What Is a Microgrid?

When a storm or disaster impacts the traditional power grid, a microgrid can keep the power flowing.

A microgrid is a small, self-sufficient power grid designed to provide electricity to a nearby area. The power could come from fossil fuels, solar panels, wind turbines and/or hydropower and geothermal sources.

Typically, microgrids connect to the main power grid and get their power from it unless that grid goes down or is preemptively shut down due to a fire, storm, hurricane or other event. In these cases, the microgrid can be disconnected from the main grid using a microgrid controller and operated in “island mode” to provide power during the days or weeks when the main grid can’t.

In this way, microgrids help ensure a more reliable electricity supply. They may be designed to serve a neighborhood, a hospital, a college campus or a large industrial facility.

In some instances, microgrids are completely separate from the traditional grid. These microgrids may provide power to a facility or a community in a remote location that could not otherwise get electricity. Military bases may have microgrids that don’t connect to the grid for security reasons.

The growing importance of microgrids

In California, wildfires and high-risk weather conditions have occasionally forced utilities to shut down power transmission. In 2019 a preemptive shutdown left millions without power. And that’s the danger of centralized power generation in a nutshell: With power plants located far from most end customers, the grid is heavily reliant on transmission and distribution infrastructure that’s vulnerable to fires, storms and other threats. California is now planning to use microgrids to increase its energy resilience.

Generating power closer to where it’s being used makes sense on several fronts. According to the U.S. Energy Information Administration, about 5% of the energy generated in this country is lost in the transmission and distribution process. Eliminating the need for long-distance transmission reduces that energy loss.

Sometimes companies or neighborhoods use microgrids to cut electricity costs. A business might rely on the traditional grid during the overnight and morning hours when power is relatively cheap, then switch to its microgrid for the more expensive afternoon and early evening hours.

Microgrid evolution

The majority of microgrids today are powered by fossil fuels, but interest in the use of renewable sources such as solar and wind power is soaring. The trend has been spurred by the development of more affordable, larger-capacity battery systems that can store excess energy generated. The stored energy can be tapped as needed by the microgrid owner.

One development that could increase the use of microgrids is the introduction of controllers equipped with artificial intelligence (AI). The AI system could optimize use of the microgrid’s power, analyzing historic energy demand and current weather forecasts to determine when to stay on the main grid and when to switch to the microgrid.

The power of these distributed energy systems is becoming clear. In 2019 alone, 546 microgrids were installed according to global consultancy Wood Mackenzie, more than in any previous year.

A mobile microgrid can be set up or transported wherever it’s needed. When a mobile microgrid fails, United Rentals can provide a seamless transition between the power source and our temporary generators. Call us at 833.426.1188 to learn more.

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