“Belnem House” is a newly built apartment complex on the Caribbean island of Bonaire.

At Bonaire, electrical energy is diesel-generated. Because the energy plant has reached its maximum capacity, new buildings are not allowed to have a grid connection. For this reason, many hotels and apartment buildings run big diesel generators.

Belnem decides for a different approach: at Bonaire, there’s plenty of sunshine! So, why not use that for energy?

They cover the entire roof surface with solar panels. That yields plenty of energy during the day. But, since it’s a pretty warm climate, a lot of energy is needed to run all air conditioners in the apartments at night. So, a good amount of energy storage is required. That’s why they contacted us.

In the Netherlands we start installing a big battery and inverter system in a reefer (an insulated and chilled container).

64 MG Energy lithium batteries of 7,2kWh each. 460.8 kWh. Almost half a megawatt.

9 Victron inverter/chargers, Quattro 48v 15k each. 135kW of inverter power.

Plus 4 big solar chargers.

The currents are huge: up to 2000A. For this reason, we install massive copper bus bars.

After the installation is finished we do extensive testing with massive electric heaters as load and a big diesel generator.

After that, we stuff hundreds of solar panels into the container and it’s shipped to Bonaire.

When the container has arrived at Belnem and the solar panels are mounted on the roofs, we fly in to commission it.

The reefer is positioned next to a small building were the diesel generator is installed. Diesel is used for backup and in case there are cloudy days with high loads.

Every inch of roof surface is used for solar panels

Solar panels on the apartment buildings

Solar panels everywhere…

Configuring and testing the entire system.

Over 100kW of solar power!

And over 100kW of diesel power!

After extensive testing and running maximum load in the buildings, concluding that we need about 50% of the battery to cover the night and by next afternoon the solar power has charged the batteries to 100% again, we have something to celebrate!

We monitor the system remotely. Now, after 3 years of full service, we conclude that with a full occupancy of the apartments the container cycles around 50% per day, there have been no major malfunctions and on a yearly basis we see about 10% of the consumption generated by the diesel genset (to cover cloudy days).