When I worked at a lumber mill as a young man, the mill generators were powered by coal but was also fed saw dust from the sawyers in the mill. lots and lots of saw dust.
That was in the 60s and it wasn’t for any “green” reasons, just a prudent use of what would have been a waste product.
I used to have my garbage picked up by Waste Management, they were always hyping the fact that they were a “green” company. When the bill reached $80 per quarter, I switched providers and went with a company that didn’t claim to be “green” for $48 per quarter. Frankly, I don’t care where or how they dispose my garbage, I’m sure they comply with the law in such matters without spending extra dollars being politically correct.
I've tried to make my sister, who makes her living as an environmentalist wacko understand this kind of thing, but she apparently has too much invested in it I guess. Smart businesses will be 'green' as a natural part of their business if it makes sense. If it doesn't make sense ... then it still doesn't make sense by calling it 'green'. Companies that don't take advantage of any 'waste' product and other processes are terminally stupid and will eventually be beaten into submission or bankrupcy by those who do.