I’m not sure how solar works in parts of the world with cold weather and gloomy skies. I think you need to see the sun for the solar panels to collect the heat, as they rely on the radiative heating effects of the sun to warm the black surfaces. Most of the heating devices that I have seen which use solar, utilize black copper tubing to heat the water or air inside. I guess that is how the heating part works when it comes to solar heating devices. I would like to have one now because my central unit just costs way too much to run on a regular basis during these cold winter days. There is no sun though so I don’t even think solar would be an option today, unless the solar can somehow store the heat that was collected previously. But I really don’t know how it works as I am not an HVAC professional or anything like that. So yeah, today is a cold one and I am going to work for a couple of hours and then ride my bike to go visit my friend who lives in a little campervan. She doesn’t have any gas heating in the van right now because she had to order a nut for the gas line. I have it because she had to get it mailed to my flat because she has no address, living in the van and all. She must be cold though because of no HVAC system and the temps this morning getting close to the freezing zone.