Types of system
There are two main types of solar water heating panels/collectors.
Flat Plate Collectors
Flat plate collectors look more like traditional solar panels. They have a flat, glazed, dark-surfaced absorber plate which contains metal tubing. The plate covering the tubing, which is normally copper or aluminium, absorbs the solar energy and the casing stops heat from escaping from it. A fluid is constantly run through the tubing which is heated up by the solar power captured from the sun.
Evacuated Tube Collectors
Evacuated tube collectors have a very different look. The panel is a collection of glass tubes in a parallel row which have an absorber insulated by a partial vacuum. They have been proven to be more effective throughout the year than flat plate collectors, but are also generally more expensive, too.
There are two different types of evacuated tube solar panels. Direct Flow, where the fluid flowing in the absorber also flows through the pipes to the hot water cylinder. And Heat Pipes which have fluid in them that evaporates at a low temperature. When the fluid evaporates it rises up in the tube and condenses, transferring the heat it was carrying and the latent heat of condensation into the pipes into the hot water cylinder. The fluid then runs back down the tube again ready to be re-heated.
Unglazed collectors are also available but they are designed to be used in conjunction with lower temperature applications like swimming pools rather than as a household hot water heating source.
Solar hot water is the use of solar panels, also known as collectors, to collect heat from the sun during the day to heat water which is then stored in a hot water cylinder.
It’s not a traditional form of solar power as it doesn’t generate electricity, but is a solar energy source of heating your home.
There are currently two types of solar water heating collectors that you attach to the roof. Either a flat plate collector, which look like more traditional solar panels, or evacuated tube collectors which is a line of tubing attached together into one sheet.
Solar water heating provides your household with hot water throughout the year. It won’t be a completely independent system though as it will need a boiler or immersion-heater through the winter months to guarantee you have hot water. But having a solar water system installed will definitely cut your bills and reduce your carbon footprint.