As part of IHA’s 30th anniversary campaign, we’re spotlighting the forward-thinking innovators who are shaping the future of sustainable hydropower. In this edition, we speak with Or Yogev, Founder and CTO of Augwind – one of IHA’s newest members – to explore how the company’s pioneering AirBattery technology could break new ground in one of renewable energy’s greatest challenges for the next 30 years: long-duration storage.

“Long-duration storage will be critical – it's the missing piece of the renewable puzzle,” says Or. “As we race to increase renewable energy penetration beyond 50%, we're facing the reality of 'Dunkelflautes' – those long periods when the sun doesn't shine and the wind doesn't blow. These aren't just minor inconveniences; they severely challenge grid stability.”

Augwind’s recently announced commercial-scale AirBattery project in Germany aims to address exactly this challenge.

Proven hydropower principles, reimagined

The AirBattery system combines two established technologies – pumped storage hydropower and compressed air storage – to deliver long-duration, grid-scale energy storage using underground salt caverns.

“The breakthrough lies in how we've combined two well-established technologies in an innovative way. We merge pumped hydroelectric principles with compressed air storage, circulating water between underground chambers to compress and decompress air at vast scales,” Or explains. “It's essentially taking the proven reliability of pumped hydro and scaling it to work with compressed air in underground caverns larger than the Empire State Building. This gives us unlimited duration potential, limited only by the cavern's volume.”

The system is already demonstrating results. “We've already reached 47% AC-to-AC round-trip efficiency at our demonstration facility in Israel, and we're confident that commercial installations will exceed 60%,” says Or. “This validates that we're not just theoretically sound – we're building on proven hydropower performance principles that work in the real world.”

And its potential extends to regions where conventional pumped hydro isn’t feasible. “It's definitely a next-generation adaptation, because we're taking the fundamental principles that make pumped hydro so effective and applying them to solve problems that traditional pumped hydro can't address – and in geographies without suitable topography or water resources,” Or says.

“Germany is the perfect example. We have over 400 existing salt caverns potentially suitable for AirBattery, with geological potential for storing 330TWh in total – that's equivalent to 60–65% of Germany's annual electricity usage. These are areas where traditional pumped hydro simply isn't feasible, but our system thrives.”

The missing piece of the net zero puzzle?

Looking ahead to the next 30 years, Or sees long-duration storage as essential to making renewable-dominant grids a reality. While classic pumped storage hydropower systems will be critical for providing future grids with flexibility and stability, innovation can extend its potential much further.

“By 2055, I believe long-duration storage like our AirBattery will serve as the resilient buffer that makes 100% renewable grids possible. We're talking about providing backup for weeks or months, helping utilities and grid operators deal with renewables intermittency while stabilising electricity markets. Without this capability, we simply can't achieve the scale of renewable deployment needed for net zero.”

Why partnerships will matter

As Augwind moves towards commercial deployment in Germany, collaboration across the energy ecosystem is vital.

“The partnerships we're building in Germany really illustrate what's needed – we're working closely with local cavern owners, utilities, energy traders, and industrial off-takers. It takes this entire ecosystem working together to make projects like this successful.”

IHA's worldwide network of hydropower stakeholders is a key part of that ecosystem. “Being part of the global hydropower community through IHA has been invaluable, because we're building on decades of proven expertise,” Or says. “The hydropower sector understands large-scale infrastructure, long project lifecycles, and the regulatory landscape better than anyone. That knowledge base is accelerating our deployment timeline significantly.

“IHA's role in fostering collaboration across the hydropower and energy storage community is exactly what we need. The organisation brings together that wealth of experience from traditional hydropower with innovative approaches like ours. This cross-pollination of ideas and expertise is essential for solving the complex challenges ahead.

“What's particularly valuable is IHA's global perspective – as we look beyond our German launch to broader deployment across Europe by 2030, having that international network and knowledge sharing will be crucial for navigating different regulatory environments and market conditions.”

A global vision for long-duration storage

While Germany is the first launch site, the opportunities for AirBattery span worldwide.

“Germany's redundant salt caverns, industrial leadership and climate ambition make it the perfect launchpad, but the potential is global,” Or says. “Our goal is to become Europe's preferred partner for multiweek storage solutions, and from there, we see enormous opportunities in regions facing similar challenges with renewable intermittency.

“Areas with significant underground geological formations – whether salt caverns, depleted gas fields, or other suitable structures – combined with high renewable energy ambitions represent our biggest opportunities. The technology doesn't rely on critical minerals or complex supply chains, so it can be deployed using locally sourced supplies and labour virtually anywhere with the right geology.”

Looking ahead to the next 30 years

As countries worldwide strive to meet ambitious net zero goals over the coming decades, technology innovations like Augwind’s AirBattery can play a defining role in overcoming one of the energy transition’s greatest hurdles: variability. What might this landscape look like by 2055?

“We expect to have proven that long-term energy storage to balance the grid is not only technically feasible, but economically sound at global scale,” says Or. “Our vision is that AirBattery technology will have enabled the final push to net zero by solving the intermittency challenge that held back renewable deployment for so long.

“Specifically, I'd love to see our technology contributing to all three pillars of the Energy Policy Goal Triangle – security of supply through weeks-long backup power, affordability by reducing price volatility and curtailment costs, and sustainability by enabling more effective integration of solar and wind energy. If we've helped accelerate the renewable transition while reducing long-term energy costs for industry and households, we'll have succeeded.”

A more connected hydropower future

For Augwind, engaging with the global hydropower community was a natural step in connecting with the wider world of clean energy innovation.

“What drew us to IHA was recognising that we're fundamentally part of the hydropower family,” he says. “Our AirBattery system uses the same proven principles that have made pumped hydro so successful.”

While pumped storage hydropower and compressed air energy storage traditionally operate in different ways, both rely on large-scale infrastructure, long planning horizons and a deep understanding of grid dynamics. Or believes that combining these strengths will help bring newer forms of energy storage into real-world use, faster.

“The collaboration I'm most excited about is this blending of traditional hydropower expertise with innovative storage technologies,” he says. “The hydropower community has decades of experience with large infrastructure projects, regulatory processes, and grid integration. Meanwhile, we bring fresh approaches to storage duration and geographical flexibility.”

Looking ahead, he envisions a more unified approach to renewable energy infrastructure, bringing together established players and new technologies under a shared goal.

“I see a future where the lines between traditional hydropower and advanced energy storage blur, creating a more comprehensive toolkit for the renewable energy transition. That's the kind of collaborative innovation that will get us to net zero.”