Microgrids in India: Possibilities and Challenges

A microgrid is defined as a controllable system consisting of distributed sources (typically renewable energy sources), loads, and energy storage systems that together can operate either in grid-connected or isolated modes. Conventional microgrids in India have been microhydroelectric (hydel) power sources, with the oldest traced back to Sidrapong Hydel Power Station, a microhydel power plant located at an altitude of about 3,600 ft at the base of Arya Tea Estate, around 12 km from Darjeeling town). Commissioned in 1897, this plant consisted of two 65-kW single-phase alternators (2,300 V, 83.3 Hz). The plant was later upgraded to 1,000 kW to cater to the needs of the residents in the town and neighboring tea gardens. Apart from hydel, biomass and wind have been in use, although, recently, a major focus has been on solar photovoltaic (PV) plants. An underlying commonality in all these plants has been that these systems have been isolated power sources supplying local loads where the grid has not penetrated or is not reliable due to inadequacy or inaccessibility. Recently, a 2,500-year-old monastery in the Ladhak region in the Himalayas was illuminated using solar PV by the Global Himalayan expedition team to cater to the needs of roughly 150 monks who live there. They had never before seen electric power lighting at night in that monastery.