I’ll be honest, I don’t know enough about the engineering or the economics to understand whether these projects can work out in the long run, but points for thinking outside the box.

Recently announced (late 2021) project in Chhattisgarh (a state in Central India): https://indianexpress.com/article/india/chhattisgarh-generate-electricity-cow-dung-7551808

Longer running project at Dodge City: https://www.tpomag.com/editorial/2019/06/a-zero-stream-discharge-treatment-plant-now-produces-pipeline-quality-methane-from-its-biosolids

Wisconsin dairy farm powered by the methane from its own cattle waste: https://www.wisbusiness.com/2021/crave-brothers-farm-highlights-manure-digester-ahead-of-earth-day/