Greenwashing complaint filed against SGN for home heating trial that risks misleading consumers

Homeowners at risk of being locked-in to potentially more expensive, more environmentally-damaging hydrogen heating systems by allegedly misleading claims made by SGN.

(28 January 2026, Fife, Scotland)

Opportunity Green has today filed a complaint to the UK’s competition regulator, the Competition and Markets Authority (CMA), against Scotland Gas Networks plc (SGN) for alleged greenwashing in relation to its hydrogen home heating trial in Fife, Scotland.

In 2026, SGN is switching around 300 homes in Fife from natural gas to green hydrogen. In its promotional materials and on its websites, SGN has presented hydrogen as “clean burning”, “zero-carbon”, and capable of “providing green energy to millions of homes”. Opportunity Green believes that many of these claims are factually incorrect, ambiguous, or leave out critical information for consumers to make informed choices.

In its complaint, Opportunity Green alleges that SGN breaches multiple principles of the CMA’s Green Claims Code and is misleading consumers by:

• Conflating the benefits of green hydrogen and other types of hydrogen.

• Failing to recognise the full climate impacts of using hydrogen as a home heating fuel.

• Omitting the scientific evidence on electric heating, which shows this to be both the more efficient and cheaper decarbonisation method for heating homes, compared to green hydrogen.

• Presenting an inaccurate picture of nitrogen oxide (NOx) emissions from hydrogen heating.

SGN claims that hydrogen heating “stands apart” in its ability to decarbonise home heating, which, Opportunity Green argues, goes against the scientific evidence. This evidence shows that electric heating is by far the more feasible decarbonisation method for heating homes and that it takes around five times as much electricity to heat a home with hydrogen as it does using an efficient heat pump; potentially locking consumers into unnecessarily high energy costs.

The UK Climate Change Committee has been clear that it sees “no role for hydrogen heating in residential buildings” and that relying on it would delay emissions reductions and slow progress towards net zero. And a review of over 50 studies shows that using hydrogen gas for home heating is neither cost-effective, nor scalable, and as such hydrogen is best preserved for hard-to-abate sectors like aviation, shipping, steel and agriculture.

SGN’s claims do not explain that different types of hydrogen production have varying degrees of environmental harm. Production methods for blue hydrogen are more scalable than green hydrogen, but it is produced from fossil gas and results in more GHG emissions. The trial, on the other hand, intends to use green hydrogen – which is produced from renewable energy, resulting in minimal GHG emissions, but is extremely energy intensive, inefficient and problematic to produce at scale, making it an inefficient solution for heating homes. In its advertising, SGN appears to refer to different types of hydrogen production interchangeably, conflating their alleged benefits and presenting a potentially misleading picture of hydrogen heating’s scalability and environmental impact.

Additionally, Opportunity Green believes that evidence regarding nitrogen oxide (NOx) emissions from hydrogen heating, which is a safety concern, is not presented accurately. SGN claims that hydrogen boilers are showing fewer NOx emissions than standard gas boilers – which is not sufficiently substantiated and goes against existing evidence.

Dominika Leitane, Legal Officer at Opportunity Green says:

“SGN is using the environmental profile of green hydrogen alongside cost and scalability claims that relate to other types of hydrogen in its promotional materials for the Fife hydrogen heating trial. We believe this pick and mix approach is inaccurate and risks misleading consumers into making decisions that are significantly worse for the environment than portrayed by SGN, such as joining the Fife trial or retaining gas boilers instead of switching to clean, efficient electric heat pumps.

“Whilst green hydrogen is a clean fuel, it’s expensive to produce and uses five times as much electricity to heat a home than a heat pump. With a limited supply of green hydrogen available, this should be reserved for sectors where there are few alternatives, like fertilisers, steel, aviation and shipping.”

ENDS

Notes to editors

Read the complaint in full here.

What are the different colours of hydrogen and what do they mean?

Green hydrogen is produced using renewable electricity and water, and in heating systems can theoretically reduce carbon dioxide and methane emissions by 100% compared with using fossil gas.

Blue hydrogen is produced from fossil gas and relies on carbon capture and storage (CCS) to remove carbon dioxide emitting during the production of hydrogen from the atmosphere. Using blue hydrogen cannot achieve zero emissions, but can achieve emissions reductions of between 42 and 93% compared to natural gas, depending on the efficiency of the CCS and methane leakage rates.

Grey hydrogen is the most common form of hydrogen, produced using fossil gas without CCS, therefore resulting in high carbon dioxide and methane emissions.

There are other colours of hydrogen that are not relevant to this complaint.

Which type of hydrogen does the trial use?

The trial uses green hydrogen. However, a number of the claims made by SGN about hydrogen home heating (in particular in relation to cost and sustainability) appear to relate to blue hydrogen. Opportunity Green argues that SGN is using the sustainability profile of green hydrogen alongside the cost and scalability profile of other types of hydrogen, to mislead consumers about the benefits of using hydrogen for home heating in the UK.

Where was the complaint filed?

The complaint was formally submitted to the Competition and Markets Authority (CMA). The CMA is the UK’s regulator responsible for enforcing competition and consumer protection law, including the laws and regulations on misleading environmental claims (i.e., greenwashing).

What is the CMA and what powers does it have?

The CMA enforces the Green Claims Code, which applies to any business making environmental claims about products or services. Under the Digital Markets, Competition and Consumers Act 2024, the CMA can investigate misleading practices and impose penalties of up to 10% of a company’s annual global turnover. The CMA has shown a strong interest in hydrogen-related greenwashing, including action against Worcester Bosch for misleading advertising about hydrogen-ready boilers.

What regulation is SGN alleged to have breached?

The complaint alleges breaches of multiple principles of the Green Claims Code, including:

• claims must be truthful and accurate,

• claims must not omit or hide important information,

• claims must be clear and unambiguous,

• claims must be substantiated with robust evidence, and

• comparisons must be fair and meaningful.

What is Opportunity Green asking the CMA to do?

The complaint requests that the CMA:

• Investigate SGN’s promotional materials and communications for potential breaches of the Code.

• Require SGN to amend its materials to ensure compliance with the Code, including:

  • Providing clear and accurate information about NOx emissions from hydrogen combustion.

  • Substantiating claims about the environmental benefits, scalability, and cost-effectiveness of hydrogen heating with robust evidence.

  • Clearly distinguishing between green hydrogen and other forms of hydrogen in all claims.

• Take appropriate enforcement action to prevent further dissemination of misleading claims by SGN.

Who else is involved in the complaint?

Simmons & Simmons LLP is acting for Opportunity Green in this complaint.

What does SGN say?

Before referring the matter to the CMA, Opportunity Green wrote to SGN regarding its allegations. While SGN denies that its claims breach the Green Claims Code, it has since amended some claims, however others remain unaltered. The NGO is using this complaint to request an investigation of SGN’s promotional materials, and for any breaches of the Code found in its communications to be amended to ensure compliance with the Code and such amendments to be communicated to its consumers.