Your questions

What is the cost of a solar PV system?

Domestic 4kWp solar PV systems start at around £5,500. Typically a fully installed system costs between £1,300 to £1,800 per kWp installed. A domestic system that costs around £6,000 will have savings and income reaching nearly £700 – meaning the investment is paid back within 8.5 years but keeps generating the income and grants for another 11.5 years.

How much will I save?

The amount of money that you save depends on how much you pay for your electricity, how much electricity you generate, and how much of that electricity you use. A 4kWp system installed at 30° south will save around £200 a year - assuming that you only use 50% of what's generated, and pay 12p per kilowatt hour.

How much will I get paid in Feed in Tariff and power exported back into the grid?

The current Feed in Tariff, the grants you receive from the Government for generating solar power, currently sits at 14.9p per kWh. In a typical home the FiT income will be around £450 and the money you receive for putting electricity into the grid will be approx. £70.

Do solar panels generate electricity only when the sun shines?

Solar PV panels generate electricity during daylight. They will generate more electricity in direct sunshine but still generate on a dull day. The electrical energy generated is either used in your home, or if you produce more than you need, exports the excess to the grid. At night or when you are not generating electricity you will still import electricity from the grid as usual.

What happens if there is a power cut?

As an automated safety measure the solar PV system will switch itself off. This is designed to protect any network engineers working on the power lines during a power cut. When the power comes back on your system will reset itself and carry on as usual.

Do I need planning permission?

Domestic solar PV systems usually fall under permitted development and do not need planning permission. There are certain stipulations that we will adhere to to ensure your installation complies with planning rules and building regulations. Even if you live in a conservation area you can usually install a PV system. However, if you live in an AONB (area of outstanding natural beauty) or in a listed building you should contact your local council. Freewatt has installed the largest installations in the UK on listed buildings.

How will the fixing system be integrated onto the roof?

You can choose an 'in roof' system (which will replace the tiles) or an 'on roof' system (which will sit on roof hooks above the roof tiles). Neither system will damage the roof. It is imperative that the mounting system is correctly installed on your roof to ensure the roof is weather proof and will perform as it should for the life of the system. Freewatt will not drill tiles but use roof anchor brackets that fix directly to the roof timbers and are either covered over by the tiles or are over-flashed with lead.

I have a very high electricity consumption. Will I be limited to a 4kWp system on my house?

Most domestic systems tend to be limited to 4kWp because of the roof size. In theory any size of system can be attached to home if you have enough space and the electrical supply is to a sufficient standard.

Does the solar PV array have to be grouped together in one block or can it be split up?

You can install across several roofs of varying elevation and orientation but this may affect the system efficiency and installation cost. We will be happy to design the best solution for you.

How long do solar panels last?

Solar panels have a manufacturers' warranty of 25 years and a working lifetime of more than 40 years.

Do solar PV panels need cleaning?

Not as long as they are mounted at a steep enough angle (over 15°) so that the self-cleaning glass works.