Why are modern wind turbines so big?
Since December 2021, the largest model of the wind turbine is the Siemens Gamesa SG 14-222 DD, designed for offshore operation. The rotor has a diameter of 222 meters (728 feet) and sweeps an area of 39,000 square meters (419,792 square feet). One of these wind turbines can generate enough electricity for 18,000 households, and there are plans to use 30 of them to fully power the city of Bilbao in Spain.
A 15 MW version called SG 14-236 DD with a diameter of 236 m (774 feet) and 43,500 m2 of swept area (468,230 square feet) is currently being developed. The first of these units will be installed in 2022 and will be commercially available in 2024.
There is a reason why manufacturers are focusing on making wind turbines as large as possible. While you could achieve 3 MW with 30 100 kW turbines, one 3-MW unit is a better choice economically.
- The wind is more turbulent near the ground due to the presence of natural and artificial obstacles and more stable at higher altitudes. Higher turbines can achieve better wind conditions, making them more productive.
- Wind turbines are also affected by economies of scale: Smaller units can cost you more than $ 5,000 per kW, while large turbines can cost you less than $ 1,500 per kW. The total cost of a wind turbine on a megawatt scale is much higher, but its cost per kilowatt is significantly lower.
In other words, a large number of smaller turbines have higher costs and lower productivity. By using fewer large turbines, you can significantly reduce project costs while achieving higher productivity. From a financial point of view, this means two things: the payback period of the project will be shortened, while the return on investment will be much higher.
Texas is currently the leading wind farm in the United States. Nationwide installed capacity has exceeded 129,000 MW, according to the latest quarterly report from the American Clean Energy Association, and 38,000 MW is located in Lone Star State. The Roscoe Wind Farm is the largest in Texas, has a capacity of 781.5 MW and 627 individual wind turbines. The project was built in four phases using turbines from different manufacturers:
- Phase 1 (Roscoe): 209x 1-MW Mitsubishi turbines
- Phase 2 (Champion): 55x 2,3-MW Siemens turbines
- Phase 3 (Pyron): 166x 1.5-MW GE turbines
- Phase 4 (Inadale): 197x 1-MW Mitsubishi turbines
With more than $ 1 billion invested and covering 100,000 acres, this wind farm is capable of supplying more than 250,000 Texas households.