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OneWorld Solar

451.5 kW · St. Thomas, U.S. Virgin Islands

Virgin Islands Port Authority: 451.5 kW Public Sector Solar on St. Thomas

451.5 kW of ground mount solar for a public authority on St. Thomas: coastal siting, salt-air corrosion, hurricane-zone structural design and a procurement process run in public.
System size
451.5 kW
Mounting
Ground mount
Location
St. Thomas, USVI
Owner type
Public authority

The 451.5 kW ground mount array OneWorld Solar built for the Virgin Islands Port Authority on St. Thomas is a public sector solar project in the Virgin Islands that had to satisfy two audiences at once: the engineers who would operate it, and the procurement process that had to justify the award in public.

Public authorities are among the better candidates for solar. They occupy their buildings for decades, they are not going to relocate, they hold land, and they answer to constituents who read the utility bill as a line in a public budget. What they do not have is the freedom to negotiate a scope informally.

What makes a public authority project different

The specification comes first. An authority publishes what it wants, takes competing bids against that document and must be able to defend the award later. That inverts the usual sequence: the engineering, the structural calculations and the interconnection technical data all have to be complete and defensible at bid stage rather than developed once the contract is signed.

This is one of the reasons we run projects as a single commercial solar EPC contract. When one party holds the design, the procurement and the construction, the document the authority evaluated is the same document that gets built. Our VP of Engineering, Chris Sandifer, is a licensed Professional Engineer and a NABCEP board-certified photovoltaic system inspector, which matters when the deliverable is a stamped package that a public body will publish.

Designing for a coastal hurricane zone

451.5 kW

Ground mount array

Built for a public authority on St. Thomas.

Coastal site

Salt-air environment

Corrosion drives material and coating choices.

Hurricane zone

Wind governs the structure

Design starts from site wind speed.

Two environmental conditions drove the design, and both of them are about durability rather than output.

Salt air. A coastal ground mount is exposed from grade upward, and salt attacks every fastener, every dissimilar-metal joint and every enclosure penetration. The response is unglamorous and mostly invisible in a photograph: material and coating specifications chosen for the environment, dissimilar metals isolated at connections, enclosure ratings selected for a marine setting. It costs more at construction and it is the difference between a twenty-year asset and a ten-year one.

Wind. In a hurricane zone the array is engineered from the site's design wind speed back through the modules, the clamps, the rails and the foundations. On a ground mount the foundations are the item that most often gets under-designed, because they are the part nobody sees on a finished site.

What we will not tell you about this site

We are not publishing production, savings or availability figures for this project. The capacity and mounting type here come from the previous OneWorld Solar website and predate our current records. Ask us for the verified data rather than working from a number on a web page.

The results

OneWorld Solar has not published production or bill-savings figures for this installation. The scope described above is what the company confirms; anything beyond it should come from OneWorld Solar directly.

On incentives, one point is worth stating carefully. The U.S. Virgin Islands is a United States territory, so federal programs such as the 30% commercial solar tax credit may be relevant to a project there. Whether any of it applies to a specific entity depends on that entity's tax position and on the rules in force at the time. A public authority has a very different posture from a private company. That determination belongs to the customer's tax advisor, not to us.

Where to go next

public sector solar Virgin Islands

Frequently asked questions

How is a public sector solar project procured differently from a private one?

The scope is fixed before the price is. A public authority publishes a specification, receives competing bids against it and has to be able to defend the award afterwards, so the technical package carries far more weight than it does in a private negotiation. For a contractor this means the engineering, the structural calculations and the interconnection data have to be complete and defensible at bid stage, not developed later.

What does salt air do to a solar installation?

It attacks the metal. Coastal sites accelerate corrosion at every dissimilar-metal joint, every fastener and every enclosure penetration, and a ground mount is more exposed than a rooftop because the structure runs all the way to grade. The defenses are material selection, coating specification, isolating dissimilar metals at connections and choosing enclosures rated for the environment rather than the cheapest option that passes inspection.

Do US federal solar incentives apply in the U.S. Virgin Islands?

The U.S. Virgin Islands is a United States territory, so federal incentive programs may be available, but eligibility depends on the entity, its tax position and the program rules in force at the time. A public authority in particular has a different tax posture from a private company. Any project should be modeled only after the customer's own tax advisor confirms what applies.

Why choose a ground mount instead of a roof array on a coastal site?

Usually because the land is available and the roofs are not suitable. Ground mounts allow the array to be oriented and tilted for output rather than following whatever plane the roof gives you, and they keep maintenance off the roof membrane. The trade-off is foundations, site work, perimeter security and a structure that has to resist wind from grade upward.

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