Earlier this year, GAI became a partner of the ELM MicroGrid. We’re excited to now be a microgrid installer and have started telling all our business contacts. In each conversation, their first question is always: ‘What exactly IS a microgrid?”
According to the National Renewable Energy Lab (NREL), “A microgrid is a group of interconnected loads and distributed energy resources that acts as a single controllable entity with respect to the grid. It can connect and disconnect from the grid to operate in grid-connected or island mode. Microgrids can improve customer reliability and resilience to grid disturbances.” (source: https://www.nrel.gov/grid/microgrids.html) Put simply, it is a miniature of the traditional power grid, pulling power from mulitple sources in order to provide a reliable electric source.
A town, neighborhood, or commercial enterprise can supply itself with electricity from the sources of its choice, depending on which source makes the most sense at the given moment. This includes green energy systems, battery backups, and even buying electricity from your utility company. The use of grid power is still possible, but the community attached to the microgrid can enter a self-supply mode in times of blackouts or higher prices such as when “Time-of-Use” rates or demand charges are a factor.
Let’s look at a diagram to get a better idea of the moving parts and pieces a microgrid.
image source: https://www.greencitytimes.com
Every residence or facility can have a different combination of electric loads, and you can see in the image above that the microgrid is shown as a hub which acts as the source for all of those loads. It is still attached to the utility, but not *only* the utility. It can combine sources of power and choose the best economic balance, or even become independent at will. When utility power is shut off or not available, the loads attached to the microgrid are powered from its other distributed-generation (DG) sources.
In the diagram, we see solar, battery back-up, wind turbines, and a generator. Microgrids can combine and coordinate all of these resources, using all of them in combination or just a select few of them based on the scale of the demand. The DG sources being used by a microgrid supply power to a battery for storage. They can remain functional even without the grid. This means that if the power goes out on a sunny day, your solar array may carry the demand and any over-production will charge your battery. Or if you lose electricity at night, the battery will meet the demand and can be re-charged by a wind system or the generator until the sun rises again. A well-designed microgrid (with a properly-sized and balanced battery and solar array given the facility’s power usage profile) could function for long periods of time even without a generator.
If you run just fine from the grid, why might you want to spend the money on this type of infrastructure? “For behind-the-meter applications, the most common use cases are: Peak shaving to limit grid purchases/demand charges, time of use shifting to limit grid purchases/demand charges during specific intervals of time when utility rates/demand charges are higher and backup power,” says Kelly Stickelmaier from ELM Microgrid.
“Peak shaving” is an energy management strategy applicable for utility rate-payers who are incurring “demand charges”. During “Peak Shaving,” a consumer draws from the battery storage as long as the facility’s demand is above a predetermined threshold. The microgrid controller does this automatically, limiting the purchased utility power and satisfying any additional demand from the battery. This allows that facility to pre-determine (and therefore budget for) their maximum peak demand.
“Time-of-Use” (ToU) rates are just what the name implies: your price for a unit of energy varies depending on the time of day you are using it. With a microgrid that has your specific utility rate plan loaded into its controls, a battery can supply electricity during higher price “peak” times of the day, thus avoiding the peak upcharge.
The benefit of backup power seems self-explanatory but as an exercise let’s list a few reasons it’s great.
First, when power goes down in a commercial setting, there’s no loss of production when the microgrid steps in. Machines don’t stop, internet and phones don’t quit, lights don’t go out, freezers stay cold, all seamlessly. Within milliseconds, the inverter switches to batteries for their power source, no starting of a generator required.
Second, imagine you have time-of-use rates and are about to enter a“peak” time period. You’re now being charged dearly for the same energy you were using an hour ago, but now the utility company rate strategy to discourage unnecessary consumption during periods of peak demand results in temporarily increased prices. You limit or avoid having to buy that overpriced electricity by supplying yourself from battery through the duration of the peak period.
It may take a long time for microgrids to become a standard in residential communities, but commercial facilities have an immense opportunity today to use a microgrid to increase energy security and manage their energy costs.
Green Alternatives, Inc has partnered with ELM to design and install microgrids. Are you ready for your company or community to reap those benefits? Contact us and we’ll assist you on your journey to renewable, sustainable, independent energy.