Wind energy exceeds 20% annual penetration in a number of European electricity grids, with Denmark exceeding 40% in 2015.
… is growing rapidly worldwide. In many areas, onshore wind now delivers the lowest cost of energy and, by 2025, only solar will out-compete wind in areas with good solar irradiance.
Wind turbines are now manufactured in very large numbers and represent a mature technology. Still, significant developments continue. Turbine sizes for the offshore market are increasing, driven by the high cost of foundations and installation. Turbines rated up to 8MW and with diameters greater than 170m are already installed, with designs reaching 12 MW and 200m. For deeper offshore waters, where bottom-mounting is prohibitive, floating turbines are starting to be piloted commercially, and are likely to achieve full-scale deployment by 2025, taking advantage of simplified installation and standardized mass-produced units, thus opening up huge new potential. By 2025, multi-rotor concepts may appear, benefitting from the mass-production of larger numbers of smaller rotors.
Further developments in turbine technology include light, flexible blades and aerodynamic control devices, innovations in transmission systems, new sensors and smart control systems. Equally important is the intelligent management of large numbers of units, using condition monitoring and central data acquisition and analysis to optimize operation and maintenance.
More advanced controls are being developed both at wind turbine and wind farm level. LiDAR technology may be used to identify approaching turbulence, allowing the controller to optimize turbine performance. Greater use of measured and estimated load data allows the operation of turbines and wind farms to be tailored dynamically, enhancing economic performance as environmental and electricity market conditions change. An example is to reduce power output to preserve component life when turbulence is high, or electricity prices are low, or forecast production is exceeded. Within timescales of just a few seconds, controllers may transiently increase or decrease power output in response to grid frequency variations, increasing grid frequency stability and facilitating higher wind penetrations.
Wind farm controllers can adjust the behaviour of individual turbines to minimize wake interactions between turbines, increasing farm production while reducing fatigue loads to extend life. In addition, controllers will be able to adjust aggregate active and reactive wind farm power in response to grid requirements.