Ensuring continuous supplies of electricity are critical to daily living, but recent man-made and naturally occurring events have demonstrated the fragility of the nation’s electrical generating system and transmission grid. Grid power outages of several hours or several days result in severe economic disruptions. Weather-related events that knock out grid power are predicted to increase, and their economic costs are expected to rise. Recent notable weather events such as Hurricane Maria in Puerto Rico (2017), and Superstorm Sandy in the eastern US (2012) are prime examples of the severe consequences of extended electricity disruptions when the grid is substantially affected.
Reducing or eliminating reliance on the central electrical power utility and generating grid are the focus of microgrids. Microgrids are a system of decentralized electric power generation and distribution. Serving a smaller number of users in generally smaller area, these self-sustaining systems have been used successfully for decades by both the military as well as some isolated communities in Alaska and other areas around the world.
Microgrids are typically a four-part integrated system: A prime power source- renewable electricity from solar or wind, storage capacity in the form of batteries or other technologies, fossil-fueled backup systems such as diesel generators, and advanced integrated control systems.
The back-up generators serve an important role when renewable prime power sources are intermittent, or not available due to weather, as well as when storage has been depleted. The integrated system enables the operator to minimize the use of more expensive fossil fuels as a prime power source but keeps them at the ready to ensure continuous electrical supply.
Whether decentralizing the generation of electrical power and its distribution to be less susceptible to grid outages or be more powered by renewables, microgrids are emerging as an important option in settings everywhere. That’s because microgrids include the renewables that you want with the reliability that you need.
Cities, colleges, industrial campuses seeking to reduce or eliminate reliance on the centralized electrical grid and/or establish new resiliency and climate change adaptation strategies are increasingly turning to microgrids.
While diesel engines have a long history of prime power source for generating electricity, the cost and access to continuous supplies of fuel can be an issue. Microgrids in Alaska have proven their value, as it is the state with the highest electricity costs and for many communities in remote locations, diesel generators have long served that role. To help lower costs and use the available, almost-free renewable sources of electricity, some communities in rural Alaska use windmills and solar panels for prime power while retaining diesel generators for most of their electricity needs.
For other communities, needs are more focused on creating an alternative to central grid-generated power from fossil fuels to pursue more sustainable renewable sources of electricity such as wind and solar.