Green claims are cheap. Proof is what convinces.
Sustainability marketing agency
Every company is sustainable now — on their website. Which is exactly why the readers who matter stopped believing websites: investors check the numbers, engineers check the technology, procurement checks the certifications. Marsmedia is a sustainability marketing agency from Amsterdam, working for greentech companies in the US, the UK and Europe — building brands and websites that convince through evidence, not adjectives.
Twenty years and more than three hundred websites, a substantial share for organisations working on tomorrow’s world: renewable energy, cleantech, circular technology and the innovations beyond.
For the investor who scans before the round, the customer who compares before the pilot, and the engineer who checks whether you actually know your own technology.
4.9 average on Google, 44+ reviews
Why greentech communication is different
Generic marketing breaks on greentech. Four reasons this work asks for a partner who knows the field.
When everyone claims green, the claim carries nothing. Worse: regulation now reads along — green claims directives, CSRD, advertising standards — and vague sustainability language has become a legal risk on top of a credibility risk.
The alternative isn’t saying less. It’s saying what’s true, specifically: numbers, mechanisms, certifications, third-party proof.
What we often find: the real differentiator is buried in a spec sheet, while the homepage talks about “a better planet”. But your buyers don’t buy the planet — they buy the technology that performs.
We dig the actual story out of the engineering and make it readable, without flattening what makes it credible.
The investor models the market, the customer calculates the business case, the engineer verifies the technology, the policymaker checks compliance. One website, four kinds of scrutiny.
We structure story and site so each finds their layer — evidence available for whoever wants to verify.
Energy transition doesn’t do local. Your investors, partners and customers sit across markets and regulatory regimes — and the website has to convince them all, in English that reads like the original.
We work from Amsterdam for greentech companies in the US, the UK and Europe. Distance was never the constraint; understanding the field is.
4.9 average on Google, 44+ reviews
Sustainability marketing: what we do, specifically
Greentech web design
Websites that explain complex technology without flattening it: structure for the scanning investor, depth for the verifying engineer, and a business case the customer can retell internally. Designed and built by one team, so what you approve is what goes live.
Sustainable branding
As a sustainable branding agency we design identities that look credible to an investor and honest to an engineer, at the same time. Logo, typography, colour and tone as one system — documented in guidelines your team can work with.
No leaf clichés, no gradient greenwash. A brand that holds because the substance underneath does.
Renewable energy and cleantech marketing strategy
Which audiences matter this phase — investors, offtakers, pilot customers, policy — what does each need to believe, and which channels reach them? Renewable energy marketing and cleantech marketing share one rule: the strategy comes before the deliverables, so the work adds up instead of piling up.
Content that carries proof
Case studies with numbers, technology explainers a non-engineer can follow, insight pieces that show how you think. Written with your technical people, not around them — the precision stays in, the jargon goes out.
In a field where trust is the currency, content either earns it or spends it.
Greentech SEO
Being found when an investor, partner or customer searches your field. Technically sound pages, content matched to real search behaviour, and authority that compounds in a niche.
Measured and reported on what actually happens — positions, impressions, enquiries.
Findable in AI answers
Investors and buyers increasingly ask ChatGPT, Claude and Perplexity before they ask you. We structure content so those systems can read and cite it correctly — and we set up the measurement.
“In greentech, trust is the currency.
Marketing that overclaims spends it.”
— Marsmedia
What working with us looks like
Picture the kickoff: your founders and engineers at the table, explaining the technology. To ask the right questions, we need to already understand how a greentech company moves from pilot to scale — the funding rounds, the offtake logic, the certification hurdles — and we do.
Twenty years with technology-driven clients taught us the vocabulary and, more importantly, when to use it.
The hardest question in this sector isn’t explaining the technology — it’s articulating why yours matters when every competitor claims the same impact. That’s usually where the kickoff earns itself.
Brilliant founders and engineers: experts in their field, rarely storytellers. That’s not a flaw. It’s why we exist.
The investor scans, the engineer verifies, the customer calculates. We structure story and site so each finds their layer — without flattening the substance that earned your credibility.
Claims that survive scrutiny, in language a first-time reader can follow.
Ninety per cent of our clients continue after the first project — some relationships run past ten years. In a sector where the story changes from pilot to scale-up, that continuity pays: we already know the technology when the next milestone lands.
“Mars had a quick understanding of our industry needs”
“With Mars, we felt supported from start to finish. Their quick understanding of our industry’s needs and proactive approach kept the project on track, ensuring both websites launched right on time.”
Stanislava | Communications Officer at Avantium
Working on something the world should understand? Let’s talk — we’ll keep up.
How we work
Three steps. Everyone knows what is needed, and when.
We listen, at level
The kickoff runs two to three hours, founder included — with your engineers at the table. We come in understanding pilots, scale-up economics and certification, so the conversation starts at the substance, not the glossary.
We find the difference
Competing companies in this field claim the same impact. We keep asking until the real differentiator surfaces — then build the story, structure and site around exactly that.
We stay through the scale-up
The story changes from pilot to commercial scale. We stay involved as it does — 90% of our clients continue after the first project, which in this sector is the whole point.
Connected services we offer
Brand
Website
Frequently asked questions
A sustainability marketing agency helps greentech companies be understood by the people who matter: investors, customers, partners, engineers and policymakers. The work spans strategy, branding, websites, content and findability — with one requirement generic agencies miss: every claim has to hold.
The test of good sustainability marketing isn’t whether it sounds green. It’s whether a critical reader believes it — and can verify it.
Because the field is saturated with claims. When every company says “sustainable”, readers stop believing the word — and regulation increasingly forbids using it loosely. What still works is specificity: numbers, mechanisms, certifications, third-party proof.
That’s a different craft than most marketing. It’s closer to making a technical case than to making noise.
Convince four kinds of scrutiny at once: the investor modelling the market, the customer calculating the business case, the engineer verifying the technology, and the policymaker checking compliance.
That means credibility first, clarity everywhere, and depth on demand — the reader who wants to verify, can.
By never claiming what can’t be substantiated. We write from your actual technology, data and certifications — and where the proof isn’t there yet, we say what’s true today instead of what sounds good.
That’s not just ethics; under green claims regulation it’s risk management. Specific and true beats green and vague, in court and in the market.
Yes — renewable energy, energy storage, cleantech, climate tech, circular technology and renewable chemistry all fit the same profile: technology-driven companies whose value depends on being understood by critical readers.
The sectors differ; the communication problem is the same. That problem is our specialism.
That’s the core of the work. We dig the story out of the engineering — with your technical people, not around them — and make it readable for the non-engineer without flattening what makes it credible.
The expert should recognise the depth; the first-time reader should follow the story. Both, or it doesn’t ship.
That depends on scope, phase and the depth of the content work. Early in the conversation we share an estimate per phase, so you see what each part of the work costs before it begins.
We’d rather help you spend the budget where it makes a difference this phase than push for the most expensive version of the work.
A brand identity typically runs six to ten weeks; a full brand-plus-website project ten to sixteen. We plan the timeline in phases at the start — and internal decision-making from day one, because that’s where projects usually slow down.
Yes — a substantial share of our clients are in the US and the UK, alongside Europe, including in this sector. We work from Amsterdam through shared Slack channels and biweekly calls, in a process built for time zones years ago.
In practice, American clients rarely see us in person. The work doesn’t suffer for it; understanding your field quickly counts for far more than sharing a postcode.
Three things.
One: twenty years and more than three hundred websites and brands, a substantial share in technology-driven fields — by a deliberately compact team of seniors. We pick up your field fast, and we know which communication survives a critical reader.
Two: strategy, brand, website and content in one team. No handovers where the technology gets lost in translation.
Three: we build for findability in both worlds — search engines and AI answers — and we measure what actually happens.
Volume isn’t our position. Depth is.
Residential solar lead generation, high-volume B2C campaigns and quick-commerce work. Not because they never pay — but because our value sits with technology companies making a substantive case to critical readers.
If your question is volume lead-gen, we’ll say so in the first call and point you elsewhere. We’d rather be the right agency for fewer companies than a mediocre one for many.
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