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Solar panels: Are they worth it?

Climate change affects us all, but are solar panels a viable alternative to carbon-releasing energy?

Solar power’s nothing new. People were making fire by reflecting the Sun’s rays as far back as the 7th century BCE. These days the process is a little more refined.

As well as being better for the environment, solar energy has the potential to save you on your gas and electricity costs. But is it worth it?

Solar panels on a red roofed house 

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How do solar panels work?

Solar panels use photovoltaic (PV) cells to absorb energy from the sun.

These PV cells use silicone that energises when hit by sunlight. This converts the energy into a direct current.

An alternator inside the panel itself converts the current from direct to alternating. This lets you use it in your home or send it to the National Grid.

 

What are the benefits of solar panels?

There are several reasons to consider having a solar panel system installed to your home, the main ones being:

You could save money

With a solar panel system installed your electricity spend could drop considerably, as you’re not paying for someone else to provide you with energy.

You could earn money

Solar panels are so efficient that most homes use between 15% and 25% of the electricity that’s generated. With the Smart Export Guarantee, anyone in England, Scotland or Wales can sell their excess energy to the National Grid, providing certain criteria are met.

If your energy company has more than 150,000 customers, they must offer at least one Smart Export Guarantee tariff. How much you get paid depends on the specific tariff.

The planet benefits

Climate change is a big issue. In an effort to reduce it the government taxes producers of fossil-fuel energies such as gas, oil and, in many cases, electricity.

Fossil fuels are such a concern because the extraction, refinement and distribution of gas and oil damages the environment through the production of carbon dioxide.

Likewise, electricity is typically produced by burning fossil fuels, unlike solar panel systems.

 

How many solar panels are needed to power a house?

The number of solar panels you need depends on several factors, including:

  • How many people live in your home
  • How much electricity you use
  • How much sunlight your home gets
  • How much space you have on your roof
  • How well insulated your home is

The average UK home uses around 3,748 kilowatt hours (kWh) of electricity a year. As solar panel systems typically range in size from 1 kW to 5 kW this means installing a 4 kW or 5 kW solar panel system.

The latter would probably be better to allow for periods of cloudy weather when less energy is produced, or for busy periods such as Christmas. With all this in mind, around 20 panels should be enough to cover typical energy requirements.

 

How long do solar panels last?

Solar panel technology has come on a long way since it first hit the mainstream radar in the 1990s. The latest solar panel systems have a lifespan of more than 40 years. And they come with warranties that cover your shiny, green solution for more than half that period.

Incidentally, most warranties guarantee performance levels of at least 80%. If your power generation drops below this level, the policy kicks in and your system should get a service.

 

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

How much having a solar panel could save you in energy bills depends how much sunlight the system can capture. It also depends on what solar panel system you have and who you sell your excess electricity to via the Smart Export Guarantee.

But, the Energy Saving Trust estimates annual savings of up to:

  • £610 per year in the south east of England
  • £580 in Aberystwyth, Wales
  • £545 in Stirling, Scotland

How much you save falls by around £80 to £100 if you don’t have a Smart Export Guarantee in place.

 

How much do solar panels cost?

The cost of a solar panel depends on its size, your location and energy requirement. According to Greenmatch, a 4 kW solar panel system costs around £6,400 and covers 29 square metres of your roof. A more powerful 5 kW system to cover 32 square metres is likely to set you back up to £8,000.

The costs may be high, but you can expect to break even within 10 to 15 years at current prices. After which time, you should be reaping the benefits of your investment.

Greenmatch also estimates that after 25 years, with a Smart Export Guarantee in place throughout, you can expect to save £9,240 with as 4 kW system or £11,088 with a 5 kW system.

 

How much does it cost to install a solar panel system?

The cost of installing a solar panel system is generally included in your solar panel quote, as it’s a specialised job. But just so you know, you can expect the firm you select to charge between £300 and £500 per person, per day.

Fitting a solar panel system is typically a 2-person job, meaning the installation part of the bill could come to £1,000, but large jobs may take longer.

Installation costs can be higher if you live in an out of the way location or have an unusual shape roof area to cover with the panels.

 

Can I install my own solar panels?

You can save on labour costs by installing your own system. But unless you and a friend are experienced roofers and electricians it’s probably not worth it given the savings.

Also, if you want to sell your excess energy via the Smart Export Guarantee you need to get your work certified by a Microgeneration Certification Scheme-accredited engineer.

In short, you probably aren't going to save all that much, and you risk losing any warranty on the panels.

Do I need planning permission to install solar panels?

Planning permission isn’t usually needed if you’re fitting a solar panel to the roof of your own house, garage or shed. But there are some rules you need to follow. These include:

  • The panel shouldn’t exceed the highest point on the roof (excluding any chimney)
  • The panel shouldn’t extend more than 200mm from the edge of the roof
  • The panel must be installed so it’s as low profile as possible and doesn’t jar with the appearance of the building or its surroundings

You must seek planning permission, which may well be refused, if you have a listed building or live in a conservation area or are on the World Heritage List.

 

How efficient are solar panels?

Solar panels are generally considered efficient if they manage to harness more than 20% of the sun’s rays that hit their surface. The latest solar panel systems top this mark.

Research from the Federation of Master Builders revealed the best solar panels on the market in 2022 could offer around 23% efficiency.

It's unlikely any standard solar setup can get much more than this. Conditions are never perfect, so you're not going to see anything close to 100% efficiency.

Do solar panels increase your house's value?

The jury’s out on whether solar panels add to the value of your home. Research from the USA suggests it does, by 4%. But this study came from an estate agent, and The US housing market may feel differently from Brits.

If you embrace green energy, moving to a home with a solar panel could well be a big plus. Others may avoid properties with them, so there’s no guarantee that they’ll have a positive effect on property values.

How much does it cost to clean solar panels?

Costs depend on several factors, including your location and the type and number of solar panels fitted.

According to Checkatrade solar panel cleaning firms charge £8.50 on average to clean one panel. This means a house with 4 people with 20 panels on a 5kW panel system installed is likely to cost cost around £112 on average.

How much does it cost to pigeon-proof solar panels?

It’s recommended that you pigeon-proof your solar panels. Doing so helps prevent pigeons making a home in the cavity between your roof and the panels themselves. It also reduces the corrosive damage their droppings can cause to the panels.

Roofing companies that offer pigeon-proofing services tend do:

  • Clear away existing nests and other detritus
  • Clean the panels and the surrounding area
  • Apply cleaning solutions
  • Install mess or anti-roosting spikes.

Costs depend on the scale of the project, but typically start from around £200.

 

Can I switch energy suppliers if I have a solar panel?

Yes, you can shop around and take advantage of any cheaper electricity tariffs. Though it's worth bearing in mind that, given the current cost of energy, you're unlikely to find competitive deals by switching.

But many energy companies that offer Smart Export Guarantee tariffs let you sign up without having to switch energy providers.