Biogas — What is it?
Biogas has gained a reputation as a flexible and renewable fuel source compared to more traditional fuel types. It’s used in agriculture, industry, and waste management, and plays an important role in responsible energy production as more sectors look to reduce emissions and make better use of organic waste.
But what is biogas, exactly? How is it produced, and where can it be used effectively? In this article, we answer these questions and explain how PowerUP helps operators maximize the performance of biogas-powered systems.
What is biogas?
Biogas is a renewable gas made primarily of methane (CH₄) and carbon dioxide (CO₂), with small traces of other gases like hydrogen sulfide, ammonia, and water vapor. It’s produced through the natural breakdown of organic matter in anaerobic (oxygen-free) environments.
This process is also called anaerobic digestion and happens naturally in environments like swamps, landfills, or the digestive systems of animals. In energy systems, however, anaerobic digestion is carried out in controlled environments such as biogas plants or digesters, which are specifically designed to optimize the process and collect the resulting gas.
Because of its methane content, biogas can be used as a fuel for heating, electricity generation, and, once upgraded, as a fuel for vehicles. Importantly, it’s produced from renewable feedstocks such as agricultural waste, food waste, sewage, and organic industrial residues, making it a sustainable alternative to fossil-based fuels.
How biogas is produced
Biogas production starts with organic feedstock, which can consist of manure, crop residues, food scraps, or sludge from wastewater treatment. The material is fed into a digester, where it is kept at a constant temperature and mixed regularly.
Inside the digester, bacteria break down the organic matter in the absence of oxygen. Over the course of several days or weeks, this biological process generates biogas, which is collected and stored in a gas-tight system. Alongside the gas, the digestion process also produces digestate, a nutrient-rich byproduct that can be used as fertilizer.
The raw biogas typically contains around 50–70% methane, with the rest being mostly carbon dioxide. For some applications, such as injection into the natural gas grid or use in transport, this gas is upgraded to remove CO₂ and other impurities, creating biomethane which matches the quality of conventional natural gas. Biomethan is also known as renewable natural gas or RNG.
Where biogas is used — Areas of application
Thanks to its flexibility and compatibility with many existing systems, biogas can be used in a wide variety of settings:
- Electricity and heat generation: One of the most common uses of biogas is in combined heat and power (CHP) systems, where it’s used to generate electricity while recovering waste heat. These systems are often found in agricultural operations, wastewater treatment plants, and food processing facilities.
- Gas grid injection: Once upgraded to biomethane, biogas can be injected into local or national gas networks. This allows it to be distributed and used just like natural gas — for heating, cooking, or industrial processes.
- Vehicle fuel: In compressed or liquefied form, biomethane can be used as a clean vehicle fuel. It’s already used in public transport, logistics, and agricultural fleets in several countries.
- Off-grid and rural applications: In areas where energy infrastructure is limited or unstable, biogas provides a local, renewable energy source for electricity, heating, or cooking.
As a dispatchable source of renewable energy, biogas is particularly useful for filling gaps in supply when solar or wind energy is not available.
The advantages of biogas
The key advantage of biogas is that it turns waste into energy. By using agricultural byproducts, food waste, and sewage as feedstock, biogas systems help reduce methane emissions that would otherwise be released into the atmosphere, while generating energy in the process.
Other benefits of biogas include:
- Renewable and local: Biogas is produced from renewable materials that are often available on-site, which reduces reliance on fossil fuels and external energy supplies.
- Supports the circular economy: Digesters recover energy from waste and return digestate to the soil as fertilizer, closing important nutrient cycles.
- Decentralized energy production: Biogas supports energy independence and resilience by producing power close to where it’s consumed.
- Flexible use: It can be used for electricity, heating, transport, or grid injection, depending on the application and available infrastructure.
- Emissions reduction: When managed properly, biogas systems reduce both methane and CO₂ emissions, contributing to climate protection goals.
Because of these qualities, biogas is especially valuable in sectors with steady waste streams and high energy demands like agriculture or food processing.
Challenges and limitations of biogas
Like any energy solution, biogas comes with limitations. One of the biggest is the need for a consistent feedstock supply. Without a stable input of organic material, the digestion process becomes inefficient or can fail altogether.
Additionally, building and operating a biogas plant involves upfront investment and technical know-how. Regular maintenance, gas quality monitoring, and safe operation of equipment are essential. In small-scale operations, these requirements can be a barrier to adoption.
In some countries, injecting biomethane into the gas grid is limited by regulatory or infrastructure constraints, which restricts wider use. And while gas engines can run on biogas, variable gas composition can lead to unstable combustion or increased wear if systems are not adapted accordingly.
These challenges highlight the importance of engine optimization, monitoring, and tailored system support to ensure safe and efficient operation.
Overview of the challenges and limitations of biogas:
- Feedstock availability: Biogas production depends on a steady supply of organic material. Inconsistent or low-quality feedstock can disrupt the digestion process and reduce gas output.
- High initial investment: Building and operating a biogas plant requires significant upfront capital for equipment, infrastructure, and system integration.
- Operational complexity: Biogas systems need ongoing monitoring and maintenance. Gas composition can vary based on feedstock, requiring careful process control.
- Gas quality fluctuations: Variable methane content and impurities in raw biogas can affect engine performance and increase wear if systems aren’t properly tuned.
- Grid injection limitations: In some regions, regulations or infrastructure may limit the ability to inject upgraded biogas (biomethane) into the natural gas grid.
- Technology and expertise requirements: Effective operation demands technical know-how, from digester management to engine calibration and emissions control.
Biogas in context: a flexible solution in the energy mix
Biogas is not a one-size-fits-all solution, but it offers a powerful tool for decarbonizing sectors that are difficult to electrify, such as agriculture, logistics, and industry. It plays an important role in supporting local energy systems as its use allows for responsible waste management and the production of renewable energy.
Unlike solar or wind, biogas can be stored and used on demand, making it a valuable addition to energy systems that require flexibility and reliability. When upgraded to biomethane, it can also be used interchangeably with natural gas. This important quality makes it compatible with a broad range of existing networks, appliances, and engines.
With proper management, biogas contributes directly to emissions reduction, energy diversification, and economic resilience.
How PowerUP supports biogas-based energy systems
At PowerUP, we specialize in helping operators run biogas-powered engines efficiently and reliably, even under challenging conditions.Biogas engines are exposed to variable gas composition, high levels of impurities, and fluctuating load profiles.
Our products and services are designed to address these challenges:
- We offer precision components and engine parts that maintain combustion quality and reduce wear, even with inconsistent gas quality.
- Our condition-based overhauls help extend engine life and reduce the risk of unplanned downtime.
- With remote diagnostics and performance monitoring, we enable operators to identify issues early and respond quickly.
- Our experts support system optimization and fine-tuning, helping you get more output from every cubic meter of gas.
Biogas-powered engines operate under conditions that can be more demanding than those fueled by standard natural gas. Variations in gas quality, moisture content, and pressure can affect combustion and lead to increased mechanical stress over time.
Supporting stable and efficient engine performance in these systems requires a combination of technical know-how, adaptable components, and consistent system monitoring. PowerUP provides tools and services that respond to these specific conditions, with a focus on maintaining combustion quality, reducing unplanned downtime, and optimizing performance over the long term.
