The reciprocating Convairs have a wing heated by augmentor duct air from the exhaust. This brings to mind an important distinction.
There are two types of heated wing systems. The system used by the Convair is known as a "running wet" system. It is not capable of evaporating the water impinging the wing. Rather, it simply prevents it from freezing. This usually, as in the Convair, leads to re-freezing aft of the protected surface. The result is typically a sawtooth pattern of thin ice ridges, more longitudinal than lateral.
The more common installation is known as a "fully evaporative" system. This is designed to evaporate the liquid water impinging the wing. The advantage, of course, is the wing will be long gone before the water re-condenses.
One caveat is that all evaporative systems necessarily transition through a running wet period while warming up to operating temperature. This requirement is what drives things like minimum N1 during descent; it wouldn't do to have the system cool into a running wet condition when the power is retarded. This is also one of the shortcomings of such designs as the MD80, in which the wing is cooling while the tail is being heated, and vice versa.
Both types of systems can be used as either anti-ice or de-ice systems. Boeing currently recommends a de-ice method in most designs, although once you select it, it functions as an anti-ice system if you just leave it on.
The required energy is driven by the wing surface area that is intended to be heated, which in itself is a function of how much chord will be protected. It also depends on the operating speeds in the design specification, and whether the system will run wet or evaporate. It can be pretty substantial. Most turboprops try to recover as much energy from the gas turbine as possible; anything that goes out the tailpipe is essentially wasted (yeah, they count it as thrust, but...). So bleed air is a precious commodity, and the energy balance between needs and availability drive manufacturers toward boots. I suppose you could hang a couple of Allisons out there or something like that, but then your specific fuel consumption goes through the roof and the customers don't really care for that.
Hope that is helpful