Will doubling wind turbine capacity double my electricity savings?

The short answer

Not necessarily. Even if annual generation doubled, the additional electricity might arrive when site demand is already covered or exports have a lower value. Compare the larger option’s incremental useful energy, export income and costs. A power-rating ratio is not an energy forecast, and an energy ratio is not a savings ratio. Both steps require their own evidence.

Keep two questions separate

First, assess how much extra energy the actual larger turbine would generate at the same site using its power curve and the same wind data. Second, determine where that extra energy goes. The larger rotor, controller and converter may have different operating behavior and installation requirements.

Use interval data to assess consumption and surplus. Annual load alone can make the site appear able to absorb all production even when a substantial portion would arrive outside its operating hours.

Calculate the value of the added energy

Hypothetical comparison, not product output: a smaller option generates 10,000 kWh, all used on site at an assumed 0.20/kWh, giving 2,000 of energy value. A larger option generates 20,000 kWh, but the site uses only 12,000; the remaining 8,000 is exported at an assumed 0.05/kWh.

The larger option’s value is 12,000 × 0.20 + 8,000 × 0.05 = 2,800. Generation doubles in this example, while the value rises by 40%. The additional 10,000 kWh contributes only 800 before added costs.

Compare the incremental investment

Set the additional foundation, tower, conversion, installation and service costs against that additional value. Also consider whether a larger connection or different approval process is required. These are proposal-specific issues, not universal consequences of increasing rated power.

A larger option may still be the right choice when demand is expected to grow or the energy can be used effectively. Keep the growth assumption and its timing explicit. Avoid sizing for an uncertain future load while valuing all added generation as if that load already existed.