Doesn't the area described by a turbine's motion scale with the square of the blade-length, so given a circular area covered by a turbine, the power will scale linearly with that area?
Yes but you’re not paying for the area the blade covers - you’re paying for the blade. Simplifying (to an extreme) for the sake of illustration - a 20m blade costs twice as much as a 10m one but produces 4 times the energy.
Obviously, cost scales more than linearly with blade length but it’s a bit like big O - the n^2 factor dominates. This is why wind turbines have been getting bigger and bigger. And why the cost of domestic or small-scale wind turbines remains stubbornly high despite the dramatic fall in the average cost per MW seen for wind turbines - as the falls are largely driven by the ability to manufacture larger and larger turbine blades. While falls in costs for solar PV can be seen at every scale.
Yes but you’re not paying for the area the blade covers - you’re paying for the blade. Simplifying (to an extreme) for the sake of illustration - a 20m blade costs twice as much as a 10m one but produces 4 times the energy.
Obviously, cost scales more than linearly with blade length but it’s a bit like big O - the n^2 factor dominates. This is why wind turbines have been getting bigger and bigger. And why the cost of domestic or small-scale wind turbines remains stubbornly high despite the dramatic fall in the average cost per MW seen for wind turbines - as the falls are largely driven by the ability to manufacture larger and larger turbine blades. While falls in costs for solar PV can be seen at every scale.