There are many excellent industrial applications for solar water heating. The most effective are those that require ‘warm’ rather than ‘hot’ water, since solar collectors operate more efficiently at lower temperatures. The most favourable applications are those where water is required between 32° and 38°C (90 to 100°F).

In a typical design, the solar water heating system connects to an existing hot water system and preheats the potable or domestic hot water. The type of system and its application are important considerations, but solar water heating systems all include solar collectors, either roof or ground mounted, facing south.

Collectors are available in various sizes, typically with low-iron, tempered glass with a matte finish to reduce reflection, and a smooth finish outside. Most industrial systems have a large collector area. While a prepackaged residential solar system is two panels of 6 sq.m, industrial systems require 40 to 400 panels, with 120 to 1,200 sq.m of collector area.