ARUBA —Wärtsilä has secured an energy storage and power system integration contract with Water- en Energiebedrijf Aruba (WEB Aruba), covering the installation of a 35 MW / 70 MWh Battery Energy Storage System (BESS) and associated energy management and maintenance services. The order was booked in Q3 2026, and final takeover is planned for Q2 2028.
The engineering, procurement and construction (EPC) scope includes installing the battery system and connecting it to WEB Aruba’s existing electricity generation assets. Wärtsilä will also provide an energy management system designed to coordinate battery storage with the wider power network, supported by forecasting capabilities and secondary and tertiary control functions. The service arrangement includes ongoing maintenance and technical support for the energy storage system.
The installation is intended to improve the stability and operational flexibility of Aruba’s electricity grid while enabling a greater contribution from renewable sources. By coordinating stored electricity with generation from existing assets, the system can help manage variations in renewable output, optimise dispatch decisions and reduce the cost of supplying electricity. The extent of these benefits will depend on operating conditions, generation availability and the island’s evolving energy mix.
The project is Wärtsilä’s largest energy storage installation in the Caribbean by both power capacity and energy capacity, according to the company’s announcement. Its 70 MWh storage capacity represents the amount of energy the system can store, while the 35 MW rating indicates its maximum power output. Together, these specifications provide Aruba with a means of shifting electricity across periods of changing demand and generation.
For Aruba’s power sector, the contract supports efforts to integrate wind and solar generation without compromising electricity supply reliability.
Battery storage and centralised energy management can help balance intermittent renewable generation with dispatchable power assets, making the project relevant to utilities and island grids that face constraints in diversifying their electricity supply.
WEB Aruba is the island’s energy provider, responsible for electricity generation and related energy operations. Wärtsilä supplies power generation technologies, energy storage solutions and lifecycle services. The agreement combines equipment installation with software and long-term maintenance, placing operational integration alongside the physical infrastructure. Its planned completion in Q2 2028 provides a timeline for Aruba to add storage capacity and strengthen the coordination of its power generation portfolio.
