Auroville’s Electricity Supply – Conventional or solar?

At present a majority of the pumps, houses and other buildings in Auroville are connected to the TNEB grid. The electricity is generated at a lignite power plant in Neyvelli. Auroville has about 300 low tension connections, witha total connected load of 900 KW. A small number of houses and communities have gone solar, making them completely independent of the TNEB grid.

The major problems experienced in the present set-up are due to the fact that Auroville is connected to a so-called rural feeder, which has to serve a very large area. There is a limited availability of three phase current, necessary amongst other things for the operation of water pumps, and Auroville experiences frequent power cuts.

Auroville is an unusual client for the TNEB. Probably no client of theirs operates with such a large number of low tension service connections. This particular situation arises out of the fact that Auroville does not yet have all the lands necessary to develop the town. We are therefore not able to distribute electricity within Auroville ourselves, except within the larger communities, and we depend on the TNEB, who alone.can cross third party lands and public roads with their lines. As soon as all the lands within the city area get consolidated, we can make the internal distribution through underground cables and get from the TNEB one or more high tension service connections, probably through a separate high tension feeder.

The first necessity for the planning of this essential service is thus the acquisition of all the lands. The second imperative is the decision regarding the location of the roads of Auroville, as the underground cables should preferably be laid alongside the roads. Afterwards we can approach the TNEB and apply for a separate Auroville feeder. This means a separate high tension overhead line from the closest TNEB sub-station to Auroville. The total cost of this line, with related equipment and transformer to step down the voltage from 22 KV to 11 KV, is estimated to be in the range of 1.5 to 2 million rupees which would have to be paid by Auroville.

The supply at 11 KV would be fed into the Auroville underground cable network. Most probably the 11 KV cables will follow the ring roads around and inside Auroville. From this cable, at various points, transformers will reduce the voltage to low tension (415/230V). The cost of an appropriate system for a township with a population of 50,000 people would be in the range of 100 to 120 million rupees, which includes high tension and low tension cabling, streetlighting and the installation of substations.

This is the picture of the future electricity supply if we depend upon the TNEB. In view of these high costs one wonders if going solar might not be the solution. Toine feels that solar and other forms of alternative energy will play a very important role in Auroville, although the application of solar energy in the immediate future will be mainly for small-scale, decentralized installations, such as for domestic lighting purposes. Costs of solar panels in India are still very high (about Rs.200/= per watt) and it is quite difficult to find funds for a big central solar plant, as the cost of inverters, grid synchronization equipment and cables etc. make it a very costly proposition. The smaller installations will mostly be used for lighting and other small loads. For normal high current consuming household apparatus, such as irons, fridges and pumps, you need many solar panels, batteries and expensive DC to AC inverters. Suitable DC equipment is not (yet) available in India.

In view of Auroville’s past experience with alternative energy projects, we might consider applying for recognition as an experimental area for solar energy, and try to obtain national and international support for this. Auroville’s set-up is unique. We aspire to be an area for unending education, research and experimentation, and the population of Auroville is in general very aware of the necessity to stimulate alternative technologies. We could have a demonstration project, which combines the use of conventional and alternative energy sources, such as solar, wind and other alternative energy systems, to show that alternative technologies have a place in solving the world’s energy problems. One way could be to show how a larger community, for example Certitude, could use solar energy. The individual houses could either be provided with solar panels and inverters, or a solar farm could be set up in the neighbourhood of the community and feed the DC, via an inverter, into the existing grid.