On this episode of Watt It Takes, we explore another approach to long-duration energy storage: compressed air.

Curtis VanWalleghem, Co-Founder and CEO of Hydrostor, started the company in 2010 after confronting surplus power challenges at Bruce Power. Without a traditional founder background, he set out to build storage systems that use compressed air and underground hard rock caverns to deliver ten-plus hours of grid-scale power.

What began as experiments with underwater balloons evolved into large-scale rock cavern projects and a major business model shift. Hydrostor transitioned from a technology provider to an independent power producer, securing PPAs and financing billion-dollar infrastructure projects.

In this conversation, Curtis reflects on the realities of building something capital-intensive: raising early checks from friends and family, enduring more than 200 investor rejections, mortgaging his home, pivoting both technology and strategy, and learning how to finance projects at true infrastructure scale.

Today, Hydrostor has raised over $550 million in equity, secured roughly $8 billion in revenue contracts, and is advancing a multi-gigawatt pipeline across North America and Australia.

About Powerhouse Innovation and Powerhouse Ventures
Powerhouse Ventures backs seed stage startups developing innovative software to advance clean energy, mobility, and industry. If you are thinking about building something in this space, get in touch with our team.

Powerhouse Innovation is a best in class consulting firm, powered by the strongest energy innovation network, data and team in our industry. We partner with world's leading corporations, investors, and utilities to source and evaluate disruptive startups shaping the future of energy and industry.

To hear more stories of founders building our energy abundant future, hit the “subscribe” button and leave us a review.

If you spend any time on the water, you’ve probably heard the joke that the two best days of a boat owner’s life are the day they buy the boat… and the day they sell it.

For today’s guest, that line isn’t just a joke. It’s a problem statement.

Mitch Lee grew up around boats. He loved being on the water, but he also experienced firsthand how loud, smelly, maintenance-heavy, and frustrating boat ownership can be. And once electric vehicles started proving what was possible on land, one idea kept coming back to him: if electrification makes sense in cars on the road, it might actually make even more sense in boats on the water.

Mitch is the co-founder and CEO of Arc, an electric boat company building both consumer and commercial vessels. Arc started in the premium wake sports market, selling directly to consumers and using those early boats to develop its electric propulsion technology. That platform is now being deployed in commercial applications, where electrification can improve reliability, lower costs, and support ports that want to electrify.

Founded in 2021, Arc has raised over $110 million through its Series B and has scaled from delivering its first customer boat, which took two years to build, to now producing multiple boats per week, while also landing major commercial partnerships at working ports.

In our conversation, Mitch walks me through his path that led to Arc, from a childhood fascination with stocks and compounding interest, to building and selling his first company in the personal finance space, to betting big on electric boats and what electrification can unlock on the water.

About Powerhouse Innovation and Powerhouse Ventures
Powerhouse Ventures backs seed stage startups developing innovative software to advance clean energy, mobility, and industry. If you are thinking about building something in this space, get in touch with our team.

Powerhouse Innovation is a best in class consulting firm, powered by the strongest energy innovation network, data and team in our industry. We partner with world's leading corporations, investors, and utilities to source and evaluate disruptive startups shaping the future of energy and industry.

To hear more stories of founders building our energy abundant future, hit the “subscribe” button and leave us a review.

As an aging grid faces rising demand, increasing complexity, and more frequent stress events, one thing has become clear: we don’t just need more power, we need power that can show up at the right time, in the right place, and at the right price. What’s far less settled is how we get there. Should large energy users build their own power? Should they treat the grid as something to work around rather than work with? Or is there a way for new load to actively strengthen the grid by contributing capacity when it’s needed most?

This moment is being shaped by real market signals. Just two weeks ago, PJM, the largest power market in the U.S., cleared its latest capacity auction at the market cap yet again, underscoring how tight supply has become and how quickly affordability pressures are building. As data center demand accelerates, those pressures are no longer abstract, they’re showing up in prices, planning decisions, and who ultimately pays.

These questions have been a throughline for us this year on Watt It Takes. We’ve talked with founders working across the grid, from storage and interconnection to transmission and large-scale development. Today’s conversation brings many of those threads together.
Dana Guernsey and her team at Voltus are tackling that challenge at the intersection of demand and supply, turning customer-side flexibility into dependable grid capacity. Voltus sits between energy users and grid operators, aggregating flexible demand from sources like demand response, EV charging, batteries, and onsite generation, and translating it into dispatchable capacity that markets value and pay for. Voltus’s business model is a value-share: the company monetizes that flexibility in energy markets and shares the resulting value with the customers providing it.

Voltus operates across all major North American power markets, even in an industry where each ISO and RTO plays by different rules. Today, the company manages more than eight gigawatts of flexible capacity and supports tens of thousands of customer sites, with resources dispatched thousands of times each year.

On this last episode of the year, I spoke with Dana Guernsey, Co-Founder and CEO of Voltus. We talked about her journey, from growing up in Queens, New York and coming of age around 9/11, to discovering energy markets during her time at EnerNOC, to founding Voltus while starting a family. That path shaped how Dana thinks about complexity, customers, and reliability, and ultimately led her to build Voltus into a platform designed to help make clean, affordable, and reliable power something we don’t have to trade off against growth.

About Powerhouse Innovation and Powerhouse Ventures
Powerhouse Ventures backs seed stage startups developing innovative software to advance clean energy, mobility, and industry. If you are thinking about building something in this space, get in touch with our team.

Powerhouse Innovation is a best in class consulting firm, powered by the strongest energy innovation network, data and team in our industry. We partner with world's leading corporations, investors, and utilities to source and evaluate disruptive startups shaping the future of energy and industry.

To hear more stories of founders building our energy abundant future, hit the “subscribe” button and leave us a review.