Electricity was stupid expensive in the 90s in Ontario so it made sense to invest in cogeneration engines to burn digester gas or even natural gas and use the electricity on site. Then electricity got cheaper so it still made sense to burn biogas generated on site to lower your peak demands especially if you were paying time of use or you were Class A and needed to do load shedding. Sometimes you’d even get a discount from the electricity company for running your systems because it meant they could delay increasing the grid.

Now, the financial incentive is for carbon credits. You don’t get those if you burn on site, you just get to buy less taxed fuels. If you instead upgrade the gas to renewable natural gas (like what is described in the article) and put that in the natural gas grid, you can sell the carbon credits to companies who are required to offset their own generation. I think that is where the money is in these schemes.

(That and the tipping costs for food waste, free slowly digesting material to regulate the digesters in the form of the manure, outsourcing the annoying regulatory bits to the farmers, and building goodwill for green data centres)