It has always been exciting to anticipate what the future scenario with regard to energy will be. There are already some indications of what is to come in the solar roofs of Japan and Germany, in the wind farms of Spain. Most importantly, it is reflected in the widely varying growth rates of various energy sources, according to Vital Signs 1999, a publication of the Worldwatch Institute in Washington, DC, USA. In 1990-98, the use of wind power expanded by 22 per cent per year and photovoltaics by 16 per cent. Interestingly, use of oil grew by a mere 2 per cent, and that of coal