MILK PRODUCERS in Tamil Nadu's Nilgiri district have designed a portable, insulated biogas plant that produces enough gas for three hours of cooking per day.

The one cubic metre capacity prototype, developed by the Nilgiri District Cooperative Milk Producer's Union, is a miniature of the now-famous, floating-dome type of biogas plant, designed and promoted by the Khadi Village Industries Commission. The portable plant costs Rs 600 as compared to Rs 4,000 for the smallest conventional biogas plant.

In winters, when the insulation is insufficient to maintain the temperature appropriate for microorganisms to produce the normal amount of biogas inside the plant, it can provide external heating using a part of the gas produced.