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Solar Panels

Finding eco friendly solar panels from ethical suppliers. Are they worth the investment?

Ranking 16 solar panel brands in the UK, with recommended buys. 

We look at the carbon footprint, pollution from manufacture, forced labour, conflict minerals, cost, buying second hand solar panels and community energy schemes. 

About Ethical Consumer

This is a shopping guide from Ethical Consumer, the UK's leading alternative consumer organisation. Since 1989 we've been researching and recording the social and environmental records of companies, and making the results available to you in a simple format.

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What to buy

What to look for when buying solar panels:

  • Is it made by a company that only produces green technology? Investing in companies that only manufacture environmental alternatives is one way to ensure that your money goes towards development of green tech. Look for our Company Ethos mark on the table.

Subscribe to see which companies we recommend as Best Buys and why 

What not to buy

What to avoid when buying solar panels:

  • Is the company causing climate breakdown? One manufacturer in our guide is now owned by a company involved in the development of new fossil fuel projects.

  • Is the company a possible tax avoider? Nine companies got worst ratings, three of which were headquartered in the Cayman Islands.

Subscribe to see which companies to avoid and why

Score table

Updated live from our research database

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Brand Score(out of 100) Ratings Categories

Our Analysis

Demand for solar panels is soaring. With more people wanting to live in a greener way and a full-blown global energy crisis underway, renewable energy is more attractive than ever.

This guide is about roof-installed, immovable panels for electricity generation. We review 16 companies making solar panels - or photovoltaic (PV) systems - and with one company scoring zero points and several others languishing near the bottom of our score table, there are differences between the brands in this market.

Read on to learn about supply chain ethics, the cost of solar panels and how to get the most value from them.

How much do solar panels cost?

It’s difficult to compare the price of solar panels because different suppliers sell different makes and charge different prices for their services, such as installation, maintenance and warranty. As a rule of thumb though, Chinese-owned companies’ panels tend to be cheaper than those that only manufacture in China.

Although over the past decade the price of solar panels has come down significantly, they are still not affordable for the general population. We looked at a few quotes and a 3.2 kWh system (depending on the manufacturer this is eight to twelve panels) will set you back £4-7000.

Homes will benefit from zero VAT on all energy efficient measures until 2027. But be aware you only get one VAT-free purchase so if you thought that you'd buy solar panels and then save up and add a heat pump in a couple of years, think again. Either you buy them together or cough up the VAT on further purchases.

Even without VAT, not many people have several spare thousands in the bank, let alone several thousand more for a battery (see later).

Loans are available but, depending on the interest rates, this would add 25-50% on top of the base cost (and who knows how your bank will use the money it makes – see our guide to ethical mortgages).

There is help available, though, in the form of grants and interest free loans (both subject to eligibility and availability). Check out in England, in Scotland and in Wales for more information.

Are solar panels worth the investment?

Once you have decided to invest in solar panels you are most likely in for a win. Based on the Energy Saving Trust's figures, it could typically take 8-12 years to recoup the costs of installing panels. From April 2023, when the price of electricity is predicted to increase yet again, this may become a shorter timescale.

It might sound obvious, but the more you use them, the quicker the investment will pay for itself.

If you don’t have a solar battery, you'll want to put the generated energy to good use. Most providers are required to purchase the surplus energy your panels are generating through the Smart Export Guarantee (SEG) scheme. To be eligible, residential solar systems are normally required to be accredited by the Microgeneration Certification Scheme (MCS).

The SEG rates don’t include transmission and distribution costs and therefore are lower than what you pay for when buying electricity from the grid. At the moment one of our recommended energy suppliers, Octopus Energy, offers the highest rate at 15p per kWh while EDF only gives 1.5p. Compare that to the current 34p per kWh you pay to use electricity from the grid and you will want to use every single kWh your solar panel generates, otherwise you will still have to purchase energy from the grid when the sun is not shining.

Incidentally, this is when UK households use the most electricity: in the morning and in the evening. (This is one reason why photovoltaic energy is a better fit in hotter countries, where electricity use often peaks in the middle of the day when people are using air conditioning).

Although using the generated electricity during the day may be easier said than done, there are ways. If you own an inversion heater and a hot water cylinder, then by installing a power diverter you can shift the surplus energy there. Storage heaters can also use daytime energy to heat up, releasing it during specified hours.

If not, you could make clever changes to your daily routine. Do the laundry, the dishes and the cooking (if you have an electric hob) during daylight but do one at a time so as not to overstretch the capacity of your system. If you’re not home during the day, you could set timers and perhaps invest in a slow cooker that does the job while you’re out.

If your concern is the climate, you should aim to deal with your heating first: insulate your home and consider getting a heat pump. The heat pump can be run through electricity generated on your roof.

Heating needs to be addressed at the domestic level, but electricity for this cool and breezy island could be better addressed with offshore wind farms than domestic solar panels.

Is it worth buying second hand solar panels?

With the ethical issues around solar panels, you may want to consider buying second hand.

It can actually be a viable idea: solar panels can still work at around 96% of their capacity after 20 years of use. You need to be careful though, solar panels are usually removed for a reason. So ask questions before buying.

House roof with solar panels and boy looking out of an open skylight window

How eco-friendly are solar panels?

The operation of solar panels – or photovoltaic (PV) systems – doesn’t create emissions while generating energy and that is one reason they are so much better than fossil fuels.

However, the environmental impact of their manufacture and disposal is significant.

The carbon footprint of solar panels

Solar panels are made primarily of silicon, which is mined in open pit mines and requires high heat for proper shaping. They also contain metals and rare earth minerals, which are mined and transported.

This is all mostly done with fossil fuels and thus has a carbon footprint: a typical house array of ten panels, each with a peak capacity of 350 watts, will have an embodied carbon footprint of around two tonnes.

Our total annual carbon footprint in the UK is about 12 tonnes each, so this looks like a sizeable proportion. But solar panels last a long time - the latest solar panel models on the market have an expected lifespan of 40-50 years. Even on our gloomy and dark island their carbon footprint can be paid back in the first six years of their operation. If you live somewhere sunnier, this can go down to as little as 1.5 years.

Furthermore, the embodied carbon in the panels has been falling dramatically and it is predicted that in the not too distant future, when they are made using recycled materials, the carbon payback time will be less than half this. For the rest of the solar panels’ lifetime their overall carbon footprint drops into the negative and owners can enjoy truly carbon-free electricity, knowing that their system will save over 900 kg of CO2 per year.

This doesn’t mean that solar panel manufacturers can rest on their laurels; they can and should cut their emissions and, as solar panel manufacturers, they have the means to do so. Our carbon rating showed that most of them weren’t doing enough, with only Canadian Solar, LONGi, and Panasonic getting best ratings.

Pollution linked to solar panels

Other adverse environmental impacts of solar panels include pollution and use of hazardous materials. The chemicals used in the manufacturing process vary depending on the make and model of the panel but they generally include PVC and compounds of copper, cadmium, and gallium. Unless these are properly handled during manufacture and are recycled at end-of-life they will contaminate both soil and water.

All companies got worst ratings in the pollution and toxics category so there is plenty of scope for improvement in this area.

Companies did better on other environmental impacts such as water use and waste reduction and nine got middle ratings in our environmental reporting category: GB-Sol, LONGi, Trina, Viessmann, Canadian Solar, Sunpower, Sharp, Panasonic, and REC Solar. The rest got worst ratings.

Are conflict minerals used in solar panels?

As makers of electronics, all our solar companies were rated for their conflict minerals policies. Only Sharp and Panasonic got middle ratings. The rest got worst ratings and lost full marks in the Habitats and Resources and Human Rights categories.

Read our article on conflict minerals to learn more about what they are and where they come from.


What happens to solar panels at the end of their life?

In the UK, it is illegal to send solar panels to landfill. Every solar panel company must join a Producer Compliance Scheme which ensures that all solar panels are collected and recycled properly. When the time comes to say goodbye (and hopefully replace) your panels, your solar installer will know what to do.

Solar panels are made of materials that are either recyclable or reusable. Unfortunately, for now, the recycling processes at work are not very efficient and recovering the materials can cost more than manufacturing a new panel. With the industry growing however, improvement on this front can be expected.

Solar Panel Companies

We reviewed and rated 16 companies making solar panels and/or photovoltaic (PV) systems.

There are big ethical differences between the brands. 

One company scores 0/20 points, and several others languishing near the bottom of our score table. 

How do solar panel brands score for carbon emissions

We assessed all companies in the guide for their carbon management and reporting. We exempted companies whose only product is solar panels from many of our usual carbon rating requirements because we consider them to be contributing to the climate transition. These companies all got a middle rating by default.

To achieve a best rating, they also had to have a credible and detailed discussion on how they had made emissions cuts in the past and would do so in the future.

Only Canadian Solar and LONGi did this because they had plans to move their operations fully to renewable energy in the next few years.

Companies which make other products were subject to our full carbon rating.

The only one to get a best was Panasonic. Sharp got a middle rating and Viessmann, REC Solar, and Hyundai all got worst.

How companies rate for supply chain management

Nearly 70% of the world’s solar cells and modules are made in China. Vietnam comes next with 8%.

Neither are countries renowned for their respect for workers’ rights. Despite publishing long sustainability reports, solar panel companies say little on workers’ rights and as a result all companies got a worst rating in our supply chain management category, apart from GB-Sol which received a best rating.

This is particularly concerning given the use of Uyghur forced labour (see below) and the fact that solar supply chains include large quantities of quartz – the mining of which is linked with silicosis – and which is often sourced from countries with poor workers’ rights regulation.

Tax conduct record of solar panel companies

The solar sector did not do well on our tax rating with only GB-Sol, Vikram Solar, Hyundai, and Yingli, getting best ratings – although there was little up-to-date corporate information on Yingli so this rating may not be reliable. LONGi got a middle rating and the rest got worst ratings.

It was notable that three of the Chinese solar companies: Jinko, Suntech, and JA Solar, were headquartered or had parents who were headquartered in the Cayman Islands (on our list of tax havens). Norwegian REC Solar itself got a best rating, but its parent Reliance Industries got a worst rating.

Political lobbying

LONGi, Canadian Solar, Sunpower, Panasonic, and REC Solar got worst ratings for their political activity. All lost marks for political lobbying in the US, some for donations to US political parties, and some for membership of the corporate lobby group, the World Economic Forum.

REC Solar did not engage in any lobbying itself but it lost marks through its fossil fuel-producing parent Reliance Industries which spent over half a million dollars on political lobbying in the US in 2022 and over a million in 2021.


Use of forced labour in solar panel supply chains

There is a high risk that Uyghur forced labour has been used in the manufacture of solar panels entering the UK. This is because most solar panels use refined silicon, known as polysilicon, to convert sunlight into electricity and the Xinjiang Region of China, where the Chinese government has placed possibly millions of indigenous Uyghur and Kazakh people in coercive labour schemes, accounts for approximately 45% of the world’s solar-grade polysilicon supply.

In 2021, Sheffield Hallam University published a report detailing the involvement of Xinjiang-based raw material suppliers and polysilicon manufacturers in forced labour schemes.

It analysed corporate documents and showed that these companies supplied some of the world’s largest solar panel manufacturers, including several in this guide.

Internment camps and forced labour

The report explains that the Xinjiang region’s well-documented detention centres and internment camps form only a small part of a much larger scheme of labour relocation programmes, justified by the government on the grounds of poverty alleviation.

These schemes are shown to operate “within an environment of unprecedented coercion, undergirded by the constant threat of re-education and internment” meaning that refusal to participate is not an option.

Those released from internment camps are often required to work in factories located near the camps in which they were interned. People with interned family members may be told that their labour will hasten their detained family members’ release.

Worker movement is restricted, with many of the factories employing supposedly free citizens being surrounded by razor-wire and security cameras, and monitored by police.

People working in the factories are either unpaid or paid far less than the minimum wage.

Which solar companies are implicated?

The report traces the supply chains of JA Solar and LONGi to silicon and polysilicon suppliers for which it found evidence of involvement in coercive labour schemes. Jinko Solar and Trina Solar were found to have also used forced labour directly.

We deducted a mark in the human rights category from these companies.

We also deducted half a mark from Canadian Solar as, while there was no evidence of forced labour in its supply chain, it was involved in a joint venture with a company found to have used forced labour.

Other companies in this guide did not appear in the report. But given the dominance of the Xinjiang region in the world’s polysilicon supply, and the fact that polysilicon from multiple suppliers is often blended by manufacturers, any companies sourcing from China are risky.

An ethical dilemma?

This makes it hard to avoid solar panels produced using forced labour in the supply chain, and you might ask whether it’s ethical to buy solar panels at all.

We would argue that it is: the transition to renewable energy generation is essential if we’re to tackle global climate breakdown. And these kinds of systemic issues can’t be addressed through consumer choices, they need governments to take action to force sector-wide change.

The good news is that there are signs that this is already happening. A new US law preventing the import of products made with forced labour has seen solar panels made by the companies named above held at the US border or shipped back to China and there are calls for similar actions in the UK.

What can you do?

If you want to support these efforts, sign the following petitions:

  • Freedom United is calling on world leaders to ensure clean energy is free of forced labour. Find out more on the Freedom United website.
  • Corporate Justice Coalition is campaigning for a new UK law to hold businesses to account when they fail to prevent supply chain human rights abuses and environmental harms. This would cover Uyghur forced labour. Find out more from the Corporate Justice Coalition website.

You are also encouraged to contact companies direct:

In January 2024 Anti-Slavery International and partners released a guidance document for investors and a policy brief to the UK Government, to help the solar and electric vehicle industries move away from reliance on forced labour in the Uyghur Region where there is systematic persecution by the Chinese government.

They say “There is no reason that green technology should go hand in hand with human rights abuses” and “it is imperative for governments and investors to divest from the Uyghur Region and diversify sourcing locations to ensure both an ethical and stable source of inputs for solar and EV technologies.”

“Consumers must use their bargaining power with companies that sell electric vehicles and solar panels, demanding information on their supply chains and links to the Uyghur Region.”

Visit the Anti Slavery International website for more information.

workers manually crushing silicon
Image: Uyghur workers manually crushing silicon in Xinjiang, China. (C) Kokodala News via Weixin.

Storing solar energy in batteries

The guide doesn’t cover companies manufacturing solar batteries. However, it’s important to talk about them as they are becoming increasingly popular for storing solar-generated energy but are associated with severe environmental harm and human rights abuses. Also, batteries are expensive, and not needed when you can sell the energy back to the grid.

Given supply issues, some argue that battery production should be prioritised for electric vehicles which do need them.


Lithium-ion batteries are currently the most popular type in the UK for solar energy storage.

Lithium extraction can be extremely environmentally damaging. It pollutes water sources, diverts water away from farming, produces massive waste, uses a huge amount of electricity, and increases CO2 emissions through destruction of vegetation in mining areas. Although lithium mining is currently not sustainable, lithium has the potential to do a lot of good.

As demand increases, innovations will hopefully be made to make the process better for the environment.

The world’s largest lithium mining nations are Australia, China, Chile, and Argentina. Some analysts predict that if battery power replaced oil, South America would become the “new Middle East”.


Another issue with lithium-ion batteries is the mining of the rare earth minerals they contain, such as graphite, nickel and cobalt. The ores of these minerals are typically mined in Central Africa, where regulations protecting workers’ rights are weak.

The southern part of the Democratic Republic of Congo sits atop an estimated 3.4 million tonnes of cobalt, almost half the world’s known supply. While conflict minerals such as the 3TG ones used in mobile phones are included in US and European (although not UK) regulations, cobalt isn’t. Investigation has revealed severe environmental and social impact in artisanal mines, where up to fifth of the cobalt production takes place.

Workers have complained of issues such as long working hours, lack of protective gear, and child labour.

Recycling batteries

It is expected that at least 11 million tons of used lithium-ion batteries will accumulate worldwide by 2030. Recycling solar storage batteries is critical because they contain highly toxic materials, however it is estimated that currently only 5% are being recycled. Thankfully, the lithium battery recycling market is expanding.

Alternatives to battery energy storage

Several alternatives are being researched by scientists trying to find cheaper, more environmentally friendly energy storage.

These include batteries made of salt, glass or even sea water and hemp! Some of the research is in its early stages but it is anticipated that we’ll see the first prototypes of sodium-ion batteries in the next one or two years.

Community energy – take action!

Power for People is an organisation that campaigns for community energy projects to be able to sell their energy directly back to their community. Although community renewables could make up 5% of all generated UK electricity, the right policy changes have still not happened to support this.

If we could buy our energy directly from a local scheme then new local projects, such as solar panels on schools and sports halls, would be viable.

To voice your support and help the Local Electricity Bill become added to any upcoming emergency energy legislation you can contact your MP. For more information visit the Power for People website.

To find community energy projects near you (in England and Wales) check out the map on Community Energy England website or find out about community energy in Scotland on the Local Energy Scotland website.

Our feature article on community energy has more information about what community energy is and how to get involved in supporting projects.

Crowd of people standing by solar panels
Image: Westmill Solar Co-operative, Oxfordshire (c) Marnee Benson

Living off-grid

Portable solar panels are a popular choice for generating electricity for people living off-grid or even for just a camping trip.

Apart from Canadian Solar and Hyundai, the solar panel manufacturers in this guide though don’t appear to manufacture portable panels.

Companies that do are quite possibly also riddled with the same supply chain issues that have been discussed here so we urge you to do some research before purchasing.

Additional research for the guide by Shanta Bhavnani.

A domestic solar energy system

Matt Fawcett of Carbon Coop considers what's required for an efficient domestic solar energy system to help save you money and reduce carbon emissions.

If there is one positive we can take from the current energy crisis, it is that higher energy bills will reduce carbon emissions by making energy efficiency and microgeneration more cost effective. A good example of this is the renewed financial viability of domestic solar panels.

What size output of solar panels should you consider?

The cost of the panels themselves has fallen dramatically over the last decade, so they make up an ever-smaller proportion of the overall price, with labour costs having (rightly) increased. It is therefore worth installing a PV array capable of producing more power than the limit on your grid connection e.g. install 4 kW+ of panels for a 3.6 kW grid connection. While your system will ‘clip’ your output at noon in summer, you’ll produce more useful power earlier and later in the day and during other seasons.

Are solar panels viable on east and west facing roofs?

Previously solar panels were only considered viable for south-east to south-west facing roofs, but falling panel prices open the way for east/west installations. While the yield will be lower, the same roof in an east/west orientation has twice the usable surface area compared to a north/south roof (as the north face is unusable).

Many inverters now have multiple inputs meaning you can connect both east and west arrays to the same inverter, making best use of your grid connection for both morning and afternoon sun.

Use more of your own energy

When you sell energy to the grid you'll get a fraction of the price you pay when buying it, so you want to use your own energy where you can. While it’s still hard to justify the financial and environmental cost of home battery storage, if you have a hot water tank, you already have a low-cost, efficient storage medium. Power diverters, such as the Eddi or the Immersun, use excess power to heat water for later use. Their installation is relatively simple and could pay for itself in as little as two years.

Company behind the brand

Sharp Corporation is a Japanese electronics company that scored reasonably well in many of our categories, including getting a best rating for Carbon Management and Reporting and middle ratings for Environmental Reporting, Conflict Minerals, and Pollution and Toxics.

However, more than a third of its shares are owned by the Taiwanese multinational Foxconn which manufactures electronics for companies such as Apple and Amazon.

Foxconn is renowned for the suicides that took place in 2010 – when assembly line workers threw themselves from dormitory buildings – and the company response of installing anti-suicide nets.

In November 2022, company workers were beaten by police during protests at one of the company’s iPhone assembly factories after the workers were denied bonuses they’d been promised. The company later apologised and blamed a technical error for the confusion over pay.

Want to know more?

If you want to find out detailed information about a company and more about its ethical rating, then click on a brand name in the Score table. 

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