Biogas
Electricity and heat from organic waste, wastewater
We produce biogas from wastewater sludge, agricultural and food industry by-products, converting it into electricity and heat, or biomethane — through the design and construction of digesters and biogas utilisation systems.
Key figures
Completed projects
20
As of August 2026
Installed biogas production capacity
100,000
Nm³/day
As of August 2026
What we do
Renewable energy from waste and wastewater
Biogas is a flexibly usable renewable energy source that can be extracted from sewage sludge, agricultural residues, or organic waste and by-products from any industry. We harness this energy source by designing, building, and maintaining biogas plants — enabling the on-site use of the electricity and heat produced, or the production of biomethane.
We have been developing and expanding our experience in anaerobic technologies since 1996, and since our founding in 2021 we have strengthened this activity with dedicated engineering expertise. Our work covers the energy utilisation of both wastewater and high-moisture-content agricultural and food industry organic by-products.
01
Biogas from waste and organic by-products
Biogas production from agricultural and food industry organic by-products is built on our in-house InwaFerm digestion technology, which we have already designed, built and continuously maintain at numerous major-city wastewater treatment plants. We purify the biogas with our own two-stage BiogInwa unit, which removes moisture, hydrogen sulphide and other undesirable components.
The purified biogas can be used in several ways: to produce electricity and heat via a gas engine, converted into biomethane for feed-in to the natural gas grid, or utilised in LNG/CNG form.
Through our fermentate utilisation technology, developed with support from the Norwegian Fund, we blend and dry the fermentate with mineral additives to produce a valuable, yield-boosting input for agriculture.
02
Biogas from wastewater
We have long professional experience in the anaerobic reactor treatment of high-organic-content wastewater from the food, paper, pharmaceutical, chemical and other industries. Our work covers the design, construction, commissioning, servicing and development of reactors — from upgrading existing sludge lines to implementing new facilities.
Our engineering team, with decades of experience, carries out the conceptualisation, technological design, permitting and construction of anaerobic wastewater treatment systems, delivering electricity, heat and biomethane production. Numerous facilities of ours demonstrate that, through collaborations spanning several years or even decades, we can continuously guarantee the stability and efficiency of these systems.
03
Biomethane
At some of our facilities, we convert the purified biogas into biomethane and feed it directly into the natural gas grid — so the energy recovered from organic waste and sewage sludge reaches users through the existing gas infrastructure, without storage or transport.
Alongside quality assurance and grid feed-in, we obtain the required certificates for the biomethane produced ourselves — including guarantees of origin and compliance with international sustainability certification schemes such as ISCC.
We entrust the sale to a trusted partner specialised in biomethane trading, who acts as an intermediary: they find buyers across multiple countries and handle the entire sales process — ensuring a continuous, predictable sales channel for our partners.
04
Consulting
Our consulting services cover the full spectrum of biogas production: from concept design and technological planning, through support during permitting procedures, to operation. Our expert engineering team provides guidance on every project with the latest anaerobic and gas purification technologies, current regulatory requirements and economic considerations in mind.
Whether it's biogas production from organic waste or from wastewater, we always develop a sustainable, cost-effective solution tailored to the specific site — from complex digester investments to individual, targeted optimization tasks.
Our approach
In-house technologies, nearly three decades of experience
We have worked with anaerobic technologies since 1996, and this experience feeds into every digestion and biogas utilisation project we undertake. Alongside our in-house InwaFerm digestion and BiogInwa gas purification technologies, we are also familiar with a wide range of solutions available on the market — this perspective ensures our cost-effective, reliable systems.
This experience spans both agricultural and food industry by-products, as well as industrial and municipal sewage sludge. The result: stable, predictable biogas systems that produce energy with efficiency proven over years, even decades.
“Biogas isn't a by-product, it's a resource — in every digestion project, we focus on how organic waste and sewage sludge can be turned into a predictable, long-term stable energy source.”
Zsolt Eszes – CEO
Featured references
Plants we maintain
The following facilities are maintained by Inwatech — some from handover, others taken over by external contract.