By Neena Bhandari
JAIPUR, India, Apr 27 1996 (IPS)

If the vast expanse of the Thar desert in northwestern India were harnessed to produce solar energy, it could light-up five of Asia’s most populated cities.

Scientists say the endless sands of Rajasthan state could well earn the distinction of being the “biggest” solar powerhouse by 2010, producing an estimated 10,000 mw of electricity.

A charged Rajasthan Energy Development Agency (REDA) has started the spadework on an ambitious project. Says Director Prabhat Dayal: “A major chunk of the desert, about 35,000 sq kms, will be declared a Solar Energy Enterprise Zone like the one in Nevada (United States).”

Dayal thinks that if the state were to install solar collectors in just one percent of its desert, which stretches over 200,000 sq kms, “we could generate 6,000 mw of electricity.” A city the size of Delhi with 10 million people needs 1,800 mw.

“This solar bowl of the desert would become the world’s biggest centre for solar power generation, research and development,” he declares.

The earth receives some 4,000 trillion kilowatt hours of electromagnetic radiation from the sun — about hundred times the world’s current energy consumption needs. At present, a 354 mw solar power project in southern California is the world’s largest, providing 90 percent of global solar energy.

Inspired by the progress made in the United States, Australia, Japan, Britain and China, which are forerunners in the field of solar energy application, the authorities in Rajasthan invited applications from 29 countries for setting up power stations of between 50 and 300 mw on a “build, operate and maintain basis”.

“Giants like U.S-based Amoco Corp and Enron, Energen Corp., Germany’s Schailac Bergermann and India’s Sun Source have already booked their spots in Rajasthan’s sun,” says a REDA official.

The Amoco-Enron Solar Power Development, a consortium of two U.S companies American Oil and Enron Power Corporation with a 50- 50 equity holding, will use the tried and tested photovoltaic conversion system.

This technology converts sunlight directly into electrical power with a solar cell, small versions of which are commonly used in calculators.

Amoco-Enron are planning “thin film” photovoltaic technology-based power generating stations with a combined capacity of 2,400 mw to be built in three phases. It has proposed the setting up of factories for the manufacture of thin film solar panels of 10, 50 and 100 mw annual capacity in Rajasthan.

Its first power station, a 250 kilowatt unit, would begin functioning by end-1996, say officials here in the state capital Jaipur, some 400 kms west of New Delhi.

REDA is proud it has steered clear of controversy like with grid electricity schemes. Opines Dayal: “The project involves no rehabilitation or maintenance costs, there is no forest land involved and Amoco-Enron will bear the entire foreign exchange risks since all payments would be made in Indian rupees … ”

Meanwhile, Energen’s project will put to use technology which is new to India. Solar energy would be produced through a solar chimney, a mechanical conversion system which consists of a solar pond or, when water is not available, some similar device which acts as a heat collection and storage area.

The area is covered with a large glass/membrane collector, causing the enclosed air to heat up. This is further heated by a heat transfer device or through heat transferred from pre- heated water in the solar ponds.

This energy is channelised and made to rise through a chimney constructed at the centre of the glass/membrane collector area. A constant flow of air through the chimney drives the wind turbines placed at the bottom. Since the project is based on solar energy there are almost no recurring expenses.

The proposed plant is to be be constructed in four stages and will be located in SEEZ, the area specially designated for solar energy projects. The height of the chimney and the heat collection area would be increased at every stage. The chimney would be 300 metres tall in the first stage and 1,000 metres in the fourth and final stage, which has been planned for the year 2000.

Building the chimney would be a labour-intensive project, and REDA officials say it will provide employment to about 5,000 people for five to six years. As the work requires semi-skilled workers, locals are assured employment.

At present Rajasthan’s 45 million people consumes 3,600 mw of electricity which costs the government 1.70 rupees (34 rupees to a dollar) per unit. Solar energy would initially be more expensive, say officials, but will rapidly become cheaper.

“After the 11th year in 2007, the rate per unit may be 50 percent of the conventional and by 2010 it could be only 10 percent. If these projects are successful one could have up to 300 such projects thus paving the way for solar energy development in the country,” says an optimistic official.

This is a possible answer to India’s perennial power shortages which cause frequent electricity failures particularly in the hot summer months. Its installed capacity of 79,000 mw is roughly two-thirds the requirement.

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