Microgrids deliver reliable electricity and strengthen resilience of communities and critical facilities by maintaining essential services during outages and providing primary power in places without a larger grid. They can also help manage cost and improve performance by using local energy resources and reducing exposure to fuel price volatility or outage-related disruptions.
Across the United States, microgrids support hospitals, military facilities, manufacturing centers, campuses, and islands. Increasingly, new microgrids are under development to support residential, industrial, and service-sector needs.
Microgrid systems can be designed around a community's economic or reliability goals. For example, in Cordova, Alaska, a microgrid helps balance the fluctuating load of the seasonal fishing industry. In Adjuntas, Puerto Rico, a community microgrid kept the power running for 9 days during a 2022 hurricane. In Estes Park, Colorado, a microgrid supports wildfire response and the local hospital while reducing peak load impacts on the utility.
What is a Microgrid
A microgrid is a group of interconnected loads and distributed energy resources within clearly defined electrical boundaries that acts as a single controllable entity with respect to the grid. Community microgrids are often designed to operate primarily in grid-connected mode, with a point of connection to the bulk system.
In practice, microgrids can range in scale from a single building or campus to an entire community. While many community microgrids operate grid-connected during everyday conditions, others are designed to operate independently at all times, particularly in remote or isolated locations. Across these settings, microgrids are used to improve reliability, support critical services, integrate local energy resources, and maintain power during grid disruptions.
Microgrid Core Components
Microgrid systems vary, but their designs are commonly organized around a set of core components:
- Generation: Local energy resources that produce on-site power and can be dispatched to meet load and grid conditions.
- Electrical infrastructure and controls: Switchgear, protective devices, interconnection, and control systems that define the microgrid boundary and match generation with loads, enabling islanding and safe reconnection.
- Loads: Critical and noncritical demand within the boundary, prioritized or shifted to keep essential services powered.
- Storage: Assets that store and release energy to balance supply, stabilize power, and enable islanding/black start.
Uses for a Microgrid
Microgrids improve local energy reliability and self-sufficiency, especially where grid service is limited or vulnerable.
Key applications include:
- Remote and islanded communities: Delivering dependable local power where grid extension is costly or impractical.
- Critical services: Keeping hospitals, schools, water systems, and emergency facilities powered during outages.
- Disaster recovery: Restoring power quickly after severe weather events, including hurricanes, wildfires, or winter storms.
- Economic development: Stabilizing energy costs, attracting businesses, and leveraging local resources.
- Grid reliability: Allowing communities to operate independently during outages or grid instability and reconnect seamlessly.
- Affordability: Managing costs through local generation, storage, and participation in grid services.
Microgrid Benefits and Challenges
- Local control over energy resources, reducing reliance on distant utility infrastructure.
- Greater economic stability through reduced fuel cost volatility and resource use.
- Improved public safety by ensuring uninterrupted power for critical services.
- Flexible design customized to site-specific needs, from villages to regional hubs.
- High upfront costs for planning, equipment, and installation.
- Complex system design and operations, requiring skilled expertise to manage.
- Regulatory and interconnection hurdles that can slow or complicate deployment.
- Ongoing maintenance and technical support needs to ensure long-term reliability.
- Financial feasibility depends on targeted funding or incentives to offset initial investments.
The U.S. Department of Energy is developing solutions to bring down the cost and complexity of microgrid development, especially for remote communities and isolated industries.
Are you exploring a microgrid for your community or organization and need resources to guide the process? Visit the Planning and Design page.
