By C.R.Bhattacharjee, 21/10/04
What happens when being off-grid is a necessity and not an option? India has nearly 25000 villages, located in islands or remote areas distant from habitation, where power from grid lines is not techno-commercially feasible. These villages, where population generally varies between 100-1000 are usually inhabited by financially weaker sections of society whose inability to pay for cost of power is a key factor. Their demand for power is primarily for lights to replace kerosene followed by small requirement for water supply.
The development of the concept of off-grid power supply has originated from the government, who have a responsibility to provide these villagers with power to meet their essential demand for lighting. Power supply systems, comprising of mini-generation plants & associated distribution system to work in off-grid mode in the evening , form a part of the national plan to reach electricity to all villages and hamlets by 2007 and to all household by 2012.
With the price of fossil fuel rising, diesel power supply system is ruled out. In these areas, depending on availability of local resources, solar PV, wind, biomass, biogas and micro-hydel based power generation are the major options, with a combination of these being quite common. The schemes started under state funding, with participation of village people in conceptual planning to the commissioning and subsequent maintenance, operation and revenue collection. However, they are gradually showing signs of implementing system. As a result the systems become subjected to market forces and move from full/partial subsidy to commercial setup.
Size of off-grid power plants range between 10-500KW catering to 50-3000 consumers with operating hours usually restricted between 5-10 hours in a day. Connected load allowed to domestic consumers is within 150W where as in case of commercial, water supply, industrial class this may vary from 100 to 2000 Watts. Energy conservation is achieved through CFL lighting, tiny, small and efficient motors, which are essentially insisted upon. Replacement of kerosene is considered as a big boon. Costlier every day, it emits insufficient illumination, black smokes and soot.
The effects of the change are far reaching. Domestic consumers reap the benefit of light in the evening for study and household work, at times to supplement income, with level of lighting far superior to that of kerosene. To give an example, 40 students in a hostel used to spend $50 a month on kerosene in the tribal area and with a 5Kw small SPV power unit, cost has fallen down to $20 only with advantage of better lighting. Commercial shops, photocopying, battery charging, tiny repair centres, etc, all contribute to employment opportunities. Refrigerators have become handy to store medicine. Market places illuminated in the evening or entertainment through TV and musical system give an impression of nearly urban style of living, an idea previously unimaginable. Water from tube-wells or micro-irrigation for agriculture is distinct contribution to community health and economy.
The off-grid power system improves the quality of life of people living far away from developed localities, deprived of essential necessities and helps create opportunities for both economic growth and social welfare, whilst harnessing natural resources in a manner benign to environment probably. Originally born of necessity, it seems there might not be any better option. Here is proof of the philosophy that small is beautiful.
Mr. Bhattacharjee is a retired Chief Engineer and is now a consulting engineer. He has been in the field of renewable energy for more than 25 years, and believes in harnessing renewable energy resources in India as a priority for energy security, reducing oil imports and arresting environment pollution.