Headquartered in Bengaluru, Karnataka, Grassroots Energy is a bioenergy company that specialises in the distributed energy sector. Launched with a mission to use technology to end energy poverty in rural areas and enable soil regeneration, the start-up’s first project was a 30 kW solar-biogas minigrid, commissioned in 2017. Since then, the company has scaled up and set up several minigrids. The energy generated from these minigrids is used for agro-based processing industries by micro-entrepreneurs, clean drinking water reverse osmosis plants, clean cooking, last-mile connectivity and additional income-generating activities by farmers. The company now plans to expand significantly in the compressed biogas (CBG) space. In an interview with Renewable Watch, Mateen Abdul, chief executive officer and co-founder, Grassroots Energy, talks about the company’s portfolio in the CBG space, product line, technology trends and business model. Edited excerpts…
What is the company’s portfolio in the CBG space? Please share the details of operational/under-construction and planned CBG projects.
Grassroots Energy focuses on providing CBG to corporate partners and city gas distribution (CGD) providers. Under the existing engagement, the company has issued letters of intent (LoIs) for projects whose techno-commercial feasibility is being explored. These include a 5 tonnes per day (TPD) CGD LOI at Unnao, a 5 TPD CGD LOI at Firozabad, a 5 TPD CGD LOI at Dakshin Kannada, and 8 TPD and 12 TPD of capacities for industrial customers (thermal application). Other projects include 50 and 10 decentralised plants of 0.6 TPD and 1 TPD capacity, respectively, for a private utility to replace diesel for backup power.
There are several social, economic and environmental advantages to the company’s solutions. They reduce methane emissions from decomposing agricultural waste, a significant cause of emissions worldwide. Additionally, they aid in community waste management by collecting large amounts of agricultural by products that could otherwise pose health risks through exposure. Furthermore, the company provides a clean fuel alternative, helping people transition out of energy poverty. The company’s circular approach involves repurposing residues from the biogas purification process to create organic fertilisers, which are then offered to farmers as a substitute for chemical fertilisers. Replacing chemical fertilisers with organic ones enriches soil nutrients, resulting in lower costs and higher incomes for farmers, and produces food safe for human consumption.
What are the recent developments and plans of the company in the CBG space?
We are excited about CBG-CGD integration (to be fed in the pipelines), which opens up a larger market for CBG operators. Given the mandate, CBG-CGD synchronisation will open up opportunities to set up CBG plants closer to the feedstock source. Furthermore, a minimum procurement price for fermented organic manure will ensure cash flows for the project. Moreover, the company is exploring support on machinery for processing of feedstock. This will ensure that such machineries are owned by the stakeholders such as farmer producer organisations, farmers and cooperatives.
What are the different production technologies of CBG that the company works on? What are the key benefits of using such technology?
Grassroots Energy uses water scrubbing and membrane technologies for biogas enrichment. Both technologies have low energy footprints. Additionally, the company utilises thermophilic digesters for higher biogas yields by maintaining temperatures up to 55 °C. Between 37 and 55 °C, the yields are higher, provided the temperature is maintained constantly. The benefits of higher yield outweigh the energy input costs. Moreover, pretreatment of diverse agricultural feedstock is critical to ensure that the input is consistent and homogeneous in order to process further. Cavitation is one such technology, which breaks down the feedstock into soluble portions and passes these on to the digesters. The processing of slurry into valuable products such as liquid fertilisers is done through the enrichment process. This process involves separating the liquid and extracting the relevant nutrients into portions that can be used later to replace fossil-fuel based chemical agriculture inputs.
Grassroots Energy has different technologies to cater to small-scale and large-scale installations. For small-scale installations, we use plug flow digesters, while for industrial scale, we use continuous stirred-tank reactors (mesophilic and thermophilic digesters). Pretreatment (biological and chemical) is a popular trend emerging in the sector. Moreover, membranes for biogas enrichment are among the popular options, and are energy efficient. Water scrubbing is also a cost-effective option for the biogas enrichment.
Plug flow digesters for anaerobic digestion are constructed from high quality, next-generation, UV-resistant polymers obtained from Grassroots’ partners, FOV Biogas and Sistema Biobolsa. These plug flow digesters are lightweight, require minimal civil work and are modular. They are paired with the company’s proprietary pre-digestors to guarantee optimal gas production. In order to enrich biomethane to 80 – 85 per cent methane, biogas from digesters is first enhanced by utilising Grassroots Energy’s own rotating disc scrubbing equipment, which operates at lower pressures. Through proprietary membrane technology from its German partner, biomethane undergoes enhancement at the second stage to reach high methane levels of 92 – 95 per cent.
Grassroots Energy has collaborated with the Indian Institute of Technology Bombay to develop a small-scale biomethane enrichment solution. When integrated with decentralised biogas plants, this technology can generate natural gas-grade fuel suitable for a variety of applications. This distinctive solution involves upgrading, which removes impurities, at a capacity of 240 m³ per day, using modular units. Additionally, the company is introducing several innovations to lower costs compared to traditional single-mold digesters, thus offering a more economical solution compared to existing technologies. This small-scale solution, at just one-tenth the size of current models, is designed to be scalable, making it ideal for deployment across rural areas. The compression and bottling technology enables the solution to serve a broader area from the point of generation. Furthermore, close-loop recycling of nutrients utilising biogas plant slurry-based manuring systems is part of the strategy for natural soil regeneration and preventive care. By enriching the biogas slurry, the company provides small and marginal farmers with an opportunity to boost agricultural yields while lowering input costs and improving long-term health.
What is the business model of the company? Who are the expected offtakers?
We have two customer segments: industries and CGD. For industries, we focus primarily on decarbonisation to reduce dependency on fossil fuels (coal, LPG, diesel, furnace oil) and help them move to bio-CNG. For CGD, we blend CBG in the pipelines to reduce dependency on imports. Ultimately, the pricing of CBG depends on the off-take agreement and the quantities produced.
The company collaborates with local stakeholders in the project area in various ways. This includes offering support for site selection; identifying local partners; facilitating farmer producer organisation (FPO) engagement for feedstock sourcing and collection; providing assistance with fertiliser demonstrations and distribution among FPOs and partner networks; sharing project information with stakeholders such as partners, investors and the community; and overseeing the overall progress of the programme through consistent monitoring.
What are the key incentives/subsidies available from the government for CBG production?
The key incentives/subsidies available from the government for CBG production include incentives for feedstock processing and storage. Other incentives include minimum pricing under SATAT for bio-CNG, and minimum price for organic fertilisers.
What are your policy suggestions to the government?
The policy suggestions include increasing the minimum price of fertilisers or enabling payment as per quality metrics; and providing incentives for carbon dioxide processing and storage. n
The interview includes information from a detailed project proposal shared by Mateen Abdul
