Garbage Power Small W2E plant powers streetlights for 12 hours in a Mumbai Suburb

Biogas and waste-to-electricity plants were once considered to be the silver bullet that would solve India’s waste processing problems, as well as generate a useful by-product. At a time when such plants are closing all over the country for various reasons, Clean India Journal spoke to Yashas Bhand, CEO of Yasasu EMS Pvt Ltd, a Navi Mumbai-based waste-biogas-electricity plant company, that has created a successful wasteto- energy model in partnership with the local residents’ association, municipal corporation and power supply company at Mumbai.

Existing landfills, where waste is blindly collected and dumped, were once located on the outskirts of, or far outside city limits. As urban sprawls expanded, the landfill sites have become part of the city, seriously affecting the health of residents in the neighbourhood. Poor city planning has led to overflowing landfills which will soon exceed their capacity, if they haven’t already. As urban populations continue to grow, more and more waste will be generated, and an everincreasing area will have to be converted to landfills.

The waste crisis can be solved if municipal corporations and citizens adhere to a simple principle: waste segregation. While organic waste can be composted or used to produce biogas (as Yasasu does), the inorganic constituent can be incinerated to generate electricity as well. As Bhand points out, the right kind of waste needs to be processed using the right kind of technology. “Waste is now a responsibility. It must be processed; whatever extra we get from it (biogas/compost/ electricity) is a bonus”.

The Yasasu story

As laws to tackle waste came into being in the late 90s, Bhand’s family-owned company began to source inputs from many biogas companies. It learned that while the technology was widely available, it needed to be adapted to Indian conditions. In 2008, it constructed and launched a small waste-to-energy biogas plant at the site of a landfill in Solapur, Maharashtra. Over the years, it experimented with what would and wouldn’t work in the local conditions, taking location-specific factors into account. While this 400-tonne capacity plant was intended to serve as a demonstration to municipal corporations, it started commercial operations (injecting electricity generated from biogas into the grid) from 2013.

Biogas in a box

Traditionally, biogas plants are high-volume installations that require all waste to be transported to and collected at a single location. Yasasu realised that smaller towns, which produce say 50 tonnes of waste daily, may not be able to sustain such a large plant, but still deserve a biogas facility, because without it, their landfills would grow over time. Yasasu also notice that the collection of a large amount of waste was not possible even in the middle of large urban areas due to lack of space.

In 2016, laws for decentralised waste processing came into being. Even before this, Yasasu had bucked the trend by downscaling their model while everyone else was upscaling, leading to the development of a decentralised biogas plant. It decided to devise a system that is portable, easy to handle and can work in a variety of environmental conditions (rainy/sunny/cold) and with a variety of waste. By treating organic waste almost at its source, this model bypasses the need to have huge collection centres. For example, if a municipal ward generates 100 tonnes of waste every day, a 10-tonne plant can be commissioned to tackle its organic component. As infrastructure continues to grow, this hyperlocal model will be the perfect fit for each neighbourhood.

Even though Yasasu is a biogas company, Bhand himself advises every area producing less than 500 kg of organic waste daily to go in for composting; anything more and he advocates a biogas plant. Waste data is important, he said, in deciding which is the best method of processing.

Yasasu uses existing freight containers to house its biogas plants. A one tonne unit is contained in a 20-foot container, while 2 5 tonne units are contained in a 40-tonne container. A storage space is provided inside for the storage of incoming waste; it is critical that this be already segregated, and only the biodegradable part enters the plant. Since the smell of waste is what makes stakeholders apprehensive about investing in a biogas plant, Bhand advises that waste should be processed as soon as it enters the facility; there are no noxious emissions once it is fed into the shredder, followed by the digester. The engine which generates electricity has 80- 85% efficiency.

While other biogas companies add large volumes of water to the waste before it is processed, Yasasu employs a dry anaerobic digestion technique, which is far more environment friendly. The plant starts producing biogas within 30-45 days of commencing operations.

“Until now,” says Bhand, “our focus was on the development of technology; now we are looking at providing integrated solutions at both the technical and system planning level. Because if you have proper plant processing but poor collection and transport of waste, your plant is bound to fail. And if you have good collection and transport but an inefficient plant, your plant site will become another landfill.”

The Pali Hill Model

Pali Hill is an upmarket area in the Mumbai suburb of Bandra. Its 1700 residents, living in 78 buildings and 23 bungalows spread across a 1.4sqkm area, have organised themselves into the Pali Hill Residents’ Association, which is proactive in dealing with the Municipal Corporation of Greater Mumbai in all civic matters.

Its secretary Madhu Poplai said that when municipal laws making the composting of all organic waste compulsory came into place, she was against the concept. Getting residents to compost waste in their own compounds was an almost impossible task as they were apprehensive of the smell, and breeding of mosquitoes. When she communicated this to the ward officer, he offered an alternative: a village in Talegaon near Pune had installed a biogas plant. Polai and the ward officer visited the site; Poplai was unhappy with the aesthetics of the plant, and wanted it to be packaged better. They visited another project which used biogas to generate electricity for streetlights, and something clicked.

With the support of local politicians and in a roundabout manner, Poplai came into contact with Bhand, whom she had spoken to earlier. No resident objected to the construction of a biogas plant in the middle of their area; the project was financed and executed by the residents’ association, and then handed over to the municipal corporation. Seeing their enthusiasm, Yasasu also decided to perform all Operations and Maintenance related activities for three years, and train the people who would keep the plant running. Poplai says, “it is a beautiful dream come true” while Bhand replies, “we couldn’t have done it without them”.

As mentioned earlier, it is critical that all waste be segregated, and only the biodegradable component be delivered to the plant. The Solid Waste Management (SWM) workers had been used to earning between `300-700 per month from selling dry waste; not only did the residents’ association educate residents about how and why to segregate their household waste, it also paid SWM workers a substantial incentive to segregate the waste they collect, as soon as they collect it. These workers soon realised that they were now earning `4500-6000 per month from selling dry waste, and enthusiastically took charge of the segregation process. Housing societies chipped in by providing a room to store dry waste.

Expectedly, no one was willing to have the biogas plant on their premises. Eventually, the association was able to obtain a portion of land owned by the municipal corporation’s hydraulic department, that housed the reservoir supplying water to the area. By a stroke of luck, it was found that a transformer was located just metres away.

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It is a beautiful dream come true. No resident objected to the construction of a biogas plant in the middle of their area; the project was financed and executed by the residents’ association, and then handed over to the municipal corporation.

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The power company’s project team was highly cooperative, and pointed out future obstacles that were eliminated. One problem was the possibility that an erratic supply of power from the biogas plant would trip up the transformer; taking a leaf out of the book of rooftop solar plants, an inverter was installed, which could also measure the amount of power produced and the fraction supplied to the streetlights. This also saved the cost of installing a highly expensive transformer solely for the mini-grid, as well as nullified the need to dig up roads to lay new cables.

“We didn’t want any organic residue to go out of Pali Hill,” says Poplai; the plant produces 300kg of compost a week, so the association started vegetable farming on the same plot of land. The produce will be handed over free of cost to orphanages and old age homes in the area, and the excess compost supplied to anyone who asks, for no charge. In this way, food waste which comes from society, goes back to society.

With a total, all-inclusive investment of `55-60 lakhs, the biogas plant was installed. With a capacity of one tonne, it receives and processes an average of 900kg of organic waste every day. About 90- 95% of this waste arrives in already segregated state, the rest is segregated manually at the site. It is usually delivered by the municipal corporation at night, which is when it is fed into the plant.

Depending upon the amount of waste coming in the plant generates 110-120 units of electricity every day, a part of which is used to power 68 street-lights in the area. By saving on the cost of waste transportation (to a distant landfill) and cutting the cost of street-lighting, Poplai estimates that this has saved the municipal corporation `12-14 lakhs in just one year of operation. Plan are afoot to expand beyond 68 streetlights, and to apply this model to the entire ward of which Pali Hill is a part, with a plant of correspondingly bigger capacity.

“It is very satisfying how much we have achieved, and the amount of support this plant has garnered,” says Poplai. Even now, if the plant falls short of waste on a given day, the staff (which has only six members, including the transport team) rushes to neighbourhood restaurants, which willingly hand over their food waste.

What’s in the future?

At present, Yasasu is executing 10 projects across India, and has brought down the project installation time down to just three months (from the handover of site). Bhand wants to take his model to countries like Vietnam and Oman, He is also working on additives that will ensure adequate gas production, even if the supply of waste falls short.

He adds that with this model, he wants to help define standards for the waste sector; there are none at present. He also hopes to see healthy competition emerge; at the moment, Yasasu often finds itself to be the only bidder for projects.

Bhand is also working on a model for Vellore in Tamil Nadu, in which hotel owners will pay a subscription fee to have their food waste collected and transported to a biogas plant on land donated to the Vellore municipal corporation. As cooking gas becomes more and more expensive, the biogas produced will be compressed in cylinders and sold back to hotels at a subsidised rate, thus creating a circular economy. Since this will generate funds, hotels and the corporation won’t have to pay for the operations and maintenance of the plant either. Well, there is one getting ready at Delhi too!