Here is something I tell every cleantech and deeptech founder I work with:
Your green claim(s) are only as strong as the questions they can survive.
Not the one from a friendly investor. Not the one from someone who wants to believe you.
The question from someone who gets/lives the technology, the physics, or the market – and has no reason to be nice.
If your claim crumbles there, it was never a claim. It was a stucco.
Why does this matter more in climate than anywhere else
In most industries, an exaggerated claim is a PR problem.
In climate tech, it is a trust problem:
– for you
– for your sector
– for the founders doing the hard work properly
You don’t want to look like what Teranos did for medtech
The bar for green claims has to be higher, not lower – exactly because the stakes are higher. Customers, regulators, investors – they’re all getting better at asking sharp questions. And the ones who aren’t yet, soon will be.
But how does this look in practice?
Everyone in Croatia is talking about the 1 GW AI data center planned near Topusko. Somewhere in the announcement: 500 MW of solar panels on the premises.
Sounds like half the energy needs covered by solar, right?
Wrong.
500 MW is peak power. What those panels can produce at noon in July under perfect conditions. The sun doesn’t shine at night. Barely in winter, on cloudy days, or for the majority of the year. Croatia’s solar capacity factor is roughly 15 to 17%, meaning those 500 MW deliver around 75 to 85 MW on average during the full year.
For a 1 GW data center running 24/7, that’s approximately 8.5% of yearly energy demand.
Eight and a half percent.
The solar investment is real. The intention could be genuine. But presenting peak capacity as if it were actual energy coverage leads anyone listening to a completely wrong conclusion.
That’s greenwashing – not because the claim is invented, but because the framing is designed to make the green part sound much bigger than it is. And the moment someone who understands energy hears it, the credibility of everything else comes into question, too.
The pattern behind the example
This isn’t unique to one data center. It’s the most common mistake I see in cleantech pitches.
A claim that is technically not false, but framed to lead to the wrong conclusion.
“We offset all our emissions.” – With what? Verified credits or purchased indulgences?
“Our building is energy efficient.” – Compared to what baseline? Measured how? Under what conditions?
“We reduce CO2 by X%.” – Calculated how? Scope 1 only, or the full picture?
“We use AI to optimize energy.” – by how much? Is it proven in the field, or only in simulations?
These are not hostile questions. They are the minimum a serious person in this space will ask. And if your answer is meh, the conversation is over – no need to say it out loud.
What a provable claim actually looks like
Before you put a green claim in your pitch deck, your website, or any investor communication, run it through three questions:
How did you measure this? Name the methodology. Reference the standard if there is one. If you calculated it yourself, explain the inputs.
What are the boundaries? Every claim has a scope. Be explicit about what’s included and what isn’t. Hiding the limits doesn’t make them go away – it just means someone else will find them for you. At – the – wrong – time
What would make this claim wrong? If you can’t answer this, you don’t fully get the claim yourself. A founder who knows the limits of their own data is far more trustworthy than one who presents everything as settled.
This isn’t about being conservative or underselling your technology. It’s about being precise. Precision is what separates a claim that builds trust from one that tears it down.
Honesty is a competitive advantage
I know this sounds counterintuitive, when everyone around you seems to be making bigger claims with less evidence.
But here is what I have seen on and on and on: the founders who are honest about what they have proven, what they are still testing, and what they don’t know yet – those are the ones who build real trust with serious investors and serious customers.
Because serious people are not looking for a perfect story. They are looking for a founder who understands reality and their own limits.
Say what your solution does. Say where it works and where it doesn’t (yet). Say how you measure results. Say what has to be true for it to scale. Say what the risks are and how you are taking care of them.
That kind of clarity is rare. Which means it stands out.
The bottom line
In deeptech and cleantech, your green claim is part of your product. It shapes how customers buy, how investors value you, and how regulators look at you.
Prove it before you say it.
Because (everywhere, but especially in this space) credibility isn’t something you rebuild easily once it’s gone.
I have no mercy for claims that collapse after the first honest question. My approach is simple: if I can’t measure it, verify it, or build on it – I’ll tell you directly, wish you luck, and walk away.
Like a dog: if you can’t eat it, drink it, or play with it – just piss on it and walk away.
Credibility is the product.
Marko Brkljačić, Founder of NUOTWO & GBChub, co-founder of MAQ, and startup mentor at BIRD Incubator, specializing in cleantech and greentech, helping founders build credible, evidence-backed green claims that hold up to scrutiny.
