A Brief Guide to Solar PV

We currently have funding available to support the installation of Solar PV for your home. To find out more and to apply, click here

1.    What is Solar PV?

Solar panels are made up of photovoltaic (PV) cells which convert solar energy from the sun into electricity for your home. When your solar PV array is generating electricity but there is no use for it at that time, this excess electricity can either be sold to the electricity grid or stored (using a battery or hot water tank) for your own use later. Solar panels can even generate electricity on a cloudy day but in a sunny city like Portsmouth, solar PV is a very effective way to make your home more environmentally friendly, because the energy generated is carbon-free.

Increasingly, because of an improvement in technology and fall in cost, people install batteries alongside their solar PV. Batteries have the effect of saving the electricity generated by the panels which would otherwise be exported to the grid; allowing it to be used at times when the sum isn’t shining. Batteries also allow, for households on multi-rate tariff electricity, to store power at night at cheap rates and off-set more expensive daytime rates.


2.    Benefits

Financial savings

A 3kWp system could cost around £4,000 – £5,500 to install, but you could save around £400 a year – depending on the placement of the panels and the amount you use in your home, or export to the grid. You can expect a typical system of this size to payback in 10-12 years, leaving at least a further 15 years of free energy during the warranty period. To see more on the payback period or return on investment read here.

Carbon savings

A 3kWp system in Portsmouth can expect to save up to 1 tonne of carbon per year. That’s equivalent to 113 gallons of petrol being removed from consumption.


3.    Property Suitability

For optimal generation it’s best to install solar panels facing south, at a 30 to 40 degree angle, with no trees or buildings shading them. Panels can be installed facing east or west too, but will only work most efficiently during the hours when they receive direct sunlight. In the UK, solar panels should not be installed facing north as these won’t receive direct sunlight and not work as efficiently.


4.    Different ways to set up your system

There are several different ways you can set up your solar PV system to work. Battery storage enables you to store electricity generated for later use, or an alternative to battery storage, especially if your household hot water use is high and you don’t have a combi boiler, is hot water storage. Any excess electricity generation can be used to heat water stored in a tank using an immersion heater.


5.    Considerations

  • Aesthetics:
    • When talking about solar PV, we predominately think of large, square panels, but there are solar tiles and more aesthetic options available which will blend in with your existing roof. However, while these are much more discrete, they are typically more expensive than standard panels.
    • Solar panels don’t necessarily have to go on your main roof – you can consider other locations such as a garage, outbuilding or the ground – they can still be connected back to your house.
  • Planning permission:
    • In most cases solar panels do not need planning permission, however you should check local planning policies with your local council, or speak to your specialist installer. Especially if your home is in a conservation area or is a listed building.
    • General planning advice on solar panels is available here.
    • You can find out more on conservation areas in Portsmouth here, and see all 30 conservation areas in Portsmouth here.


6.    Typical Costs

The cost of your system will vary depending on several factors. The type of panels used, the size of the array and the ease of access to your roof and more will all have an impact. Always get at least three quotes from different installers and remember that the cheapest may not be the best option. The Switched On Portsmouth team will be able to assist with reviewing any quotes you receive, just get in touch.

Estimated installation costs are given below:

Size of PV array Average cost per kWp installed
0 – 4 kWp £1,562
4 – 10 kWp £1,703
10 – 50 kWp £1,076

7.    Income from your system

Feed-in-tariff (FIT) (expired)

The Feed-in-tariff (FIT) – this scheme is no longer accepting new applicants. This was introduced on 1 April 2010 and closed on 1st April 2019.

Smart Export Guarantee (SEG) (Currently operational)

This scheme came into place from 1st January 2020. Through this scheme electricity suppliers pay households for any excess electricity generated that they return to the grid at an agreed rate. To see which supplier provides the highest rate of SEG, refer to this list and to read more on SEG read here.


8.    Payback Period/Return On Investment

The payback period of your array is the point in time when you have recouped or saved the amount equivalent to the cost of installing your system. The shorter the payback period, the better.

If your installers’ quote includes a payback period or ROI, ensure that that you can see that the calculation was tailored to your property and the quoted system.


9.    Installation

Solar panels are typically a simple installation which on average will only take a day to complete.

Your roof will have to be in good condition, safe for works to be completed and able to take the weight of the panels. If any roof work is needed prior to installation this could increase costs.

The installer will undertake a roof survey and advise you of any issues regarding the electrical connections and proposed locations of equipment.



MCS certification:

This covers low-carbon heating installer and confirms the install is completed by a certified installer who has passed the quality and technical standards. You can read more on MCS here.



Solar PV systems are largely maintenance free. Rain should keep your panels quite clean, but dust, grime or bird droppings can impact the productivity so it is worth having them cleaned occasionally, or if you notice a fall in the production of the system. Panels are made with a special coating making them self-cleaning, if installed at a pitch above 10 degrees. If you do need to clean your panels, pick a company that is equipped to do the job safely and to a good standard.


12.PV and Portsmouth City Council

The South Coast is the sunniest area of the UK, receiving over 1,900 hours of sun each year. This makes it a great place for solar PV. Portsmouth City Council has been investing in solar to help reduce operational costs and lower carbon emissions. The Council has installed PV on as much of its building portfolio as possible, including schools, community buildings and residential housing blocks. There are solar panels on the Civic Offices at Guildhall Square, which makes running the offices more environmentally friendly but also helps save the council money on electricity which can then go towards other services in the city.


13.Useful links