Buying guide
Water and Power on a Private Island
Water and power determine whether an island is comfortable or merely picturesque. Both are engineering questions with well-established solutions, and both need to be scoped before purchase rather than after.
By Private Island Listings Editorial Team · Last updated 2026-08-20
Water options
| Source | Where it suits | Considerations |
|---|---|---|
| Rainwater catchment | High-rainfall tropical and temperate sites | Roof area and storage volume drive capacity |
| Wells and boreholes | Larger islands with a freshwater lens or aquifer | Requires testing; over-extraction causes salinity |
| Desalination | Small saltwater cays and higher demand | Energy intensive; membranes need servicing |
| Delivered water | Mediterranean islets and interim supply | Ongoing cost and dependence on boat access |
Power configurations
The current standard on remote islands is solar with lithium battery storage and a diesel generator for redundancy. Grid connection by submarine cable exists in parts of Scandinavia, the Great Lakes and near-shore Mediterranean locations and materially increases value where present.
Designing for reliability
- Size storage for the worst realistic period without sun or rain
- Keep critical loads separated so essentials survive a partial failure
- Plan fuel storage and delivery logistics with safety compliance in mind
- Hold spares on site for pumps, membranes and controllers
- Train a caretaker to operate and monitor the systems
Keep reading
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