Today I gave a presentation to a group of people who supported our crowdfunding campaign last year. The story I often use then is: "Biogas has three times the contribution to the SDGs of planting trees. The source of this is the Gold Standard, a well-known certification for voluntary emissions trading.
While researching the source, I found a report on the differences between Biogas and other efficient cookstove projects.
Firstly, the difference between Biogas and tree planting: the SDGs monetised per carbon credit is $465 for Biogas and $177 for tree planting, so we see 2.6 times greater impact. By the way, one carbon credit is not necessarily one tonne, but it is generally recognised as one tonne. You can find an explanation of this in the link below, too.
https://www.goldstandard.org/blog-item/carbon-pricing-what-carbon-credit-worth
Using the same logic here is a report that shows the difference between biogas and efficient cookstoves/projects such as rocket stoves.
This report also shows that Biogas' contribution is $465, while other efficient cookstove projects are $267. This means that Biogas contributes 1.74 times more than rocket stoves and other stoves.
When it comes to what are called greenhouse gases under the Kyoto Protocol, there is no difference between rocket stoves and Biogas. When it comes to soot (black carbon) and organic carbon -- greenhouse gases not covered by the Kyoto Protocol, rocket stoves seem to create slightly more value. But when it comes to health and other aspects of life, there is a big difference between the two home energy projects.
Biogas, which emits no smoke at all, is three times more benefits than rocket stoves when it comes to health. Biogas creates twice as much value as rocket stoves, which are more efficient but still need to pick up firewood, whereas we don't have to pick up firewood at all. These add up to an overall difference in SDGs contribution of 1.74 times.
How we calculate this is explained briefly in this report. As mentioned in my article on calculating SDGs, there is sociological fuzziness, but this report has some credibility.
Biogas was presented as the technology that creates the most socio-environmental value at the 5th Global Climate-Smart Agriculture, which I attended in 2019. Even at the last paper of TransRisk, a research project of the European Commission Horizon2020, it was reported that Biogas is the only project in developing countries that fits the investment value.