What is A Microgrid?
As the world grapples with environmental awareness and the adverse effects of climate change, technological advancements have been devised to enhance and supplement the traditional power-generating grids and supplying methods.
One of these solutions is the microgrid. So, what is a microgrid? And how does it work? In this article, we are set to unpack the microgrids and their working mechanisms. Keep reading!
Microgrid Types
What are the most common microgrid types? The following are the major categories of microgrids. Each category of the microgrid features special applications and characteristics.
1. Grid-Connected Microgrids
This microgrid category connects to the main grid and it is designed to work analogously to it. The grid-connected microgrids are capable of providing power to the main grid and also draw power from it when necessary.
Additionally, it can address other issues such as potential capacity, demand response, voltage regulation, and reliability. They are commonly used in hospitals, universities, and fire stations, among other larger institutions.
2. Islanded Microgrid
The island microgrids operate separately from the main grid. They are designed to generate and provide power on a small scale.
3. Off-grids or Remote Grids
These microgrids are isolated from the utility grid and they function in an island mode. Usually, this system lacks affordable and available transmission and distribution infrastructure close by. The off-grid microgrids are best suited for powering operations in hard-to-reach geographical areas.
4. Community Microgrids
The community microgrids are designed to provide power to a certain community in a specific geographical area such as a small town or neighborhood.
5. Networked Microgrids
A networked microgrid is made up of multiple DERs, that are connected to one utility grid circuit segment. It is designed to serve a wide geographical region.
The networked microgrid system is usually managed and optimized by a control system that operates and coordinates every grid connected to a different tier of the hierarchy. The networked microgrids are usually installed for use by communities or smart cities.
How Do Microgrids Work?
Typically, electricity grids connect to a central power source and distribute power to homes and buildings using overhead or underground cables over long distances. Unlike the electricity grids, microgrids generate power on-site. However, depending on the size of the microgrid, the power generated can be distributed to nearby businesses, factories, or homes.
Usually, microgrids use a combination of renewable energy sources such as solar or wind and gas generators to generate electricity. Additionally, the microgrids must incorporate battery systems for power storage for later use such as during outages or grid peak hours.
For improved efficiency, microgrids are managed using intelligent and sophisticated software which helps in regulating power production depending on the level of production required. In addition, the microgrids require hardware which is crucial for distributing the power.
An example of a practical microgrid is in The Brooklyn Navy Yard in Manhattan, New York. The microgrid system provides power to important facilities such as the New York City Fire Department's training academy. This microgrid system generates electricity by combining wind turbines, solar panels, and gas generators. The microgrid has reduced the Yard's overreliance on the grid systems, thus increasing resilience during outages.
Another example of a microgrid system is located in the Block Island of Rhode Island. It was the first community-based microgrid project in the US.
The microgrid system is powered by wind turbines, solar panels, and diesel generators. It has significantly reduced the island's reliance on the grid and fossil fuels.
Microgrids: Beneficial or Not?
Microgrids are beneficial due to their ability to reliably and stably provide power. The systems generate power from multiple sources which aids in mitigating the impact of power outages. Why should you build a microgrid?
1. Cost savings on Energy
Building a microgrid enables you to hugely save on the costs of energy as you use a combination of renewable energy sources, i.e. solar, wind, and energy storage systems. By cutting off the use of fossil fuels, microgrid systems help to minimize energy costs.
2. Energy Independence
Microgrid systems give you energy independence since you can generate and store power. These systems come in handy for people living in remote and off-grid locations where power access is limited or non-existent.
3. Power Reliability
Microgrid systems provide a reliable power source, especially for areas that experience frequent power outages or have unreliable on-grid infrastructure. By generating electricity and storing energy, microgrid systems ensure that critical loads are always powered.
4. Environmental Sustainability
Building microgrid systems greatly reduces carbon footprint through generating and storing renewable energy. It helps you reduce your carbon footprint, thus reducing your impact on the environment which is geared towards sustainability goals.
5. Resilience
In the face of natural disasters, extreme weather conditions, or on-grid disruptions, a microgrid system will provide resilience. The system continually provides power to critical loads, especially when the main grids are down.
Cost: How Much to Build a Microgrid?
The cost of building a microgrid varies depending on the location, size, and complexity of the system. However, one major driver for the cost of the microgrid is its power generation capacity. According to a study by the National Renewable Energy Laboratory, the average cost of a microgrid in the USA is approximately $2 million to $5 million per megawatt (MW).
Other factors that might influence the costs of the microgrid include Government incentives and other clean energy incentives. Some of the states offering incentives for microgrid installation include California, Maryland, New Jersey, Connecticut, Massachusetts, and New York. These incentives and rebates can significantly lower the cost of building a microgrid.
Is Scale the Main Difference Between Microgrids and the Grid?
Scale is a major difference between the grid and the microgrid. However, there are other major differences.
1. Scale
Typically, a microgrid is a miniature of the grid system. It functions similarly to the grid system. Here comes the difference; grid systems supply electricity on a large scale to thousands and millions of consumers, while Microgrids supply electricity to a very minimal group of consumers.
Other differences between the grid and the microgrid system include:
2. Autonomy
Generally, the grid systems are centralized and are interconnected to various regions or countries, and managed by utility companies.
A systematic failure can affect an entire region. Microgrids are independent because they disconnect from the grid and operate on their own, during outage emergencies.
3. Purpose
The grid systems are designed to produce and distribute mass energy to a large population.
On the other hand, a microgrid's purpose is to achieve energy independence, control, and resilience. Microgrids are aimed at serving critical infrastructure such as hospitals, remote areas, and areas predisposed to calamities.
4. Operation/Functionality
The Microgrids integrate clean energy ideology with a flexible and advanced operation and control mechanism, which aims at improving the performance of the grid's peak load management and reliability.
Additionally, the microgrid enhances the resiliency of the grid and it is adjustable to the dynamics of the Microgrids.
Is My RV Solar System a Microgrid?
Most people who do not understand the concept of a microgrid are likely to call a rooftop solar panel a microgrid. Note, that a microgrid will keep electricity flowing even when the main grid is out.
If your RV has only solar panels or a backup generator, it is not a microgrid yet. However, if the RV solar system is capable of providing power 24/7/365 or continuously when you are using the RV, then it is a microgrid.
As such, your RV solar system must generate electricity through solar panels, have a storage system for future use, and have an energy management system or a charge controller to regulate the flow of electricity to the battery.
Additionally, it must have an inverter to convert electricity from DC to AC. The complete RV solar system is self-contained and allows the RV to operate self-sufficiently from external power sources, thus qualifying to be a microgrid.
Conclusion
From the foregoing, microgrids seek to provide energy solutions to communities, institutions, and companies aiming at power independence and sustainability. Microgrids are built to seamlessly integrate with renewable energy sources such as wind, solar, and hydroelectric power. Microgrids help in reducing overreliance on fossil fuels, thus contributing to combating climate change.
Frequently Asked Questions About Microgrid
1. Can my home energy system be considered to be a microgrid?
Yes. On a small scale, your home power system can be ranked into a category of microgrids. However, it is not equal to the community microgrid in terms of capacity and scale. A home system serves one household, while a microgrid serves on a larger scale. While both systems are microgrids, they differ in complexity, scale, and coverage.
2. What is the difference between an off-grid microgrid and an on-grid Microgrid?
Off-grid microgrids or the island mode are more common in remote regions or where it is impossible to construct main grids. However, lately, they are increasingly becoming popular in providing autonomy and resilience for various communities. The on-grid microgrids integrate into the grid systems to supplement the grid power. To integrate perfectly with the grid systems, on-grid microgrids require careful planning and coordination with grid utility companies to ensure no interruptions to the larger grid system.
3. What is a microgrid controller?
It is a device for monitoring and managing energy resources and power loads on the microgrid. It helps in maintaining grid stability and minimizing operating costs.