The report proposes significant upgrades to supply back-up power to cell towers. Photo / Bevan Conley
Cellphone towers in Hawke’s Bay need larger back-up batteries to help prevent outages in natural disasters, a move that would likely cost close to $20 million but would help save lives, a report has found.
A body representing New Zealand’s three big mobile phone operators says while the report is “well-meaning”, the key recommendation is not efficient or cost-effective and “generators are the solution in emergency management”.
The report was compiled by telecommunications expert Jonathan Brewer and commissioned by two groups, the Hawke’s Bay Regional Economic Development Agency (Reda) and the Hawke’s Bay Regional Recovery Agency.
It was released publicly in early December but was initially released to the two agencies in July.
During the height of Cyclone Gabrielle in 2023, 185 cell sites were offline in New Zealand on February 14.
“Most of these were in the Hawke’s Bay region, where only 20% of the region’s cell sites remained online, and restoration was hampered by roads covered due to flooding, slips and bridge washouts,” the report read.
“Without significant improvements in resilience, another similar multi-day communications outage is likely to happen again in the near future. It’s imperative the region do everything it can to protect against this eventuality.”
The report recommended the best way to make the cell network more resilient was to install large and powerful batteries for 48 hours of back-up at each cell site in the event of the main grid being down.
“Given the principle that the first 48 hours are the most important for saving lives following a natural disaster, all sites that are the primary communications platform for any part of the region should be provisioned with 48 hours of standby power,” the report read.
Most cell towers already have back-up batteries, but those batteries only last a matter of hours and are for short-term outages, not natural disasters. The industry relies on generators during emergencies.
The study stated the batteries that would be required for 48-hour back-up included the likes of “cabinetised” 100-120kWh batteries, and solar could potentially be used with the batteries.
The report stated one such battery on the market had a 20-year design life, occupied around two cubic metres of space, weighed around 1.3 tonnes and sold for less than US$80,000 each ($135,000).
“With around 167 towers providing 700MHz coverage in Hawke’s Bay ... the investment required to bring the region up to 48 hours of complete autonomy should be less than $20m.
“It would be a small sum for 20-year assets providing to a region that likely contributes around $68m in annual mobile revenues to the three operators [One, Spark and 2degrees].”
The industry gave feedback as part of the study. That included the main mobile phone providers One, Spark and 2degrees, as well as the New Zealand Telecommunications Forum (TCF), which represents the industry.
“The TCF and mobile operators have raised significant concerns regarding the 48-hour target,” the study stated.
“They believe that several factors make this target challenging to achieve.”
That included high costs and a number of other issues, including restrictive regulations to carry out such a recommendation.
“The resistance to providing 48 hours of power from the TCF is unlikely to do with the cost of providing for Hawke’s Bay, but the cost of providing a similar service-level across the entire country,” the report claimed.
“Increased resilience here would be met with demands for the same from other regions around Aotearoa and a national investment could cost the three operators around $700m.”
TCF chief executive Paul Brislen told Hawke’s Bay Today the study was “well-meaning” and asked the right questions, but there were issues with the key recommendation.
He said firstly, there were constraints on how large the batteries could be on many sites, such as roadside cabinets, due to Government regulations which would prevent sizeable batteries being installed.
However, he said those regulations may be revised soon.
Secondly, he said there was “no such thing as a 48-hour battery” as each site was different and used different amounts of power.
“Generators are the solution in emergency management.”
He said the industry has protocols to dispatch a “fleet” of portable generators to sites ahead of big storms, and the cyclone was challenging to prepare for as it hit the East Coast hardest despite forecasts predicting other areas would be worse hit.
He said some cell sites had fixed generators and the industry was working on installing more fixed generators.
Brislen’s third point was that cell towers need two things to function, with electricity being just one of those things.
The other is fibre optic cables (known as backhaul), which connect a cell site to the network.
If the fibre optic cables are damaged, which was the case for some cables during the cyclone, a cell site will go offline whether it has power or not.
Lastly, he conceded large batteries about “the size of a shipping container” could generate 48 hours of power, but that was not considered viable or a good use of resources at each site.
“It is not cost-effective, and it is also not very efficient in terms of electricity supply for each individual tower,” he said.
“We have about 4500 towers up and down the country – that is not a good way of doing it.”
He said antenna equipment on a cell tower is owned by the three main cellphone operators (One, Spark and 2degrees) whereas the towers themselves have been bought in recent years and are separately owned, including by major player TowerCo.
A Hawke’s Bay Regional Recovery Agency spokeswoman said the report had been helpful.
“Increased battery back-up was one of the areas addressed in the report.
“While we are not locked into a blanket increase to 48-hour battery power, the RRA supports investment to increase battery back-up at key sites as one of the measures that could improve resilience.”
The full report, “Improving Telecommunications Resilience in Hawke’s Bay”, is available on the Reda website.
Gary Hamilton-Irvine is a Hawke’s Bay-based reporter who covers a range of news topics including business, councils, breaking news and cyclone recovery. He formerly worked at News Corp Australia.
