A biogas plant in New Town that converts waste collected from houses, restaurants and offices into power started operating on Friday.
Two trucks filled with food waste collected from hawkers and food stalls in Sector V went to the plant where the waste was put into the “feeder and settler tanks” of the plant, an official of the New Town Kolkata Development Authority (NKDA) said.
The waste will be allowed to “settle and decompose” for around a week before it starts generating biogas that will be used to light up streetlights in areas around the plant.
The plant has come up near Balaka Abasan in New Town’s Action Area I. It is expected to power streetlights on a 2km-stretch on either side of the housing complex once it reaches optimum operating capacity.
It is the township’s first such plant. It will process wet waste or biodegradable items and has a composting tank. The tank is filled with vegetable peels and fruit pulp collected from houses, offices and restaurants.
It takes 15-20 days for the biodegradable waste to break down and produce biogas.
“We want to reuse and recycle as much as possible in New Town. A biogas plant is one such way that waste can be converted into power. It also reduces the amount of biodegradable waste that finds its way to landfills,” said Debashis Sen, chairman, NKDA.
The streetlights near the plant are now lit with power drawn from the regular electric grid in New Town, an NKDA official said. “Once the biogas plant starts generating electricity, the regular power lines will be kept as back-up.”
A biogas plant — described as an anaerobic digester — comprises an airtight tank filled with microorganisms and bacteria that can transform biomass into biogas.
The new plant has the capacity to process around five metric tonnes of wet waste Vegetable peels, fruit pulp and maize stalk can be put into the tank to produce biogas.
The compost, which is produced at another unit in the complex, will be mixed with the soil in the median dividers where trees have been planted. “After the production increases, we will use the compost at Eco Park, the Tall Tree Nursery and other places that have greenery,” an NKDA official said.
The composting unit, which the official said will be sealed and odourless, will produce at least 100kg of compost after every refill.
Sen said collecting raw materials for the biogas plant and composting unit would not be a problem because most houses, offices and restaurants in New Town segregate their waste. The biodegradable waste is handed in separate containers to door-to-door collectors.