Their big claim, in spite of overwhelming evidence to the contrary, is that coal can produce electricity three times cheaper than natural gas. (judithcurry.com)
Per energy unit, oil produces less CO2 than coal, but more than natural gas. (newworldencyclopedia.org)
Forest chips were 2 - 3 times more expensive than natural gas and coal but cheaper than heavy oil. (sciencedaily.com)