Before considering the installation of a solar hot water system, steps should be taken to decrease consumption, increase efficiency, and reduce loss of hot water; a few simple changes can make a big difference. Turning down the hot water heater thermostat to 120°F, insulating hot water pipes and the water heater, repairing leaky hot water faucets, and replacing an inefficient hot water heater and/or plumbing will reduce hot water consumption and increase efficiency of an existing domestic hot water system. And because typically the shower is the largest consumption of hot water in the average residence, replacing a showerhead with a low-flow model can help reduce hot water usage.
The Solar Resource
With over 300 days of sunshine per year in Colorado, most locations are good choices when considering solar installation. The location of your home will help determine whether solar is a good choice. Data is available from the U.S. Department of Energy National Renewable Energy Laboratory (NREL) for many locations in Colorado and elsewhere. A fundamental requirement for a solar system is to have a sunny location where solar collectors can function properly. Locations were the sun is blocked from the collectors by the slope or aspect of the land, trees, neighboring buildings, or other obstructions will reduce efficiency. Solar collectors need to be placed where plenty of sunshine strikes the surface of the collectors, year round.
Prior to making the decision to install a solar system, determine if there are restrictions to placing solar collection panels on your home, by checking with your homeowner’s association, local building codes and zoning ordinances. Colorado law prohibits homeowners associations from preventing the use of solar energy devices, including solar hot water systems, in a way that would significantly increase the purchase price or operating costs of the system to the homeowner, or decrease performance.
It should be noted that although the state receives plentiful sunshine, the economics of solar hot water work better when offsetting propane than natural gas because of the current low price of gas. For those with electric hot water heaters, it is likely more economical to offset your use with solar PV than with solar hot water. Tax credits are available for solar hot water.