OT: Typical hotel power for a cruise ship

There is full Streetview coverage of most German cities, many smaller towns and villages and also of roads linking the towns. All those I checked are dated 2023.

I did actually ask one of the engineering officers why they used diesels, not gas turbines, given CCGT is the standard fossil now on sure. He said turbines used more fuel. I didn't quiz him much though, it was his dinner break!

Andy

I think you need efficient heat exchangers for a gas turbine, or most of the heat energy goes out of the exhaust.

Gas turbines have an awful thermal efficiency at part loads. Their only advantage is a lower weight.

Diesels on the whole are more efficient, cheaper, simpler and easier to maintain.

This is surprisingly correct. A steam turbine using steam - even superheated steam - as a working fluid maxxed out at about 37%, but temperatures in a diesel combustion chamber are way higher than that, and in a marine application where weight is not especially critical, and excellent charge and exhaust cooling is possible, you can build for efficiency that you could never do in a car.

I think 45% eff. is not unkown. Its the same reason oil fired power statins were phased out on favour of CCGT, there the overall efficiency is 67% or thereabouts, and that is higher then a an oil fired turbine AND a big diesel running bunker oil, and in fact natural gas was at the time almost a waste product.

Typos 'R' Us! I did of course mean on shore, and I'm sure you don't mean statins...

Why if a CCGT works on shore is it not the best solution for a ship?

Andy

Its not great carrying gas around in a ship. The alternative. using something akin to kerosene in a gas turbine followed by a steam plant would work, but bunker oil is way cheaper than kerosene.

In the end, as with all commercial operations, free of gummint interference you use what technology ends up cheapest.

Currently that's roads tar in a diesel...:-)

Interestingly ALL those big ships do with the diesels is make electricity. The motors are electric. Lots of them ...