Talk about the importance of microgrids has reached a fever pitch in recent years. Many have discussed the need for industrial campuses, military bases, universities, and many other critical loads to operate when isolated from the utility grid — or, in other words, as a microgrid. Is this some fancy new smart grid concept? Hardly. A microgrid is essentially any isolated electrical system that has its own generation source, and they’ve been in existence practically since we began using electricity as an energy source. The first true microrgrids were remote, built for cities or businesses that didn’t have an economical way to tie into the nearest utility system. Oil refining, mining, lumber and other business brought generators on site to provide the power they needed to operate.

“Quasi” microgrids — where loads use utility generation as their primary source of electricity, but also have local back-up generation sources if there’s a disruption in their utility service — are not a new concept, either. They emerged as certain load types (think hospitals, airports, critical manufacturing processes, and more) grew very dependent on constant energy to operate. These facilities typically brought in two different utility sources of power to assure that if one failed, the other could be used as a back-up. Onsite generation was used as an emergency backup in case of a loss in both utility sources.

So…if microgrids have been around for decades, why are they such a hot topic today?

The difference is advancements in renewable energy generation and energy storage. Renewable energy generation has only recently have become efficient enough to provide the volume of power that facilities demand. With this increase in efficiency, it’s become practical to use renewable energy generation as a back-up, or even primary, source of generation for important loads. Renewable energy is also becoming more reliable because new battery-based stored energy systems ensure the microgrid can meet demand when production of intermittent renewable sources like wind and solar energy is low.

This combination has drawn the attention of many operators of critical facilities, because the energy source holds the potential to be cheap, secure, readily available, and green. The U.S. military, for one, sees potential in these new energy technologies, as do electricity users ranging from data centers to universities. Though industry continues to advance these technologies, they are making their way into real-world microgrid applications. S&C recently worked on a microgrid project at the Santa Rita Jail in California where both renewables and battery-based storage are applied.

What do you think of the current state of microgrids? Have we reached a point where we’ll begin to see broader use of microgrids incorporating renewables and stored energy, and if not, why not? Please use the comment form to share your thoughts.

This blog was originally published on S&C's Blog and was republished with permission.