2,075% efficient!!
Collecting solar energy only requires the energy of a pump. Efficiency is defined as the energy returned from each unit of energy supplied. Because the heat energy of the sun is free, providing the energy to power a pump (a lightbulb or two) can provide you with enough heat energy to heat your house...your hot water...your hot tub!
Solar water heating converts 65% of the sun's energy to heat!
Most of the US southwest has ideal conditions for solar heat. Northern Arizona has better than ideal conditions because of the cold, sunny winters. As long as you build your home with a hydronic (water) based heating system, you can augment that heating system and reduce your energy bills by using solar hot water.
Even if you don't have hydronic heat you can cut your energy bills by using solar hot water for your domestic hot water.
Notable reductions in your home's emissions of carbon and carbon dioxide are a welcome side effect.
If this is interesting to you, contact Radiance Heating and Plumbing, Inc at 928-380-6294 or info@radianceheating.com