Algal biofuels, like crops, demand land, water, fertilisers, pesticides and inputs that are costly for India, says Hoysall Chanakya
Of late, there is heady euphoria over 'green' algal biofuels that are dangled as a panacea for developing countries such as India. While it is true that algal biofuels can contribute to a fossil fuel-free future, the promises of runaway successes are unrealistic. Scientists and policy makers need to address several critical issues that raise doubts over the sustainability of an extensive algal biofuel system. Do we need to re-learn sustainability lessons all over again in the light of first 'green revolution' which raised crop yields but left a trail of environment impacts?
Sustainability criteria need to be spelt out before anyone claims breakthroughs in this field. All claims need to be demonstrated on appropriate field-scale sizes; and an authenticated overall energy and resource balance established. Such a filter will make awareness, research, action and policy elements more realistic, achievable, accountable and transparent.
The spectre of more land, water, chemicals and pollution
Algal cultivation, like crops, will need land, water, farmers, fertilisers, pesticides and weedicides.
As it is, water-deficit India can barely meets it agricultural needs â€” cumulative losses due to transpiration are 50-100 per cent higher than the rainfall. Producing 10 grams of algae per square metre from a water body daily will lead to a water loss of 10 litres and a conservative oil content of 20 per cent from the algae. So, producing a kilogram of algal oil will need 5,000 litres of water. A typical rainfed crop would function at a tenth to a fifth of this water use.
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Algae image via Shutterstock