Fox's electric energy storage (Fox ESS ENERGY CUBE), which works on the principle of pushing air into individual battery cells (electrolyte circulation system or ECS) is high performance, expandable system for storing electrical energy.

The modular design allows maximum flexibility, making it suitable for a wide range of applications. Additional batteries can be installed in series. Installation is easy and works on a "plug and play" system, which saves installers a lot of valuable time.

What are the advantages of solar energy storage?

The fact is that a solar power plant produces electricity only in daylight, at most, of course, when the sun shines. On the other hand, the highest energy consumption occurs precisely in the evening, when production is reduced.

To put it a little differently, a solar plant often produces the most energy just at a time when demand is lower, i.e. during the day when the sun is shining, in the evening, but when the demand is the highest, the production is significantly lower or even zero. This means efficient storage of solar energy in electricity storage units opens up a wealth of possibilities both for owners of private houses and apartments, as well as for companies.

Storage of excess energy produced by a solar power plant is essential to maximize the efficiency of any solar system.

Storing solar energy in electricity storage system has quite a few advantages:

  • REDUCTION OF ENERGY LOSS: If electrical energy is not stored, it must be used the moment it is produced. Energy storage, on the other hand, allows excess production to be stored for when consumption is at its peak. Storing excess energy allows the lights to stay on even after the sun goes down. Simply put, energy storage allows a reservoir of energy to be filled when production is high and demand is low, and then released when production declines and demand rises..
  • INCREASED ENERGY SECURITY: Short-term solar energy storage enables a consistent flow of energy during short interruptions, such as e.g. passing clouds or regular maintenance.
  • ENERGY RESISTANCE:  The power grid is vulnerable to disruptions and outages due to a variety of mishaps, from forest fires to severe weather. Solar energy storage, on the other hand, creates a protective bubble during any such events.
  • ENVIRONMENTALLY FRIENDLY: By having more control over the amount of solar energy you use, battery storage can reduce your carbon footprint. Large solar panels can also be used to help charge electric vehicles and turn any device in your home into a “solar powered” device.
  • SAVINGS: Storing electricity in a battery also helps lower your electricity bills, as you use more of your own energy this way.


2.88 kWh

ECS 2900

4.14 kWh

ECS 4300H

4.74 kWh

ECS 4800



  • The Fox ESS Energy Cube can boast of extremely easy and quick assembly. It consists of the main unit (master) in and additional units (slave).
  • The maximum size of a cube is the main unit + 6 additional unitswhich are stacked lego-style, i.e. one on top of the other.
  • 1 M (master) + 6 S (slave) can be connected to one inverter.
  • 10 inverters can be connected in series, to which 1 M (master) + 6 S (slave) can be connected. So 70 battery modules..

Remote performance monitoring:

The operation of our solar power plant can be easily monitored via the Fox ESS application, which is also available in the cloud.