Renewable heating options: heat pumps, solar panels and wood stoves

You could save money on your heating bills and reduce your carbon footprint by switching to renewable heating but which option suits you best – a heat pump, wood stove or solar thermal panels?

Heat pump

Heat pumps extract warmth from the earth,
water or air to heat your home

A heat pump produces hot water and heating for your home by utilising free, natural heat found in the ground, air or water. A pump cycles refrigerant round pipe work, which collects heat to transfer into the home through radiators, ducts or underfloor heating. In the summer pumps can be reversed to cool your home. Helen Durose, from Evergreen Renewables in Derbyshire says heat pumps are so popular because: “They are environmentally-friendly, require little maintenance and can increase the retail value of your home.”

Is your home suitable for a heat pump?

You need a well insulated home to install either a ground, water or air source heat pump. Installing a ground or water source pump requires space in the garden for either drilling boreholes or laying coils of pipe in a trench. Air source pumps however, fit neatly onto the outside of your home and are about the size of a fridge.

Pumps tend to work best with underfloor heating and are most cost effective when installed in a new build. Panning permission is not needed for ground or water pumps but you must check with the local authority before installing an air source heat pump.

How much can a heat pump save you?

Heat pumps are measured by their coefficient of performance (COP) this measures how much heat is produced compared to how much energy is needed to power the pump. “Heat pumps have an efficiency of around 4:1,” says Frank Harris from H.D Services Ltd in Buckinghamshire. As well as requiring very little electricity to run, installing a heat pump will eliminate gas, oil or solid fuel bills completely.

According to the Energy Saving Trust (EST), replacing gas heating with a ground source heat pump would save £190 a year and replacing electric would save £840 and six tonnes of CO2. Air source pumps result in less dramatic cuts and you will save most when replacing electric heating; around £700 and five tonnes of CO2 per year.

How much do heat pumps cost?

Helen says that: “A heat pump for a five-bed house could cost between £12,000 and £15,000.” The Low Carbon Buildings Programme suggests that an 8-12kw system could cost £6,000 to £12,000.

Solar thermal heating

Solar thermal heating can provide up to
65% of your hot water needs per year

Solar thermal heating produces hot water for your home by using either evacuated tubes or plate collectors to capture the sun's radiation. Many people think the UK isn’t hot enough for solar panels, but according to the Solar Trade Association (STA), the UK receives 60% of the solar energy received on the equator. What’s more, panels can operate on clear days with no sun too.

Howard Johns, Chairman of the STA says: “There are an excess of 100,000 of these systems out there already, far more than any other renewable heat technology.” Solar thermal heating usually comes with a five to ten year guarantee and requires very little maintenance, says the EST. A check each year and professional service every three to five years is advised.

Is your home suitable for solar thermal heating?

To install solar panels, your roof should ideally be south facing and have an incline of 35 degrees (panels can be mounted onto flat roofs). At least a five metre squared space is needed for panels to be effective.

In England if you live in a listed building, conservation area or world heritage site then you will need to apply for planning permission for solar panels. Planning shouldn’t be a problem on other properties as long as you follow guidelines, which include making sure the panels don’t protrude more than 200mm and that they take up no more than a nine metre squared space. Always apply for planning permission if you live in Wales, Scotland or Ireland.

How much can solar thermal heating save you?

The STA say that solar thermal heating could provide a family of four with 50 - 65% of their hot water needs per year. According to the EST solar thermal heating can reduce your bills by around £50 to £85 a year and save up to 580kg of CO2 a year, depending on what type of heating you are replacing.

How much does solar thermal heating cost?

The EST says that panels cost between £3,000 and £5,000, depending on size.

Wood stove

You could save up to £410 a year with a wood stove

Wood burners run at around 70-80% efficiency and produce less carbon than any fossil fuel when heating your home. Whatever CO2 they do produce is offset by the amount of CO2 the plant has absorbed during its lifetime. “If you replant the trees you cut down, wood burners are completely carbon neutral,” says Alex Hunt, from Bright Green Homes in Brighton. You can choose between a standalone stove or a central wood boiler connected to the main heating system.

To maintain your wood stove you will need to remove ash regularly and clean the throat plate occasionally. The most important thing is to have your chimney swept: “I would recommend doing this at least twice a year,” says Paul Labus, from Bolney Stoves Ltd in Sussex.

Is your home suitable for a wood stove?

You need a chimney and working flue in order to install a wood stove and somewhere to store wood for burning. You will need to apply for planning permission for your wood stove if you live in a listed or historical building, the chimney flue extends more than one metre above the roof or you live in an area of outstanding beauty. In smokeless zones only exempted burners are allowed - always hire a HETAS registered engineer to install wood burners.

How much can a wood stove save you?

According to the EST, you can save as much as £410 a year and 9.6 tonnes of CO2 if you replace a coal fired heating system with a wood stove. The cost of buying wood or pellets also needs to be taken into account. Paul says: “On average you might need two tonnes of wood over winter at a cost of around £100 per tonne. I would advise people to buy wood in April and store it until it contains around 18% moisture.”

How much does a wood stove cost?

Wood stove specialist Paul says that a stove may cost around £2,000 including installation in a home with an existing chimney. The EST say an automatically fed stove would cost around £9,000.

AB