Submarine cables to use for transmission

[viking684]

Here is some information:

An island that utilizes 13.2 kV lines would like to lay submersible cable to transmit power to an island that is approximately 20km away. The depth of the water is between 150-200 meters deep. What is the best submersible cable for this scenario?

 

[waross]

The best? Cheapest? Most reliable? Bullet proof reliability?
We used direct burial cable to feed an island about 300 meters off shore. the cable was three twisted conductors; each conductor being lead sheathed, paper insulated and PVC jacketed.
The cable was purchased on the surplus market.
The cable was jetted a foot or so below the surface with divers using "T" nozzles to give protection from dragging anchors.
I doubt that you will find 20 km of any type of cable on the surplus market. You are most likely looking at a special purchase and custom mill run.
A more robust construction for submarine cable consists of a concentric wrap of steel rods for mechanical protection. The sample I saw used rods about 1/4 inch in diameter, wrapped to give 100% coverage.

Bill
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"Why not the best?"
Jimmy Carter

 

[davidbeach]

13.2kV seems like an awfully low voltage for such a long run; have you considered stepping up to a higher voltage? At a high voltage you'll be able to use a smaller conductor and you'll have better voltage regulation across the range of minimum to maximum load.

 

[viking684]

I'd like to know what the best, most reliable cables would be feasible for this type of project. I agree about the 13.2 kV lines, just wanted to put a little information about what nominal voltage is used on the main island. The smaller island is currently being supplied by 2- 100 kW gensets. With the cost of shipping fuel, spare parts, and maintenance, we are looking into using submarine cables to supply power from the main island. We are currently doing a cost analysis to see if it is feasible.