Pune Engineer Develops Vaayu: A Household Biogas System to Tackle LPG Shortage

At a time when the uncertainty around the delivery of liquefied petroleum gas (LPG) cylinders is causing consumers sleepless nights, a Pune-based engineer’s innovation is drawing renewed attention as a sustainable alternative to cooking gas. Named ‘Vaayu’, the compact household biogas system developed by IIT Mumbai alumnus Priyadarshan Sahasrabuddhe, converts kitchen waste into methane gas for cooking purposes. With the uncertainty around LPG supply in recent weeks, Sahasrabuddhe says he has seen a surge in ‘Vaayu’ enquiries.

‘Vaayu’ uses organic waste generated in kitchens—vegetable peels, leftover food, rice, chapatis, etc.—to produce methane gas. The waste is placed in a digester containing methanogenic microorganisms which break down organic matter in an oxygen-free environment, producing methane through anaerobic digestion. The gas is stored in a balloon-like structure connected through a pipeline to the kitchen stove, allowing households to cook in a manner similar to LPG.

Sahasrabuddhe himself has completely stopped using LPG since installing the system at his Pune home in 2019. To run the system efficiently, around five kilograms of wet waste are required daily. From about 11 kilograms of organic waste, each unit can produce nearly 800 liters of methane gas per day, which is enough to meet more than 70% of a household’s cooking needs.

“The standard Vaayu unit accepts around two kilograms of organic waste daily and produces about 200 liters of biogas in 24 hours, equivalent to roughly 40 minutes of cooking gas,” he explained. The system does not require electricity and usually needs cleaning only once every six months. The leftover slurry generated during the process can be used as fertiliser for plants.

Since launching the technology in 2019, more than 450 Vaayu systems have been installed across cities such as Pune, Sangli, Aurangabad, Nashik, Palghar, Umarkhed, and Hyderabad. Around 250 of these systems have been installed in households, while the remaining operate in housing societies, hostels, corporate canteens, and hotels.

For some Punekars, Vaayu has already become part of their daily lives. Dr. Varsha Gadre and IT professional Amol Gadre, who live in Sahakarnagar, have been using biogas generated from kitchen waste for the past four years and rarely depend on LPG cylinders.

“For the last four years, we have been using biogas generated from our kitchen waste. We keep LPG only as a backup and use it for a few days in a year when gas generation is low,” said Dr. Gadre.

The family installed Vaayu after learning about Sahasrabuddhe’s work and invested around ₹1 lakh in the unit. “Over time, the investment has been recovered. More importantly, we are managing our own wet waste instead of sending it to the municipal system. The leftover slurry is also useful as fertiliser for our garden,” said Dr. Gadre.

However, Vaayu takes about four weeks for the microbial ecosystem in the digester to stabilise and begin producing gas efficiently.

“People want immediate alternatives because they are facing LPG shortages. But this is a natural biological process, so it needs time to start working properly,” Sahasrabuddhe said.

Despite this limitation, he believes waste-to-energy solutions can significantly reduce landfill waste and LPG consumption if adopted widely by households, housing societies, and institutions. His long-term goal is to convert 200 tonnes of food waste into energy every day within the next five years through community participation.