Frequently Asked Questions
General Solar Thermal and PV questions
Will my roof need to have any drilling?
This depends on the type of roof you have. Normally to mount the frame on your roof we use brackets that slide under the roof tiles. Where any drilling is required you will be informed at the time of the survey.
Will I need to arrange planning permission?
Planning permission is normally not needed for Solar Photovoltaic, Solar Thermal and Ground and Air Source Heat Pumps. If you are planning to install on a listed building, a conservation area, or are just unsure then please check with your local authority.
Will my panels work only on sunny days?
Solar Thermal and Solar Photovoltaic panels work best when the sun is shining directly on to them. However even on typical British cloudy days your panels will produce electricity and/or hot water. Just how much depends on how bright the day is.
How do I know if my home is suitable for solar energy?
Ideally your home/business should have a roof facing roughly south with enough space to accomodate the panels. Most domestic properties are suitable, however a full home survey will be carried out by us before any work is undertaken.
How much roof space will it take up?
A 2kWp (kilowatt peak) PV system would take up roughly 10 square metres. A Solar Hot Water system for a 3 to 4 bedroom house would use approximately 2 quare metres. This figure can change depending on the type of panels required for your install.
How much energy will I save?
This is entirely dependent upon the size of the system you purchase. A 1KW system, facing south, may produce approximately 800kWh (units of electricity) a year.
Is the CO2 produced by manufacturing and installation saved over the systems life span?
It has been calculated that Solar PV would take approximately 7 years to pay back the carbon cost of installation. Since your PV panels will
last much longer than this they will offset their carbon cost many times. There is a detailed page on this subject at the Centre For Alternative
Solar Thermal systems will normally pay back their carbon cost much quicker than PV. Wikipedia has a detailed assessment of this here
How long does installation take?
For PV systems, normally a day and a half. Solar Thermal systems will take around 2 days.
Does the system make any noise?
Solar Hot Water systems make virtually no noise. PV systems are effectively silent.
Are the panels easily damaged?
No, modern panels are designed to with-stand all types of weather including snow and hail stones. A determined vandal will be able to cause damage though.
What maintenance is required
PV installations have no moving parts and are usually maintenance free. Once the system is installed you may forget about it. Solar Thermal systems are also virtually maintenance free. It is advisable to have the transfer fluids changed every few years, however this not set in stone.
PV Specific Questions
Will I need large batteries?
If your property is not connected to the electrical mains supply (grid) then a standalone battery system may be the best way of getting an electricity supply. In all other cases it is financially more wise to feed unused electricity back into the grid.
What is the 'Feed In Tariff'?
In April 2010 the governent introduced this scheme to make purchasing PV installations more financially attractive for the consumer. The Feed In Tariff makes it compulsory for the six big energy suppliers to make regular payments to property holders who generate their own electricity. In the case of Solar Electricity the payment is based upon the number of units (kWh) you generate regardless of whether you consume the energy or not. Solar PV installs by us qualify for the Feed In Tariff. Please see this page at the Energy savings trust website for further details.
Will there be any disruption to my electricity supply?
Sometimes your supply may need to be switched off for a few minutes. This is not always the case though, systems can often be installed without any disruption.
Solar Thermal Specific Questions
What is the 'Renewable Heat Incentive'?
The RHI is similar to the 'Feed In Tariff'. It is a government scheme to make payments to people who generate heat from renewable sources.
Payments for residential properties are scheduled to start in October 2012, in the interim period there will be an "RHI Premium Payout" for up to 25,000 homes
which appears to be a capital grant for any systems installed before then. The implementation of the RHI is still ongoing. For the latest news
please see here (rhiincentive.co.uk)
Solar Thermal systems installed by us will qualify for the Renewable Heat Incentive.
Rainwater Harvesting Specific Questions
What can you use rainwater for?
Toilet flush, watering the garden, washing the car and domestic appliances such as dishwasher and washing machines. If you wish to use rainwater as drinking water you will require special filters and a UV treatment system.
Will I save on my water bill?
Yes if you have a water meter installed.
Will my water company install a meter for me?
Yes, the water board is obliged to install a meter at a home owners request.
Should I put my tank underground?
It is usually a good idea for many reasons. Including space saving for small gardens, frost damage risk and no unsightly equipment on show (large water tanks are not pretty). You may want to put your tank above ground if you want to keep installation costs to a minimum.
Do I need a filter and pump
It is highly encouraged to use both. A pump will maintain a constant water pressure when it is being drawn and a filter will stop debris such as leaves and dirt getting into the tank
Do I need a big roof?
No, even a small terraced house is capable of collecting many thousands of litres of water a year. The bigger and flatter your roof is the better though.
What maintenance is required?
Very little. The filter should be washed 3 to 4 times a year.
Heat Pumps Specific Questions
Will the heat pump give me hot water as well as room heating?
Yes it can although supplementary heating by an immersion heater will be required to increase the temperature.
Do I need to change my radiators or install underfloor heating?
Ordinary radiators are designed to have water at 75C pumped round them and a heat pump will not be able to do this. You will need larger radiators that are designed for 45 to 50C. Your house must be really well insulated for this to work and a ground source heat pump may be necessary. Underfloor heating is usually the advised route for heat pumps.
Can I benefit from the 'Renewable Heat Incentive'?
Yes, although the RHI has not been finalised yet. The proposed tariff is 7p per kWh for domestic ground source installations and 7.5p per kWh for air source. In order to qualify for the RHI, your installer must be MCS accredited. Solar Utilities are MCS accredited.
Is my home suitable for a heat pump?
If you are looking to install an air source heat pump an ideal place would be a sunny wall away from a bedroom window. For a ground source heat pump you need somewhere to lay the pipes that will absorb the heat from the ground, for this you can elect to drill a bore hole (about 100m deep) or dig shallow trenches (about 1.5m deep). Bore holes have the advantage of causing less disruption and a consistent temperature all year round. However they are usually more expensive and require access for drilling equipment.
How big are the trenches for ground source heat pumps?
It all depends on the climate where you live however a general rule of thumb is 53.9 metres of trench per kw of output required. Trenches are usually dug in a zig-zag pattern up and down the garden in order to keep the layed pipe 1 metre apart. After this sand is used to cover the pipe, this stops any sharp stones from the back fill puncturing the pipes.
A 100 metre deep bore hole will give approximately 5kw of energy.
How much noise does the air source heat pump make?
Air source heat pumps use a fan to extract the outside air. They are not very loud, however you would want to place the unit away from bedroom windows and other places where silence is required.
How big are the air source heat pumps?
The NIBE pumps that we supply are 1045mm high, 1200mm wide and 520mm deep.
What maintenance is required?
Extremely low to no maintenance is needed. You may have an annual check up of your system if you wish.