Hybrid Microgrids

The raising electricity demand and the need for reliable power source at appropriate cost are motivating towards distributed energy sources at the load centre what we call as the Microgrid. Hybrid Microgrids are a combination of interconnected renewable energy sources and the conventional generators along with energy storage. These grids can operate as standalone grid (islanded mode) or connected to the existing grid (grid connected mode). Microgrids can improve customer reliability and support to grid disturbances.

Conventional generation includes diesel power generation or gas fired engine or turbine power generation. The hybrid system includes the conventional unit along with Renewable sources and storage. The energy storage plays a vital part in Microgrids. They facilitate the RES to integrate to the Microgrid thereby reducing the fluctuations caused by them, improve power quality, support system frequency and many other ancillary services. Mostly used energy storage includes, battery energy storage, compressed air energy storage system, flywheel, pumped hydro energy storage system, super-capacitor etc.

Microgrids usually range from a few kilowatts to few hundred Megawatts. They can serve a single building or a community of buildings.?They can be connected either as an off-grid type where it individually supplies its customers or grid tied type where the Microgrid is connected to the main grid. The Microgrids have several benefits which includes the following:

1. Reduces green house gases

2. Utilizes the full energy generation otherwise the energy is lost in transmission lines.

3. Reduces investment in transmission and distribution of utility companies.

4. They can support the grid stability and operation.

5. Can facilitate de-centralized operation of power systems.