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Home & garden.

12 August 2021

Is solar PV a good investment?

Find out when your solar PV should start paying for itself and whether solar panels are worth it for your home
SI
Sarah Ingrams

Buying solar panels is a long-term investment that should help cut your electricity bills and carbon footprint. But will they pay for themselves and earn you money? And could they affect the value of your home? Read on to find out more.

Solar panels are often marketed as a way to save money on electricity, and sometimes as a way to make money too. This is because you can get paid for the electricity they produce and you don't use.

Keep reading to find out how long it's likely to take to break even if you buy in solar panels, and how much you could earn from them. 

Plus our unique survey of estate agents reveals the effect solar panels will have on the value of your home. 

If you've decided to go ahead with solar panels, use our solar panel brand reviews to find the right solar PV option for you.

How long do solar panels take to pay for themselves?

Solar panel close-up

How long it will take for your solar panels to pay for themselves, and whether you can make money from them, will depend on:

  • the cost of your solar PV system
  • how much of the electricity generated you are able to use
  • whether, and how much, you are paid for electricity exported.

A more expensive system upfront will need to be balanced with how much money you can save by using the renewable electricity it generates (instead of buying power from your energy firm), plus how much you can earn from selling any excess.

Which? members can log in to see examples of how long it can take for solar panels to pay for themselves. if you're not a member, join Which? to see our calculations.


Out until 6pm
Home all day
System cost (4kWp)
Electricity bill savings (per year)
Smart Export Guarantee payment (per year)
Years to break even

You can cut the time your solar system takes to pay for itself by several years by finding the best SEG tariff rate, so you get paid more for electricity you produce. Find out how much you could earn with the Smart Export Guarantee.

If you've had your solar panels for a while and get Feed-In Tariff (FIT) payments, you also get paid for how much electricity you generate. See tips to make the most of your Feed-In Tariff

What affects your solar panels' payback time?

House with 7 solar pv panels on the roof

The amount you earn from either the SEG, the FIT or the savings you make by using the renewable electricity your system generates can be affected by:

  • Electricity price changes These affect how much you save on your electricity bills by using the electricity generated by your system. The higher electricity prices go, the greater your savings.
  • Solar panel installation cost A smaller upfront cost could mean that it's quicker to break even, though if your system is also smaller then it may generate less electricity.
  • SEG tariff rates These vary wildly between companies. A fixed tariff guarantees the same rates for the length of the deal, while variable tariffs change based on the price of electricity (for example, rates could be linked to wholesale costs).
  • Inflation This affects feed-in tariff payments, if you’re signed up for them. They change in line with RPI each year.

Find out how much solar panels cost for your home.

Tips for investing in solar panels

Big house next to little house

Some companies market solar panels as a money-making investment. But there are significant differences between traditional options (such as savings and investments) and buying and installing a solar panel system.

It you already receive Feed-In Tariff payments, they are guaranteed for between 20 and 25 years (depending on when you had the panels installed). The price per kilowatt hour you're paid changes annually with the Retail Prices Index (RPI) and any money you make is tax-free.

If you'll be getting paid for electricity via a SEG tariff, they have less long-term security. Fixed tariffs are valid for a certain period of time (typically 12 months), after which you'll need to find a new one. Variable tariff rates can change when companies choose.

Boost your savings and earnings from solar PV by putting them into a cash Isa, regular savings account or even a high-interest current account. Use Which? Money Compare to compare savings and Isas to find the best for your money.

Paying for your solar panels

The most cost-effective way to pay for the installation of solar PV panels is upfront and in full. 

If you don't have the cash to pay upfront, you could consider a loan or remortgaging. You'll have to pay interest on any money you borrow and loan repayments could exceed the returns you make from the solar PV system, so make sure you do your calculations carefully.

Entering into a 'Free solar panels and solar buyback' or 'rent-a-roof' scheme is another option, but we advise caution here.

Will solar panels affect the value of my home?

Solar panels on a detached house

Don't assume that solar PV installation will guarantee a comparable increase in the value of your property. In fact, the majority of estate agents we surveyed** think that having solar panels makes no difference to how much your home is worth.

Just 8% said they thought solar panels increased property value, and 17% said they decrease its value. But 67% of estate agent businesses told us that having solar panels makes no difference to the value of a property.

Impact of solar panels on property value

These factors can all have an impact, too: 

  • the age of the solar panels 
  • whether they’re owned by a company rather than the homeowner 
  • their effect on the appearance of the property.

Also, remember that the system's inverter might need changing over the 25-year period and that, over time, the panels will reduce in efficiency. These factors need to be considered if you invest in solar PV and want to sell your home later on. 

If you’re buying a property with solar panels installed, it’s worth getting a surveyor to check them.

We've spoken to solar panel experts and solar panel owners for their top tips on Make the most of your solar panels.

**NAEA Propertymark surveyed 1,252 estate agent businesses for Which? in June 2017.