5 Common Questions About Microgrids Answered

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1.?What are microgrids?

Although microgrids have been around for decades, the technology has matured over the last 10 years and become an important part of energy plans that focus on reliability, sustainability and cost savings. Therefore, more and more people are hearing the term and asking, “What are microgrids?”

Short answer:?A microgrid is a local cluster of energy resources within a defined footprint, such as a building, campus or neighborhood. Microgrids keep the power flowing to nearby customers when the central grid fails. They also act as a tool to help energy customers manage costs, participate in energy prosperity and reduce carbon emissions. It’s hard to describe a typical microgrid because they vary by size, depending on the need they serve. They also differ in terms of the kind of power generation they use depending on owner preference, price and availability of resources. A sunny locale may warrant solar panels, for example. A building that needs consistent power, such as a hospital, may include diesel or natural gas generators in its microgrid. Some microgrids have battery storage, others do not.?

2. What role do microgrids play during a power outage?

Hurricanes, wildfires and deep freezes can devastate the central electric grid. The?US experienced 70% more power outages from 2010-2019 than in the preceding decade. And since then, incidences have mounted that have left millions without power — among them Hurricanes Laura?and Ida, Winter Storm Uri in Texas and wildfire-related utility shutoffs in California.?

Short Answer: Microgrids keep the power flowing to their customers by islanding or disconnecting from the central grid when it fails. The generation resources within the microgrid — perhaps solar, storage, batteries, wind, natural gas, diesel or combined heat and power — then kick in to provide power to the local customer. In an advanced microgrid, the shift from grid to microgrid happens seamlessly, so that those inside microgrid-protected facilities may be unaware that there is a power outage on the grid. Microgrid Knowledge has extensively covered microgrid performance during power outages. Here are a few articles:

• Facing Off Climate Disaster in Louisiana: The Tale of Two Microgrid Champions
• Hurricane Hanna Demonstrates Value of Microgrids for 30 MW of Texas Load
• Nature Offers Real-Life Drama During Microgrid Tour in Wisconsin

3. Who uses microgrids?

Short answer: Any operation that benefits from local power, especially those that need their energy to be reliable, clean or cost-effective.

Longer answer: Microgrids are used by a range of entities — communities, hospitals, research universities, businesses, military installations, critical facilities (such as fire stations or water treatment plants), agricultural facilities, airports, ports and transportation systems, government buildings and remote locales. Utilities also install microgrids to augment their systems or serve specific customers.

• Hospitals Need Microgrids, Not Just Backup Generators
• Hospitals need a microgrid to ensure they have reliable backup power in a time of crisis. Microgrids can power a hospital for weeks or months at a time.

4. What are the different kinds of microgrids?

Short answer: There are two basic types of microgrids: connected and remote (off-grid). Grid-connected microgrids are common in the United States and other places with a well-established central grid. A grid connection allows the microgrid to buy energy and services from the grid when that’s the best choice; for example, during times of the day when grid prices are low. Conversely, the microgrid can sell power and services to the grid when prices are high or the grid is under strain, providing a revenue stream for the microgrid owner.

Most microgrids are stationary, but there are also mobile microgrids installed on trailers that can be moved to disaster areas or military outposts. Sometimes microgrids are described based on the dominant fuel or technology they use — renewable microgrids, fuel cell microgrids or natural gas-fired microgrids. Modular microgrids are those that can be built in a Lego-like fashion over time as expansion is warranted. Microgrids-in-a-box are partially assembled in the factory for easy installation on-site. Nanogrids are small microgrids that serve one building or house.

5. Are microgrids expensive? How do I finance mine?

Short Answer: Microgrids are increasingly being built under energy-as-a-service models, where the host puts no money down, or a small amount, and pays for the services from the microgrid through a monthly charge. Microgrid developers strive to keep the monthly charge below what the customer would pay their local utility for power, but a range of factors can affect the pricing. Under these arrangements, a third party usually owns, operates and maintains the microgrid on behalf of the host. Financing also is widely available under other scenarios, including through leasing.

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