Pipelines, energy and natural resources

[suffolkowner]

i took it to be capacity efficiency

 

[ytz]

65% efficiency is impossible.

The Betz limit is around 60% for turbine energy capture of wind going past it. After you calculate in other efficiency losses (turbine conversion to electricity, resistances both mechanical and electrical) the best efficiency you're every going to get is 80% of that 60%, (so 50%).

That's not a bad conversion rate.

You're right on Betz law. Gawd. I haven't read my textbook in a decade. Correct.

Either way it most certainly wasn't 25-30% of rated capacity for offshore though. Quick Google says UK is currently at 44% offshore. I think you get closer to the 50-60% of rated capacity with size.

 

[suffolkowner]

My mistake. I haven't read my textbook in a decade. Correct. But it most certainly wasn't 25-30% for offshore though. Quick Google says UK is currently at 44% offshore. I think you get closer to the 50-60% range with size.

50 of 60 is 30 though

 

[Underway]

50 of 60 is 30 though

Yes, but 80% of of 60% is 48% (~50%).

We are hyper simplifying things though and really just confounding the maximum energy you can pull from the wind with the turbines output.

Rated capacity on a wind turbine is calculated by the turbines engineered capacity. Turbines when installed are designed to maximize the available wind energy and run at their highest capacity as much as possible. This means they have gearing in them to stop them from "running away" if the wind is higher.

Then you figure out how many hours a turbine is actually producing at its rated capacity (maximum). You divide those by each other x 365 days and you get.... the actual capacity. 44% means that the wind blew to only 44% of the turbines maximum capacity (full out turbine every day all day).

The Betz law only really applies during design, so that you can properly size/engineer the turbine to match the wind where you're going to locate the wind turbine. You're trying to get to the point in the cost curve where you minimize the turbine cost and maximize the power produced. 44% might be the sweet spot where any larger the turbine gets to expensive and any smaller you're leaving power (aka money) on the table.