The best active renewable energy investment most homeowners can make is solar thermal water heating. Generating electricity using photovoltaic panels (PV) is being highly publicized, but compared to solar thermal collectors and systems, the PV systems are comparatively inefficient and expensive. In Denver for example, SWH collectors can convert approximately 70% of the energy in sunlight striking the collector into hot water, typically producing five times more usable energy per dollar invested then electric generation options. A professionally installed system with only 50 to 60 square feet of collector area can produce 15 to 20 KWH per day at an installed cost of $6,000. to $8,000. To generate that amount of energy with PV, a system size of about 3.5 KW would be required, costing $30,000. to $35,000. and taking up to five times the roof area. While each home is different and the optimal system type depends on a wide range of variables, packaged systems developed and proven in the European SWH market have simplified and streamlined solar thermal applications and are now available here in the U.S. The Velux Solar Water Heating System is a complete packaged system that is now available for installation by Velux certified installers, and provides the homeowner with a worry-free system warranty from one manufacturer. | 
