Vodafone uses Redflow batteries to store energy for remote telecom tower site in New Zealand

January 20, 2020 3:16 pm Published by Leave your thoughts

Zinc-bromine flow batteries from Australian company Redflow Limited have stored and supplied more than 50 MWh (megawatt-hours) of renewable energy for a Vodafone telecommunications tower in New Zealand during the past three years.

Vodafone NZ’s Kauaeranga Valley tower site is located east of Thames by the Coromandel Forest Park in a remote part of New Zealand’s North Island, Sites such as the Kauaeranga Valley are so remote that it is unfeasible to lay or connect power cables. Alternative power sources, such as diesel generators, come with their own set of challenges including a second generator for redundancy, high maintenance costs and expensive and difficult diesel deliveries.

Vodafone New Zealand has met the challenge of bringing broadband connectivity to the remote site, where no grid power is available, by deploying a best-in-class green energy cell site, powered by Vertiv’s Hybrid Energy Storage System (HESS) with energy stored by Redflow batteries. The site, which contains five Redflow ZBM2 zinc-bromine flow batteries, has improved mobile phone coverage and high-speed wireless broadband for thousands of locals and visitors in the region.

The Redflow batteries store renewably sourced energy from 12 kilowatt peak (kWp) of installed photovoltaic solar panels and two kilowatts (kW) of installed wind capacity. Since they were installed in 2016, the Redflow batteries, with a total energy storage capacity of 50 kilowatt-hours, have stored and supplied more than 50 MWh (megawatt-hours) of energy.

Working with Redflow partner Vertiv, Vodafone NZ has improved mobile coverage and high-speed wireless broadband for thousands of locals and visitors in the southern Coromandel region. As part of the New Zealand Government-led Rural Broadband Initiative (RBI), Vodafone has delivered 541 new and upgraded mobile towers on time and within budget. The RBI program now makes high speed wireless broadband accessible for hundreds of thousands of rural homes and businesses.

Vodafone delivered its RBI commitments in the Kauaeranga Valley by deploying Vertiv’s Hybrid Energy Storage System (HESS), which, with its five Redflow batteries, provides continuous off-grid power, reduces fossil fuel consumption, lowers maintenance costs and enhances reliability.

The system uses wind, solar and Redflow batteries as primary energy sources for the tower, with a diesel generator only for minimal backup power during low radiation days. Capable of withstanding the harsh NZ climate, Vertiv’s HESS solution comes in a rugged IP55 outdoor enclosure that contains Vertiv’s newest generation of rectifiers, solar and wind converters and associated electrical protection devices.

Vertiv chose the innovative Redflow batteries for their intelligent management, remote monitoring and recharging capabilities. High temperature ratings and low environmental emissions also make this an attractive alternative to its valve-regulated lead-acid (VRLA) counterparts.

Redflow batteries can also tolerate temperatures as hot as 50 degrees Celsius without any active cooling. Their ability to provide 100 per cent depth-of-discharge daily makes this technology ideal for unstable grids and renewable energy sources. Unlike traditional battery technologies, the ZBM2’s inherent depth-of-discharge characteristics prevent battery damage from prolonged outages. Redflow batteries are made from easily reused or recycled components and contain a fluid electrolyte that is inherently non-flammable.

“We take great responsibility in our role to deliver broadband to the entire country,” said Tony Baird, Technology Director at Vodafone NZ. “Using a hybrid model means a mix of natural energy sources that gives us the ability to provide our customers with an always-on broadband network.”

For more about using Redflow batteries for the telecommunications sector, visit  or contact John Harris, PR for Redflow at