Frequently asked questions
How do solar panels work?
A solar photovoltaic (PV) panel is made from many cells made from layers of semi-conducting material, most commonly silicon. When light shines on this material, a flow of electricity is created.
The cells don’t need direct sunlight to work and even work on cloudy days. However, the stronger the sunshine, the more electricity generated. Yes, solar panels work in winter!
What are the benefits of going solar?
With a solar & battery system, you’ll be buying less electricity from the grid and you’ll be able to sell any excess electricity to the grid (earning on average £350 per year). Combining these savings, your annual electricity bills can fall by 103%, on average.
Electricity prices are expected to remain high until at least the late 2030s, so your system will protect you against rising energy costs. It could also increase the value of your property by up to 3%.
Your household carbon footprint will drop on average nearly 1,100kg per year, equivalent to a return flight from London to New York. Over your solar panels’ lifespan, this adds up to 30 flights. So you’re not just saving money — you’re helping the planet, too.
Sources
This 103% figure is based on a household experiencing average UK irradiance with a 4.4kWp solar panel system and a 5.2kWh battery, using 3,500kWh of electricity each year and signed up to the Intelligent Octopus Flux export tariff. If you opt for Sunsave Plus, your savings will work a bit differently, but you could be looking at more money in your pocket each month (despite the loan repayments) - find out more here.
An industry forecast predicts that power prices will remain high until the late 2030s. Cornwall Insight, July 2023.
Adding solar to a property with a D-rated EPC usually increases the rating to a C. A Rightmove study found that increasing your EPC from D to C results in an average property price increase of 3%, or £11,157. Source: Rightmove, August 2023.
Do solar panels work all year round?
The UK’s not the sunniest country all year round but it’s still worth installing a solar system. Modern solar panels generate electricity on cloudy and rainy days, so you can cut your energy bills and rely less on the grid. Also, solar panels tend to operate more efficiently in lower temperatures — perfect for the UK!
In the summer, you'll likely generate more electricity than you consume, so you can earn money by selling the surplus energy back to the grid. If you add a battery to your solar system, you can use smart tariffs to optimise your energy export and import, saving even more money.
For example, consider a typical property in London that uses 3,500kWh of electricity each year but also has a 4.3kWp solar panel system. This system will generate around 16.5kWh of electricity in June, but only 1.8kWh of electricity in December. However, the system’s overall annual output (3,223kWh) almost entirely covers the household’s annual usage.
How much money will I save going solar?
With a solar and battery system, you’ll be buying less electricity from the grid. You can also sell any excess electricity to the grid (earning on average £350 per year). Combining these savings, your annual electricity bills can fall by 103%, on average, which means you across a year you actually earn more than you spend.
This might sound too good to be true, but it’s all because of the high performance of modern solar panels and storage batteries, as well as export income. The panels will dramatically reduce the amount of electricity you buy from the grid, and you’ll also earn money by selling your unused electricity to the grid. Octopus Energy's export tariffs have transformed the financial benefit of solar panels, and it's easy to sign up for one.
This 103% figure is based on a household experiencing average UK irradiance with a 4.4kWp solar panel system and a 5.2kWh battery, using 3,500kWh of electricity each year and signed up to the Intelligent Octopus Flux export tariff.
If you sign up for Sunsave Plus, your savings will work a bit differently. But you could have more money in your pocket each month, despite the monthly payments. Find out more about savings with Sunsave Plus.
These figures are all estimates and every household is unique. Your exact savings with a solar and battery system will depend on a number of factors, including how suitable your roof is, where your property’s located, and your annual electricity consumption.
For a better estimate of how much you could save, try our online savings calculator and book a call with one of our friendly solar experts.
Can I sell my excess solar energy to the grid?
Yes. Whenever you generate more electricity than you need (or can fit in your battery), you can sell it to the grid through a scheme called the Smart Export Guarantee (SEG).
All UK energy suppliers with over 150,000 customers have to offer a price to households that export renewably-sourced electricity. Smaller energy suppliers can opt in, too.
Your export tariff provider doesn’t have to be the same as your energy provider, but many energy suppliers offer better rates to customers.
The best available rate is currently Intelligent Octopus Flux. It pays up to 29.4p per kWh (on average) and is accessible only to Octopus customers.
Are you accredited and what do the accreditations mean?
We’re fully accredited by MCS, EPVS, HIES, NAPIT and TrustMark. Find out more about what these accreditations mean below.
The Microgeneration Certification Scheme (MCS)
MCS certifies, assures quality and provides consumer protection for microgeneration installations and installers, including solar PV. We’re a member of MCS, so you can be assured your solar PV system will be installed to a high standard and built to last. With your MCS certificate, you’re eligible to sign up to an SEG (Smart Export Guarantee) tariff with an energy supplier to make money from your excess electricity.
Energy Performance Validation Scheme Gold (EPVS Gold)
EPVS is a certification standard that ensures solar PV and battery energy-saving estimates are accurate by validating installers’ processes. Our EPVS Gold rating means we’re best in class for the accuracy of our savings calculations. So when you choose Sunsave, you’ll know that an independent third party has validated the individual energy-saving estimates in your proposal.
The Home Insulation and Energy Systems Quality Assured Contractors Scheme (HIES)
HIES is CTSI-approved Consumer Code that gives you protection for renewable energy installations, including solar photovoltaic panels, batteries and inverters. When you install solar with Sunsave, HIES protects any deposit you’ve made to us in the event that we can’t install your solar system. Through their insurance-backed guarantee, they ensure your workmanship guarantee is upheld, in the unlikely event that we can’t. HIES also provides a fair and independent arbitration mechanism if you believe that we haven’t delivered the installation experience you expected.
TrustMark
TrustMark is the Government Endorsed Quality Scheme that covers work you choose to have carried out in or around your home. We’ve been vetted to meet TrustMark’s high standards and have made a commitment to provide good customer service.
How do you ensure the highest quality installations?
We’re a Which? Trusted Trader and are fully accredited by MCS, EPVS, HIES, NAPIT and TrustMark. Our dedicated in-house team has decades of solar experience and manages your solar installation from start to finish, working exclusively with MCS-accredited subcontractors to ensure your system is built to last. We handle everything from design, DNO application, survey, supply and install, monitoring and financing — so you don’t need to lift a finger.
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How are solar panels installed?
By Josh JackmanWhat is Sunsave Standard?
Sunsave Standard is our traditional solar and battery solution, with upfront payment. Our solar experts will create a bespoke design tailored to your household, taking into account a whole range of factors including the size of your roof, your annual electricity consumption, and your budget. We use premium kit, and all of our Sunsave Standard systems come with a two-year workmanship warranty. From site survey to scaffolding, we’ll take care of everything. Once we’ve started, your installation will be complete in a few days.
We typically take a 15% deposit when you sign the contract (you can pay by bank transfer or card), and the remainder after we’ve installed your system. Learn more about Sunsave Standard.
How does upfront purchase work?
You can pay us via bank transfer or card. We typically take a 15% deposit upon contract signature, and the remainder after we’ve installed your system. If you like, you could use a loan from another provider to pay for this. Many high street banks offer home improvement loans at competitive rates which can be used for solar systems.
How long do I have to wait until my solar panels are installed?
After your survey, we’ll give you a finalised price and contract that you can discuss with your solar expert. If you’re ready to go ahead, we’ll ask you to sign the contract. We can usually install your system within 3 to 6 weeks from contract signing — we’ll work with you to find a convenient date.
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By Josh JackmanWill I start seeing energy bill savings immediately?
If everything goes smoothly with your installation, your solar panels should start generating electricity immediately. This means that you’ll be using clean, green electricity from day one, and you should see this reflected in your next monthly electricity bill.
If you pay a fixed amount to your energy supplier each month, you won’t see your energy bills come down immediately. Instead, you’ll most likely build up credit with your energy supplier, which will be paid to you at the end of the year. To avoid this happening, we recommend contacting your supplier to change your monthly payment - many allow you to do this in your account.
When will I break even on my solar & battery system?
Most people see solar panels and solar batteries as a long-term investment, so it’s understandable that you want to know when you’ll pay back the initial cost. The answer to this question depends on many factors, including:
- price
- system size
- property location
- roof direction and angle
- export tariffs
- cost of electricity
- weather
- solar panel and battery quality
For example, some properties might recoup the cost of their system in as little as five years, whereas others might take closer to 15.
For a quick estimate of how much you could save, use our online calculator.
What are the benefits of installing a battery with solar panels?
Adding a battery to a solar panel system means you can store excess electricity that you would otherwise have exported to the grid. With solar panels on their own, you'll probably only end up using about 50% of what they generate, but the addition of a battery can usually take this up to about 75-80%.
If you’re out during the day and your solar panels are producing electricity, this goes into your battery to use in the evening. Most solar systems have a battery sized according to your property, so it should provide enough electricity for the night before it needs recharging.
A solar battery also works well with time of use tariffs. It allows you to buy and store cheap night-time grid electricity to use later in the day when electricity would normally be much more expensive.
We’ll make sure you are on the best tariff to maximise your solar savings day and night. So you can sit back and enjoy the extra cash.
How reliable are solar panels and solar batteries?
Solar panels are very reliable. They have no moving parts and all of their components are kept together in a sturdy aluminium frame. Most solar panels don’t require much cleaning or maintenance, and all our solar panels come with a 25-year product warranty and a 25-year performance warranty.
Batteries are also built to last a long time, although typically not as long as solar panels. Most solar batteries last around 10-12 years (our batteries come with a minimum 10-year warranty), so they usually need to be replaced about halfway through the lifespan of your solar panels.
With Sunsave Plus, we’ll provide you with one free out-of-warranty battery replacement, so you don’t need to worry about getting a new battery when your old one stops performing.
Is my roof suitable for solar?
Most roofs in the UK are suitable for solar panels. Your roof needs to be strong enough to support the weight of solar panels, but this is rarely a problem in UK homes.
We’ll inspect your roof before going ahead with installation. If we have any doubts, we’ll let you know.
It’s also important that your roof can maximise the output of your solar panel system. The optimum UK roof for solar panels is south-facing with 0% shading and angled at 35-40 degrees. But this doesn’t mean other roofs can’t have an effective solar system.
East-facing and west-facing solar panels can be very productive. We can install panels on a north-facing roof, but we don’t recommend it. There’s very little sunlight so you won’t generate as much electricity.
How does the remote survey work?
A remote survey is a pre-booked video call with one of our friendly solar experts. It’s an important stage of the process where we check your property and make sure we can deliver the system we’ve designed at the price we’ve quoted.
Remote surveys are faster and more accurate than in-person visits or sending photos. A survey usually takes 10-30 minutes, depending on your property size and the information we get on the call. We can usually approve an installation 20 minutes after your survey.
How does the installation process work?
Once we’ve agreed an installation date, we’ll start planning your scaffolding and organising the delivery of your kit. On installation day, our engineers and roofers will install your system and connect everything to your electric meter.
We’ll usually finalise your installation in two days, but we’ll leave your scaffolding up for five more days in case there are any issues. Once everything’s wrapped up, we’ll send you a handover pack with all the certificates and documents you need.
For more information, check out our full guide to solar panel installation.
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By Josh JackmanHow do I know Sunsave is built to last?
We’ve taken careful steps to ensure Sunsave is set up for the long term.
- We’ve raised substantial investment from established venture capital funds that have previously invested in Google, Airbnb and PayPal, and we also have backing from successful investors like industry leader Bill Nussey, author of Freeing Energy, and Stuart Rose, Chairman of Asda.
- We’ve achieved full recognition from all the industry-leading accreditation schemes, including the MCS, HIES, EVPS, and Trustmark. We’re fully approved by the Financial Conduct Authority, and we’re also a Which? Trusted Trader.
- We’re government backed. In May 2023, we received a £200,000 grant from the UK government via its Green Home Finance Accelerator initiative to fund the research and development of our solar subscription. In January 2024, this was followed up by a further £2 million to launch Sunsave Plus.
- We’ve hired a talented team with decades of experience in the solar and energy industries.
As a safety net, the HIES consumer protection scheme provides deposit and payment insurance, as well as an insurance-backed guarantee that protects you in case Sunsave stops trading.
Sunsave Plus
What is Sunsave Plus?
Sunsave Plus is everything you need to go solar, delivered as a 20-year subscription. It includes the design, supply, financing and install of a system tailored to your home, plus ongoing monitoring, maintenance and insurance through the Sunsave Guarantee for the length of your subscription. Learn more about Sunsave Plus.
How does Sunsave Plus work?
We offer low cost, long-term financing that spreads the cost of your system over 20 years. So instead of paying for a solar system in one go, you make a smaller monthly payment that allows you to save money on your energy bill from day one.
The subscription ends after 20 years, but you’ll keep your system and continue to save on your energy bill.
Our best-in-class kit works with smart tariffs like Intelligent Octopus Flux, so you can sell your excess energy to the grid and maximise your savings.
Learn more about Sunsave Plus.
Who is Sunsave Plus for?
Sunsave Plus is a good option for people who want to save on their energy bills with solar, without making a large upfront payment for a system. It also offers security and peace of mind with the Sunsave Guarantee, so you don’t get any surprise costs.
You need to be a homeowner in England or Wales to get Sunsave Plus.
Do I own my Sunsave Plus solar and battery system?
Yes. Sunsave Plus isn’t a lease or rental — you own your system from the day it’s installed.
How long do solar batteries last?
Solar batteries are built to last a long time, although typically not as long as solar panels which work for longer than 25 years. Most batteries last around 10-15 years (our batteries come with a 10-year warranty), so they usually need to be replaced about halfway through the lifespan of your solar panels.
With Sunsave Plus, as part of the Sunsave Guarantee, we’ll provide you with one free out-of-warranty battery replacement, so you don’t need to worry about getting a new battery when your old one stops performing.
What's the Sunsave Guarantee?
We only use best-in-class kit, and we’re fully accredited by MCS and other relevant industry bodies. The independent experts at Which? have also put us to the test and endorsed Sunsave as a Trusted Trader, demonstrating that we’re one of the highest quality solar installers around.
That said, sometimes things go wrong. And if that happens, you’re covered by the Sunsave Guarantee for the length of your subscription. It includes full system insurance provided by Aviva, 24/7 remote monitoring, a free battery replacement, and any parts and repairs that are out of warranty.
What’s included
- 25-year manufacturer’s warranty on panels
- 12-year manufacturer’s warranty on battery and inverter
- one free out-of-warranty battery replacement
- one free out-of-warranty inverter replacement if required
- 24/7 system monitoring so we can see if something’s not working as expected
- troubleshooting and support with any warranty claims
- insurance for damage, fire, theft, and any financial losses if the system isn’t working for an extended period of time
What’s not included
- panel cleaning
- repair or replacement of bird netting
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By Charlie ClissittDoes Sunsave Plus come with insurance?
Every Sunsave Plus system comes with insurance (provided by Aviva) that protects against damage from theft, vandalism, natural catastrophe and fire. We also provide downtime cover, so if your system is not working correctly for an extended period of time, then we’ll credit your monthly fees while we work to get it back to health.
For instance, if your system is experiencing an issue (e.g. not generating electricity) which hasn’t been resolved with remote troubleshooting, we’ll credit 1/30th of the monthly payment for each day that the issue persists.
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By Charlie ClissittWhat are the eligibility requirements?
Your Sunsave Plus application can have up to two applicants.
- The lead applicant must be an owner of the property
- At least one applicant must be between 18 and 60 years old
- Both applicants must be UK residents
Can I end my subscription early?
Even though Sunsave Plus starts as a 20-year subscription, you are free to make a full repayment to end your contract whenever you want - without any fees or penalties.
- For full settlements, the remaining balance would just be the outstanding credit amount (i.e. not any interest or monitoring & maintenance fees you would have incurred had your subscription continued).
- For partial settlements, any repayment you make would be deducted from the outstanding credit amount. The term of your contract with Sunsave will be reduced but your fixed monthly fees will stay the same. This means you’d accrue interest on a smaller remaining balance, and pay less overall.
If you end your subscription early, you’ll no longer be covered by the Sunsave Guarantee.
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Sunsave Plus: a flexible way to go solar
By Charlie ClissittWhat happens if I move home?
We know moving home can be stressful, so you’ll have a dedicated Sunsave customer service representative to help you at every step.
We can’t move your Sunsave system, as it’s tailored to your home. But with Sunsave Plus, we have two options that make it simple for you to move.
1. Transfer your subscription to the new homeowner
You can transfer your system to the new homeowner*, in the same way that you transfer a utility contract.
In countries where solar subscriptions have taken off (such as the US and Germany), passing on the contract has proven to be very popular. For example, Sunrun, the US solar subscription provider, sees 98% of their customers who move home during their subscription successfully transfer their contract to the new homebuyer.
*Subject to acceptance. The new homeowner will need to pass the same eligibility requirements as any new Sunsave Plus customer.
2. Pay off the remaining balance
Alternatively, you can include the value of your solar & battery system in the sale price of your home and make a full early repayment either before the sale or using the proceeds from the sale. There are no additional charges or hidden fees for this and you do not need to repay any future interest or monitoring and maintenance fees.
- Research from WWF & Scottish Power found that solar increases the value of a house by 0.5% to 2.0%. This study excludes the impact of batteries which would likely increase value further.
- A Rightmove study found that increasing a home’s EPC rating raised the value of that home. Adding solar to a home typically increases an EPC by one level, and the study found that increasing EPC from D to C resulted in an average increase of 3%, or £11,157.
When can I get Sunsave Plus?
Sunsave Plus is available now. Answer some quick and easy questions using our online questionnaire for a free quote and savings estimate.