Going with the flow: Renewable energy battery breakthrough - Published A 3D-printed battery developed at Queen's University Belfast could "make a genuine impact" on the road to net zero, say the researchers behind it. Flow batteries are seen as key to scaling up renewable energy, allowing it to be stored for when the wind is not blowing and the sun is not shining. But they are expensive and typically use a metallic element - vanadium - that is only produced in a few places round the world.

Now, scientists at QUB have developed one based on iron, which is much easier to source, and have sent it around the world to help standardise research. It is hoped it will accelerate the renewable energy revolution, making research more reliable and its findings more scalable. How did this discovery happen?

Post-doctoral researcher Dr Hugh O'Connor began tinkering with the design of flow batteries when he needed one for his PhD - and realised it would cost £2,000-£3,000. "I started 3D-printing them and I made lots of little tweaks. After a lot of trial and error, eventually these started to work really well." The cell he printed allowed him to carry out the tests he needed for his PhD.

But when he compared his results to other research, O'Connor struggled to find the standards he wanted. "We were at various conferences and meetings and calls, we noticed that other people were having the same problems, and lots of our colleagues were really interested in this work. "All of a sudden, we were in this position where we had this really nice cheap cell and we were all tackling the same problem." 'Ikea-style instruction manual' Discoveries like this are usually monetised by research institutions, constantly seeking funding to support their work.

And O'Connor admitted he briefly "cynically" considered selling his product to colleagues. But after discussing it with his supervisor, they decided to provide the design to the entire international research community for free. "We kind of saw it as an opportunity to grow our network rather than make a small amount of money, and we feel like it can really benefit this technology." His design costs roughly £74 and involves about ten components, from the printed pieces that the liquid flows through, to a membrane, gaskets, electrodes and current collectors.

And it involves careful assembly, simplified by the free guide supplied with the kit. "It was really important that we sent out like an Ikea-style instruction manual to our participants. "And I think they followed it quite well." What is a flow battery?

A flow battery is a device that stores energy in liquids, rather than solid electrodes as lithium-ion batteries do. The liquids usually contain the metallic element vanadium. There is more vanadium in the Earth's crust than lithium, but it is less accessible and more volatile in economic terms.

So while flow batteries are regarded as a potential game-changer in the renewable energy race to net zero, they have not been developed widely due to cost and geopolitical constraints. China has constructed some large-scale batteries, and a trial has also taken place in Scotland.