Waste treatment and energy potential

AJIT RANADE: A key point is that Mumbai is perhaps the only city having a garbage dump within a kilometre of a power plant (Tata Power). Technology for conversion of garbage to a fuel, usable by thermal energy plants, has been available for 20 years. Technology which does not need wet and dry garbage separation is also available since 15 years.

Tata Power has been doing pilot projects, so can this city become the example for generation of electricity from garbage? A calculation say this could be worth 200 MW, which could reduce power shortages and generate revenues of Rs 1,000 crore to pay off workers involved in collection and transport.

AJOY MEHTA: On waste-to-energy, there is a wrong impression that energy generated from the waste will pay for everything else. It doesn’t. Beyond the capex itself, Mumbai’s waste has typical problems. It is not segregated and waste in monsoon months is dripping wet. Third, key calorific components – paper and plastic –are generally removed by scavengers, so what reaches is has very low calorific value.

That said, we are looking at two things. First is bio-reactions, to convert this into gas and the compost goes off to methane. We have put a small gas engine in Kanjur. In Deonar, we are looking at a wasteto-energy plant with capex of around Rs.1, 000 crore.

Tenders are out and hopefully in next three months this should be closed. We are technology neutral on the tenders, Swedish or Israeli, segregation or non-segregation. Just bring technology and deliver on cost and performance parameters. On the debris side, we are putting up waste-tobuilding-material type of plants to create value, so that waste does not end up on the roads or in mangroves.