On-Grid MPowerTank System

Empowering Sustainable Grid Independence

On-Grid MPowerTank System


Our system empowers you to take control of your energy, live sustainably and independently of the grid, using it only as a backup power source for power peaks or if the mechanical battery gets low. Chemical fire risk-free and guaranteed to last, enjoy peace of mind with our MPowerTank.

Reduce your electricity bill with powerful, durable, reliable and safe energy storage


Are you unhappy with your electricity retailer – have you had a shock on your electricity bill, or regular and long black-outs, or you just think the solar feed in price is unfair? Perhaps you’re increasing your energy usage, like charging your EV, expanding your home, adding air-con to cope with the heatwaves or cold, and want to use the grid only as a backup? We call this grid independence…



The MPowerTank presents key advantages over chemical batteries in reducing your power bills sustainably. Together with our innovative pricing and wholesale price offer, we are confident we can make you grid, and electricity bill, independent.

30+ year investment

Boasting an amazing 11,000 cycles, or 30 years of storage at 1 cycle a day. Finally a battery that lasts as long as your property.

Blackout protection

Increase your resilience to natural disasters, with a full back-up load circuit that can power your home and emergency power loads during a black-out event.

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.

Power for your whole home

Boasting 8kW of power ability, power air conditioners, pool or garden pumps with ease. Power sufficient even for large homes, rural properties and estates.

EV charger friendly

No matter how much you use the system, it will always have the same capacity at the end of its life as it did brand new. Feel satisfied charging your car with your excess solar every night.

Wholesale energy price offer – COMING SOON

Regularly have spare solar? Become a PowerHouse and store it and sell it to the grid every night when the price is right. Our system does all the thinking and work, you just sit back and earn passive income from your solar.

On-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 turn-key AC coupled energy storage system, that we can customise if needed for your on-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.

On-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 on-grid system in Sawyer’s Valley, Western Australia. Learn more about the project


Invest in a lower grid bill for over 30 years


Our system can save you more money than solar alone, and depending on your usage may be able to make you fully independent of the grid except in rare circumstances where you use a lot of energy or prolonged periods of low solar energy. Customers that can export and sell energy back into the grid, even at low “feed in tariff” rates are achieving credits to their bills once again!

Compared to traditional storage solutions like lithium batteries, flywheel technology has a significantly lower Levelised Cost of Storage (LCOS) starting from c. $0.15/kWh, compared to the LCOS average for lithium batteries from $0.28/kWh. If you pay more than $0.15/kWh for peak period electricity, then you will be saving with our storage system. 

You can start with a standard basic package or we offer custom options for your project to make it work for your home and property. 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 from the nearest depot.

Upfront outright purchase

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). Prices start from around $1,400 / kWh fully installed ex freight ex GST (i.e. $33,600 for the 24kWh size system, or $44,800 for the 32kWh system) fully installed ex freight ex GST for a single MPowerTank system, and can rapidly reduce in cost per kWh if multiple mechanical batteries are added (as you generally only need to pay for additional mechanical batteries), but could also increase in price if more components are required.

Leasing and third party financing options

Key Energy offers a range of flexible financing options designed to make owning a flywheel energy storage system accessible and impactful. Some of our lease payment plans and lengths can result in a monthly payment of less than $500/month ex GST at current interest rates and depending on the length of the lease. Call us to find out more about what your system investment is!

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.