0,06 - 0,07 Euro Cent/kWh!

No longer tolerate the super expensive energy bill?

Get yourself a Barrel! install it easily by following our video tutorials.

Spot electricity in this period is around 0,40 euros / kWh

So let's talk about increases of 500%! + 500%. Not even bitcoin. But it's not bitcoin ... it's the energy that moves our lives..

Example in Madrid
5650 kWh / year.

with 4000 Wp PV installed you can produce 10-11 kWh / day in winter and 20-22 kWh / day in summer of electricity 'per day. Average cost of 0.069 cents/Euro.

How is works

Barrel provides the flexibility of storing the energy you generate during the day and use it at night.
Moreover, in this era of climate change, it’s a great system for protecting your family and your business with back-up solutions in case of emergency, first aid or natural disasters. Barrel is a compact Solar Hybrid System offering cutting-edge Storage Lithium. 
Barrel allows you to create an island photovoltaic system with energy storage to be used at any time. 
Thanks to the integrated charge controller it is possible to connect in series of photovoltaic panels and accumulate the energy to the battery.
The inverter, thanks to the UPS function, can supply up the energy and it is possible to assign the source priority between batteries and the grid.
  • Barrel is a hybrid inverter designed to meet all the needs of customers who intend to build a simple and reliable hybrid photovoltaic system.
  • The inverters can operate both in UPS mode, thus giving priority to the electricity grid and subsequently to the batteries in the event of a black-out; both in inverter mode, giving priority to the batteries or even to the photovoltaic generator, diesel generator and subsequently to the electricity grid in the event that renewable sources are unable to supply energy.
By programming the hybrid inverter in UPS mode (electricity grid priority), using the keys located below the display, it allows you to withdraw energy from the batteries and solar panel in the event of a black-out.
How does the exchange take place?

The electricity grid, through the inverter, supplies energy to the electrical loads in operation and in the event of a black-out, Barrel notices this event and automatically connects to the photovoltaic generator which together with the batteries guarantees the continuity of power supply to the loads.

Furthermore Barrel can be programmed, the input voltage range, to safeguard loads sensitive to voltage fluctuations coming from the grid.


Solar can be used to provide the majority or all of the power in a remote cottage or home. Ideally, the solar system is designed by a professional to match your lifestyle and electrical load. The systems are modular so they can grow as your power needs change. Off-grid solar systems have storage bat- teries, and often have generators for back- up. The inverter systems for off-grid appli- cations have built-in battery chargers, and can even be used to start the generator automatically if needed.

Different size of PV modules will produce different amount of power. To find out the sizing of PV module, the total watt peak (Wp) produced needs. The peak watt (Wp) produced depends on size of the PV module and system location. We have to consider “sunlight factor” which is different in each site location. For central europe the factor is around 3, and corresponds to about 3 hours of sunlight, per day, expected average over the whole year (including in the winter time).

To determine the sizing of PV modules, calculate as follows:

2.1 Calculate the total Watt-peak rating needed for PV modules

Divide the total Watt-hours per day needed from the PV modules (from item 1.2) by 3 to get the total Watt-peak rating needed for the PV panels needed to operate the appliances. The factor 3 corresponds to the day-hours sun radiation under central european conditions and all season working mode (also winter), if PV system working in spring-summer-autumn the factor will be around 4-5 and for systems working only in summer, around 6-7 hours sun per day (factor=6 to7).  

2.2 Calculate the number of PV panels for the system

Divide the answer obtained in item 2.1 by the rated output Watt-peak of the PV modules available to you. Increase any fractional part of result to the next highest full number and that will be the number of PV modules required.

Result of the calculation is the minimum number of PV panels. If more PV modules are installed, the system will perform better and battery life will be improved. If fewer PV modules are used, the system may not work at all during cloudy periods and battery life will be shortened.

Solar mode : The inverter powers the loads by drawing energy directly from the photovoltaic system.In the event that the electricity from the photovoltaic system is not sufficient to power the loads, the inverter will also draw energy from the batteries. The network or diesel generator will only intervene if one of the two underlying conditions occurs:

There is no production of energy from the photovoltaic generatorThe battery voltage reaches too low values.

Battery mode : The inverter powers the loads by drawing energy from the photovoltaic generator. In the event that the energy from the sun is unable to power the loads, the inverter also draws energy from the batteries. The inverter draws energy from the electricity grid only in one condition: when the battery voltage is too low.

Yes, the generator can be connected to the grid port (no line selector required, the Barrel can charge the battery with genset and serve the loads).

Yes, with full-back-up

Yes, in the battery Report covers UN 38.3 (UN ST/SG/AC.10/11/Rev.6)
Transportation Testing for a Rechargeable Lithium-Ion (LiFePO4) Battery Packs - UN Specified Packaging, Lithium Battery Class 9 Label and Cargo Aircraft Only Label. Packaged in accordance with
packing instruction P903.

Yes, battery pack included of 2. 8 kWh. you can increase sizing from 2.8 kWh to 100 kWh max outside of the Barrel.