Can a solution to a problem be more problematic? In the case of biofuels, especially ethanol production, this question needs to be discussed seriously.
India’s renewable energy sector is making strides year on year. Earlier this month, the Government proudly announced achieving the ethanol blending target of 20 per cent E20. The question that needs to be raised is the stress that the increasing use of ethanol will put on our land and water resources, already under duress due to the changing climate.
One of the key research questions of a December 2024 study by Centre for Study of Science, Technology and Policy (CSTEP) was about the sustainability of E20, especially in the long term and the land, water, and food security implications of using the currently favoured feedstock—sugarcane and maize. It found that ethanol blending adoption does have benefits and trade-offs across the value chain.
While ethanol blending can reduce fossil fuel use in the transport sector (and its corresponding GHG emissions), it can also lead to increased land-use change emissions, it said.
Currently in India, ethanol is produced mainly from sugarcane, followed by other products such as maize. Sugarcane is a major water guzzler and using it for any secondary product will leave a larger impact.
“Ethanol use might improve the financial health of sugar mills and therefore sugarcane farmers’ income, but groundwater depletion due to extensive sugarcane cultivation will negatively impact both sugarcane and other farmers in the long run,” the CSTEP study said. So, what is being advocated as green fuel needs to be re-looked from its water footprint and also, from the land footprint too.
Reaching and maintaining the E20 by 2025 target leads to an annual ethanol demand of 10 billion litres in 2025, 12 billion litres by 2030, and 20 billion litres by 2050, it pointed out.
“Meeting this demand, without compromising on food and nutritional security, requires 3.5–10 million hectares of additional land to be brought under cultivation (of maize or sugarcane, depending on the scenario) in the coming two decades,” the study added. Also needed is quantifying the energy input that goes into sugarcane production and ethanol processing.
An April 2023 study in journal ‘Clean Energy Systems’ on ‘Net energy analysis of sugarcane-based ethanol production’ reported the findings from field investigations into the energy use practices of sugarcane production from a sugar-belt place in Maharashtra and a study of energy use in sugar industry. “Net energy value is reported in MJ per litre of Ethanol and is found to be 40 per cent surplus,” it said. One of the study's recommendations was to shift sugarcane cultivation to regions with favourable rainfall and adopt energy-efficient water-use practices, which, it stated, can increase the net energy value of Indian ethanol production.
