Solar energy in the 90s – 1:

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carter road mangroves

In 1998, Energy & Lifestyles – a paper by Winin Pereira and Subhash Sule – was written in the Centre for Holistic Studies in Carter Road, Bandra, overlooking the mangroves that they and others worked so hard to save. Some extracts follow.

The sun delivers enough energy to the Earth in one year to meet mankind’s current consumption some 10,000 times over. The problem has always been how to trap and make use of this solar power.

The achievements of India in the field of renewable energy seem remarkable. Over 400,000 solar photovoltaic systems (producing about 28 MW) have so far been installed for commercial applications, home and street lighting, water pumping and rural telecommunication systems in remote areas. About 400,000 square metres of solar collector area have been installed, for domestic, commercial and industrial water heating. Nearly half a million box-type solar cookers are also in use.[Nishad, 1997] About 925 MW capacity of wind power is installed.[TERI Newswire, 1997]

In spite of all this, by the year 2012, only some 10% of the total installed power generating capacity in the country is likely to be based on renewables. [Nishad, 1997]

Winin Pereira3(Ed:World Energy Outlook 2012: Global Energy Trends (IEA, page 218), however, estimates renewables’ share of total generation in India by 2012 at 14%. Pereira, an accomplished physicist, also highlighted the polluting and energy intensive nature of solar PV technology in a way that few care to dwell on even today. He predicted that, over time, these adverse factors will gradually be addressed and minimised – see Mulvaney 2005 onwards: Silicon Valley Toxics Coalition, author of ‘Towards a just and sustainable solar industry’: Hazardous Materials Used In Silicon PV Cell Production, which also touches on measures which are reducing energy use in the production process.)

In the fabrication of PV cells large amounts of energy are required for producing the basic very high purity silicon and for every further stage of PV cell manufacture. Because of the need for other non-renewable resources for the manufacture of voltage converters, their voltage inverters (DC to AC), and other infrastructure, they would add to an already resource-depleted and over-polluted world. [Pereira, 1992, p 22] It is quite possible that the total fossil energy consumed in the fabrication, installation and maintenance of the PV cells, as well as that of the required storage systems, will be high compared to their output during their limited lifetime.

While PV systems do not emit CO2 and other gaseous pollutants, the efficient types use cadmium sulphide and other chemicals as dopants of silicon, in their manufacture. Because these chemicals are highly toxic and persist in the environment for centuries, disposal of used cells could become a major environmental problem. However, the most promising cells in terms of low cost, mass production, and relatively high efficiency are those being manufactured using silicon, either crystalline or amorphous. These materials make the cells less expensive and environmentally safer than the heavy metal cells. [Pimentel et al., 1994] The PV industry uses the ‘below-specification’ silicon of the waste of the semiconductor industry to lower costs but this source is getting exhausted. If a dedicated manufacturing concern is now set up, a huge quantity of fossil fuels will need to be used and costs will rise.

Some of the latest materials being worked on in thin film cells – selenium, cadmium and titanium dioxide are highly toxic. At present the industry uses some very strong acids to chemically etch the surface of the solar cell to improve light entrapment. These materials, and their recycling, have to be handled carefully.

There is a proposal to build a huge PV installation in the Rajasthan desert. This could have unpredictable effects on the local microclimate. It would deprive large areas of sunlight, which could have disastrous effects on plant photosynthesis, causing a large loss of biomass, reducing the fodder and fuel production of the region. [De, 1997].

rajasthan solar projects mapped

The discredited Enron corporation, in partnership with Amoco, withdrew from its 50-MW solar PV project at Jaisalmer in Rajasthan, but many others proceeded – see the interactive map.

Next: Solar energy – 2: almost twenty years later

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