels
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Home batteries
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Electric cars and chargers
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Smart home appliances (washers, dryers, refrigerators, home heating, AC cooling, pool pumps, etc.)
Applications DERs can talk to each other and respond to grid signals delivered via the internet or smart meters. They provide localized generation to help offset the need for increased centralized generation and transmission resources. They also enable customers to adjust their energy use based on electricity pricing and other signals. In some cases, it may be possible to utilize DERs to go off grid for a short period of time—like the way a microgrid operates—thus improving overall system reliability.
Electricity Canada | Electricity Fundamental in Canada: Student Handbook
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