A microgrid is a localized group of electricity sources and storage (batteries) that normally operate connected to the traditional grid. A microgrid can also disconnect to “island” away from the traditional grid as economic or physical conditions dictate.
A microgrid is a smaller version of the larger traditional electrical grid which is generally controlled by a local or state energy or power company. The traditional electrical grid exists to supply our electricity based on demand. In practice, a microgrid works in the same way, just for a smaller location or geographic area. A microgrid might serve a local community,commercial building, small business, or even an estate home which may have high power usage or issues with power loss due to weather or environmental issues concerns like fires.
To meet the electricity demands of its users, a microgrid must have one or more sources of power.
A microgrid can be powered by distributed generators, batteries, and/or renewable resources such as solar, wind, or water. With the increased cost of traditional grid power generated from fossil fuels, many microgrids are switching to a combination of solar plus battery storage to supply electricity that is cost effective and also has environmental benefits.
Microgrids are capable of becoming isolated from the traditional grid in the event of an outage. When the grid goes down due to anything from a severe weather event or fire, the microgrid can be disconnected or is landed in order to continue to produce electricity.
In some microgrid implementations, a secluded or isolated location may not be able to receive grid power. In this scenario a microgrid may be the only option and is used to supply power to the location as an alternative to the traditional grid. This is sometimes the case for countries, like Costa Rica.
The impact of losing electricity varies widely depending on who, what, or where the power loss occurs. If an individual home loses electricity for a couple of hours, it might not be much of an issue.However, a loss of electricity at a hospital is absolutely a life-threatening scenario.
There are a number of applications of microgrids, from powering emergency response buildings to providing grid resiliency for communities with a large population of people whose health would be put at risk by a prolonged power outage. These communities may also have no alternatives due to location of alternative emergency response buildings.
Microgrids achieve resiliency by islanding from the central grid during an outage. On-site generators then supply local customers. Buildings served by microgrids can act as electrified oasis, places of refuge where community members can seek shelter, charge phones, get medical help, buy food and fuel cars. An example of this would be a microgrid project for a fire department, a school, or military base.