Solar PV FAQs

Frequently Asked Questions About Solar PV Systems

Solar PV electric panels do not require bright sunlight in order to operate, meaning that you can still generate electricity on cloudy days. The electricity produced is either consumed directly by appliances in the building or, if more power than required is generated, it is exported to the grid. At night, or when the system is not producing enough energy, power is supplied by the grid in the normal way. Visit our how solar pv works page to find out more.

The feed-in tariff is a financial incentive backed by the government and paid by your energy supplier to encourage you to create your own clean electricity. Every kWh of electricity generated earns a fixed income, regardless of whether you use it yourself or not. Additionally, any electricity not consumed in the property can be sold back to the grid. For further information visit the feed in tariff page.

Once your installation is complete, and has been registered with the MCS (Microgeneration Certification Scheme) by EWS, you will receive your MCS certificate. You will then need to complete a FIT application with your electricity provider - EWS will be available to help complete your application with advice and guidance.

Yes, EWS solar PV installations will be eligible for the feed-in tariff.

Solar PV works from daylight and not direct sunlight, but normally more power is produced on a sunny day than on an overcast or cloudy one. PV panels do not produce energy in the dark and so during the night electricity is drawn from the grid in the normal way.

Any shade from trees, neighbouring buildings or overhead cables can have a huge impact on the performance of your PV system, so panels should be sited to avoid shading as much as possible. Visit our is solar pv right for you page to find out more.

This depends on the amount of power you want to produce but normally installations are a minimum of about 1kW peak power which will need approximate 10 square metres of roof space.

No, it is possible to use mounting systems to locate panels on the ground or in circumstances where no other option is available it is even possible to mount them on the side of a building.

If the visual impact of panels on your roof is a major concern there are a number of possible solutions that can make the panels less visually obtrusive –

  • Site the solar panels on the ground.
  • Mount the solar panels into the roof, rather than on the roof, so that they are flush with the roof tiles.
  • On slate roofs we often recommend panels with a black edging, rather than the standard silver.

We also offer innovative traditional solar slates which combine the latest in photovoltaic technology with a roof slate that is so convincing and visually pleasing that it has been approved for use on a Grade 2 listed building. Perfect for use in areas of outstanding natural beauty or when aesthetics are a major consideration.

PV panels work best when installed at an angle of 30 to 40 degrees on a south facing roof. However, other orientations such as south east or south west can be viable with a relatively low drop in expected performance. A site survey will determine the best option for your property.

This varies depending on manufacturer but most come with a five year manufacturers warranty and have an expected  life well in excess of 25 years.

The total installed cost of a system will depend on the size of the system and ease of installation. It is not possible to give a precise figure without viewing your property. However as a general guideline, most homeowners install a system of between 2-4kWp at an installed cost of around £3700-£6000 (inc VAT) per kWp.

It is not possible to give an estimate of what your system will generate without visiting your property, as there are five main factors that will affect how much energy your system will generate:

  • Total size of the PV array (number of panels)
  • Latitude of the location
  • Direction the panels face
  • Angle the panels are mounted
  • Any shading

However, to give you an idea we would expect a typical unshaded 4kWh system installed on the south facing roof of house in Somerset to produce at least 3840kWh of electricity annually, earning approximately £514 a year from the feed-in tariff.

We would expect an average system to take roughly 6 to 8 years to pay for itself, after which time any money earnt will be profit for the owner. The feed-in tariff is inflation linked and offers a guaranteed income for 25 years. For further information visit the feed in tariff page.

For systems less than 4kW peak power we will inform them once the installation is complete. For larger systems, permission will need to be gained in advance from the network operator.

Installation normally takes 1-2 days.

In most cases installing solar panels on your roof does not require planning permission as they are considered 'permitted development' under planning law. There are, however, some rules and exceptions that must be observed. For example, it is important to consult you local council's planning department for advice if your house is in an area of outstanding natural beauty or is a listed building. We are happy to advise and guide you in this area.

Yes, it is a good idea to speak to building control about your intentions and they will advise you if you need to take any further action.

Most roofs are strong enough to support a PV installation without any reinforcement, but we will perform a site survey and make an assessment of this prior to installation.

Our PV systems are entirely connected. If there is a power cut the system is automatically switched off as a safety measure to ensure power does not leak onto the grid in order to protect personnel working to restore the power supply. There will be no power to the building during the power cut.

No, solar PV systems do not need batteries as excess electricity is fed back in to the grid.

Usually dust and dirt washes off when it rains if the panels are installed at an angle of at least 15 degrees. In extreme cases, dirt may cause a power reduction of about 10%. We suggest an annual clean using a pressure hose.

It is possible to install a system yourself using an electrician, however it is important to realise that if you do not use an MCS Accredited installer you will not be able to claim government backed incentives such as the feed-in tariff, and in most cases this will render manufacturer warranties invalid.

An EPC is required on all buildings benefitting from renewable energy, and will need to be included in the "feed-in tariff" application. EWS will arrange an EPC on your behalf, if required.