Frequently Asked Questions

Below you will find a collection of Frequently Asked Questions (FAQ's). The FAQ's are split into sections; please click on any question to reveal the answer. If you do not find the information you are looking for then please call now on 01934 622891 to discuss your requirements, or use our contact form.

General Questions

FAQ How much energy can I generate with PV on my roof ?

Domestic properties normally have a single phase electricity supply  and as such the maximum PV system allowed to be installed is a 4kW array.

Depending on the pitch of your roof, the direction it is facing and the amount of shading from nearby obstacles  ( like trees or other buildings), a 4kW system can generate over 4000 units of electricity (kWh) each year.

According to the Energy Saving Trust, the average 3 bedroom house consumes 3,300  kWh a year (cooking and heating using non electric supply).  

We recommend that you look at your last few bills or call your electricity supplier to find out how many units you consume, you can then compare this to the  calculated output of the system we recommend.

We are strictly governed by MCS regulations to calculate a conservative generation estimate based on the average amount of daylight expected each year at your postcode, for your roofs orientation, pitch and shading factors.

Please call us for a no obligation free survey to ascertain your requirements and your generation potential . 

FAQ Do I need planning permission?

Solar PV:
NO - (as long as panels are not more than 180mm above the plane of a pitched roof.) However, if you are in a conservation area or a listed building then permission maybe required.

Solar Thermal:
NO - (as long as panels are not more than 180mm above the plane of a pitched roof.) However, if you are in a conservation area or a listed building then permission maybe required.

Wind Turbine:
Yes - All wind turbines currently require planning permission.

GSHP / ASHP:
Not usually required.

FAQ What are F.I.T’s?

The Feed in Tariffs (F.i.T’s) are a government backed guaranteed payment for all renewable electricity producing technologies in the UK. For further information please see our Feed In Tariffs Page.

You can be paid for the electricity you generate, even if you use it yourself, and for any surplus electricity you export to the grid. And of course you'll also save money on your electricity bill, because you'll be using your own electricity.

There are different tariffs for different renewable technologies and for different sizes of generators, for further information please see our Feed In Tariffs Page.

FAQ What is MCS ?

The Microgeneration Certification Scheme (MCS) is an independent scheme that certifies microgeneration products and installers in accordance with consistent standards. It is designed to evaluate microgeneration products and installers against robust criteria providing greater protection for consumers.

The MCS is the only certification scheme to cover all microgeneration products and services, and has support from the Department of Energy and Climate Change, industry and non-governmental groups as a prime method for making a substantial contribution to cutting the UK's dependency on fossil fuels and carbon dioxide emissions.

John West Renewables are accredited MCS installers, and with this certification it enables you as the customer to qualify for the F.I.T’s.

FAQ Is VAT payable?

For domestic customers VAT is rated at 5%.

For commercial customers VAT is rated at 20%.

This is the VAT rating for 2011, there maybe changes in this rate with budget events. If there are changes VAT will be charged at the new rate as applicable.

Solar Energy Questions

FAQ What is Solar PV ?

Solar PV is a renewable energy system which uses photovoltaic [ PV ] cells to convert sunlight into electricity. The PV cells consist of thin layers of a semi-conducting material, usually silicon, which generates an electric charge when exposed to daylight (rather than heat). The greater the intensity of the light, the greater the flow of electricity.

In a Solar panel there are many photovoltaic cells linked togther which are then covered by a protective transparent screen and framed for structural rigidity.

Cables attached to the panels are connected to an inverter which converts the DC (Direct Current) electricity produced to usable AC (Alternating Current) electricity which can be used as power.

FAQ Will a PV system work well in the UK ?

Yes.

The PV modules only require daylight to work, and so will generate energy on cloudy and even rainy days.

Depending on the pitch of your roof, the direction it is facing and the amount of shading from nearby obstacles ( like trees or other buildings), a 4kW system can generate over 4000 units of electricity (kWh) each year.

According to the Energy Saving Trust, the average 3 bedroom house consumes 3,300 kWh a year (cooking and heating using non electric supply).

Temperature is also a factor when determining how much electricity a pv system will generate. The efficiency of a PV module decreases by a fraction for every degree the temperature is above 25 degrees Celsius. Therefore, a clear cold day is perfect, because PV modules operate more efficiently at cooler temperatures.

FAQ What is a unit or kWh (kilowatt hour) of electricity?

You are billed by your electricity company for the units of electricity you use from their supply, 1 Unit is 1kWh.

1kWh is the amount of electrical energy required to run a piece of electrical equipment using 1000 watts [ or 1 kW ] for 1 hour. e.g. To run a 100 watt lightbulb for 10 hours, you require 1,000 watt hours or 1 kilowatt hour (1 unit) of electricity.

Wind Energy Questions

FAQ How much does a wind turbine cost?

There are various systems available, with varying costs.

For full details, please contact us and tell us about your requirements.

Heat Pump Questions

FAQ What is a GSHP ?

  

GSHP is an abbreviation of Ground Source Heat Pump; these use pipes which are buried in the ground outside your property to extract heat from the earth. This heat can then be used to heat radiators, underfloor or warm air heating systems and hot water in your home.

A ground source heat pump circulates a mixture of water and antifreeze around a loop of pipe - called a ground loop - which is buried in the grounds of your property. Heat from the earth is absorbed into the fluid and then passes through a heat exchanger into the heat pump. The ground stays at a relatively constant temperature under the surface, so the heat pump can be used throughout the year - even in the middle of winter.

The length of the ground loop depends on the size of your home and the amount of heat you need. Longer loops can draw more heat from the ground, but need more space to be buried in. If space is limited, a vertical borehole can be drilled instead.

FAQ Do I need a large amount of land for a Ground Source Heat Pump ?

 

Not necessarily, digging a trench is one method of laying out the ground loop; this can up and down your land reduce the length of the trench.

Another method is to utilise vertical boreholes which go straight down it not the ground and can be installed using only a parcel of land as small as 5m by 5m.

A 3rd solution is to utilise an "Octopus" installation where the bore holes radiate outward at 60 degrees from a central circle approximately 1.5m in diameter , this means the installation can be done from a very small parcel of land and sometimes even from within an existing building as the equipment used fits through a set of double doors.