What is a microgrid, and why do you need one?


Aries Clean Energy

Publication Date

November 12, 2018

A city, community, or company that has a wood waste and biosolids disposal challenge may be a candidate for adding a clean, renewable gasification system to its microgrid.


The U.S. Department of Energy (DOE) defines a microgrid as local energy grid with control capability, and that means it can disconnect from the traditional grid and operate autonomously. A microgrid can be powered by distributed generators, batteries, and/or renewable resources like a gasification plant or solar panels. Depending on how it’s fueled and how its requirements are managed, a microgrid might run indefinitely.

According to the DOE, the US suffers more blackouts than any other country in the developed world. The DOE also reports that power outages lasting more than an hour are increasing and cost American businesses approximately $150 billion a year. The DOE says that North America is comprised of two major and three minor alternative current (AC) power grids. All microgrids supplement the owner or the grids with their excess power. This is practical and reliable in the case of storm damage, grid failure, or sabotage.

In the power industry, an electrical grid is a network for delivering electricity from the site where the electricity is generated to consumers like you and me. This process is called transmission.

Before the grid was as well organized as it is today, smaller “grids” (or power plants) were built near a consumer or in a particular geographic area. So microgrids are not a new concept but some of the technology that increases electrical efficiencies available today may be new to the grid and its contributors.

Microgrids can be supported by generators powered by burning fossil fuels, collecting wind, solar or water energy, nuclear reactions, or gasification. They are often used to provide backup power or supplement the main power grid during periods of heavy demand or damage. The practice of using microgrids is known by other names you may have heard, such as distributed, dispersed, decentralized, district, or embedded energy production.

Buildings equipped with electric generation capabilities through solar panels and generators can also generate energy and revenue during downtime because they make their own power behind the meter. The same goes with a microgrid location only excess power is usually sold back to the grid. By connecting together with smart grid deployments, excess energy can be used to create a new revenue stream in addition to providing more power.


To understand how a microgrid works, you first need to understand how the big electric grid works.

The grid connects schools, hospitals, homes, businesses and other buildings to central power sources that allow us to use appliances, heating and cooling systems, and electronics. This is great until part of the grid needs to be repaired, and then that affects everyone as we do not want to live without our electronic devices such as cell phones and computers.

This is where a microgrid can help because it can generate power whether it is connected to the big grid or not. This makes a microgrid a necessity during times of power interruptions, such as a damaging storm or other unforeseen power outages.

Some of the pros surrounding microgrids are financial benefits, reliability, faster construction, and jobs. Microgrids can be money savers when the initial construction and start-up costs are paid, and its electrical generation eliminates traditional power bills thus freeing up funds. Most microgrids also cut down the distance electricity must travel making power transmissions extremely reliable. Construction is faster than traditional plants due to the smaller size. Both construction and day-to-day running of the plant create new jobs.

Cons can include resistance from utilities, regulations, and evolving technology. Energy flows both ways via the grid and microgrid. Users need power from the grid, and by means of renewables, users also sell surplus energy back to the local grid. With new power locations comes the likelihood of additional legislation to guard that new power source and/or the local community from misuse or abuse. Microgrid employees sometimes struggle to keep up with changing laws as well as the changes within the technology or user software itself. Replacing the grid would be too costly, so the microgrid is a viable addition to our power-hungry world.


A microgrid not only provides backup for the grid in case of emergencies, but can also be used to cut costs, or connect to a local resource that is too small or unreliable for traditional grid use. The term “micro” does not mean a small amount of electricity as it refers to a smaller power generation site when compared to large power plants. A microgrid allows communities to maintain the quality of life that comes from electricity, and, in some cases, become more environmentally friendly.

A city, community, or company that has a wood waste and biosolids disposal challenge may be a candidate for adding a clean, renewable energy gasification system to its microgrid. A downdraft gasification plant can take wood and biosolids and convert them into a syngas that is combusted to generate green power behind the meter. A fluidized bed gasification plant can run entirely on biosolids and generate power. Both gasification technologies divert waste from landfills and lowers a community’s greenhouse gas levels and carbon footprint.

A manufacturing plant or university that utilizes a microgrid is better protected from power interruption by a human threat and less likely to be a target. The control that a microgrid offers allows the plant to balance the demand on utilities for peak production times. Although microgrids are mainly electrical systems, they can also contain a thermal energy component, such as combined heat and power, which will also save the company money in the long run. Also, the manufacturing facility or microgrid owner may qualify for green initiatives backed by the US government.


A microgrid comes in a variety of designs and sizes. A single facility like the Santa Rita Jail microgrid in Dublin, California, is powered entirely by a microgrid. Or a microgrid can power a larger area. For example, in Fort Collins, Colorado, a microgrid is part of its larger goal to create an entire area that produces the same amount of energy it consumes.  The microgrid at the University of California at San Diego not only saves the school millions of dollars but also provides uninterruptible power to its labs and learning opportunities to its students. The school can now use a Cloud projection technology to calculate how much solar energy will be generated on a particular day (much like meteorologists predict the weather) and reallocate extra solar-generated power to other areas as needed.

Additional resources

https://www.youtube.com/watch?v=TEx4gm3523I (Univ. of CA San Diego)

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