- Biogas electricity costs remain significantly higher than wind and solar, with feedstock and operating expenses driving the gap.
- Researchers urge policymakers to target biogas projects at waste management, grid flexibility, energy storage and green chemical production.
Biogas costs have remained largely unchanged over the past decade, prompting researchers to call for a more targeted approach to biogas deployment rather than treating it as a direct competitor to wind and solar.
A 2026 perspective article published in ENGINEERING Environment examines the economic and resource constraints facing biogas development. Mingze Shi and Xinmin Zhan of the University of Galway in Ireland led the research alongside an international team from Spain, the Netherlands, the United Kingdom, China and Japan.
The analysis shows that wind and solar costs have fallen by 70% to 90% over the past decade, while bioenergy costs have remained nearly unchanged. Bioenergy costs increased slightly from $0.086 to $0.087 per kilowatt-hour.
Germany illustrates the cost gap. In 2024, biogas recorded a levelized cost of electricity between 20.2 and 32.5 euro cents per kilowatt-hour. Wind power ranged from 4.3 to 10.3 euro cents, while utility-scale solar photovoltaic projects ranged from 4.1 to 6.9 euro cents per kilowatt-hour.
The researchers attribute much of the difference to biogas’s recurring feedstock requirements. Wind and solar projects mainly incur capital costs during construction and then generate electricity without continuously purchasing fuel. Biogas plants, however, must continually source, process and manage feedstock.
The authors noted that biodigester installation accounts for only 20% to 40% of total biomethane production costs. Feedstock procurement, processing and plant operations account for the remaining costs, creating an ongoing financial burden.
The International Energy Agency (IEA) estimates global biomethane potential at about 730 million tonnes of oil equivalent. However, only about 55 million tonnes could be developed at a cost below $10 per million British thermal units, highlighting the economic limits of large-scale deployment.
Feedstock availability also creates pressure on agricultural land. Germany used 1.35 million hectares for biogas energy crops in 2024, with maize occupying nearly two-thirds of the area. Producing another billion cubic metres of crop-based biomethane could require approximately 0.17 million to 0.25 million hectares of agricultural land.
The researchers warned that this expansion could intensify competition between energy production and food cultivation. Germany, Italy and Austria have already shifted some biogas feedstocks from organic waste toward purpose-grown energy crops to maintain plant viability.
Subsidies also play a significant role in project economics. Between 2021 and 2023, European Union fossil-fuel subsidies increased while renewable-energy subsidies fell from €83 billion to €61 billion. The authors noted that biogas projects frequently require several support mechanisms simultaneously.
An Irish case study further illustrates the challenge. A 40 GWh-per-year anaerobic digestion plant using cattle slurry and grass silage required biomethane certificates and capital grants, alongside an additional farm subsidy of €893 per hectare to remain economically viable.
“The numbers are clear: biogas cannot compete with wind and solar on cost, and it never will if we keep treating it as a primary electricity source,” the authors said.
The researchers nevertheless identified several applications where biogas could provide value beyond electricity generation. They highlighted grid flexibility, organic waste management, seasonal energy storage and green chemical production as areas where biogas can provide services that other renewable technologies cannot easily replicate.
They also pointed to the potential of existing gas infrastructure to support seasonal energy storage and rapid load balancing. The researchers argued that these applications could provide strategic value where battery storage faces economic or technical limitations.
Anaerobic digestion can also provide environmental benefits. According to the analysis, the process can inactivate more than 99% of major pathogens in livestock manure. Full utilisation of manure for biogas could also help mitigate about 1,000 million tonnes of carbon dioxide equivalent in agricultural greenhouse gas emissions annually.
The researchers therefore recommend that policymakers evaluate biogas projects individually and prioritise developments that deliver benefits beyond energy production.
“The real value of biogas lies not in competing head-to-head with renewables on price, but in providing grid flexibility, managing organic waste, and enabling green chemistry,” the authors said. “We need to stop subsidizing biogas as if it were wind power and start funding it for what it actually does well.”
The study concludes that policymakers should avoid broad biogas expansion targets that depend heavily on subsidies. Instead, they should direct investment toward projects with clear waste-management, energy-system or industrial benefits while accounting for feedstock availability and land-use constraints.