Clean Energy Storage: Why Flow Batteries Matter

No one wants to ship water around the world. That odd sentence may explain why long-duration storage is becoming an energy-security issue. My guest is Min Tang, Director of International Business at Rongke Power, one of the world’s leading vanadium flow battery companies. Min works at the sharp end of a climate tech question that is becoming impossible to avoid: how do we build cleaner grids that are also stable, affordable, resilient, and able to handle rising demand from electrification, industry, and AI data centres? The energy transition is no longer just about adding more solar and wind. That part is moving, unevenly, but visibly. The harder question is what happens next. Once renewables reach higher shares of generation, grid operators need duration, flexibility, black-start capability, and storage that can still perform after years of heavy cycling. Otherwise, we risk building clean power systems with fragile nervous systems. And that would be a very human achievement: solving one problem while quietly manufacturing another. What changed my thinking in this conversation was how practical the flow battery case becomes once you stop comparing it to lithium for the wrong jobs. Min explains why vanadium flow batteries are aimed at infrastructure, not phones or EVs; why they can run for more than 20,000 cycles; and why a 100MW / 400MWh system in China completed a grid-scale black start experiment. We also get into the economics: why longer duration can reduce levelised cost of storage, how electrolyte leasing can cut upfront CapEx, and why local supply chains may become as important as battery chemistry. The localisation point is particularly important. The electrolyte is 60% water and can account for 40-80% of total battery cost. That makes shipping it across the world look less like efficiency and more like industrial theatre. If countries can assemble systems and produce electrolyte closer to demand, storage becomes part of energy security, not just decarbonisation. This is not a silver-bullet conversation. It is about where flow batteries fit, where lithium still makes sense, and what real-world deployment teaches us when the spreadsheet finally meets the grid. For business leaders, policymakers, investors, energy executives, and climate professionals working on emissions reduction, clean energy, grid resilience, and net zero implementation. If you’re working on long-duration storage, renewable integration, or energy policy in the real world, I’d be interested in your perspective. 🔗 Climate Confident podcast: https://www.climateconfidentpodcast.com 🎧 Subscribe or follow Climate Confident wherever you get your podcasts 📺 Subscribe on YouTube for more practical climate solutions grounded in deployment ⏱️ Chapters / Timestamps 00:00 – Why storage is now an energy-security issue 01:36 – What vanadium flow batteries are built to do 04:33 – Why 20,000 cycles changes the battery comparison 05:40 – Why flow batteries are not replacing lithium 06:47 – The grid pressure driving long-duration storage 09:08 – Reliability, AI data centres, and volatile electricity prices 12:11 – The first grid-scale black start battery test 16:20 – When flow batteries beat lithium on storage economics 19:32 – How costs have fallen by more than 50% 21:30 – The 100MW Dalian system proving scale 22:46 – How 25-year life changes the financial model 33:35 – Why countries should not ship water around the world