Vanadium flow batteries (also called vanadium redox flow batteries or VRFBs) are gaining serious attention in New Zealand and around the world as the go-to solution for long-duration energy storage. They’re showing up in solar farm proposals, commercial peak-shaving projects, microgrid designs, and even utility-scale tenders that need 8–24+ hours of reliable power.

But with any emerging technology, myths spread fast, especially when people compare them to the more familiar lithium-ion batteries.

Some of these myths come from outdated information, others from early prototypes, and a few are just plain misunderstandings that refuse to die.

In this post, we’re going to tackle the most common myths we hear every week from customers, developers, and even some engineers. We’ll explain where each one comes from and what the real-world facts look like in 2025–2026 especially here in New Zealand.

Let’s clear the air.

Myth 1: “Vanadium flow batteries are too new and unproven”

Truth: Vanadium flow technology is actually one of the oldest and most field-tested battery chemistries still in commercial use.

The concept was first demonstrated in the 1980s by Maria Skyllas-Kazacos at the University of New South Wales (right across the ditch in Australia). The first grid-connected systems were running by the early 2000s.

Today:

• Rongke Power (our partner) alone has deployed more than 2 GWh of vanadium flow capacity worldwide more than any other manufacturer.
  
• Some of the earliest large-scale installations (Japan, China) have been operating continuously since 2005–2010 and still show 95%+ capacity after 15–20 years.
  
• In New Zealand, several early commercial and pilot systems are already quietly running, proving the tech in our climate and grid conditions.
  

Bottom line: Vanadium flow isn’t experimental. It’s mature, bankable, and has more operational history in grid-scale applications than most people realise.

Also Read: The Benefits of Vanadium Redox Flow Batteries for Renewable Energy Integration

Myth 2: “They’re too big and take up too much space”

Truth: Yes, vanadium flow batteries need more physical footprint than lithium-ion for the same kWh, but that’s only half the story.

Because power and energy are decoupled:

• A 1 MW / 4 MWh lithium system might fit in 1–2 containers.
  
• The same 1 MW / 4 MWh vanadium system needs roughly 3–4× the space (mostly for the electrolyte tanks).
  

But here’s the key point most people miss:

• For most New Zealand sites farms, industrial yards, solar farms, community land space is rarely the limiting factor.
  
• The extra footprint is a worthwhile trade-off for:
  
  • 25–30 year life (no mid-life replacement)
    
  • Zero fire risk
    
  • 100% usable capacity every day
    
  • No degradation over decades
    

In dense urban environments with tiny footprints, lithium might still win. Everywhere else (which is most of NZ), vanadium’s space requirement is rarely a deal-breaker.

Myth 3: “Vanadium flow batteries are way too expensive”

Truth: Upfront capital cost per kWh is higher than lithium-ion today. That part is honest.

Typical 2025–2026 installed prices in NZ:

• Lithium-ion: ~$500–850/kWh
  
• Vanadium flow: ~$650–1,200/kWh
  

But cost isn’t just the sticker price it’s the levelised cost of storage (LCOS) over 20–25 years.

Vanadium flow wins on lifecycle cost because:

• No replacement after 10–15 years (lithium often needs one)
  
• Minimal maintenance (annual pump/filter checks)
  
• 100% depth of discharge → you get every kWh you paid for
  
• No cooling/heating parasitic losses
  
• Lower insurance and fire-suppression costs
  

For projects needing 8+ hours of storage and heavy daily cycling, vanadium frequently comes out 20–40% cheaper over the full project life.

Myth 4: “They’re inefficient too much energy lost in pumping”

Truth: Round-trip efficiency is typically 75–85% slightly lower than lithium-ion’s 85–95%.

But the “pumping loss” myth is overstated.

Actual pumping energy is usually <3–5% of total throughput and that’s only when the battery is charging or discharging. When idle, pumps are off.

Compare that to lithium systems that often lose 5–15% just keeping the battery at the right temperature in our climate.

For long-duration applications, the slightly lower efficiency is more than offset by:

• No capacity fade
  
• Full daily discharge
  
• 25–30 year life
  

In real projects, vanadium’s overall delivered kWh per dollar invested is often higher.

Know More: Vanadium Flow Battery vs. Lithium-Ion: The Ultimate 2026 Comparison Guide

Myth 5: “Vanadium flow batteries can’t respond fast enough for grid services”

Truth: This one comes from very early prototypes.

Modern VFBs (especially Rongke Power’s latest generation) have response times in seconds, fast enough for frequency regulation, voltage support, and most ancillary services.

They’re already providing:

• Frequency regulation
  
• Voltage support
  
• Spinning reserve
  
• Black start capability
  

In New Zealand, where we’re seeing more distributed renewables, that fast, reliable response is becoming more valuable every year.

Myth 6: “The electrolyte is dangerous or toxic”

Truth: The electrolyte is a mild sulfuric acid solution with dissolved vanadium salts, similar in strength to a car battery.

It’s:

• Non-flammable
  
• Non-explosive
  
• Contained in double-walled, leak-proof tanks with multiple safety layers
  
• Fully recyclable and non-toxic in normal use
  

Compared to lithium’s flammable organic electrolytes or lead-acid’s highly corrosive acid, vanadium is one of the safer large-scale chemistries available.

Myth 7: “They’re only for massive utility projects too big for homes or businesses”

Truth: Early systems were large, but today’s modular designs scale down very well.

Zion Technologies offers vanadium flow battery solutions starting from tens of kWh for commercial sites, farms, and larger homes, up to multi-MWh for grid-scale.

The same core advantages safety, longevity, and full DoD apply at any size.

Myth 8: “Lithium is always cheaper vanadium will never catch up”

Truth: Lithium has had a massive manufacturing scale advantage for years, but vanadium costs are dropping fast.

Rongke Power’s production ramp-up, improved membrane technology, and local supply chains are bringing prices down year on year. For long-duration applications (8+ hours), vanadium is already competitive and in many cases cheaper on a full lifecycle basis.

The Bottom Line

Vanadium flow batteries aren’t perfect for every application. But for long-duration energy storage, the kind needed to make renewables truly reliable, reduce fossil backup, and lower lifetime costs, they’re hard to beat.

They’re safe, they last decades, they scale easily, they’re sustainable, and they’re proven at grid scale.

As New Zealand pushes toward 100% renewables, the projects that succeed won’t be the ones with the cheapest upfront battery, they’ll be the ones with the storage that can actually carry the load when it matters most.

Vanadium flow batteries are built for exactly that job.

At Zion Technologies, we’re proud to be New Zealand’s exclusive partner for Rongke Power, the global leader in vanadium flow battery technology.

Whether you’re planning a solar farm, commercial site, microgrid, or utility project, we’ll give you a straight, no-pressure assessment and show you how VFBs can deliver the long-duration energy storage your system really needs.