What Is Distributed Power Generation?

Distributed power generation is the production of electricity from small-scale sources located at or near the point of consumption, in contrast to the centralized model in which large generating stations transmit power over long distances through the bulk transmission grid. Individual units typically range from a few kilowatts for residential solar installations to several megawatts for small gas turbines or combined heat and power plants. The technology base includes photovoltaic panels, small wind turbines, microturbines, fuel cells, diesel generators, and small-scale hydropower, reflecting a broad range of primary energy sources rather than a single generation technology.

Distributed generation shifts some of the functions traditionally reserved for large, centrally dispatched power plants to assets located on customer premises or embedded in the distribution network. This shift requires changes to the operational practices and protection systems of utilities, because electricity flows that once ran exclusively from the bulk system toward the customer can now reverse, requiring bidirectional power flow management. IEEE Standard 1547, the primary technical standard governing interconnection of distributed energy resources with the electric power system, specifies requirements for voltage, frequency, protection, power quality, and islanding behavior at the point of common coupling.

Microgrids

A microgrid is a locally controlled grouping of distributed generation sources, energy storage, and electrical loads that can operate connected to the main grid or, when a fault or deliberate isolation occurs, as an autonomous island. The islanding capability is what distinguishes a microgrid from a simple collection of distributed generators: local control systems must maintain stable voltage and frequency within the island without support from the bulk grid. The US Department of Energy's overview of distributed energy resources and microgrids describes how microgrids combine solar, storage, and controllable loads to improve both resilience and the integration of variable renewable generation.

Control of microgrids involves coordination among inverter-based resources, rotating generators if present, and storage assets. Droop control, which allows generator output to adjust autonomously in proportion to frequency deviation, is widely used for primary frequency response in islanded operation. Higher-level energy management systems optimize dispatch across the microgrid's resources, subject to constraints on state of charge, generation capacity, and load priorities.

Hybrid Power Systems

Hybrid power systems combine two or more generation technologies, typically pairing a dispatchable source such as a diesel generator or fuel cell with an intermittent renewable source such as wind or solar, often supplemented by battery storage. The combination allows the system to reduce fuel consumption and emissions while maintaining reliability: when renewable output falls short, the dispatchable source compensates, and when it exceeds demand, excess energy charges the storage. Hybrid configurations are particularly common in remote communities, island grids, and industrial facilities where connection to the main grid is absent or unreliable.

The Lawrence Berkeley National Laboratory's Distributed Energy Resource Microgrid research program has studied hybrid architectures extensively, examining how storage sizing, dispatch logic, and interconnection standards interact to determine system performance and cost. These findings inform both utility planning and regulatory frameworks governing distributed generation deployment.

Vehicle-to-Grid Integration

Vehicle-to-grid (V2G) technology enables electric vehicles to act as mobile distributed generation assets, discharging stored energy back to the grid during periods of high demand and recharging during periods of low demand or high renewable output. A fleet of V2G-capable vehicles represents a substantial aggregate resource: a typical passenger EV battery holds 60 to 100 kWh, far exceeding the daily energy consumption of a residential customer. The IEEE Xplore paper on microgrids and distributed power generation situates V2G within the broader context of distributed energy integration and the control challenges that arise when large numbers of individually small resources must be coordinated.

Applications

Distributed power generation has applications in a range of fields, including:

• Residential and commercial solar plus storage systems
• Remote community and island power supply
• Industrial facility peak demand management
• Emergency backup power for critical infrastructure
• Grid support services including frequency regulation and voltage control