Given their lower cost and higher output, solar hot water systems are generally more cost effective than solar electric systems.
There are many different technologies of solar hot water heaters. The most appropriate solar hot water technology for Louisiana is known as active, indirect drainback. These systems are efficient, durable, safe and generally require little maintenance. In addition to collectors on the roof and a storage tank, these systems include a heat exchanger and controller to monitor and limit water temperatures.
Solar hot water systems vary greatly in cost. A high output system that will produce 90% or more of your hot water needs will generally cost in the range of $6,500 to $7,500 per house.
The high output solar hot water system described above can be expected to produce the equivalent of 2,600 kWh per year or approximately 3-4 times the energy output that would be expected from an equally-priced solar electric system.