GAS OR OIL ?

[Cassis]

Blimey!  There's food for thought.  In reality, I guess the difference is tempered somewhat by the relative efficiency of appliances in giving useful and usable heat (like how much goes up the chimney and how well heat is delivered to where it is needed).

[Gyn_Paul]

At least with electric heating you are getting close to 100% heat out of the energy consumed. While oil may be (comparatively) cheap, I can't put my hand on the boiler flue, so clearly there's a hell of a lot of heat going up the flue warming the outside wall of the barn. I suspect something like 30% of my 63c/L is warming La Creuse.

Which is probably no bad thing today with the amount of snow we have here at the moment: it's been coming down continuously for the last 26 hours, and is now some 8 -  10 inches deep except in the drifts where it's a fashionable mid-calf depth.

p

[Gluestick]

Which, of course, a decent condensing boiler would partially capture, GP.

With a wood-fuelled burner, the same waste applies.

However, with judicious use of the flue, then much of this "Waste Heat" can be employed to radiate heat into the building before it finally vents into the outside.

Using electricity, though, yes, you are absolutely correct: once the heater has raised the core (heater) temp to its working temp level, then it will radiate far more than any indirect heat-exchanging system.

That's why straight Cost/Kw comparisons can be highly misleading.