Off-Grid MPowerTank System

Sustainable energy independence

Off-Grid MPowerTank System


MPowerTank empowers on-grid living, off-grid. If connecting to the grid is too expensive, complicated or impractical, enjoy the peace of mind that comes with fire safe self-reliance with our uniquely sustainable solution.

A durable, reliable, valuable stand alone power system


Our MPowerTank leverages the benefits of both mechanical batteries and our Australian engineered and manufactured, industrial grade SENSSA Energy Management & Control System, to endure the harsh Australian conditions. Enjoy 30+ years of empowerment with an energy system that lasts as long as your property.



Key Energy’s MPowerTank is designed and built to withstand the extremes of the Australian environment. More durable, more reliable, safer and more valuable than chemical batteries, this is the alternative for those who want to power themselves for the long term.

Lasts 30+ years

11,000 cycles (30 years at 1 cycle per day) at full capacity throughout means this is what you’ve finally been waiting for. This system will have as much power and energy storage capacity at the end of life as it did brand-new.

Works in extreme temperatures

Tested in up to 50 degree ambient heat and 100% condensing humidity, the MPowerTank will operate even in the harshest conditions, guaranteed.

Safe from chemical fires

The mechanical battery does not use chemicals as the method to store energy, so there is no risk of lithium fires that can’t be put out, or other chemical fires.

More valuable than a grid connection

Our systems are generally cost-neutral with a new grid connection for off-grid customers who have to pay for new poles or transformers, let alone ongoing electricity bills. With a variety of flexible payment options, (operating leases, third party finance, or upfront purchase), cost won’t stand in your way.

Simple yet robust industrial grade components

Key Energy’s MPowerTank uses industrial grade components to support the ultra-durable mechanical battery. Originally designed for solar farms and industrial plants, we’ve re-purposed the flywheel to the harshest known conditions in the world – Australia’s off-grid market, featuring IP56 cabinets and industrial cabling.

Easy to install and maintain

Designed by our installer team to minimise on-site time and complexity, the system is pre-cabled, pre-terminated and plug and socket based where possible – the only electrician required termination is to connect to the main switchboard.

Off-Grid Projects


Request to see a local MPowerTank

Contact us and mention that you would like to see a local MPowerTank system so we can arrange with your nearest demonstration site!



The MPowerTank is a a turn-key AC coupled energy storage system, that we can customise if needed for your off-grid project.

What’s Included in the MPowerTank System

  • Flywheel (Amber Kinetics’ M-series flywheel and e-box, vacuum pump and accessories)
  • Above-ground enclosures (24kWh or 32kWh models available)
  • 20kW Inverter – 3 phase, multi-mode (off-grid and on-grid/generator ready), hybrid (solar + battery) inverter
  • Key Energy SENSSA Energy Management and Control System (Hardware + Software)



SpecificationMPowerTank M24MPowerTank M32
Energy Capacity (kWh) modular, up to MWh24 32
Charge & Discharge Power Capacity (kW)88
Charge/Discharge Duration (hours minimum)34
Cycle Design Life (cycles) no daily cycle limit11,000
GHG EmissionsNone
Temperature (℃ operating) -20C to 50C
Round trip efficiency (DC to DC includes self discharge)~90% >86%
Max output DC current (A)13
DC Input-Output Voltage Range (VDC), nominal550 – 750, 650VDC
Self Discharge (Watts, Average over charge/discharge cycle)<100W (average), <350W (max)
Auxiliary Power (Watts, 240VAC Average over SOC range)<140W (average), <300W (max)
Full Power Response (mS)>80mS
Installation MethodAbove Ground
Noise (from electronics box)<65dB(A)
Modularity1 to 16 units (24kWh to 512kWh) per array, multiple arrays possible
Illustration and performance data are for reference only.
Materials and specifications are subject to change without notice.

Off-grid MPowerTank Real Time Operations Dashboard via our SENSSA Energy Management & Control System


Our industrial grade SENSSA Energy Management & Control System provides a real-time view of your power system, with more detailed information and customisable to your needs. This live real project data is of the pilot off-grid system in Armidale, NSW. Learn more about the project


Lower Total Cost of Ownership than a Grid Connection


Compared to a grid connection, a Stand Alone Power System, (or off-grid system) can be significantly more valuable in the immediate and long term. We are often told that our system is cheaper than getting a grid connection to the property, due to the cost of new poles, new transformer, new cables, not to mention the ongoing annual cost of an electricity connection and retailer electricity costs. Once you factor in those costs, generally an off-grid system that lasts 30+ years will be more valuable and the smart choice for those with sufficient foresight.

Compared to traditional storage solutions like lithium batteries, flywheel technology has a significantly lower Levelised Cost of Storage (LCOS) at c. $0.15/kWh, compared to the LCOS average for lithium batteries of $0.28/kWh. This means your investment yields greater long-term value, as the initial cost is distributed over the system’s extended lifespan. 

We offer options and special deals, this entirely depends on your requirements. Every project is different, and pricing depends on many factors such as where your project is, how much solar you have or will need to add, panel type and size, scope of works, government rebates and grants, project complexity and distance.

Generally, a good budget guide is to estimate roughly 10-20% more than a good quality battery system, fully installed, excluding freight (which we provide at cost) and GST (as our customers are mainly GST registered businesses). This means prices start from around $1,400 / kWh ($33,600 for the 24kWh size system, or $44,800 for the 32kWh system) fully installed ex freight ex GST for a single MPowerTank unit, but can rapidly reduce in cost per kWh if multiple mechanical batteries are added, but could also increase in price if more components are required (for example, generators, complex wiring or design, Variable Speed Drive for high inrush current motors etc.).

Key Energy offers a range of flexible financing options designed to make owning a flywheel energy storage system accessible and impactful.

Early Adopter Offer

If you are the first client to install a mechanical battery in your area and are open to future customers taking a look at your system, you will be able to access a variety of benefits for your project. Simply request a quote and tell us where the project is, and if you’re the first in the area we’ll make the offer to you automatically!

Key Energy’s Design to Discharging Process

Initial enquiry, design meeting, and site inspection
1-2 weeks

Give us a call on or fill in an Enquiry Form to begin the journey of using more of your own power. Tell us about your home or project, energy or lifestyle goals, and ideally have some data available for us to design your project correctly. If your project is simple and you just want one of our MPowerTanks, we will explain the system in detail and answer any questions you may have. For complex projects we will assess the data to give you a high level solution design proposal and rough order of magnitude project costs.

If you agree to continue, one of our technicians or representatives will visit your proposed site to collect additional data if necessary, confirm access and other installation requirements, update the quote if necessary, and talk you through the draft solution design.

Final Design and Contract
1-2 weeks

With an agreement on all the project details you will be provided an accurate final technical plan with scope of works, solution outcomes, possible variations and a total cost of work, as well as areas that could risk fee over-runs, though we try to minimise these as much as possible. Once you understand and are happy with the project proposal, you will be able to sign the contract to begin the delivery process.

Site preparation (e.g. slab preparation) and delivery
2-6 weeks

If you are still building your property or have no pre-existing base slab, then you will need time to prepare the concrete slab to our standardised specification, or we can provide a pre-cast concrete slab. If you have an existing concrete base and location on site to use, we will confirm that it is suitable for the loadings of the MPowerTank. Stock is kept on-shore in our Sydney factory and warehouses in capital cities in Australia, but can be shipped to order to any port destination as required. We generally arrange delivery that suits you or your client’s timing and minimises expensive logistics costs. We can have a unit shipped within the week if you have everything ready.

Installation and Commissioning
2-3 days

Before the system is installed Key Energy with prepare all material, installers and certificates before the project starts. Key Energy keeps local stock on hand so depending on location and logistics, delivery can be arranged for a suitable date. Installation usually takes 1-2 days.

Commissioning is the process of turning the system on and providing power to your home or business, and running a series of tests to ensure the system is working. Key Energy performs and monitors a full cycle test, both locally and with remote support, and once tested, hands over the system providing all information on how to operate, troubleshoot and monitor the system

Maintain and enjoy your MPowerTank

Key Energy will remotely monitor your system for any alarms or faults. We provide SMS alerts to a designated number (or up to 12 email notifications) for any critical faults that need on-site attention. We’ll also provide you the number of a dedicated support engineer. We remind you for your scheduled maintenance, comprising an annual vacuum pump oil inspection, and dust filter cleaning. We continue to provide ongoing support and maintenance to ensure the system is operating as good as it did brand-new.