The temperature they are getting on the water loop is about 105 F. This isn’t hot enough for baseboard heaters to do much they really need to be 165 to 185 F. But it would be plenty hot for radiant floor heating and you could probably get up to 120 for hot water. If it would make enough voltage to run the circulation pump it would be really handy off grid. 100 watts on the biggest unit and probably the stove has to be really cranking to do that. But this is the first time I have seen these used for something besides a toy fan on top of a wood stove.