SAVED: PAGE: ACTIVE AREA:
Title:
Type ID:
1
Type:
Text
ID:
91
Active:
True
Parent:
3
Pos:
0
Style:
Title:
Type ID:
2
Type:
Image
ID:
96
Active:
True
Parent:
4
Pos:
0
Style:
Title:
Type ID:
2
Type:
Image
ID:
97
Active:
True
Parent:
4
Pos:
0
Style:

An Introduction to Solar Thermal

Solar water heating systems, (also known as solar thermal), capture the heat from the sun and use it to heat up water for use in the home. It’s a fairly simple process with the panels on your roof absorbing heat from the sun. These panels are known as the 'collectors'. The liquid in the panels heats up and is then pumped through a coil in the cylinder which in turns transfers the heat to the water in the cylinder.

Is solar thermal suitable in the U.K?

The ideal situation for solar panels is facing due south, although they are effective facing anywhere between south east and south west. As a rule of thumb you need between 1 and 2 m2 of collector (solar panels) per person living in the house. Shade on the panels at any time of day will reduce the performance.

It is important that they get direct sunlight and are usually roof mounted. To get the best results they should be at an angle between 20 and 50 degrees from horizontal (most pitched roofs fall within this bracket).

There are some important issues to bear in mind.If you have an electric shower it won’t use your solar hot water. Similarly cold-fill dishwashers and washing machines heat the water they use. In a situation like this, solar water heating is less likely to be suitable unless you use the bath for most of your washing and bathing as you won't be able to use much of the solar hot water you generate

Solar panels are compatible with most existing hot water systems. However, you will need a new cylinder with two or more coils and ideally it should be big enough to hold two days worth of hot water. Solar thermal solutions are more complicated when using a combination-boiler but it still possible. If you have a combi boiler it is important to check with the manufacturer that it will accept pre-heated water.

If your present system is gravity fed, it will need a control such as a valve and pump for the hot water circuit so the panels can work effectively in winter when the boiler is running for central heating.

How much hot water from solar thermal panels?

Solar thermal panels should provide most of your hot water from April to September, and make a worthwhile contribution in the months on either side of that period. The Energy Saving Trust found that solar thermal panels will provide about 60 per cent of a household's hot water needs, if well-installed and properly used.

They also identified a huge range of performance, with the best system producing 98 per cent of the household's hot water, and the worst just 9 per cent. The median across all systems was 39 per cent, so it is important to be proactive to maximise your solar gain.

How much you benefit will depend on a variety of factors:

• How much hot water your household or business uses. The higher the usage, the more benefit you get from a solar thermal system.

• How much interest you take in how the system works and adapt to make the most of the free hot water (ie having showers in the evening rather than the morning). The sun isn’t as reliable as a timer clock.

• The size of your cylinder. Many cylinders only hold enough water for a day’s supply of hot water, so a day or two of cloud and rain will mean you have to turn on the boiler or immersion heater.

• How you programme your back up heating. If your control panel does not allow you to programme the hot water and central heating separately, you may not get the maximum benefit from the solar panels when the heating is turned on. By only boosting the hot water once the sun has gone down, you maximise opportunity for solar heating.

• Adequate insulation of both cylinder and pipes carrying hot water.

• Allowing hot water temperature to vary. If you do not need high temperatures all the time, you will have less need for back-up heating. You will also reduce heat loss. However, it is important to make sure your cylinder reaches more than 60 degrees centigrade at least once a week to avoid the risk of Legionella.

For a free no obligation quote, or to find out more, enquire below or contact WMQ on 01698 372113.

> Contact WMQ

 
Solar thermal evacuated tubes

Solar thermal evacuated tubes

Solar Thermal Flat Plate

Above we see pictures of the different styles of solar thermal panel that are available - the top image shows the 'evacuated tube' style of panel and below this the 'flat plate' design.