Capabilities

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These systems are connected to the utility grid and operate in coordination with it. Power can flow bidirectionally between the microgrid and the utility grid. When the grid becomes unavailable, the microgrid may be able to island itself and continue to provide power to the site.

To improve ROI, these microgrids can provide grid support during peak demand, especially at the grid edge. And, renewable energy sources within the microgrid reduce operating costs. Typically, they are larger systems serving campus or industrial sized sites.

Key Summary Points

-Operating cost reduction

-Resiliency

-Grid support revenue

Challenges

-Initial Capital Cost

-Long development time

-Grid interconnection agreement

-Available footprint (real-estate) for location

These systems operate independently of the grid and provide full power to the site. Since they do not export power to the grid, they generally don’t need any interconnection agreement and can be deployed rapidly and become quickly operational.

Initially developed for remote locations or limited or poor grid access, these systems are becoming increasingly popular for their resiliency and use of renewable energy sources, with local generation for local consumption.

Key Summary Points

-Resiliency and independence

-Self generation and self consumption

-Always on, no switching between grid and inland modes

-Rapid deployment and instant operation

-Renewable and other power source integration

-Design can future proof demand through modularity and expandability

Challenges

-Initial cost, especially battery storage

-Up-front planning and design critical to meet all load profiles as well as future.

-Control system for load and source management critical for smooth operation

These microgrids can serve entire communities or campuses. They provide resilience to the entire neighborhoods, rather than individual entities. They may be coupled to the utility grid, especially for revenue from grid support. They are complex design entities, especially with regard to high numbers of individual connections within their perimeter.

They can also be quite complex with regard to operating within regulated locations and must generally meet local Public Utility Commissions regulations and rate/tariff structures. They are well suited for municipal utilities and greenfield communities, or large area campuses such as colleges, hospitals and military bases.

Key Summary Points

-Resiliency and self-reliance

-Local generation and local consumption

-Lower energy cost potential

Challenges

-Complex design, especially mixing AC and DC distribution

-Complex development involving different stakeholders and permitting agencies

-Lengthy design, development and installation, especially for power distribution schemas

-High capital cost

Nano grids are small off-grid or hybrid microgrids typically serving smaller loads such as an individual residence. They can range from simple solar + storage that may be grid tied for revenue generation to fully resilient, full site power systems. Uses include back up power, either whole home or critical loads to always-on, full site power independence. They are blurring the distinction between solar + storage for grid tied and more complex, multiple power source entities.

Key Summary Points

-Small size, generally for a residence, communication tower, water and irrigation or small C&I

-Grid tied or hybrid

-Many possible providers evolving from solar installers to more complex offerings

-Easy integration with rooftop solar

Challenges

-Grid tied require interconnection agreements and compliance wit utility rules and requirements.

-Cost may be a limiting factor for a residence

-Choosing a reputable system and installation company