Heating water

Sun, 19 Jul 2009 12:58:13 +0100

Solar water heating systems use free heat from the sun to warm domestic hot water. A conventional boiler or immersion heater is then used to provide hot water when solar energy is unavailable.

How do solar water heating systems work?

Solar water heating systems use solar panels, called collectors, fitted to your roof. These collect heat from the sun and use it to warm water which is stored in a hot water cylinder.

A boiler or immersion heater can then heat this water further until it reaches the temperature set by the cylinder's thermostat. (This should be set at 60 degrees centigrade.)

Larger solar panels can also provide energy to heat your home as well - though usually only in the summer months when home heating is unnecessary.

Hot water throughout the year: the system works all year round, though you'll need to heat the water further with a boiler or immersion heater during the winter months.
Cut your bills: sunlight is free, so once you've paid for the initial installation your hot water costs will be reduced.
Cut your carbon footprint: solar hot water is a green, renewable heating system and doesn't release any harmful carbon dioxide or other pollutants

Is a solar water heating system suitable for my home?

To tell if solar water heating is right for you, there are a few key questions to consider:

Do you have a sunny place to put solar panels? You'll need around 5 square metres of roof space which faces east to west through south and receives direct sunlight for the main part of the day. Alternatively, if you have space, you could install two panels, one facing east and one facing west - but this will make installation more complex and costly.

Do you have space for a larger, or an extra, hot water cylinder? You will need this to allow room for a solar heating coil to warm your water.

Is your current boiler compatible with solar water heating? Most conventional boiler and hot water cylinder systems are compatible with solar water heating. If your boiler is a combination boiler (combi) and you don't currently have a hot water tank then a solar hot water system may not be compatible.

Do you need planning permission? In England most solar water heating systems don't need planning permission, but it is always best to consult your local planning office if you live in a Listed Building, or a building in Conservation Area or World Heritage Site. If you live in Wales, Scotland or Northern Ireland you will need to consult your local authority.

Cost and savings

Costs for a typical solar water heating system range from £3,000 to £5,000.

Savings are moderate - a solar water heating system can provide about a third of your hot water needs, reducing your water heating bill by between £55 and £95 per year. It will also save up to 645kg of CO2 emissions, depending on what fuel you will be replacing.

Maintenance costs are very low. Most solar water heating systems come with a 5-10 year warranty and require little maintenance. You should take a look at your panels every year and have them checked more thoroughly by a professional installer every 3-5 years.

Fuel Displaced	£ Saving per year	CO₂ saving per year
Gas	£65	325 kg
Electricity	£95	635 kg
Oil	£85	365 kg
Solid	£55	645 kg

All savings are approximate and are based on the hot water heating requirements of a 3 bed semi detached home with a 4m squared panel.

heating-water

Heating water

How do solar water heating systems work?

Is a solar water heating system suitable for my home?