A new kind of batteries to help pave the way

Redflow has deployed a hybrid redox flow battery, Zinc-bromine batteries. These are not normal kinds of batteries, as they are built to store more energy by plating zinc metal as a solid onto the anode plates in the electrochemical stack during charge. Thus, the total energy storage capacity of the system is dependent on both the stack size (electrode area) and the size of the electrolyte storage reservoirs. As such, the power and energy ratings of the zinc-bromine flow battery are not fully decoupled. These batteries are also harder to break down into individual pieces to avoid theft and criminals to take and sell. 

Who are behind these batteries?

Tim Harris is the Chief Executive Officer and Managing Director of Redflow Limited. It is the innovative ASX-listed sustainable energy storage company based in Brisbane, Australia. This company is the one behind the compact and deep-cycle zinc-Bromine flow batteries. Tim Harris joined the company back in March 2018. Before, he worked as a global telecommunications executive. That alone was more than 20 years of experience, working in New Zealand, Australia, Asia, UK, and the US. 

red flow ceo tim harris
Photo Credit: cisp.cachefly.net

Why create a new battery?

The success of the company is due to the ZBM2 zinc-bromine flow battery. Redflow was able to become a world-leading energy-based storage system with it. The batteries proved to become an innovation due to having unique advantages. Lead-acid and Lithium-based traditional batteries were at a disadvantage because of it. Part of the reason for the deployment of these Zinc-Bromine batteries was to help stall theft. 

There have been reports and news in the past about the theft of batteries. The traditional-based ones – Lead-acid and Lithium – are a big reason for the use of zinc-bromine batteries. They’re built to help prevent theft and vandalism.

The company’s batteries also help in reducing the use of diesel. This helps with lowering carbon tax liabilities, stemming from South Africa’s regulation, which was enforced on June 1st, 2019. The regulation focused on new carbon pollution reduction regulations.

A Newer, Sturdier, and Innovative Way  Batteries
Photo credit: onestepoffthegrid.com.au

How do these zinc-bromine batteries work in the first place?

These zinc-bromine batteries are usually used to produce power for at least four hours. They can also provide power for longer periods. The batteries additionally need an annual inspection during their ten-year lifespan. It can operate in temperatures up to 50 ºC without it degrading in performance. Additionally, it doesn’t see the need for cooling. 

The batteries deployed by the Brisbane-based company have reached many telecommunications towers. The company has deployed these batteries in Australia and New Zealand since 2016. When it comes to the sites that needed the use of diesel generators, the Redflow batteries proved to be a good help. The Redflow batteries can reduce the costs of diesel to power the towers, at most to 66%. To further add, it reduced more factors as well. It reduced the need for logistics, re-fuelling, service, and maintenance costs. 

The zinc-bromine flow battery technology is more for stationary power storage applications. The applications shift available energy from intermittent generation sources (wind, solar photovoltaic, etc.). The power enabled from those sources gives it use at night or when there is no wind blowing. 

Redflow is certain that its batteries can counterbalance a lot of factors in Africa. The company believes it can offset similar diesel, service, and logistics costs. It can help with allaying intermittency in weak grid conditions. It can also actually set up some towers to the point that it only needs to use renewable-energy sources. All the segments and factors that comprise the flow battery can be reconditioned. The batteries’ components are electrolyte tanks, pumps, zinc electroplate stack, and electronics. After a lifespan of ten years, it is still good to be recyclable. 

A good change of thievery to security

As stated earlier, zinc-bromine batteries are harder to break down on and to steal and sell. There’s almost no chance of it breaking into individual components. The batteries have extra protected security features. It helps with making it easier to track and disable them. 

One key factor to the technology of the flow battery is that its value is actually very limited. Compared to other different types of batteries, it has little to no use aside from its intended purpose. It also has a rather lower risk of theft as well.

“Our flow battery – the smallest in the world – weighs 240 kg and has no residual value outside of its primary function” according to Tim Harris.

Additionally, Tim Harris further stated that “There are no components that can be traded on a secondary market. We have also developed several additional anti theft features”. 

Deployment towards success

The deployment of these zinc-bromine batteries reached many. It has seen many commercial, industrial, and micro-grid applications in some countries. It has been used in Thailand, the Pacific, and Australia. It has also an eye on similar uses in South Africa and Africa when it has settled an already steady market. The batteries are modular. Also, the batteries combined help power systems up to a multi-mWh scale.

“Because our batteries serve as solid work-horses, they can also be used in conjunction with other battery and energy technologies. In an off-grid village in Thailand, lithium-ion batteries were used in the microgrid to meet transient peaks and the zinc-bromine flow batteries served the baseload demands of the system”, according to Tim Harris.

Tim Harris, concluding his statement that, “We believe our batteries are particularly well suited for use in telecommunications networks to ensure reliable infrastructure and service uptime. “We are exploring further opportunities in telecommunications and other industries in Africa.”

deployment of redflow batteries
Photo Credit: redflow.com

A brighter future but still expecting some loss?

On February 27th, 2020, Redflow announced the results of its batteries. The results come from up to the half-year to December 31, 2019. There was a dramatic increase in revenue from sales, reaching A$1,436,000 for the half-year. It reached up from A$800,072 for the full financial year ending around the middle of 2019. 

The telecom towers in South Africa, Asia, and the Pacific area have the vast majority of sales. The telecom towers from those areas either don’t have local grids or reliable ones. Usually, towers such as this rely on the power of diesel generators. These diesel generators though always need to have a regular schedule of re-fuelling. Not to mention as mentioned earlier they are very prone to theft and vandalism. 

The Redflow company presents a more convenient and cheaper approach for these countries. One good reason is due to the countries having a very large source from the Sun. With plenty of Sun helps with the combination of both the solar panels and flow batteries. As stated earlier, the batteries don’t present much of a value aside from their intended use. The batteries themselves don’t hold that much resale value for potential thieves. The solar panels meanwhile are a different story.

Vodafone, Europe’s largest mobile and fixed network operator, has set a goal. By 2025, it aims to buy 100% of electricity, up from 15% back on March 3rd, 2020. Most of these will come from a grid but all off-grid towers rely on renewable energy

Vodafone although still believes that diesel generators are still needed. They believed it can still serve as a back-up for when bad weather occurs for days, limiting generation from the solar panels.

This gives an attraction for markets based on lithium-ion and other flow batteries. Despite this, Redflow claims that it still has advantages with the batteries. The company claims that their batteries can discharge more than lithium-ion, live a longer lifespan, and tolerate high ambient temperatures better (only needing some ventilation). 


All in all, the zinc-bromine batteries show good promise with their built. Soon this technology might be on top of the industry and will need more efficient monitoring. With the expected growth of the market, more people and devices are connecting, then more towers and batteries will be needed. Traditional manual battery temperature monitoring system would require additional manpower just to check the battery strings once or twice a week. Installing a permanent 24/7 battery temperature monitoring system can bring smarter and lighter work for the tower operation. Just the most basic is a temperature sensor installed can give you a graphed real-time report of the temperature. More advanced battery monitoring systems can monitor individual cell temperatures, charge current, voltage and load current, and voltage.

Reference Links:


Leave a Reply

Your email address will not be published. Required fields are marked *