Distributed generation

  • Topic

Conventional power stations, such as coal-fired, gas, and nuclear powered plants, as well as hydroelectric dams and large-scale solar power stations, are centralized and often require electric energy to be transmitted over long distances.

By contrast, DER systems are decentralized, modular, and more flexible technologies that are located close to the load they serve, albeit having capacities of only 10 megawatts (MW) or less.

These systems can comprise multiple generation and storage components; in this instance, they are referred to as hybrid power systems.

DER systems typically use renewable energy sources, including small hydro, biomass, biogas, solar power, wind power, and geothermal power, and increasingly play an important role for the electric power distribution system.

A grid-connected device for electricity storage can also be classified as a DER system and is often called a distributed energy storage system (DESS). By means of an interface, DER systems can be managed and coordinated within a smart grid.

Distributed generation and storage enables the collection of energy from many sources and may lower environmental impacts and improve the security of supply.

One of the major issues with the integration of the DER such as solar power, wind power, etc. is the uncertain nature of such electricity resources.

This uncertainty can cause a few problems in the distribution system:

  • it makes the supply-demand relationships extremely complex, and requires complicated optimization tools to balance the network,

  • it puts higher pressure on the transmission network,

  • it may cause reverse power flow from the distribution system to transmission system. Microgrids are modern, localized, small-scale grids, contrary to the traditional, centralized electricity grid (macrogrid).

Microgrids can disconnect from the centralized grid and operate autonomously, strengthen grid resilience, and help mitigate grid disturbances.

They are typically low-voltage AC grids, often use diesel generators, and are installed by the community they serve. Microgrids increasingly employ a mixture of different distributed energy resources, such as solar hybrid power systems, which significantly reduce the amount of carbon emitted.


Name

Distributed generation

Description

Distributed generation, also distributed energy, on-site generation (OSG), or district/decentralized energy, is electrical generation and storage performed by a variety of small, grid-connected or distribution system-connected devices referred to as distributed energy resources (DER).

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