Everything you need to know about solar energy, in one place.

Solar cooling uses energy from the sun to provide ventilation, refrigeration, or air conditioning. It can be as simple as a small solar attic fan or as complex as a thermal chiller for a commercial building. I find the technology useful because cooling demand often rises during the same sunny...

Solar panels on a roof usually suggest electricity, but some roof-mounted collectors serve a different purpose. Active solar heating captures sunlight as heat and uses pumps, fans, sensors, and controllers to move it through a building. The system can support hot water, space heating, radiant floors, or swimming pools, but...

Installing solar panels should not feel like a gamble with the roof protecting your home. Still, warranty concerns are one of the things homeowners raise before signing an installation contract. I prefer to look at the fine print before assuming the worst, because the answer is rarely a simple yes...

A 25-year promise sounds reassuring, but solar coverage is rarely that simple. One warranty may protect the panels, another may cover power output, and a third may apply only to installation work. The problem is that these protections often run for different periods, follow separate claim rules, and exclude costs...