Trilogy on electricity storage

Part I: The world needs a new battery

Most of my professional time, I spend on thinking about batteries. Every day, I’m breaking my brain on how batteries work and how I can make them better. And I love talking about that too. That’s why I decided to write this three-part series on LinkedIn. To share what I am doing and why. This first article is about the basics, about why the world needs better batteries to start with. And I will share how we manufacture the ReFlex™, a new and better type of battery I am working on, and where they are put to work. If you are interested, I will continue the series by sharing the technology behind the battery and its validated features in every detail.

The world needs a new battery

Today, the world demands more power than ever. The needs for electricity have caused global battery demand to soar. The World Economic Forum estimates a 14-fold increase in ten years’ time, reaching 2,600 gigawatts per-hour. The world not only needs more power, but it needs to be clean, reliable, and affordable too. Battery storage is an essential part in the global transition to cleaner energy, and our increasingly digitalised society drives demand of uninterrupted, high quality power.

  • In developed countries, battery storage helps keeping the aging electricity grid resilient and reliable. By using storage batteries as a buffer, old electricity grids can integrate intermittent renewable sources as solar and wind.
  • Battery storage also enables microgrids (smart, mini-versions of the classical electricity grid), that deliver uninterrupted, high quality power to residential, industrial and commercial customers.
  • In underdeveloped regions, outlying villages or islands, battery storage is a critical component of remote electrical grids to deliver clean, affordable power.

Battery storage will be omnipresent around the globe.

Batteries with less risks and more benefits

There are several battery technologies to store energy. Currently, lithium-ion is the benchmark. But fire accidents, and in some cases even chemical burns, have been widely reported. In addition to the risk of setting a fire, there are concerns over the degradation, cycle life, and the sustainability of the materials that are used in Li-ion batteries.

Some of you might recall that I worked at the Pacific Northwest National Laboratory of the US Department of Energy eight years ago. With a team of battery experts, we started our quest for an alternative to Li-ion batteries. We invented a new generation flow battery. Our new battery uses vanadium metal that is dissolved in a novel battery liquid.

In the following years, the battery was commercialized by Vanadis Power and UniEnergy Technologies (UET), where we advanced our invention into a robust product: the ReFlex™ battery. We achieved this through eight years of engineering optimization, vigorous testing and deep learnings from the field experience with our early products. The result is a highly modularized product, that is nowadays deployed worldwide and has proven to be a valuable energy storage solution.

A gigawatt factory

Our batteries are built in a factory that covers the size of multiple soccer fields. A highly automated production line turns out electrical stacks with an annual production capacity of one gigawatt (GW). That is quite some energy. One gigawatt lights about a few 100 million LED bulbs. And do you remember Doc’s DeLorean? In Back to the Future it takes 1.21 gigawatt of power to travel through time. I haven’t figured out yet how to do that, but the power capacity is there.


Back to the factory. Tireless robot arms place all components with precision, and move the electrical stacks down the production line. At the end, fully assembled stacks enter parallel testing stations. The stacks are then integrated into grey blue cabinet modules before the final quality tests are done. This is the first giga-factory making flow batteries in the world.

Battery-powered island in the Great Barrier Reef


Twenty of these cabinet modules were shipped to Heron Island, a coral cay located in the southern Great Barrier Reef, 80 kilometres north-east of Gladstone, Queensland, Australia  ( Upon arrival, the cabinet modules were lined up and electrically connected into a system, rated 160 kilowatt and over 600 kWh. The ReFlex™system stores power generated from sunlight during daytime and releases it at night to power hotel rooms, restaurant bars, a research station and other loads on the island. The storage system enables the island’s microgrid to provide uninterrupted, reliable power to meet the load demands on the island, with much use of solar energy.

99% available during 700,000 hours

Meanwhile, similar ReFlex™ systems have been deployed at over a dozen sites in the US, Europe, and Asia pacific. For example, by Mitsubishi Electric Power Products Inc. They commissioned a 100kW/400kWh ReFlex™ system, that operates at a test station outside Chicago. As a pilot, this storage system is evaluated for electrical grid transmission and distribution applications. Another example is the 10-unit ReFlex™ system that Rongke Power factory (the giga-factory described earlier) commissioned in northern China. This outdoor system powers the factory’s microgrid that integrates solar energy generation on the roof of the facility and an electrical vehicle charge station at a corner of its parking lot. With a simplified heat management, the storage system has been running through hot summers and cold winters, where the environmental temperatures vary from ­‑25oC to 30oC.  There were no glitches, such as leaking, gas release, etc. over this past two years. The 75kW/300kWh system with an earlier version of the ReFlex™ modules enables the factory microgrid to provide smooth power for the production area and other loads, with mainly green energy.

As alternative to Li-ion, up today nearly 100 of ReFlex™ units have been deployed and are running in the fields, accumulating a total of over 700,000 hours with 99% availability.

With the success in the field, we now start to deliver the latest version ReFlex™ that is capable of delivering 10kW for four hours (40kWh) with a further improved efficiency.

Compact and competitive in footprint

ReFlex™ is a battery developed and produced specifically for stationary use. But that does not mean it is hard to transport or comes in an unhandy size. Using the new generation in vanadium chemistry, ReFlex™ doubles its energy density over the traditional vanadium flow battery, allowing for a compact design. ReFlex™ is the only flow battery that can be carried with a dolly through a standard size door. Although the overall energy density is much lower than that of Li-ion, the required space for a large configuration can still be competitive with that of Li-ion. This is because Li-ion needs an extra safety space in large installations and a vanadium flow battery doesn’t. With the successful demonstrations for varied applications at up to 100kW scales, ReFlex™ is being deployed for broader applications and at megawatt scales. These impressions show layouts of a 100kW vehicle charge station and a 10MW energy storage station.

Time to talk

So, this is what I have been up to and breaking my brain on during the past years. Even more than writing about batteries, I like to discuss them. What are your thoughts on the topic? Please keep the conversation going and add a comment. Meanwhile I will type up my next LinkedIn article, in which I’ll share and explain the technology behind ReFlex™.


Part II