Guam's Power Authority says its proposed seawater cooling project may encounter problems getting a permit.
Also known as "seawater air conditioning system," the process uses cold water pumped from the depths of the ocean to cool adjacent buildings.
The authority's general manager Kin Florence says the buildings they want to service are mainly hotels, which pay a lot for air-conditioning.
But he says the next stage is to ensure it doesn't damage the pristine tourist environment.
"Unfortunately the Tumon Bay district is designated as a shoreline right out to the reef as a marine reserve. So when we put in this very large pipeline, we have to avoid all the impacts on a marine reserve, which is a very sensitive area for environmentalists so permitting is very difficult."
Kin Florence says a feasibility study has just been completed for the four year project.