thisischemistry t1_ituqtws wrote on October 26, 2022 at 1:38 PM

Reply to comment by Prolapseinjudgement in Move over, diesel: Ohio gets ‘first of its kind’ renewable gas station by redingerforcongress

It's a net positive as long as they are getting the methane from sources that would be there already. For example, if the animals are already being farmed for other reasons and the manure is just fermenting and releasing methane that's not being captured.

Capturing this existing methane and burning it is a pretty big win for greenhouse gas reasons. Using that energy to replace burning diesel is also a pretty big win. It's not as good as phasing out the need for both farming animals and running internal combustion engines but it's a great bridge to when that can happen.

mirhagk t1_itxnmdh wrote on October 27, 2022 at 1:30 AM

Getting it from sources that would already be there, or from sources derived ultimately from the atmosphere.

For instance even if the animals are farmed solely for methane, the animals are converting carbon in plant matter to methane, and those plants are convert atmospheric CO2 to carbon. So ultimately the process is net-zero carbon.

thisischemistry t1_itxvs7m wrote on October 27, 2022 at 2:33 AM

It's only net-zero if you don't consider all the other inputs, such as the fuel used in processing and transporting feed. A considerable amount of energy goes into farming and there are considerable impacts from the farming.

I agree that if this methane capture and use is a side-effect of farming then it's a bonus to reduce the impact of the farming. It would still be tough to call it net-zero carbon.

mirhagk t1_itxx944 wrote on October 27, 2022 at 2:45 AM

Well yeah the processing and transportation always complicates things, the net-zero is talking about where the carbon that is released is coming from.

Stuff like feed you can't really analyze in the abstract, since there are many different ways it's done, and AFAIK most cattle farms either grow feed on-site or are grass-fed. Transportation costs are expensive, and better farming techniques have expanded the locations grain can be grown. Of course there definitely exists farms that do transport feed in, but looks like this dairy farm in particular is also a grain farm.

I think when looking at investing in things like this it's more important to look at whether it can be net-zero, and whether it's improvement on the status quo. In this case both are true, it could be net-zero with improvements in other areas and it's definitely an improvement on the status quo.