Waste sites (such as landfills and agricultural waste storage) produce biogas from the decomposition of organic materials, including the powerful greenhouse gas methane. With the right infrastructure and systems, companies and municipalities can capture this methane and either destroy it or convert it into energy. Biogas capture projects cause a clear reduction in greenhouse gas (GHG) emission, but it is unclear whether waste biogas carbon offsets actually cause the projects to be implemented. While have not yet found any biogas-related carbon offsets to recommend, we do believe that there are likely circumstances where these offsets do cause real emissions reductions. Better biogas offsets are in places where methane capture is not mandated by regulation (either current or future), and in sites where the electricity generated by biogas is not enough to make the project profitable.
Overall, we believe that there are likely good biogas offsets that are additional, but currently we have been unable to find any that meet our criteria. As not all offsets are offered online, it is possible that these high-quality offsets are being directly sold to corporate buyers or are only transacted through brokers. Giving Green will continue searching for biogas projects we can recommend with confidence.
Waste biogas capture as a carbon offset
Landfills and agricultural waste sites produce biogas from the decomposition of organic materials. Biogas is composed of primarily methane and carbon dioxide (CO2), along with a small amount of other organic compounds. Both methane and CO2 are greenhouse gases that trap heat in the atmosphere. Methane is 28-36 times better at trapping heat in the atmosphere than CO2 over a 100 year period, making it a particularly potent GHG . Of all methane produced in the United States, landfills are the third-largest source with approximately 14% of overall emissions . Reducing methane emissions is a key priority in combating climate change.
Waste sites emit methane through an anaerobic process. Large amounts of organic material (e.g. food, wood) are deposited into landfills, and agricultural waste sites contain production byproducts (such as plant husks or animal excrement). Bacteria decompose these materials and produce a mixture of gases, which is then emitted into our atmosphere and contributes to global warming.
Biogas normally escapes from waste sites into the atmosphere soon after it is produced. However, if the right infrastructure and systems are put in place at waste sites, companies and municipalities can capture the methane and either destroy it or convert it into energy. Gas extraction wells and piping systems can be set up at waste sites and used to move biogas from the production site to treatment locations. At the treatment locations, biogas is either flared (burned to convert methane into a less harmful gas)  or converted into energy like electricity or car fuel.
To encourage biogas flaring or capture, the US Government regulates large emitters of GHG through the Clean Air Act and through reporting requirements to the Environmental Protection Agency (EPA). Regulations require landfill emissions to be measured and publicly documented. Large emitters are required to either capture and destroy or convert their landfill gas into a reusable resource . However, biogas emissions from agricultural operations and smaller landfills are more lightly regulated, if at all.
Carbon offsets fund the construction and upkeep of biogas capture and treatment infrastructure. In the absence of regulation or profitable circumstances, biogas capture and treatment is unlikely to occur.
Overall, if projects are executed correctly, then waste biogas capture is highly likely to cause reductions in atmospheric greenhouse gas emissions.
In the absence of regulation or profitable circumstances, biogas capture and treatment is unlikely to happen. As such, carbon offsets can be catalytic for these projects in cases in which they are additional.
The cost of biogas projects depends on the size, location, and configuration of the site. There are significant capital outlays at the start of a project, as the physical infrastructure is designed and created. After the initial expenditure, there are routine costs to upkeep equipment and oversee operations. For projects that are not profitable and exempt from government regulation (e.g. too small), carbon offsets can provide a financial incentive to capture and use the biogas.
The EPA estimates that a privately owned and operated project with a 3 megawatt turbine and no previously installed capture system costs approximately $8.5 million to install and will lose approximately $3.5 million over a 15-year lifetime . While the above cost does not factor in tax credits or exemptions or the ability to use the electricity produced for on-site operations, the cost of biogas capture and treatment systems are often prohibitive for companies and municipalities .
The marginal additionality of waste biogas carbon offset projects varies based on where the project is in the project lifecycle. Before construction, while trying to achieve sufficient financing for the project to go ahead, carbon offsets are likely to be marginally additional (as long as the target goal is eventually reached). After construction, however, the marginal additionality of waste biogas capture projects is relatively low as the binding financial outlay is for the construction of the initial system. While in some cases carbon offsets might continue to fund operational expenses, we have not found any projects in this space that make a compelling claim to use carbon offsets in that way. Overall, we are not confident in the marginal additionality of this type of project, although do think that it is possible the marginal additionality could be there for the right project.
The improvement in emissions caused by waste biogas projects that destroy emissions is high. Once the emissions are captured and destroyed, they are not at risk of leaking back into the atmosphere and we do not think that the capture of these emissions is likely to increase the rate of other emissions.
For waste biogas projects that use the capture of these emissions to create electricity or other energy, we see the permanence as lower than that of the projects that destroy the emissions. These projects will often use the gases to create energy through a process that eventually emits them, meaning that they are not permanently removed from the atmosphere. In these projects, the benefit is more “clean” energy created by gases that would otherwise have just leaked into the atmosphere without any additional benefit. That said, we are less excited about these projects because the permanence of emission reductions is not as high as with the projects that destroy the gases altogether.
With projects that use waste biogas to create electricity or other energy, the co-benefits are more energy produced for the surrounding regions. We view this co-benefit as fairly weak as most of the surrounding where these projects are happening have other sources of energy.
Assessment of waste biogas capture projects
Carbon offsets for biogas are most “impactful” when they meet the best-in-class standards for carbon offsets - additional, not overestimated, permanent, not claimed by another entity, and not associated with significant social or environmental harms - along with meeting the following conditions :
Project is not required by regulation to implement biogas capture and treatment
Project is not profitable from the sale of renewable resources from biogas treatment
Project is capital constrained and will not happen without carbon offsets
Carbon offsets go directly to purchasing biogas project infrastructure or maintenance, as opposed to non-essential inputs
When reviewing projects for this report, we found that it was difficult to get enough information to determine whether projects met the above conditions, and simply being certified by one of the major certifying agencies did not give us confidence that the project was indeed additional. Given that these conditions are likely to be met by some projects, we expect that some biogas projects will meet the conditions to be impactful, and yet some will not. This appears to be confirmed by what other organizations that are researching this same topic have concluded .
For example, the GHG Management Institute and Stockholm Environment Institute say that the usefulness of landfill gas projects and associated carbon offsets depends on the project. They state: “Varies by location. Projects are likely additional in most parts of the developing world. In developed countries, including the United States, some projects are pursued to avoid triggering regulatory requirements, and projects that generate energy can be economical without carbon revenue.” The report also describes how there is uncertainty in baseline levels of methane output with these projects, which further adds to the difficulty of quantifying their impact .
We thought a good place to look would be waste biogas projects in developing countries, as these are less likely to have regulation requiring these systems. Unfortunately, we found few available for sale online. There were a couple of promising candidates offered directly by the UN, capturing biogas from agricultural waste in India and Thailand. However, after further consideration, we didn’t feel comfortable recommending either.
The Ratchaburi Farms Biogas Project in Thailand is a biogas capture system that generates energy for use on a large pig farm. The first issue with additionality is that the system may be profitable, and as a large company it’s plausible that the farm may have made the investment without the carbon credits. But more worrisome is that the project is quite old. It started operating in 2008, and in its original application for offset certification, it requested credits for 10 years. The project was a partnership with the Government of Denmark, who committed to buying some of the credits as part of their commitment under the Kyoto accord. So as far as we can tell, the current offsets for sale were generated before 2018 but were not part of the purchase agreement with Denmark. Given this, it is quite hard to believe that expectation of voluntary offsets purchases 10 years in the future actually contribute to additionality.
The Mabagas Power Plant in India is somewhat more promising. It generates energy by procuring animal waste from nearby farmers and creates energy by feeding this waste into its digesters. Without this plant, this waste would degrade and release biogas into the air. There are no regulations requiring the construction of the plant. However, there are a couple of worries that have prevented us from recommending these offsets. First, the project seems plausibly profitable. Although the IRR documents submitted as part of the offset certification procedure claim that selling carbon credits is necessary to achieve viability, these numbers are hard to verify. Next, there is a question of who precisely is on the receiving end of these offsets. Mabagas was launched as a joint venture between two companies that mainly deal in (petroleum-based) oil and gas: the state-owned Indian Oil Company, and the German company Marquard & Bahls. As revenue from offsets will ultimately flow to these companies or their subsidiaries, it is unlikely that this capital will fuel more green projects. Overall, we don’t feel like we can recommend these offsets given the information available at this time.
Frustrated by our search for international projects, we instead turned our search towards the US. Although large emitters are required to install methane capture systems, small landfills are not covered by regulation, and can certainly be spurred to build capture systems due to carbon credits. However, regulations are constantly changing , and plants may install landfill gas capture systems in anticipation of coming under regulatory authority (due to expansion or changing regulations).
We explored US landfill gas offset options and at least given the data available, felt unable to confidently recommend any of them. For instance, this landfill in Massachusetts seems to be a project that was very much spurred by carbon credits, with credits originally issued for ten years. However, the offsets available for purchase now are for the second issuance of offsets, while the actual infrastructure seems to only have been modestly updated. So it’s unclear what additionality these new offsets are providing. The Hilltop Landfill in Virginia was a small landfill that installed methane capture financed with carbon credits. But the landfill closed in 2013, and it seems like the investment has already been refunded from previous carbon credit sales . So further sales are likely not additional. Other options we explored are larger landfills that seem likely to fall under methane capture regulations as they grow or as new regulations are put into place.
Overall, we believe that there are likely good biogas offsets that are additional, but currently, we have been unable to find any that meet our criteria. As not all offsets are offered online, it is possible that these high-quality offsets are being directly sold to corporate buyers or are only transacted through brokers. Giving Green will continue searching for biogas projects we can recommend with confidence.
This work is preliminary, and subject to change. Questions and comments are welcome at email@example.com.
 Direct-use projects (i.e. where the energy created is used to power upkeep of the landfill) cost less and have a slightly higher ROI, but are less common because they require their facilities to be nearby.