Ideal climate for mega-battery Johan Cruijff ArenA


In order to regulate the temperature and humidity of the mega-battery in the Johan Cruijff ArenA in Amsterdam, APAC supplied two cooled water computer room close-control units. Future expansions were taken into account during the installation process.


In order to make the Johan Cruijff ArenA sustainable, a circle of solar panels was installed on the roof. If the panels generate more power than is needed, the power will remain available via a mega-battery that consists of second-hand Nissan Leaf batteries. As with mobile phones, these batteries get hot during charging and discharging. BAM Bouw en Techniek asked APAC to provide a system that creates the ideal temperature and humidity in the room that houses the mega-battery.

Our solution

The ArenA already had a cooling water system for heat and cold storage. APAC linked two units to that system, creating a joint cooling capacity of 60 kW for the battery room. These units send water with a temperature of 7°C into the system and it is returned at 17°C. The machines extract moisture from the room through condensation on the cool battery. In order to increase humidity, the units are also fitted with a steam humidifier. Project leader Willem-Jan Kloet of BAM Bouw en Techniek is happy with our proactive approach: ‘APAC has contributed a lot of knowledge, for instance, by coming up with suggestions relating to the location of ventilation tiles for an optimal distribution of air throughout the room from the cooling machines via the raised floor.’

The result

After installation, the cooling machines were extensively tested and fine-tuned, for instance by intentionally raising the temperature. In June 2018, the mega-battery and cooling were taken into use. The system currently maintains an ideal battery climate in the 200 m2-large room: 24°Celsius and a humidity level of 45%. On APAC’s advice, the connections for two additional units are already in place. This creates options to expand the battery when the time comes. Kloet: ‘The Johan Cruijff ArenA won the Green Apple Award, an international sustainability award, for this project. And APAC contributed to that.’

Johan Cruijff ArenA

BAM Bouw en Techniek

Cooling water system

Basic principle:
Cooling mega-battery

APAC is BAM’s expert partner for these types of innovative projects.

Willem-Jan Kloet, project leader BAM Bouw en Techniek

Equipment used
Two air-cooled water cooling machines FX-Z-K 2722, each with a capacity of 664 kW.