Wärtsilä’s 35-megawatt storage project pairs batteries with energy management and maintenance, with takeover expected in the second quarter of 2028
Wärtsilä has signed an engineering, procurement and construction agreement with WEB Aruba for a battery storage project intended to coordinate the island’s generating assets and support greater use of renewable energy. Announced October 13, the agreement covers 35 megawatts of power capacity and 70 megawatt-hours of energy capacity, together with an energy management system and maintenance services.
The order was booked in the third quarter of 2026, and takeover is expected in the second quarter of 2028. Wärtsilä describes it as the company’s largest Caribbean project by both power and energy capacity. That is a comparison within Wärtsilä’s project portfolio, not a claim that the installation will be the largest battery system anywhere in the Caribbean.
WEB Aruba currently generates electricity using wind, solar and engine power plants, according to the announcement. The project’s stated purpose is to optimize that combination and increase renewable penetration. The battery is therefore presented as part of a wider system-management effort, rather than as a stand-alone replacement for the island’s existing generation. The release does not specify a resulting renewable-energy share.
The two capacity figures describe different aspects of the installation. Megawatts measure power, while megawatthours measure stored energy. At the stated ratings, 70 megawatt-hours divided by 35 megawatts corresponds to two hours. That arithmetic helps explain the system’s nominal scale; it is not an operating guarantee or a prediction of how WEB Aruba will dispatch the battery in actual conditions.
For U.S. energy executives, the announcement offers a concrete example of storage being purchased together with control technology and ongoing services. Its relevance lies in that project structure and the challenge of coordinating different generating assets. The packet provides no basis for claiming that the Aruba agreement will change U.S. electricity prices, affect domestic supply or produce orders for American companies.
“WEB Aruba emphasises cleaner energy production, and our new agreement with Wärtsilä strongly supports this strategy. We currently generate power by utilising wind and solar energy along with our engine power plants. Wärtsilä’s well-proven technologies will allow us to optimise the overall energy system and provide the most efficient power output, while maximising our use of renewables.” WEB Aruba Chief Executive Alfredo Koolman made that statement in the announcement.
Koolman’s comments set out the utility’s expectations for the project. They do not document measured improvements from a system that has yet to reach its expected takeover date. The release supplies no before-and-after operating data, emissions reduction estimate or quantified fuel savings. Cleaner production and more efficient output are the objectives described by the customer, not demonstrated results of this installation.
Risto Paldanius, vice president for the Americas at Wärtsilä Energy, similarly said the combination of storage, energy management and services would support better power quality and reliability, lower delivery costs and greater efficiency. Those are supplier claims about anticipated benefits. The announcement does not attach a financial estimate to the cost reduction or identify a specific change in electricity rates for customers.
The construction agreement is a concrete commercial commitment, but several details important to a financial assessment are absent. The announcement does not disclose the contract value, project financing or a forecast return. It also does not quantify the respective contribution of storage, control software and maintenance to expected performance. Readers should not treat the stated capacity as an economic result in itself.
The project’s next test is delivery, followed by operation within WEB Aruba’s existing power system. The expected 2028 takeover date separates today’s signed agreement from the future benefits described by both companies. For now, Aruba has committed to additional storage and system coordination; the extent to which that investment improves reliability, costs and renewable use remains to be demonstrated.
Source: Aruba
