Thanks, didn't see this comment while I was digging for references for mine... I'm sure I read something more recent & more quantitative. But the site you link

Thanks, didn't see this comment while I was digging for references for mine... I'm sure I read something more recent & more quantitative. But the site you link has this which is not bad: https://solar.lowtechmagazine.com/2011/09/peat-and-coal-fossil-fuels-in-pre-industrial-times.html https://solar.lowtechmagazine.com/2011/09/peat-and-coal-foss...