A solar water heater is a fairly easy way to become more energy independent, more environmentally friendly, and save some money in the long run. Solar water heaters absorbs the sun’s energy, and use it to warm your household’s water, so less electricity is needed to get it to the temperature you want. The result is an energy bill reduction of 10-20% for the average American household.
Solar waters use one of two possible systems: active and passive. Active systems use pumps to move the water through the cycle. They are more expensive, and require a secondary power source to run the pumps. Most of this is made up for by their increased efficiency, though, and they allow for greater design flexibility. In colder climates, active systems may be your only option.
Passive systems don’t have pumps, but rather use natural convection currents to move water through the cycle. The water tank is positioned above the heating panel, and as water is warmed it naturally moves upwards to the top of the tank. This pushes out the cooler water, which drops to the heating panel where it is warm and the cycle starts anew. Passive systems are cheaper, but less efficient than active systems.
Take a look at this article if you’re interested in building your own solar water heater.
In the US, a solar water heater will generally run in the range of $2000 to $8000, with installation costing another 10-20%. The cost will depend on your climate and your water needs. Your costs can be reduced by taking advantage of government rebate program that offers to compensate you for 30% of your total costs, up to $2000. The offer is place until 2016, but to be eligible your system needs to be certified by the Solar Rating Certification Corporation.
Good luck and stay prepared!