Rising energy costs, nature and environment concerns … solar heating
With the increasing cost of gas and electricity, the decline in traditional energy resources and the constant reminder of global warming, domestic energy conservation is now a high priority.

Solar heating for domestic hot water is the now regarded as a leading green technology and is a viable solution in all parts of the UK. The technology is well developed with a large choice of equipment to suit many situations. Solar water heating systems work alongside your conventional water heating system.

How does solar energy provide domestic hot water heating?
In simple terms the sun’s energy is used to heat water in a storage cylinder. The energy collectors are placed on an approximately south facing roof or wall and a fluid is pumped around a sealed system to an indirect heating coil in a hot water cylinder to heat the domestic hot water (very similar to the way a boiler does the same job).

The solar heating works along side your boiler reducing the need for the boiler to heat your domestic hot water. The existing cylinder is exchanged for a cylinder with two heat exchanger coils; one from the boiler in the property and a second from the solar panels.

More details of a Typical Domestic Solar Heating System for Hot Water

How effective is solar heating likely to be in the UK?
The solar panel technology is now well developed and the solar panel collectors absorb energy from the sun even on cloudy days in the UK. The solar thermal technology does not rely on sunlight but on solar radiation so it can work efficiently in our UK climate.

Typically a well designed domestic hot water solar heating system should provide approximately 50% of your domestic hot water heating needs of your home averaged throughout the year. This provides a worthwhile saving in energy costs and is helping the environment.

Solar Heating Grants
Grants are available to help meet the cost of installing domestic solar hot water heating systems.

A Typical Domestic Solar Heating System for Hot Water
A typical solar panel domestic hot water heating system layout uses a twin coil cylinder which is fed by both a boiler (or other heat source) and the solar panels. The solar panel system and the conventional heating system work together to heat the domestic hot water. They share the hot water storage cylinder (which you would normally have to change to a suitable twin coil cylinder).

The solar panel hot water system has its own pump, expansion vessel, pressure relief valve, air vent and controller.

The solar panels are mounted on a roof or suitable wall selected to maximise the exposure to the sun’s energy – so ideally a south facing roof with a 45 degree angle.

The solar panels are then connected via pipe work to the lower coil of a twin-coil hot water storage cylinder.
The energy in the sun’s rays is collected by the solar panels and the heat is transferred into the pipe work. The pipe work is filled with a suitable heat absorbing liquid (a glycol and water mix) that won’t freeze in cold weather. The liquid is circulated by a pump to the coil in the hot water cylinder to exchange heat. The solar heating system is equipped with a simple controller to regulate the flow of energy from the panels to the storage cylinder to maximise the use of the available free solar energy.

The conventional boiler tops up the heat provided by the solar heating system as required and continues to supply hot water for the central heating system.
Effectiveness of Siting of Solar Panels

Ideally the solar heating panels should be installed in a southerly direction at an angle of around 45 degrees. Where this is not possible the installation should move towards a westerly facing direction. East and North facing directions should be avoided.

Hot Water Storage Cylinders
The solar panel system and the conventional heating system work together to heat the domestic hot water within the twin coil storage cylinder - which you would normally have to swap for your existing cylinder.
To make the most of summer sunlight and the higher potential solar energy gains a 2 panel solar hot water system should ideally be combined with a 300 litre cylinder. If this is not possible it is recommended that a storage cylinder of at least 200 litres storage is used.

Planning Permission
In general the installation of solar panels is reasonably straight-forward with most local authorities regarding the solar panels as similar to flush fitting roof-light windows, where planning permission may not be required.
However it is wise to seek the opinion of the local authority on planning matters prior to starting work on the solar panel hot water system installation. Requirements vary from one authority to the next both with planning permission and building control procedures.