Fabian Heilemann, AENU: Reinventing Venture to Solve the Climate Crisis
- ImpactVC
- Jul 23, 2025
- 2 min read
For this episode, we were joined by Fabian Heilemann, founding partner at AENU, a climate-focused Article 9 fund reshaping what institutional-grade impact investing looks like in Europe.
A former serial entrepreneur turned VC heavyweight, Fabian spent nearly a decade at Earlybird before launching AENU alongside his brother. Today, he leads a €170M early-stage climate tech fund with one clear mission: backing ventures that can decarbonize at gigaton scale.
In this episode, we dive into Fabian’s journey from angel investor missteps to system-level innovation, and what it takes to truly build an impact-native VC platform—beyond surface-level ESG.
We talk about why the old fund structures don’t cut it for deep tech and climate moonshots, what real accountability looks like for impact metrics, and why mission-aligned founders are starting to demand more than just capital.
🎯 This Episode’s Themes
Why Fabian walked away from generalist VC to go all-in on climate
The hard truths of raising an evergreen fund in a bear market
What it takes to measure impact—beyond the marketing slide
How AENU’s founders “walk the talk” in company operations
Why biodiversity collapse may hit harder than climate
Here’s what’s covered:
00:45 Meet Fabian: From founder to Earlybird GP to climate VC
03:30 When the science became too loud to ignore
06:00 Early mistakes in angel investing—and how it shaped AENU
08:45 Building AENU: Clean slate, pure play, Article 9
12:00 Impact metrics that matter: CO₂e saved or removed
15:30 Walking the talk: Travel policy, green ops & founder integrity
18:45 Challenging the 10-year VC fund model
22:30 Why climate tech exits need more patient capital
26:00 The failed evergreen experiment—and what it taught them
30:00 Climate vs. biodiversity: The next systemic wave
33:30 Why Sequoia won’t fix this—but emerging managers might
36:15 Founder redemptions: Building for impact after fast commerce
40:00 The reality of fundraising as an impact-first VC
43:00 AENU’s three pillars: Energy, decarb & climate adaptation
✍️ Show Notes
Impact Isn’t an Add-On
Fabian explains why AENU was built from scratch—not retrofitted—and why true impact requires in-house teams, hard metrics, and full-firm alignment.
The VC Model is Broken for Climate
Hardware, deep tech, and climate moonshots need time. Traditional VC cycles don’t work. Fabian shares how their evergreen model flopped—but what’s next.
Biodiversity is Coming
Climate risk is just the start. Fabian flags biodiversity collapse as the next wave—more complex, more global, and tightly intertwined.
Founders Who Mean It
The most compelling founders today? They don’t just want to build a green product. They embed impact into culture, ops, and decision-making.
Why Institutions Said No
Fabian gets real about trying to raise in 2022, how institutions weren't ready for structure innovation, and why persistence still matters.
💡 Investor Takeaway
System change doesn’t come easy. It takes intentional structure, operational edge, and relentless founder support. The next wave of climate unicorns will be built by those who design for impact from day one—and demand the same from their investors.
