Get a better concept of the BTUs in firewood on the sticky here @ chimneysweeps online. It's a clear listing ( same as some of .edu listings from universities) with 2 columns for comparison of heating values.
Red/Soft Maple is at the low end OF THE HARDWOODS in millions of BTUs per cord. Cottonwood is way down among the softwoods in heating power per cord = 12.6, with Balsam Fir for example @ 13.1 MBTY/cord. No comparison to Soft/Red Maple.
Soft Maple is one our primary woods with Paper/White Birch (20.0 MBTU/cord). We got our first bought trailer load of 24' Red Maple logs last year which came out to close to 10 cords in volume on the ground before bucking, splitting, stacking. Cost=$800. Reason: shiny new titanium hip.:hmm3grin2orange:
Burns OK, hard starting unless bone dry, but holds coals well overnight. Soft Maple tends to heart rot easily, so some of the log is lost for firewood, though it stores better than our other primary wood, Paper Birch ( scored along the bark for butt storage ).
We burn what we got, avoiding softwood except in shoulder seasons.