FAQ
GROUND SOURCE HEAT PUMPS
Are ground source heat pumps really environmentally friendly and efficient?
Most electrical suppliers offer 'green energy' from a renewable source so using this power your heat pump will be not be producing any carbon emissions to heat your property. For each kilowatt used, three to four kilowatts are delivered to the house.
How expensive are they to install?
With the current rises in oil prices (July 06) , the pay back period for a ground source heat pump is anything from 4 - 8 years and less for a air source heat pump. The cost of maintenance is low and there is virtually no servicing needed.
Can a ground source heat pump work with existing radiators or do I need underfloor heating?
Both Ground Source and Air source heat pumps can be linked into existing heating and hot water systems and will work well and efficiently. However they work even better well with underfloor heating.
How much land do I need for ground source heat pump?
That depends on the size of the house , what pump will be needed and whether the property is a newly build or older property. For a four bedroom newly built house with good insulation, a 11 Kwp will need about 300m of ground loop.
Are grants available to install these systems?
In order to meet a 10% reduction in carbon emissions the government ,through the low carbon buildings program, is offering the following grants:
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Ground Source Heat pump - £1,200.00
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Solar Hot water - £ 400.00
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PV Electric - £3,500 (max ) per KWp to 50% max
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Wind Turbine - £1000.00 per KWp £5000.00 max or 30% of total installation.
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Biomass - £1,200.00
Some councils will add to these grants for their local residents. In addition to these, there are grants available for community projects.
Can I use a ground source heat pump (or air source heat pump) to heat my pool in the summer?
Yes if the pool is not situated to far from the house.
Do I need underfloor heating upstairs?
No Radiators can be used.
Can they be used to cool a property?
Yes, GSHP can in the summer months, cool a building.
What is the payback period?
With oil prices rising a pay back period is anything up to 11 years.
SOLAR THERMAL and Solar PV
Do I need planning permission for solar panels?
It depends on whether the property is listed or not. However the government is looking at reviewing its policy on this.
Must Solar Panels be positioned at an angle and facing a particular direction?
Solar Panels gain most heat from facing due South and being pitched at 35 %. There are rotating systems that follow the sun in order to maximize potential solar gain.
What happens on very dark cloudy days?
In the UK, solar panels work best from March through to October. Cloud will affect the performance of solar panels quite dramatically, Solar thermal works on solar radiation, solar pc works on light intensity.
What is the payback period?
For Solar panels the payback period is up to 14 years. Photovoltaic panels are expensive to buy and as such the pay back period in more like 30 years.
Wind Turbines
How much wind will be needed to generate electricity for my house?
A medium sized average house needs between 4-6MWh of energy per annum. In good locations one can expect wind speeds of six meters per second and on the coast they can be as high as 8 meters per second. However in urban areas, wind speeds, with lots of buildings around , you are probably looking at four meters per second and that will considerably affect performance. You can find out what your annual mean wind speed is by accessing the DTI's NOABL free wind speed database by typing in your post code.
Can I sell any extra electricity back to the grid?
Yes you can and when there is no wind your system will take energy from the grid.
How much space do I need for a stand alone wind turbine?
Your wind turbine will have to be positioned well away from obstructions like buildings ,trees etc. for these can cause turbulance. In general it should be twice the height of any obstructions . The best sites are on bare hills. They have to be at least 50maway from the nearest neighbours.
Do I need planing permission for a roof top wind turbine?
At present you do but the government is reviewing this. Obtaining Planning permission for wind turbines ranges from £600 to £3,500
What is the payback period ?
It depends on whether one buys a stand alone system or a much smaller roof top wind turbine. Anything up to 20 years
Biomass Heating
Should I use wood chips or pellets?
Pellets are more suitable for the average size house as they do not require as much space for storage.
At present no pellets are manufactured in the UK so have to be transported from Europe which adds to CO2 emissions but there are moves a foot to start producing them in the UK.
Wood chips are sourced in various locations in the UK and are more suited to large houses where the wood chip can be stored and kept dry.