Author: EcoJouleE

Four criteria that determine whether distributed storage holds up in a low-voltage network that is no longer balanced.

The low-voltage network is no longer balanced, and it is not returning to a balanced state. Single-phase rooftop solar, single-phase EV charging and uneven load growth mean that voltage imbalance across the three phases is now the normal operating condition on most feeders.

This has a consequence for distributed storage that is often overlooked in procurement. The reliability of a distributed battery is not only a question of cell chemistry or warranty terms. It is a question of whether the asset keeps delivering in the network as it actually is, whether it avoids the failure modes that take enclosed batteries offline, whether it can be restored quickly when it needs service, and whether the operator retains control of it once it is connected.

Those four criteria are where a specification for distributed storage should focus.

Correcting the network the asset operates in

Modern networks are being driven towards unbalance. The prevalence of high power single phase generation and loads – such as PV or EV charging – introduce unbalance that interferes with 3 phase inverters that lack STATCOM capabilities.

In an unbalanced feeder, the modern utility grade BESS with STATCOM capabilities regulate each phase independently, absorbing or injecting reactive current per phase to bring phase voltages back within limits, and it maintains that correction continuously while it charges or discharges real power. It creates its own voltage headroom, then uses it.

A conventional three-phase BESS injects balanced current across all three phases. Where the feeder is already unbalanced, or sitting near a per-phase voltage limit, that inverter has little room to deliver its rated real power. It curtails, or it trips. The more single-phase DER and EV charging on the feeder, the more often this occurs.

As imbalance becomes the standard condition, an asset that corrects the condition it operates in is materially more resilient than one that depends on the condition being favourable. The specification point is independent per-phase real and reactive control, maintained continuously during charge and discharge.

Operating without air conditioning

This removes one of the most common failure and maintenance points in enclosed battery systems. Air-conditioning is an active mechanical system with its own compressors, fans and refrigerant circuit. When it fails, the battery it protects is exposed, and it is a recurring service item over the life of the asset.

It also removes the parasitic load that air-conditioning draws continuously, which improves round-trip efficiency: less of the stored energy is lost to running the enclosure. It lowers the acoustic footprint of the asset, verified by type testing, which matters wherever storage is sited near residential or community areas.

The specification points are an auxiliary-load ceiling, an acoustic limit expressed in dB(A) at a stated distance, and no active mechanical cooling as a single point of failure. Passive cooling meets these on engineering merit.

Modular service by unit swap

Modern distributed storage keeps the inverter/STATCOM and the battery enclosure as separate modules. Damage or a scheduled service event in one module is contained to that unit; the other is unaffected.

For the operator, this changes the maintenance model. Field service becomes a module swap against a spare, rather than an on-site repair. The site is returned to service in a short, planned window, and the damaged module is repaired off-site. Spares can be pooled across a fleet, so the effective mean time to restore is the time to swap a unit rather than the time to diagnose and rebuild one in the field.

Uptime therefore becomes a property of the deployment model, not only of the hardware. The specification point is independent replaceability of the power conversion and storage modules without decommissioning the other.

Operator control of the asset

Cybersecurity compliance is paramount, and legacy BESS that require a manufacturer connection or phone home introduce cybersecurity risks. Modern BESS communicate over, widely supported protocols: DNP3 and Modbus, fully controlled by the operating utility. There should be no mandatory link back to the manufacturer, and the asset does not require any connection to the vendor to operate.

This means the network operator owns the control, software and firmware lifecycle. The asset is held to the operator’s own compliance and security posture, and kept within network compliance conditions by the operator. Remote support from EcoJoule is available if the operator wants it, but it is optional, not built into how the system runs.

There are power conversion systems manufactured in Australia. For operators applying trusted-origin or sovereign-supply criteria to grid-connected devices, an increasingly common part of procurement, that origin is a material point.

The specification points are open protocol support, no mandatory vendor communications, operator ownership of the firmware lifecycle, and trusted origin of the power conversion equipment.

What this means for planners

A reliable distributed battery is one that keeps delivering in an unbalanced network, avoids the failure modes that take enclosed batteries offline, can be restored inside a short planned window, and stays under the operator’s control. None of these is decided after installation. They are architectural choices — a per-phase STATCOM front end, passive cooling with no active HVAC to fail, separable modules, and open protocols with no vendor dependency — made in the design of the asset.

These key design choices are integrated in the EcoJoule EcoSTORE pole mount BESS.

Specified as outcomes rather than mechanisms, these four criteria give a procurement team a defensible basis for selecting distributed storage that will hold up in the network as it actually operates.

The problem

When a large load switches onto a low-voltage feeder (a fast EV charger, a heat-pump compressor, a welding set, an irrigation pump), it draws a step change in current. That current flows through the upstream impedance of the supply: the distribution transformer, the LV main, and the service conductor. On a weak network (high source impedance, low fault level) the resulting voltage drop is large enough to be seen as a sag at the point of connection and at neighbouring premises.

The drop is approximated by:

ΔV ≈ (P·R + Q·X) / V

Two features of LV networks make this acute. First, the inrush of motors and switched-mode loads is reactive-heavy, so Q is momentarily large. Second, most large LV loads are single-phase, so the sag, and the voltage unbalance that comes with it, appears on one phase while the others are largely unaffected.

Conventional responses are poorly matched to the problem. Switched capacitor banks produce reactive output that falls with the square of voltage, giving least support exactly when voltage is depressed, and they cannot act per phase or respond within a cycle. On-load tap changers are too slow for switching events and act on the whole feeder rather than the affected phase. Reconductoring removes the constraint but requires capital and an outage.

How the EcoVAR responds

The EcoVAR is a shunt-connected LV distribution STATCOM. It measures voltage continuously and injects a controlled current at the point of connection to oppose the disturbance. Three characteristics matter for switching sags.

Current-source behaviour

As a voltage-source converter under closed-loop control, the EcoVAR’s injected current is set by its controller, not by the line voltage. Unlike a capacitor, its support does not collapse as voltage falls; it holds its commanded output through the sag, up to its rating.

Per-phase injection

The EcoVAR controls each phase independently. When a single-phase load causes an unbalanced sag, it supports the affected phase and corrects the unbalance without disturbing the other two — something a positive-sequence or three-phase-balanced compensator cannot do.

Fast closed-loop response

Power-electronic switching lets the converter react within a few cycles, fast enough to arrest the step a switching load produces rather than ride it out.

Because the same converter also performs active harmonic filtering, a load that both depresses voltage and injects harmonics (a drive or a charger) is addressed by one device.

What to expect, and how it scales

Reactive shunt compensation acts on voltage through the network reactance, X. The EcoVAR is strongest where the sag is reactive-dominated (motor inrush, switching transients) or unbalanced — which covers most LV switching events, and where per-phase injection corrects the sag and the unbalance together.

Where a sag is instead driven by a sustained, largely balanced real-power draw on a resistive feeder, reactive injection alone has less to work with. The EcoVAR can then be upgraded with EcoSTORE storage to supply the real-power component alongside its reactive support, addressing the P·R term of the voltage drop directly while retaining per-phase voltage control, phase balancing and harmonic filtering. The connection point and platform are unchanged; the same asset scales from reactive support to combined real-and-reactive support as the network’s needs grow.

In deployment

The EcoVAR installs without a network outage and retrofits to existing pole-mount (Alto) or ground-mount (Terra) sites. From a single shunt connection it provides per-phase voltage support, phase balancing and active harmonic filtering — relieving a switching-sag constraint without reconductoring or a transformer change.

How a STATCOM connects to the LV network is a work-practices decision, not a technical one. The unit performs identically across every arrangement below — what changes is only how technicians isolate and power it down.

The shunt connection

A low voltage distribution STATCOM, such as the EcoVAR, connects to the LV feeder as a shunt device — it taps the network in parallel rather than in series. The feeder continues to carry its normal load; the STATCOM draws from the same connection to inject or absorb reactive current per phase. Because the connection is parallel, the feeder does not need to be de-energised to connect or remove the unit. Only the shunt tap point is worked, so there is no customer outage to bring a STATCOM into or out of service.

Every shunt connection needs a device between the STATCOM and the feeder that provides overcurrent protection and a means of isolation. Three arrangements are common. The choice is driven by the utility’s work practices and risk appetite — not by any difference in how the STATCOM performs. All three deliver identical operation.

Option 1 — Outdoor fuses

The lowest-cost method is a set of outdoor fuses, rated at 100 A, connecting the STATCOM to the overhead line on the shunt circuit.

The 100 A rating reflects the EcoVAR’s operating profile and its thermal environment. Full rated current is 63 A continuous, with a short-time capability of 1.5 × rated (about 95 A) under fault conditions. Most off-the-shelf MCBs derate their current rating at elevated ambient temperatures; at the EcoVAR’s 50 °C maximum, a marginally-sized breaker could trip spuriously at full output. Rating the device at 100 A holds margin above the derated threshold, so it carries full load without nuisance operation while remaining low enough to protect the connection. The rating is standardised at 100 A for both the fuse and circuit-breaker arrangements.

This is the fastest, simplest and most economical arrangement, with the fewest components in the circuit and therefore the fewest potential points of failure. Isolation is achieved by pulling the fuses. Because the STATCOM draws its operating supply from the same connection, removing the fuses is also the only way to override the unit and power it down.

The constraint is operational: some utilities’ work practices prohibit technicians from pulling live LV fuses. Where that rule applies, fuses alone are not a workable isolation method.

Option 2 — Switchboard with circuit breaker

For utilities that do not permit live fuse pulling, the connection is made through a small outdoor switchboard on the shunt circuit, between the STATCOM and the LV feeder. The switchboard houses a circuit breaker rated at 100 A.

The circuit breaker is a load-break device. It provides a rated switching point that brings the STATCOM in and out of service without pulling fuses, satisfying work practices that prohibit live fuse operation. The trade-off is one additional component and the associated cost, in exchange for an operator-friendly switching point.

Option 3 — Switchboard with circuit breaker, fuses and surge protection

The most conservative utilities add backup fuses and surge protection to the switchboard. The fuses provide backup overcurrent protection and fault coordination; the surge protection guards against transient overvoltages entering from the LV network.

This should be weighed carefully. Every additional device is a potential point of failure and a maintenance item. The marginal protection gained needs to be balanced against reduced overall reliability, a larger enclosure, and higher lifecycle cost.

Choosing an arrangement

The STATCOM operates the same way in all three cases. Match the connection arrangement to your work practices and your risk appetite, and avoid adding components whose protection you will not use. For most utilities the decision comes down to a single question: are technicians permitted to pull live LV fuses? If yes, fuses are sufficient. If no, a switchboard with a circuit breaker is the practical minimum.

By Mike Wishart, Founder & CEO, EcoJoule Energy

As Australia accelerates its transition to renewable energy and retail energy prices continue to rise, initiatives like the Commonwealth Government’s Solar Sharer program are a positive step forward.

Encouraging households to use electricity during the middle of the day, when rooftop solar generation is at its peak, makes sense. It rewards consumers, supports clean energy utilisation, and helps reduce reliance on fossil fuel generation during other parts of the day.

However, as with any major shift in how and when energy is consumed, there are technical realities that must be carefully managed.

The Solar Sharer concept is simple: offer households a defined window of free or heavily discounted electricity during peak solar production hours. The goal is to soak up excess generation and avoid curtailment. But when thousands, or potentially millions, of households respond to the same pricing signal at the same time, the impact on local low-voltage networks can be significant.

Electricity distribution networks were not designed for synchronised behaviour at this scale. Historically, household demand has been relatively diverse and staggered. People cook, run appliances, and charge devices at different times. This natural diversity smooths out demand peaks.

Programs like Solar Sharer risk compressing that diversity into a narrow window. When the free power period begins, EV chargers ramp up simultaneously. Home batteries switch into charging mode. Pool pumps, air conditioners, hot water systems, and high-load appliances are programmed to start. While the intent is to align demand with solar supply, the local network can experience rapid voltage rises, swings, and phase imbalances.

Voltage management at the low-voltage level is becoming one of the most critical challenges of the energy transition. High rooftop solar penetration already creates periods of elevated voltage in many suburbs. Adding synchronised demand spikes on top of high generation can cause voltage instability in both directions.

These fluctuations are not just theoretical. Excessive voltage swings can trigger inverter protection settings, leading to solar export curtailment. Sensitive equipment can also be affected by poor power quality. Transformers and distribution assets may experience additional thermal stress. Over time, unmanaged localised stress accelerates wear and increases maintenance costs for network operators.

Importantly, this is not an argument against Solar Sharer or similar programs. On the contrary, they are well-intentioned and necessary as we rethink how to better integrate distributed renewable energy. But price signals alone are a blunt instrument. They need to be supported by intelligent, localised voltage and power quality management.

The grid is no longer a one-way system. It is dynamic, bidirectional, and increasingly decentralised. That means solutions must exist not only at substations and along feeders, but also behind the meter, within homes, businesses, and community assets.

Smart voltage regulation technology can provide the responsive buffering required to smooth these synchronised events. By dynamically absorbing or supplying reactive power, managing voltage levels in real time, and stabilising local phases, advanced systems can prevent the cascading effects of large-scale behavioural shifts.

This is where infrastructure innovation becomes critical. The energy transition is not just about adding more solar panels or batteries. It is about ensuring that the foundational electrical architecture can handle new usage patterns safely and reliably.

At EcoJoule Energy, we see this challenge firsthand. Our EcoVAR and EcoSTORE technologies are specifically designed to strengthen low-voltage networks in high renewable penetration environments. EcoVAR actively manages voltage and power factor in real time, smoothing fluctuations and improving power quality. EcoSTORE provides fast-response energy storage that can absorb excess generation or support demand spikes, reducing strain on local assets.
Together, these systems help create a more resilient and flexible grid at the edge. They allow innovative programs like Solar Sharer to succeed without compromising stability. Instead of networks reacting to volatility, they become adaptive and self-balancing.

Australia is leading the world in rooftop solar adoption. That leadership brings both opportunity and responsibility. As we introduce new market mechanisms to better utilise renewable energy, we must ensure the technical foundations keep pace.

The future of energy is distributed, digital, and dynamic. By combining smart policy with smarter infrastructure, we can unlock the full value of programs like Solar Sharer — delivering lower costs, cleaner power, and a stable grid for all Australians.

The transition is happening. The question is not whether we move forward, but how intelligently we do it.

About Mike Wishart

Electronics industry veteran Mike Wishart founded EcoJoule Energy in 2014 after a long career in the power electronics industry. EcoJoule Energy develops and deploys Low Voltage Distribution STATCOMs and Battery Energy Storage Systems (BESS) for electricity distribution networks. The company’s EcoVAR platform is in service across four continents. In 2025, the company raised $15 million of growth capital from investors, including Ellerston Capital and the Clean Energy Finance Corporation (CEFC).

EcoJoule Energy, a leading Australian energy technology company focused on improving grid stability and enabling renewable integration, has announced the appointment of former NOJA Power executive Martin van der Linde as Chief Commercial Officer (CCO).

As Chief Commercial Officer, Mr van der Linde will lead EcoJoule’s global commercial strategy, including market expansion, customer engagement and revenue growth.
Martin joins EcoJoule after more than 13 years in various roles with NOJA Power, most recently as General Manager Marketing. He is a seasoned management, marketing and engineering leader with extensive international experience.

An accomplished communicator, Martin has presented to executives, engineers, conferences and training audiences across 23 countries. He has been published in eight industry magazines on topics related to power systems, utilities and the broader energy sector.

Martin is a member of Engineers Australia and a member of the Electrical Energy Society of Australia (EESA).

EcoJoule Founder and CEO Dr Mike Wishart said Mr van der Linde was a widely-respected leader in the energy industry and he would play a crucial role in EcoJoule’s continued growth.

“Martin brings a rare combination of engineering depth and commercial acumen, which is exactly what EcoJoule needs as we scale,” Dr Wishart said.

“His ability to apply engineering principles to marketing and commercial strategy will be instrumental in accelerating our growth both in Australia and internationally.”

Mr van der Linde said he was excited to be joining EcoJoule at such an important time in their history.

“EcoJoule is at the forefront of solving one of the most critical challenges facing modern electricity networks,” Mr van der Linde said.

“I’m excited to help scale the company’s commercial operations and bring its innovative technologies to more markets globally.”

With a growing customer base that includes major network operators such as Endeavour Energy, Essential Energy, Ausgrid and AusNet Services, EcoJoule is playing a key role in enabling a more stable, resilient and renewable-ready electricity grid.

EcoJoule Energy’s technology platforms include pole-mounted community energy storage units that store the excess solar energy generated by residents for later use, and a voltage regulation device to help integrate more renewables into the grid.

EcoJoule Energy, a leading Australian energy technology company focused on improving grid stability and enabling renewable integration, has announced the appointment of former senior Ausgrid executive Trevor Armstrong as a Non-Executive Director.

As Non-Executive Director, Mr Armstrong brings significant board-level experience and strategic oversight, and will support EcoJoule’s governance, growth strategy and engagement with key stakeholders across the energy sector.

EcoJoule Founder and CEO Dr Mike Wishart said the appointment would strengthen the company’s governance and strategic capability as it continued to scale its operations across Australia and international markets.

“Trevor brings valuable experience and insight that will support EcoJoule’s continued growth,” Dr Wishart said.

“As demand increases for technologies that help electricity networks manage the impacts of distributed energy resources like rooftop solar, strong leadership and governance are critical to delivering on our strategy.”

Trevor has more than 35 years’ of experience in the energy sector. He has held senior executive roles with Energy Australia, Networks NSW and Ausgrid, including interim Chief Executive Officer and Chief Operating Officer.  More recently, Trevor was the Chief Executive of ACEREZ, the Network Operator of the first renewable energy zone in NSW.

Trevor is currently on the Board of Power and Water in the Northern Territory and a Partnership Representative on ACEREZ. He has served on the Reliability Panel of the Australian Energy Market Commission, and Chair of CIGRE Australia.

EcoJoule is playing a key role in enabling a more stable, resilient and renewable-ready electricity grid. And works with a growing client base that includes major network operators such as UK Power Networks (UKPN), Endeavour Energy, Western Power, Essential Energy, Ausgrid and AusNet Services,

EcoJoule Energy’s technology platforms include pole-mounted community energy storage units that store the excess solar energy generated by residents for later use, and a voltage regulation device that helps integrate more renewables into the grid.

In a significant development for renewable energy initiatives, EcoJoule Energy has been awarded a contract to supply 17 cutting-edge pole-mounted battery systems for a new energy storage trial across five regional communities in New South Wales.

The trial, led by Essential Energy in partnership with Origin Energy, aims to enhance the utilization of rooftop solar energy while providing valuable support to communities during the ongoing energy transition.

Innovative Energy Storage Solutions

EcoJoule Energy will provide advanced pole-mounted batteries that will be strategically installed on power poles. These batteries will store excess energy generated by residential solar systems during daylight hours, making it available for use during peak demand periods, particularly in the evening when solar generation ceases.

This partnership signifies a leap forward in our efforts to harness renewable energy at a community level. By equipping the energy network with these pole-mounted batteries, we can help local residents maximize their solar investments without the need for individual home batteries.

Enhancing Community Energy Resilience

The integration of these batteries allows for localized energy storage, enabling residents to generate, store, and utilize renewable energy within their neighborhoods. This innovative approach means that energy can be stored where it is generated, close to customers’ homes, effectively reducing the need for long-distance energy transportation.

Essential Energy’s Chief Operating Officer, Luke Jenner, expressed enthusiasm for the project: ‘The benefits of local energy storage are immense. We’re excited to see how these pole-mounted batteries can empower communities to take control of their energy usage while supporting the broader electricity network.’

With a growing reliance on rooftop solar systems, the electricity network is experiencing a two-way flow of energy, which these batteries will help manage. By addressing peak demand and maintaining voltage stability, the trial aims to create a more resilient energy infrastructure for regional areas.

For further information regarding our partnership with Essential Energy, please visit:

https://www.essentialenergy.com.au/media-centre/media-release/news-25072024-pole-mounted-batteries

In April we were very pleased to welcome Hon Mick de Brenni the Queensland Minister for Energy, Renewables and Hydrogen and Minister for Public Works and Procurement together with his team to our premises in Loganholme.

During the visit, Minister de Brenni was very interested in our wholly Queensland-based development and manufacturing, as well as our plan to further expand our operations, thus creating more jobs in the Clean Tech Renewables space.  As more and more solar is installed on Queenslanders’ roof tops, it is critical that voltage is regulated and solar is stored and used at appropriate times of the day.  We believe our product is a great, efficient solution to this problem and will contribute towards Queensland achieving its 70% renewables target by 2032 and 80% by 2035.

Minister de Brenni’s message to all our staff was one of optimism and how vital it is for all of us to play a role in shaping the future of energy and renewables in Queensland.  EcoJoule Energy can make a difference and we are planning to!

Endeavour Energy’s Power Quality and DER Integration Manager Albert Pors said, “We are excited to commence deploying low voltage network support batteries.  They provide Endeavour Energy the ability to improve power quality and solar hosting capacity for customers as well as reducing network peak demand, which can defer traditional network augmentation requirements.”

EcoJoule Energy’s Principal Engineer, David Courage, said the batteries offered multiple benefits. “The EcoSTORE community battery offers the opportunity to maximise the value of rooftop solar energy while at the same time relieving pressure off the electricity grid,” he said. “Endeavour Energy is demonstrating its customer-focused leadership in the rapidly changing electricity industry, and we are proud to supply our Australian-designed, Australian-manufactured solutions to this project.”