Batch solar water heaters use the sun’s energy to heat water for your home. Batch solar water heaters are the simplest and most reliable solar water heaters, being simply a water tank inside a well-insulated box with a glass cover. Batch solar water heaters are also called breadbox, integral, or self-contained solar water heaters.
If you live in a sunny climate where frosts are rare, this simple appliance could cut your water-heating costs 50 to 80 percent. The larger your water-heating usage, the larger your savings. Batch water heaters cost from $2500 to $5000 installed.
The design idea is over a century old, originating with a model called the Climax, patented in 1891. By 1897, thousands of Climaxes dotted the landscape in Southern California. They were commonplace in California until the late 1920s, when natural gas was discovered there and fuel prices fell sharply. Florida had 60,000 batch water heaters by 1941, but again fuel prices fell and the market for solar all but disappeared.
On cloudy days or when household hot water use is high, most batch water heaters can’t supply enough hot water. Therefore, the water heated by the batch heater flows through your existing water heater where it can be heated further to the desired temperature.
The average household consumes most of its hot water in the morning. Batch water heaters, however, deliver most of their hot water late in the afternoon and early evening. For this reason, you’ll get maximum benefit from a batch water heater if you use hot water in the afternoons or evenings. Since, the batch water is connected to a standard water heater you won’t notice the difference in water temperature between morning and evening. The difference is that afternoon and evening use will save more energy and money.