This is not well captioned. I guess this is a chart of fuel combustion? Meaning, mostly coal, oil, and natural gas (with relatively small amounts of wood, peat, and other combustibles)?
Excluding non-combustion energy (hydroelectric, etc)? All reduced to a single unit of measurement, for example BTU's? Is this correct?
Just trying to figure out what it's a chart "of".
5 posted on 05/16/2020 9:01:12 AM PDT by Mrs. Don-o
(Enquiring minds want to know.)