SINGAPORE – Nearly 10 years ago, two scientists from Nanyang Technological University (NTU) had ambitions to create giant batteries that could power towns and buildings at night with clean electricity.

Their vision will take shape on Pulau Ubin soon.

Instead of using the more common lithium metal, which is synonymous with batteries, the duo banked on the lesser known vanadium metal, which is known to be safer and longer lasting.

After years of research and forming start-up VFlowTech, the duo – Dr Avishek Kumar and Dr Arjun Bhattarai – have built a container-like energy storage system that can store energy from the sun or wind.

VFlowTech’s technology attracted local energy players, and its battery will soon help to power parts of Pulau Ubin, as its main village seeks to have up to 90 per cent of its electricity from solar energy by next year.

The heart of a vanadium flow battery are two tanks filled with a soup of vanadium ions. One tank has a positive charge, and the other a negative charge.

Surplus solar energy will be pumped into the battery system for storage. At night, or when it is cloudy or supply in an electric grid is unstable, the battery will discharge power to homes, for instance.

A vanadium flow battery lasts 25 years – similar to the lifespan of solar panels – compared with a lithium-ion system which needs to be replaced every seven years, said Dr Avishek, VFlowTech’s chief executive.

Professor Subodh Mhaisalkar from NTU’s School of Materials Science and Engineering noted that lithium-ion batteries’ drawbacks include costs and limited lifetimes.

Vanadium flow batteries can be readily scaled to megawatt levels and can be cheaper over their life cycle, he added.

While the more compact lithium-ion energy storage system is the most viable storage solution today, Singapore should continue to track emerging storage technologies and harness them when they become competitive, said the recent Energy 2050 Committee report commissioned by the Energy Market Authority.

VFlowTech is believed to be the first and only manufacturer of such batteries in South-east Asia.