Are solar panels worth it?

By Tom Seymour

Last updated: Mar 15th 2024

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Harnessing the power of the sun is key to a more sustainable and renewable energy future

Solar panels have been around since the Victorian era, before being perfected in the 1950s. But does it still make sense to invest in the latest solar technology at home for those looking for more sustainable energy solutions?

If you already have a solar array but are wondering about buying an EV charger that can use them, be sure to head over to our charging your electric vehicle with solar panels feature to learn more.

How do solar PV panels work?

PV or 'photovoltaic' means converting light into electricity. A solar PV panel can generate direct current (DC) from sunlight and this is then converted into alternate current (AC) electricity through an inverter.

This inverter is then connected to the electricity national grid, or the fuse board at your business or home to provide electricity.

PV cells, usually made from silicon, are mounted within the solar panel and an electric field is created when light hits the cells. More intense sunlight can cause a greater flow of electricity that can then be converted into energy.

Why should we use solar energy?

Investing in solar energy can be beneficial in terms of sustainability, as well as financial.

Solar power is a source of renewable energy and can help reduce a home's carbon footprint, as well as the UK's total carbon footprint as more of the energy market looks to phase out reliance on fossil fuels.

The Government has a target to increase the UK's current 14 gigawatts of solar power capacity by up to five times by 2035.

It is currently consulting on the rules of solar projects, particularly with a view to boosting the installation of solar panels on domestic and commercial rooftops.

This forms part of the UK's renewable energy strategy target to be 100% renewable from a combination of wind, solar, biomass, hydro power by 2035.

Increasing the use of solar also helps to reduce air pollution from fossil fuels, which is one of the biggest challenges facing air quality in the UK and globally.

Utility company E.ON has also estimated that it's possible to cut energy bills by up to £400 a year by generating power through solar panels. It's also possible to sell any excess solar energy generated back to the grid to cut energy bills further.

Are solar panels efficient in the UK?

One of the persistent myths about solar panels is that they don't work if it's not sunny.

This is a particular worry in a nation obsessed with the weather like the UK that has its fair share of cloudy and rainy days.

While it's true that solar panels will generate more power on a sunny day, as long as there is light you can still have electricity generated by your solar panels.

This means solar panels can generate power all year round, including in the autumn and winter.

Having said that, shorter days in winter are going to produce less energy due to fewer hours of daylight, but a bright and crisp cloudless winter day will still produce a good level of power.

What's the difference between solar panels and solar thermal panels?

Like solar panels, solar thermal panels collect energy via the sun's energy but instead of converting that energy into electricity, solar thermal panels convert it into heat, which can then be used to warm your home.

We will cover solar thermal panels in more depth in a separate guide.

Are solar panels the right choice for your home?

There are certain considerations to be made before taking that next step to invest in a solar array.

This includes whether your current building is suitable, the total installation costs and how the position of your home's roof may impact solar panel performance.

What are the building requirements for solar panels?

Before looking to install solar panels, homeowners need to check that the existing roof is able to carry the weight and this has to be proven.

Where roofs are not able to carry the load of the solar panels strengthening work to the roof will have to be completed.

There also needs to be enough space on the roof.

According to the Energy Savings Trust (EST), a typical solar array will take up around 25m2 of roof space.

Those homeowners that have a South facing home which is unshaded are in luck, as this is the ideal set-up to reach maximum electrical output.

Houses that are East or West facing can still produce a good level of performance, but North facing homes are not recommended for solar panel installation.

The EST said East and West facing homeowners should expect to yield up to 20% less energy compared to a house facing directly South.

Building regulations will also apply to electrical installation work.

All solar PV systems must be registered with the local Distribution Network Operator (the company responsible for getting energy to your home).

It's worth contacting a competent solar panel installer or energy company to get some advice on some of the requirements.

How much do solar panels cost?

Solar panels are a long term investment and it's likely going to cost thousands of pounds for a typical set-up.

E.ON estimates that a typical six panel array on a home's roof would cost around £4,000 including the panels and installation and this increases to around £6,260 to double the size of the array to 14 panels.

The more panels, the more energy can be generated, but that also comes with a higher up-front cost.

Energy companies can offer advice on the costs, but can also offer 0% or low APR rate finance deals to help spread the cost over multiple years.

The example from E.ON shows that a smaller six panel array would cost around £111 a month over three years on 0% finance.

It's going to take a while to reap back that investment, but it will eventually add up.

Are solar panels worth the investment?

Investing in solar panels makes the most sense for a homeowner that knows they are going to be in the same house for enough time to get a return on investment (ROI).

The biggest savings of around £400 a year are made from the energy being directly used by the household the array is connected to.

Homeowners can also save money through the Government-backed smart export guarantee (SEG) scheme. This works by paying those homeowners with solar panels installed a set rate for the energy they produced that isn't being used.

The SEG replaced the feed-in tariff (FIT) scheme in January 2020.

EST estimates that a typical household could make between £80 and £110 a year through the SEG scheme, so this is a lower level of savings compared with houses using the energy they are producing directly.

Furthermore, if you already have an electric car then charging your EV with solar energy can help reduce your EV charging costs even furher. Of course, you will need to factor in the costs of the solar installation and EV charging alone is arguably not a big enough reason to install solar panels as the upfront costs are quite high.

However, if you are planning to have solar panels to reduce your dependency on the national grid, fossil fuels, and reduce your energy bills, then being able to charge your electric car with free solar energy is a great perk. 

How much can I save on my electricity bills with solar panels?

Andy Rogerson, better known as the YouTuber EV Man, has put a recent guide together to help give an idea of the kind of savings that can be made by investing in solar panels.

Rogerson advises that it's more cost effective to use the energy produced to help reduce your own household energy bills than it is to export the energy back to the grid through SEG.

While each calculation will be different depending on the size of the array and position the house is facing, Andy's East to West solar array set-up generates around 3.0 megawatt hours (MWh) a year.

According to the Department for Business, Energy & Industrial Strategy (BEIS), the average household uses 3.7 MWh a year.

Rogerson said: "My advice is go as big as you can afford to go. The price of solar panels is only going to go up and the cheaper you can get them installed the quicker your return will be.

"If the array is costing you £5,500 to install and you're saving £525 a year on your electricity bills then your ROI period is roughly 10 years.

If you can increase your household energy consumption from the power generated by the solar array then the ROI can be significantly shortened.

You have to think about how much energy from the solar array you can utilise rather than export."

Andy said some of the ways to make sure the energy being produced is utilised is to think about energy use on bright days by charging your electric vehicle (EV), or timing things like a dishwasher load to make the most of the extra power.

Smart Home Charge did an in-depth interview with Andy earlier this year as part of our Plugged In feature series.

Are there any grants or incentives towards the cost of solar panels?

The UK government introduced the ECO4 (energy company obligation) scheme from April 2022 which will run until March 2026.

This scheme has £4 billion of funding available to help improve the energy ratings of homes and reduce carbon emissions.

Local councils can allocate funding to help with solar panel investment based on things like the age of the occupants, the number of occupants, the number of children or the condition of the house etc.

This is aimed at helping low-income households, but it's possible to check if you qualify for any financial assistance on ECO4's website.

Energy companies like E.ON can offer 0% finance to help spread the cost of investing in renewable technology. Have a chat with your energy provider and see what they can offer.

The Scottish government also has the Home Energy Scotland loan and cashback scheme that offers up to 40% on the cost of installing solar panels up to a maximum of loan amount of £5,000.

This would work out at £2,000 off the cost of a solar PV system and the remaining 60% can be paid off over a five year period with the loan.

Further details on the Home Energy Scotland scheme are available on Home Energy Scotland's website.