Distributed Generation Overview
– Distributed generation refers to electrical generation and storage performed by small devices called distributed energy resources (DER).
– DER systems are decentralized, modular, and located close to the load they serve.
– DER systems can use renewable energy sources such as small hydro, biomass, solar power, wind power, and geothermal power.
– Grid-connected devices for electricity storage can also be classified as DER systems.
– DER systems can be managed and coordinated within a smart grid.
Integration Challenges
– Uncertain nature of electricity resources like solar power and wind power can cause complex supply-demand relationships.
– Integration of DER puts higher pressure on the transmission network.
– DER may cause reverse power flow from the distribution system to the transmission system.
– Integration of DER requires complicated optimization tools to balance the network.
– Uncertainty in DER integration may lead to environmental impacts and affect the security of supply.
Microgrids
– Microgrids are localized, small-scale grids that can operate autonomously.
– They can disconnect from the centralized grid and help mitigate grid disturbances.
– Microgrids often use a mixture of different distributed energy resources.
– Solar hybrid power systems are commonly used in microgrids to reduce carbon emissions.
– Microgrids are typically low-voltage AC grids and are installed by the community they serve.
Central Plants vs Distributed Generation
– Central plants were historically an integral part of the electric grid.
– Central plants supply the traditional transmission and distribution (T&D) grid.
– Central plants became less competitive in delivering cheap and reliable electricity to remote customers.
– Distributed generation offers efficiency gains by locating smaller units closer to sites of demand.
– Distributed energy resources are mass-produced, small, and less site-specific.
Grid Parity
– Grid parity occurs when an alternative energy source can generate electricity at a cost equal to or lower than the retail price.
– Reaching grid parity means the energy source can be developed without subsidies or government support.
– Solar and wind energy have reached grid parity in several markets.
– Grid parity has been achieved in Australia, several European countries, and some states in the U.S.
– Grid parity for solar and wind has become a reality since the 2010s. Source: https://en.wikipedia.org/wiki/Distributed_generation
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).
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: (i) it makes the supply-demand relationships extremely complex, and requires complicated optimization tools to balance the network, and (ii) it puts higher pressure on the transmission network, and (iii) 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.
