Hydrostor’s Oonagh O’Grady outlines why Europe must urgently prioritise long-duration energy storage to secure a resilient, competitive, and fossil-free future.
Oonagh O’Grady, Vice President of International Origination at Hydrostor, believes that long-duration energy storage is the missing link to meet Europe’s ambitious clean energy goals. She argues that energy storage can balance renewable generation with demand, cut fossil fuel dependency, and strengthen industrial competitiveness.
How does the European energy sector turn shared ambition into collaborative action?
Turning shared ambition into collaborative action in Europe’s energy sector, in my mind, requires a shift in mindset. The sector must shift from siloed strategies to system-level thinking. The energy transition is not a linear pathway. It’s an interconnected ecosystem where intermittent renewable generation must be balanced with steady-state demand across electricity, heat, and mobility. The missing link in this equation — and the one that has received far too little attention — is energy storage, particularly long-duration energy storage.
LDES — especially technologies like Hydrostor’s Advanced Compressed Air Energy Storage (A-CAES) — delivers the flexibility, resilience, and reliability needed to balance intermittent renewables. It’s not a support act; it’s strategic infrastructure. A-CAES offers all the benefits of pumped hydro (inertia, black start) with added advantages: faster build times, drought resilience, minimal land use, and proximity to demand centers. Without it, Europe risks decades of gas lock-in, stranded assets, and exposure to volatile global markets.
Europe’s energy transition demands more than ambition — it requires coordinated execution. To move from ambition to action, Europe must embed LDES into policy frameworks. That means setting MW targets, creating transparent procurement schedules, and unlocking private capital. The technologies are ready. What’s needed now is strategic foresight and coordinated execution.
What does Europe need to do to deliver competitive, resilient energy by 2030?
Europe’s 2030 energy goals hinge on renewables — but without LDES, reliability and affordability are at risk. Lithium-ion batteries meet short-term needs, but only LDES can provide multi-day balancing, grid services like inertia, and long-term resilience.
Policymakers must act now. LDES projects have 8–10-year delivery timelines. Without urgent support, Europe will default to new gas infrastructure — locking in emissions for 30 years and weakening industrial competitiveness. Hydrostor’s A-CAES is a proven alternative: emission-free, flexible, and reliable for over 50 years.
Europe should follow the wind and solar playbook: set binding targets, publish procurement schedules, and adopt investment mechanisms like the UK’s Cap and Floor or Australia’s LTESA. These tools de-risk investment and accelerate deployment.
LDES is essential to safeguard Europe’s energy security, independence, and workforce. The time to act is now.
It’s 2030: what does Europe’s energy mix look like?
By 2030, Europe’s energy mix will be fundamentally transformed — led by renewables, enabled by storage, and shaped by strategic policy. The EU has set a binding target for at least 42.5% of total energy consumption to come from renewable sources by 2030, with an aspirational goal of 45%. In the electricity sector, we’re likely to see renewables contributing upwards of 60–70%, dominated by wind and solar. But with that shift comes a critical challenge: intermittency.
To manage variability and ensure reliability, energy storage will become a central pillar of the system. Short-duration storage like lithium-ion batteries will continue to play a key role in fast-response balancing, but long-duration energy storage will be essential to replace the flexibility once provided by fossil-fuelled thermal plants. Technologies like Advanced Compressed Air Energy Storage (A-CAES), flow batteries, and other emerging solutions will provide the intra-day to multi-day resilience needed to stabilise the grid and optimise renewable output.
Ultimately, the success of Europe’s 2030 energy mix will depend not just on technology, but on policy alignment, investment mobilisation, and system-level planning. Long-duration energy storage will be a key enabler — turning high renewable penetration into a reliable, secure, and affordable energy system.
Is there another industry vertical that has vital lessons for the energy sector?
The energy sector is uniquely complex, shaped by the interplay between heavy infrastructure and dynamic markets. Few industries require such tight coordination between physical delivery systems and financial mechanisms. To function effectively, these two components must be aligned — and policy is the bridge. It guides infrastructure development through investment signals and shapes market frameworks that enable viable business models. Without coherent policy, the system risks fragmentation.
Perhaps, one valuable parallel is the telecommunications sector. Like energy, it underwent a major transformation — from centralised, state-run systems to liberalised, competitive markets. Success hinged on clear regulatory frameworks, significant infrastructure investment, market liberalisation paired with consumer protection and resilient, regionally anchored supply chains.
Ultimately, the energy transition is not just about technology — it’s about systems thinking. We must retain and transfer knowledge, align infrastructure with market signals, and build resilient supply chains that support both decarbonisation and economic growth.
What is the biggest workforce issue for the energy transition?
The biggest workforce challenge is retaining and redeploy the deep expertise of conventional energy and Oil & Gas sector workers. Hydrostor’s A-CAES technology shares many principles with these sectors — making legacy skills not just relevant, but essential.
We have a unique opportunity to reskill and redeploy experienced professionals into emerging asset classes like LDES. These workers bring decades of operational knowledge that can accelerate project delivery and mentor the next generation.
Europe’s energy transition isn’t just technological — it’s human. We must invest in training, create clear reskilling pathways, and ensure communities tied to fossil industries are part of the clean energy future.
LDES projects offer long-term employment, regional investment, and infrastructure-grade reliability. By valuing people as much as technology, we can build a resilient, inclusive energy system.
What sustainability practice in your organisation are you most proud of? And how have you reduced your personal carbon footprint?
At Hydrostor, sustainability is our core mission. We’re proud to deliver long-duration energy storage solutions that directly address one of the biggest gaps in the energy transition: grid reliability without fossil fuels.
Our A-CAES technology replaces thermal peaking plants with emission-free, flexible infrastructure that lasts over 50 years. It uses minimal water, has a small land footprint, and can be sited near demand centers — making it a drought-resilient, community-friendly solution.
Personally, I believe sustainability starts with information and knowledge, I’ve found the most powerful impact comes from sparking informed conversations. Helping others understand the climate impact of everyday decisions — and empowering them to act — this creates a ripple effect.
Sustainability must be relatable, actionable, and inclusive. That’s how we build momentum — one project, one conversation, one decision at a time.
What are the biggest challenges facing energy leaders today?
Energy leaders today face a dual challenge: navigating geopolitical and economic volatility while accelerating the transition to net zero. Rising energy costs, supply chain disruptions, and global instability threaten progress — but they also underscore the urgency of action.
One of the biggest risks is defaulting to new gas infrastructure. Without immediate support for long-duration energy storage (LDES), Europe could lock in fossil emissions for decades, undermining climate goals and industrial competitiveness.
Hydrostor’s A-CAES offers a proven alternative. But to scale, we need supportive policy, streamlined permitting, and investment mechanisms that de-risk high-CapEx projects. Leaders must advocate for market reforms that enable new revenue streams and bankable business models.
The business case for LDES is clear: it strengthens reliability, reduces curtailment, and unlocks the full value of renewables. Europe has the ambition — now it needs the execution. That starts with leadership.
How are your industry experts going to address these challenges at Enlit Europe in Bilbao?
Enlit gives us the platform to showcase how long-duration energy storage — like our Advanced Compressed Air Energy Storage (A-CAES) — can complement or replace pumped hydro and lithium-ion batteries, offering greater flexibility and reliability.
We see Enlit as a unique opportunity to engage with the full European energy ecosystem — not just to share ideas, but to bring proven best practices from other markets into the European context. Our contracted projects in Australia and California provide real-world insights into technical, commercial, and regulatory success. We can bring our experience with proven financial frameworks, deployment models, and policy precedents to help Europe accelerate LDES adoption. These projects give us real-world knowledge — technical, commercial, and regulatory — that we’re ready to share.
Ultimately, our goal is to offer Europe optionality: proven, scalable clean energy solutions that support grid stability and decarbonisation. And we’re here to collaborate — with policymakers, grid operators, and industry leaders — to make that vision a reality.
If you had a magic wand what is one thing you would implement today?
If I had a magic wand, I would ensure the Flexibility Needs Assessments mandated by the EU are completed on an informed basis by all countries. I’d then implement a Europe-wide procurement mandate for 8+ hour long-duration energy storage (LDES), backed by clear targets and timelines.
This single action would unlock the scale-up of technologies like Hydrostor’s A-CAES — delivering emission-free, flexible, and reliable energy infrastructure that lasts over 50 years. It would reduce reliance on imported gas, cut carbon emissions, and strengthen industrial competitiveness.
LDES projects take 8–10 years to deliver. Without urgent action, Europe risks defaulting to new gas plants — locking in fossil fuel dependency and stranded assets for decades. The technologies are ready. What’s needed is bold policy and coordinated execution.
Hydrostor stands ready to partner with policymakers, utilities, and investors to build the infrastructure Europe will need tomorrow. Let’s act now — and secure a clean, resilient energy future.
