Community microgrids (CMGs) are getting more press these days as people recognize that they may provide an alternative to the traditional energy grid. The traditional energy grid has provided power to billions of people, globally, for decades. However, with bigger and more violent storms, like Hurricane Sandy, which left over 600,000 stranded without power; and incidents like this one in 2003, that left 50 million people in Canada and the northeastern US without power, and resulted in the largest blackout in history; the cracks are beginning to show. Along with the fact that the traditional grid is highly reliant on fossil fuels from big power plants, and highly susceptible to interruptions and attacks due to its centralized structure.

Enter Microgrids

Community microgrids are defined by the US Department of Energy as “a group of interconnected loads and distributed energy resources with clearly defined electrical boundaries that act as a single controllable entity with respect to the grid. [A microgrid can] connect and disconnect from the grid to enable it to operate in both grid connected or island mode.”

In other words, CMG’s connect smaller, decentralized sources of power and create a network of energy sources that feed into and out of local grid system, while also providing storage for clean sources of power like wind, solar, and biomass. A microgrid empowers a geographic area to use its own electricity when it’s available and to rely on the existing utility grid when it’s not. If the big grid flickers, the microgrid can hum along in “island mode” and keep critical functions running.

Here’s an example of the elements of a microgrid and how they might work together from Clean Coalition.

Why Community Microgrids?

Building community microgrids would not only make a city’s energy supply less vulnerable, it would also result in an energy savings of 15% – the amount of energy that is lost in transmission via the traditional grid over the miles of power lines that must be traveled before delivery. Another reason CMGs are an important technology is the fact that they integrate renewables into the energy mix and would encourage cities and regions to consider what kinds of energy sources they are choosing to power their lives – and give them control over the sources they choose. With community microgrids as an option, they’d be more inclined to choose a diverse mix of renewables like rooftop solar PV panels, biomass-fired power plants, wind turbines, and fuel cells. The result is a small-scale electricity-generating powerhouse that can balance and smooth variations in energy supply; provide services, such as voltage support and frequency regulation, to the conventional grid; and export electricity to the larger grid to make a profit or provide a boost during emergencies.

Legislative Support and Incentives

Two years after Hurricane Sandy hit, in his January 2014 State of the State address, Governor Cuomo announced the allocation of $40 million to New York’s Community Grids NYPrize competition with an aim to fund the creation of ‘independent, community-based electric distribution centers’. The competition is part of a larger $17 billion plan in New York that seeks to modernize New York’s grid, protect against vulnerabilities and outages during storms, and demonstrate what a cleaner and more resilient New York power system would look like.

In California, Governor Jerry Brown signed a bill reauthorizing the Self Generation Incentive Program in June 2014. Over the next five years, this bill will provide a total of $415 million dollars in incentives to develop renewable energy sources and storage on the customer side of the grid. The bill is also helping California reach its 2020 goal of adding 1.3 gigawatts of storage to its grids. The sources the bill is aimed at are all components of community microgrids, including wind turbines, waste heat to power technologies, fuel cells, and advanced energy storage systems.

Working Examples

Microgrids already make sense in areas with high energy prices, in remote locations (such as islands that have historically burned expensive imported diesel fuel for electricity), or facilities, such as military installations, that cannot risk losing power.

The Clean Coalition, a California-based non-profit, is testing a CMG concept that it hopes to make publicly accessible as a turnkey model for other cities. The testing ground is Hunter’s Point, a southeastern neighborhood of San Francisco, that makes an interesting study for a few reasons. The microgrid would generate most of its power from rooftop solar installations and in parking lots – about 50 MW.  The challenge is that this power would be added onto the grid in a location that was not initially designed for the task of local generation, but for long distance integration from remote power plants.

The Clean Coalition is working with the local utility, Pacific Gas & Electric, to model how to integrate bulk power onto the grid at the substation level. Once they release their results, later in 2014, and have the CMG up and running in 2015, they want to make the process as accessible as possible for other cities to replicate their process. 

The Hunters Point Community Microgrid would not only add a significant amount of renewable energy to San Francisco, but also contribute $233 million to the regional economy, avert $80 million in transmission-related costs over 20 years, reduce greenhouse gas emissions by 78 million pounds and save 15 million gallons of water annually.

Projects like these are paving the way for other cities and regions to understand the process, costs, and updates to their infrastructure that it might take for them to be able to choose clean, local power sources.