Acclimate Ventures Research
Investment Thesis
Acclimate Ventures is an early-stage investor in US and UK deep tech ventures that build the core technologies behind AI performance, efficiency and scale. The site frames the firm as partnering with AI visionaries who are redefining compute. Its conviction is that rapid growth in data centers and AI compute is creating transformative business opportunities at global scale, and that energy and infrastructure bottlenecks are the binding constraint. The older tagline, early stage investing in US and UK based deep tech climate ventures, still appears on the site, so the firm sits where climate, energy and AI infrastructure overlap.
Sector Focus
The portfolio clusters tightly around AI infrastructure and the power it needs:
- Compute silicon and architectures: FemtoAI (sparse processing units for edge AI), Vaire Computing (near-zero energy computing), OpenLight (integrated silicon photonics for AI), Conductor Quantum (AI for ubiquitous quantum computing), Callosum (compute orchestration across heterogeneous hardware)
- Data center infrastructure: Hammerhead AI (flexible data center infrastructure), Ferveret (liquid cooling), AI Fabrik (managed inference infrastructure)
- Power and energy: Amperesand (solid state transformers), Exowatt (modular renewable energy for data centers), GridCARE (unlocking stranded grid capacity for speed to power)
- Applied AI: Plumerai (edge AI for smart home cameras), Gruve (AI native enterprise services)
Stage Focus
The firm describes itself as early stage. It has also appeared as a new investor in later rounds of portfolio companies, including GridCARE's Series A (reported May 2026) and an oversubscribed Series A for another portfolio company alongside Industry Ventures and SG Growth Capital. Check size and fund size are not disclosed on the site.
Check Size
Not disclosed. The firm is a small, partner-led vehicle, so checks are likely modest and aimed at participating in rounds led by larger funds.
Lead Tendency
Unknown, leaning toward participating. A GridCARE founder testimonial says Acclimate was in their corner early and helped build the relationship with their lead investor, which suggests a supporting and connecting role. Press mentions list Acclimate as a participant rather than a lead.
Recent Activity
The portfolio page lists 13 companies. Recent public mentions include participation in GridCARE's Series A (May 2026) and an oversubscribed Series A that added Industry Ventures, Acclimate Ventures and SG Growth Capital as new investors alongside existing backers Xora Innovation, Material Impact and TDK Ventures. The site copyright says 2024, but portfolio images were updated through 2026, so the firm appears active.
Portfolio Highlights
GridCARE, Amperesand, Exowatt, OpenLight, Vaire Computing and Plumerai are the most visible names. Several have raised from well-known deep tech and climate funds. No exits are listed.
Team
- Mark Younger, founder and sole named partner. Spent years building and scaling technology businesses inside Apple and Samsung, studied at Harvard Business School, and moved from Silicon Valley to Oxford in 2022 when he pivoted into deep tech investing. His work also extends into philanthropy, policy engagement and scientific research on energy bottlenecks and AI infrastructure.
Decision Process
Solo GP. Mark Younger is the only named investor, and founder testimonials all credit him personally.
Founder Preferences
Leaders and teams obsessed with solving customer problems, building core technology for AI compute and its energy supply. Founders cite value beyond capital: Silicon Valley connections, product and operations insight, customer discovery, route to market in the US and UK and Europe, pilot income and first commercial customers, and introductions to follow-on capital and corporate partners.
Value Add
The site lists four support areas: lessons from tech (strategies and playbooks), customer discovery, opening routes to market in the US and UK/Europe, and access to growth capital through follow-on investors and corporate partners. The firm lists many co-investors it has invested alongside, including Future Energy Ventures, MATTER, Samsung Catalyst, nVentures, Intel Capital, Cisco Investments, Walden Catalyst, Xora, Partech, OTB, Mayfield, Breakthrough Energy, MCJ, Felicis, a16z, Y Combinator, Tiny VC, 7percent Ventures and SHV.
Geographic Focus
United States and United Kingdom, with the firm based in Oxford, UK and a Silicon Valley network.
Gaps
No disclosed fund size, AUM, check size, or investment dates. No team members other than Mark Younger are named. Stage at investment is omitted for all portfolio companies because no source names each round.