Archive for May, 2014


water and power

Like humans, machines generating power also need water…….that too fresh water!!. Around the world, electricity is generated from different sources…..oil, gas, coal, biomass, solid waste, wind, solar, water, ocean, geothermal……and so on. The list never ends. But all these sources that produce electricity consume substantial amount of water. Recently the International Energy Agency brought out this truth. Any policy maker in the Govt. or the Govt itself, “if” reads this report, then their top priority agenda should be water and energy and not only energy. For example, in 2010, 583 billion cubic meters of fresh water was consumed globally to generate 534434 petajoules of electricity. This amounts to 15% of the world’s total fresh water withdrawal. Conventional gas consumes 1000 L/toe; coal and oil -10000; ethnol-1000000;- in case of green energy sources: wind- <10 L/MWh; nuclear-10000; solar pv- 1000; CSP- 10000; geothermal- 100000 (includes EGS). When technology to extract heat from hot rocks matures, CO2 can be used as extraction medium instead of water and the water consumption falls down drastically. In hydrothermal systems, part of the water is injected back into the reservoir. The projections are that the water demand for power will touch 691 billion cubic meters by 2035. One should keep in mind the drinking water demand that is not included here. This demand will grow exponentially with growth in population. Countries have to strike a balance between water for power and water for people. Future scenario will be reduction in CO2 and reduction in consumption of fresh water. Are we not heading towards ancient civilization who lived simple life without much of materialistic needs?