James Beck said:
Why run a wire through the thing when hot "water" would do just as well,
AND the technology is already out there. Small hot water heater,
radiant floor tubing, recirculator pump, a pressure bladder for reserve
liquid/expansion control, temp sensor and/or manual switch. A 50/50 mix
of automotive antifreeze and water. Done.
The hot water heater won't be small; or if it is, the driveway won't be
melting snow for more than the first few feet of tubing. The bill to run
it will be large. Any have the common sense to use polypropylene glycol,
not ethylene glycol - any leaks will kill less of the neighborhood pets.
The ONLY way this makes any sense, and limited sense at that, is if you
use solar heat, and are content to have the driveway more effectively
melt off when the sun shines (ie, faster and/or more throughly than it
would do just from the sun shining on the snow). The cost to do so is
still high, but at least it's not an ongoing expense. It would let you
relocate heat from where the sun shines to less sunny parts of the
driveway.
Not completely true: if you happen to have a hot spring or other source
of vast waste heat in your house, the driveway makes as good a place to
dump it as any. But that isn't a common problem...