How Solar Water Heating Works

07/05/2021

1. Light is absorbed by solar collector
The solar water heater absorbs light by means of a collector placed on the roof and converts it into heat. Water flows through the panel and is heated by the sun.

2. Heat transferred to water tank
It then runs to a solar storage tank connected to your existing water heater. Your water heater only turns on if the solar-heated water still needs a temperature boost. Hot water flows out of your taps just like it always has, but your water heating bill could be cut 60-80%. You will also reduce greenhouse gas and other air polluting emissions from your home!

3. Insufficient sunlight? Back-up electricity heating system
When there is insufficient sunlight, you can open the electric heating system. This system can therefore be used at a constant temperature throughout the year. Most solar water heaters with electricity heating system for extra charge, you can consult your supplier for details. There are two basic types of rooftop solar collectors:

Flat-plate collectors contain a working fluid (water or a waterglycol mix) that flows through tubes in the collector, is heated directly by the sun and carries that heat to the hot water storage tank. The dark glass covering and insulated backing are specially designed to collect heat and prevent it from being radiated back out of the collector.

Evacuated tube collectors have a set of long dark glass tubes with metal absorbers in their cores, which are heated by the sun. Cool working fluid flows past the top of the metal absorbers, is heated, and carries that heat to the hot water storage tank. The glass tubes are vacuum-sealed, making them very efficient heat collectors. The round tubes also help to capture solar energy even when the sun is lower in the sky.