🎙️ Leaders in Cleantech – Episode Notes

Guest Name: Pete Armstrong, CEO/CTO of Mixergy

Episode Summary

This was a conversation I’ve been looking forward to revisiting.

When Pete first came on the podcast back in 2018, Mixergy was an early-stage university spin-out with a big idea; using hot water as a form of energy storage. Listening back now, what’s striking is not just how far the company has come, but how non-linear that journey has been.

At its core, the mission hasn’t changed: unlocking flexibility in the grid through something deceptively simple.

What has changed is everything around it.

A few themes stood out:

Technology vs. reality
The product is clever; smart, stratified hot water tanks coordinated through software. But the real challenge wasn’t building it. It was understanding how products actually get adopted; installers, specifiers, and supply chains matter more than most founders expect.

From chaos to focus
Like many startups, Mixergy tried multiple routes early on. Direct sales, installer networks, merchant channels. The shift to a more focused “spec and tech” model; driven by specification and licensing; feels like a defining moment.

Hidden scale
~9 million hot water tanks in UK homes. Even a fraction becoming “smart” creates meaningful grid flexibility. It’s a good reminder that some of the biggest opportunities in cleantech come from rethinking what already exists.

Leadership and perspective
Pete was candid about the role of investors and experienced operators. Left unchecked, founders can easily chase too many directions. The right board doesn’t just govern; it sharpens focus.

Culture and evolution
From farm-based R&D and a slightly renegade spirit, to a more disciplined, commercially focused organisation. That balance between curiosity and execution is where most companies either break or scale.

Books mentioned

• Predictably Irrational – Dan Ariely
• The Idea Factory – Jon Gertner

Both speak, in different ways, to how innovation actually happens; through human behaviour, systems, and environment; not just technology.

About our Guest

Dr. Pete Armstrong:

Dr.Pete Armstrong is the CEO/CTO and co-founder of Mixergy, a smart hot water technology company

About Hyperion Search:

At Hyperion Search, we specialize in building world-class teams for the cleantech and energy transition sectors. We focus on leadership roles but also recruit strategically critical individual contributors who drive business growth. Whether you’re a founder scaling a startup, a board member guiding a scaleup, a VC/PE investor, or a corporation committed to energy and mobility transitions, we find the talent that will deliver impactful, sustainable results.

• Linked In: https://www.linkedin.com/company/hyperion-search-ltd
• Website: www.hyperionsearch.com

Follow us online, write a review (please) or subscribe

I'm very keen to hear feedback on the podcast and my guests, and to hear your suggestions for future guests or topics. Contact via the podcast Linked In page.

If you do enjoy the podcast, please write a review on iTunes, or your usual podcast platform, and tell your cleantech friends about us. That would be much appreciated.

• LinkedIn: https://www.linkedin.com/in/david-hunt-cleantech/

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Philipp Man – terralayr

In this episode of Leaders in Cleantech, I’m joined by Philipp Man, co-founder and CEO of terralayr, a company building a new kind of energy infrastructure platform focused on flexibility and battery storage. Philipp shares his journey from commodities and entrepreneurship into the energy sector, and the insight that led to terralayr: the growing flexibility gap in power systems as renewable generation scales.

As he puts it:

“We wanted to build something akin to the AWS for power.”

terralayr combines battery asset development with a software platform that virtualises and commercialises storage capacity, enabling customers to access flexibility without owning and operating assets themselves. The conversation explores how this model sits at the intersection of infrastructure and technology — and why that distinction may become less relevant as energy systems evolve.

We also discuss the state of the European storage market. Despite the growing focus on batteries, Philipp is clear that we are still early:

“We’re really just at the beginning… you need to grow over 10x in the next four years.”

From there, we move into some of the real-world constraints holding the sector back — particularly grid access and bureaucracy, and what needs to change to accelerate deployment.

The discussion also touches on broader themes shaping the energy transition, including:

• The role of battery storage in enabling renewable integration
• Why flexibility is becoming a critical part of the energy system
• The shift from asset ownership to access and platform models
• The impact of geopolitics and energy security on policy direction
• The need to reframe the transition around energy sovereignty and abundance

On the talent side, Philipp shares a disciplined approach to building teams, with a strong emphasis on hiring quality over speed and creating a culture where high performers set the standard:

“The most important thing you can control is who comes through the door.”

He also reflects on the realities of building a company in this space, from landmark commercial deals and fundraising milestones to the operational challenges that come with scaling infrastructure.

Finally, we discuss leadership, resilience, and the importance of mindset, seeing challenges not as problems, but as opportunities to build capability and long-term

About Hyperion Search:

At Hyperion Search, we specialize in building world-class teams for the cleantech and energy transition sectors. We focus on leadership roles but also recruit strategically critical individual contributors who drive business growth. Whether you’re a founder scaling a startup, a board member guiding a scaleup, a VC/PE investor, or a corporation committed to energy and mobility transitions, we find the talent that will deliver impactful, sustainable results.

• Linked In: https://www.linkedin.com/company/hyperion-search-ltd
• Website: www.hyperionsearch.com

Follow us online, write a review (please) or subscribe

I'm very keen to hear feedback on the podcast and my guests, and to hear your suggestions for future guests or topics. Contact via the podcast Linked In page.

If you do enjoy the podcast, please write a review on iTunes, or your usual podcast platform, and tell your cleantech friends about us. That would be much appreciated.

• LinkedIn: https://www.linkedin.com/in/david-hunt-cleantech/

Also follow the podcast and to stay up to date.

• LinkedIn: https://www.linkedin.com/company/leaders-in-cleantech-podcast...

In this episode of Leaders in Cleantech, I’m joined by Adrien Pinsard, CEO of Telis Energy, a Carlyle-backed renewable energy platform targeting a 10GW development pipeline across Europe by 2030.

Adrien reflects on nearly two decades in the renewables sector, moving from private equity investor to platform builder and entrepreneur. Before launching Telis in 2022, Adrien spent 14 years investing in renewable projects at Platina Energy Partners and later served as Interim CEO of Macquarie’s 11GW European solar developer, Cero Generation.

We discuss the thinking behind Telis’ decentralised development model, with dedicated local teams operating across the UK, France, Germany and Italy, and how that structure helps navigate the realities of developing infrastructure in different markets. As Adrien explains:

“To be a successful developer, you need a very strong local presence. You have to understand communities and the local market.”

The conversation also explores how the European renewables landscape is evolving. Adrien highlights two key shifts in recent years: the growing saturation of solar in some markets, and the rapidly increasing role of battery storage, driven by falling costs and rising power market volatility.

We also discuss broader themes shaping the next phase of the energy transition, including:

• The changing economics of renewable development
• Why batteries and hybrid energy hubs are becoming central to projects
• How grid constraints are shaping development strategy
• The importance of capital discipline in a tougher investment environment
• The impact of geopolitical volatility on energy security and renewable deployment

Looking ahead, Adrien sees renewables playing an increasingly important role in Europe’s energy resilience:

“Renewables are very well placed to provide energy security. Once the assets are in the ground, they’re homegrown.”

Finally, Adrien reflects on the entrepreneurial journey of building a platform from scratch, and the importance of trust and culture when building teams across multiple markets.

Adrien Pinsard:

Adrien Pinsard has a 17-year track record of renewable energy investment and development.

Prior to founding Telis, Adrien was Interim CEO of the Macquarie Group 11GW European solar energy developer, Cero Generation. Adrien spent 1

About Hyperion Search:

At Hyperion Search, we specialize in building world-class teams for the cleantech and energy transition sectors. We focus on leadership roles but also recruit strategically critical individual contributors who drive business growth. Whether you’re a founder scaling a startup, a board member guiding a scaleup, a VC/PE investor, or a corporation committed to energy and mobility transitions, we find the talent that will deliver impactful, sustainable results.

• Linked In: https://www.linkedin.com/company/hyperion-search-ltd
• Website: www.hyperionsearch.com

Follow us online, write a review (please) or subscribe

I'm very keen to hear feedback on the podcast and my guests, and to hear your suggestions for future guests or topics. Contact via the podcast Linked In page.

If you do enjoy the podcast, please write a review on iTunes, or your usual podcast platform, and tell your cleantech friends about us. That would be much appreciated.

• LinkedIn: https://www.linkedin.com/in/david-hunt-cleantech/

Also follow the podcast and to stay up to date.

• LinkedIn: https://www.linkedin.com/company/leaders-in-cleantech-podcast...

In this episode I’m Joined by Mike Nakrani, CEO of VEV. Mike is an OG in the electrification of transport, and that’s ignoring the milk float joyride! We talk about the challenges, opportunities and many converging technologies and factors that impact fleet electrification.

There are of course many examples now that light and heavy-duty electric fleets are here and scaling. Grid connections aside, the biggest challenges is to demonstrate and achieve better TCO and true commercial viability. As Mike said during our conversation, “Electrification only works when it works commercially.”. We also talk about how having worked in behemoths like Ford and BP have been a positive rather than a negative as he leads a nimble start-up, taking the good and the bad, and how he sees and leads innovation at speed.

We talked through:

• The new economics of fleet electrification
• What genuinely drives ROI
• Why scaling is very different from running a pilot
• Financing models and infrastructure ownership
• The role of software and optimisation
• And what kind of leadership this next phase requires

It’s a thoughtful conversation about what it really takes to move from ambition to operational reality, from pilots to scale.

I hope you enjoy it.

Mike Nakrani:

With more than two decades of experience spanning automotive OEMs, mobility services and energy transition, Mike Nakrani is steering VEV’s mission to support commercial fleets in moving to electric power.

He stands at the intersection of automotive, mobility services and the energy transition – three sectors converging rapidly. Through his role at VEV, he represents how commercial fleet electrification must be executed at scale: not just with EVs, but with systems, infrastructure and business models that work. His leadership offers insight into how fleets can drive real-world decarbonisation.

Nakrani promotes a pragmatic, ‘technology-neutral’ view of fleet decarbonisation – emphasising the transitional role that fuels such as HVO have to play, while reinforcing the scale and operational efficiency electrification delivers in the long term, delivering the most compelling business case for organisations needing to decarbonise.

About VEV:

VEV helps organisations deliver on their carbon reduction ambitions with an end-to-end fleet electrification solution that integrates across vehicle

About Hyperion Search:

At Hyperion Search, we specialize in building world-class teams for the cleantech and energy transition sectors. We focus on leadership roles but also recruit strategically critical individual contributors who drive business growth. Whether you’re a founder scaling a startup, a board member guiding a scaleup, a VC/PE investor, or a corporation committed to energy and mobility transitions, we find the talent that will deliver impactful, sustainable results.

• Linked In: https://www.linkedin.com/company/hyperion-search-ltd
• Website: www.hyperionsearch.com

Follow us online, write a review (please) or subscribe

I'm very keen to hear feedback on the podcast and my guests, and to hear your suggestions for future guests or topics. Contact via the podcast Linked In page.

If you do enjoy the podcast, please write a review on iTunes, or your usual podcast platform, and tell your cleantech friends about us. That would be much appreciated.

• LinkedIn: https://www.linkedin.com/in/david-hunt-cleantech/

Also follow the podcast and to stay up to date.

• LinkedIn: https://www.linkedin.com/company/leaders-in-cleantech-podcast...

In this episode, I’m joined by Johannes Kirnberger, co-founder and Managing Director of Delta Charge, a Swedish-German company building Europe’s next-generation charging and battery infrastructure for electric freight. Johannes shares his journey from advising global institutions like the OECD and World Bank to co-founding a startup that's tackling one of Europe’s most complex infrastructure challenges—how to electrify heavy-duty transport at scale.

Johannes Kirnberger is the co-founder and managing director of Delta Charge, a Swedish-German energy company pioneering integrated charging and battery storage solutions for European industry and electric fleet. He previously advised the OECD, the World Bank and the Intergovernmental Panel on Climate Change (IPCC) on energy, digital, and climate policy. Johannes serves as a guest lecturer at the Technical University of Munich (TUM) and holds a Bachelor of Science in Management from ESCP Business School, a Master of International Public Management from Sciences Po, and a Master in International Affairs, Energy and Environment from Columbia University.

About Delta Charge:
Headquartered in Munich, Delta Charge is a Swedish-German energy infrastructure company pioneering end-to-end charging and battery storage solutions for Europe’s freight sector. The company develops and finances a pan-European network of truck-charging depots and battery-enabled industrial hubs. Its platform combines intelligent software, grid-connected batteries, and fixed-price charging services to help fleet operators electrify their operations while supporting a more flexible and resilient power grid. Backed by Delta Capacity, one of Scandinavia’s leading battery energy storage developers, the company aims to deploy over €300 million in infrastructure and deliver 1.8 TWh of clean energy annually by 2030, anchoring the backbone of Europe’s zero-carbon freight future.

Social links:
Johannes Kirnberger LinkedIn: https://www.linkedin.com/in/johanneskirnberger/
Delta Charge on LinkedIn: https://www.linkedin.com/company/deltacharge/
Delta Charge website: https://www.deltacharge.com/

Episode Links:
Book Recommends:
Termination Shock- Neil Stephenson - https://amzn.eu/d/1XmpfDC
About Hyperion Search:
At Hyperion Search, we specialize in building world-class teams for the cleantech and energy transition sectors. We focus on leadership roles but also recruit str

About Hyperion Search:

At Hyperion Search, we specialize in building world-class teams for the cleantech and energy transition sectors. We focus on leadership roles but also recruit strategically critical individual contributors who drive business growth. Whether you’re a founder scaling a startup, a board member guiding a scaleup, a VC/PE investor, or a corporation committed to energy and mobility transitions, we find the talent that will deliver impactful, sustainable results.

• Linked In: https://www.linkedin.com/company/hyperion-search-ltd
• Website: www.hyperionsearch.com

Follow us online, write a review (please) or subscribe

I'm very keen to hear feedback on the podcast and my guests, and to hear your suggestions for future guests or topics. Contact via the podcast Linked In page.

If you do enjoy the podcast, please write a review on iTunes, or your usual podcast platform, and tell your cleantech friends about us. That would be much appreciated.

• LinkedIn: https://www.linkedin.com/in/david-hunt-cleantech/

Also follow the podcast and to stay up to date.

• LinkedIn: https://www.linkedin.com/company/leaders-in-cleantech-podcast...

In this episode, David Hunt discusses the key insights from the Hyperion Q4 Market and Talent Review, highlighting the significant shifts in the cleantech sector during 2025. The conversation covers the maturation of the industry, the focus on execution over exuberance, and the evolving demands for leadership and talent across various sectors, including energy storage, EVs, and renewables. The episode also touches on the challenges faced by hard tech and the implications for the future as the market prepares for 2026.

Takeaways

• 2025 was a year of maturity in cleantech.
• The focus has shifted from technology to execution.
• Nearly 50% fewer companies reached seed to Series A rounds.
• Talent demand is focused on operational discipline and execution.
• AI-driven optimization is becoming crucial in mobility.
• Solar has overtaken coal as the EU's largest electricity source.
• The pilot to readiness gap in hard tech is widening.
• Boards need to be operator-led for effective scaling.
• Talent markets are becoming more selective with higher expectations.
• The next phase of the transition is about delivery, not invention.
• Navigating the Cleantech Landscape: Insights from Hyperion
• 2025: The Year Cleantech Matures

Sound Bites

• "The pilot to readiness gap is widening."
• "Boards need operators, not just advisors."
• "AI becomes invisible infrastructure."

Chapters

00:00Introduction to the Hyperion Q4 Review

01:212025: A Year of Maturity in Cleantech

03:20Energy Storage and Grid Market Insights

05:09EV and Future Mobility Developments

07:01Renewables: Milestones and Talent Trends

08:35Challenges in Hard Tech and Funding

09:55Looking Ahead: Key Themes for 2026

Links

• Hyperion Q4 Market and Talent Review - https://hyperionsearch.com/market-reviews/
• Net Zero Insights -State of Cleantech 2025 - https://stateofclimatetech.com/

About Hyperion Search:

At Hyperion Search, we specialize in building world-class teams for the cleantech and energy transition sectors. We focus on leadership roles but also recruit strategically critical individual contributors who drive business growth. Whether you’re a founder scaling a startup, a board member guiding a scaleup, a VC/PE investor, or a corporation committed to energy and mobility transitions, we find the talent that will deliver impactful, sustainable results.

• Linked In: https://www.linkedin.com/company/hyperion-search-ltd
• Website: www.hyperionsearch.com

Follow us online, write a review (please) or subscribe

I'm very keen to hear feedback on the podcast and my guests, and to hear your suggestions for future guests or topics. Contact via the podcast Linked In page.

If you do enjoy the podcast, please write a review on iTunes, or your usual podcast platform, and tell your cleantech friends about us. That would be much appreciated.

• LinkedIn: https://www.linkedin.com/in/david-hunt-cleantech/

Also follow the podcast and to stay up to date.

• LinkedIn: https://www.linkedin.com/company/leaders-in-cleantech-podcast...

Devrim Celal– Kraken

In this episode of Leaders in Cleantech, David Hunt is joined once again by Devrim Celal, Chief Flexibility & Marketing Officer at Kraken, nearly six years after their first conversation in 2019—back when Devrim was CEO of Upside Energy.

Since then, Upside Energy was acquired by Octopus Energy and evolved into Kraken, now one of the world’s leading energy technology platforms, serving tens of millions of customers and optimising flexible power at global scale.

Rather than a linear success story, Devrim reflects on the last decade as a series of distinct phases: early uncertainty, pivotal strategic pivots, the acquisition decision, rapid scaling within Octopus, and now Kraken’s transition into a fully independent global company.

The conversation explores leadership at scale, the reality of building culture through growth, the trade-offs founders face between conviction and adaptability, and what the future holds for flexibility, storage, EVs, data centres and grid optimisation.

This is a thoughtful, honest discussion about long-term impact, not short-term hype—and what it really takes to build enduring companies in the energy transition.

Devrim Celal:
Devrim is the Chief Flexibility and Marketing Officer at Kraken. Overseeing Kraken’s flexibility and product capabilities, the cloud-based flexibility platform controls and optimizes distributed energy resources such as batteries of all sizes, EVs, solar and wind generation or heat pumps with machine learning and AI to match electricity supply and demand, helping the electricity grid deal with the natural volatility of renewable generation. Kraken is currently contracted to manage over 42 GW of power.

Previously, Devrim was the CEO of Upside Energy, which was acquired by Kraken in 2020. Before starting Upside Energy, Devrim’s professional career saw him take up executive roles with blue chip management consultancies and finance companies such as Publicis Sapient, Kearney and Lansdowne. He also holds an MBA from Yale University. In 2023, Devrim joined the Elexon Board, which manages the Balancing and Settlement Code of Great Britain’s energy system, as a Non-Executive Director.

About Kraken:
Vienna-based innovator enspired is known for pioneering automated energy trading and Kraken is the most-loved operating system for energy.

Powered by Utility-Grade AI™ and deep industry expertise, we

About Hyperion Search:

At Hyperion Search, we specialize in building world-class teams for the cleantech and energy transition sectors. We focus on leadership roles but also recruit strategically critical individual contributors who drive business growth. Whether you’re a founder scaling a startup, a board member guiding a scaleup, a VC/PE investor, or a corporation committed to energy and mobility transitions, we find the talent that will deliver impactful, sustainable results.

• Linked In: https://www.linkedin.com/company/hyperion-search-ltd
• Website: www.hyperionsearch.com

Follow us online, write a review (please) or subscribe

I'm very keen to hear feedback on the podcast and my guests, and to hear your suggestions for future guests or topics. Contact via the podcast Linked In page.

If you do enjoy the podcast, please write a review on iTunes, or your usual podcast platform, and tell your cleantech friends about us. That would be much appreciated.

• LinkedIn: https://www.linkedin.com/in/david-hunt-cleantech/

Also follow the podcast and to stay up to date.

• LinkedIn: https://www.linkedin.com/company/leaders-in-cleantech-podcast...

In this episode of Leaders in Cleantech, I speak with Juergen Mayerhofer, CEO and co-founder of enspired, the Vienna-based company using fully automated, AI-driven trading to optimise flexible power assets – especially grid-scale batteries – across multiple European markets.

Juergen shares how he stumbled into energy via Austrian gas market liberalisation, fell in love with physical energy systems, and eventually founded enspired in early 2020 with the simple but powerful idea that flexibility is the key resource for integrating more renewables. We talk about how the company has scaled from its first pump storage and thermal assets in Germany to managing ~5 GW of flexibility (including over 1.3 GW of batteries), now active across ten markets and expanding into new geographies.

We dig into why enspired thinks like a software and R&D company rather than a classic trading house, how they use automation, machine learning and reinforcement learning in practice, and why they’ve chosen to publish independently verified revenue performance instead of leaning on AI buzzwords. Juergen also reflects on the realities of founding just before COVID, expanding rapidly across borders, and building a diverse, high-performance culture designed to move into new countries in weeks, not years.

About Juergen Mayerhofer:

enspired CEO and co-founder Juergen Mayerhofer holds an MBA in energy management and has worked in the energy sector for over 20 years, contributing to the expansion of renewables in the grid in various expert positions. Under his bold and devoted leadership, enspired evolved from a small-scale startup with a workforce in the single digits into a successful institution with global recognition. As an enthusiast and first mover in BESS optimization, Juergen is a highly respected and trusted figure in his field as well as the power industry at large.

About enspired:

Vienna-based innovator enspired is known for pioneering automated energy trading and cross-market battery storage optimization across Europe with an advanced technical infrastructure running on billions of data points, AI, machine learning, and reinforcement learning. The self-developed optimization platform is operated 100% in-house, which makes it highly flexible in adapting to new markets and changing market conditions. By optimizing the power assets of their customers across all available energy markets, enspired unlocks essential flexibili

About Hyperion Search:

At Hyperion Search, we specialize in building world-class teams for the cleantech and energy transition sectors. We focus on leadership roles but also recruit strategically critical individual contributors who drive business growth. Whether you’re a founder scaling a startup, a board member guiding a scaleup, a VC/PE investor, or a corporation committed to energy and mobility transitions, we find the talent that will deliver impactful, sustainable results.

• Linked In: https://www.linkedin.com/company/hyperion-search-ltd
• Website: www.hyperionsearch.com

Follow us online, write a review (please) or subscribe

I'm very keen to hear feedback on the podcast and my guests, and to hear your suggestions for future guests or topics. Contact via the podcast Linked In page.

If you do enjoy the podcast, please write a review on iTunes, or your usual podcast platform, and tell your cleantech friends about us. That would be much appreciated.

• LinkedIn: https://www.linkedin.com/in/david-hunt-cleantech/

Also follow the podcast and to stay up to date.

• LinkedIn: https://www.linkedin.com/company/leaders-in-cleantech-podcast...