LED light actually generate plenty of heat already. The problem is that to make them an easy replacement unit for the old incandescent bulbs, the heat-sinks were put on the back of the unit. Moving the cooling fins around to the front would have made them very efficient snow-melters, maybe even better than the old bulbs. As I recall from previous discussions about these, over in Europe they don't have a problem with snow build-up in new LED equipped lights, because they were designed to make use of their heat.

I wonder if a maser might be a better delivery system than a laser. Might be able to ignite lower volatility liquids.