What Makes a Microgrid Resilient?

Over the past three months, Mother Nature has shown her force with the hurricanes that hit Texas and Florida and tore through the Bahamas. These destructive weather patterns test our energy grids, and highlight how susceptible they are to outside forces. Nearly a month and a half after Hurricane Maria hit Puerto Rico, 60 percent of the island is still without power, according to a recent NBC Report. It took several weeks to fully restore power to the 36% of Florida residents who went without after Hurricane Irma, according to a report by CNBC.

These natural disasters have prompted renewable energy leaders, such as Tesla’s CEO, Elon Musk, to challenge our thinking about energy production and storage. His solution to Puerto Rico is to install more solar with battery storage, basically creating a distributed energy network of microgrids. The question you may ask is, what makes a microgrid more resilient than the grid that is currently in place?

  1. A microgrid can create and store its own power from multiple distributed energy resources (DERs). These DERs are typically a combination of renewable energy sources, such as wind and solar, and a high-efficiency engine that runs on natural gas. In addition, there is power storage available via a battery. In the event of the loss of grid power, the microgrid will have up to three power sources to rely on.
  2. The key to a successful microgrid is a smart power management system, or a microgrid controller. This controller can detect interruptions in the main grid and put the entire system into island mode. This means that the system will disconnect itself from the main electrical grid and operate with its own energy resources. The controller also receives weather data so the system can anticipate the risk of an outage, in which case it will prepare for an emergency by fully charging the batteries either with grid power or with power from one of the DERs.
  3. Since microgrids are a combination of distributed energy resources located at the point of use, there are no transmission lines. All connections are done underground or inside a structure, where they are protected from high winds and flooding. This eliminates the risk of being disconnected from the grid and losing power.

Recently on the CBS 60 Minutes segment “Puerto Rico’s Storm of Misery,” Lieutenant General Todd Semonite was quoted as saying, “I think the majority of people will hope to have their power up in January, maybe February. I would predict (there are) some people on that last mile that are (going to) be close to spring or summer” before their power is restored. This would be four to nine months after the storm before power is fully restored on the island.

We are dependent on energy; that point is undisputable. In a world where dependency can lead to risk if the right factors were in play (storms as we’ve seen recently, but perhaps cyber-attacks or even terrorist attacks), how would our electrically dependent nation respond to such crisis? This is the type of important question that is being asked. Perhaps Puerto Rico is an opportunity to demonstrate the energy grid of the future.