Before having the new energy storage, from time to time, the island was forced to curtail power distribution to ensure the supply of electricity for critical systems. Even though the conditions for wind power production are excellent, without sufficient energy storage it is impossible to use it in an optimal manner – the times when energy is produced and when it is consumed do not coincide. Currently, wind turbines are capable of accommodating up to 90% of the island’s peak energy demand.

Bonaire, located in the Caribbean, has a land area of less than 300 square kilometres. The energy storage system now delivered complements the island’s earlier power supply system, which used to consist of an 11 MW wind farm, a 14 MW power plant, a 3 MW reserve power plant and a 3 MW energy storage.

Tightly packaged energy

The battery containers were manufactured in Tampere and transported to Bonaire on a ship, so logistics played an important role in the project from the very beginning. In terms of dimensions and handling, a 6 MW energy storage corresponds to two 12-metre High Cube containers. The fixing and lifting points as well as the corners are made in the same manner as in a transport container. The ground transport is easy with a side loader truck.

Both containers contained battery racks, which can accommodate over thousand batteries, weighing slightly over fifty kilos each. The combined weight of the batteries amounts to more than 55 tonnes. Therefore, it was clear that the batteries would need to be installed in place on the final project site.

12 weeks at Arnon, 2 weeks on Bonaire

For Arnon, supplying the battery containers meant an efficient 12-week project.

The project began with the mechanical design of the container frame, including strength calculations, penetrations, reinforcements and transport frames. The automation centre and DC switches, fire detection and suppression system and air-conditioning channels were designed at the same time.
The manufacture of both the containers and electrical centres was launched as soon as it was technically possible.

The fire detection system installed in the containers consists of temperature and smoke detectors and a gas identification system. If the systems detect a fire, Novec gas with no harmful impact on humans or the environment is released into the containers.

Given the tight scheduling of the project and amount of integration works to be completed required Arnon to send a strike force of two to Bonaire to complete the project and tie up all the loose ends.

“The scheduling and logistics worked well, the design and manufacture proceeded to allow containers for shipping in time, and the completion work on Bonaire went smoothly,” says Verneri Hanhilahti, Arnon’s Account Manager, in summary of the project.

Successful cooperation

Wärtsilä was responsible for overall turnkey delivery of the full energy storage system to Bonaire including batteries, inverters, transformers, medium voltage gear and the GEMS energy management system.

“The integrated system will significantly increase the reliability of the island’s power system. The project was important for Bonaire, and we are delighted that we had an opportunity to supply an environmentally sustainable solution for the island’s power production and distribution,” says Akshay Ladwa, Vice President of Engineering, Energy Storage and Integration at Wärtsilä.