As with every energy related project, at the end of its operating lifespan it has to be decommissioned. Many of Europe’s oldest wind turbine fleet are more than 30 year’s old, at the end of their planned operating lifespan. Since they are often seen by their operators as not as competitive as the latest much bigger and productive installations being installed.
In 2017, Denmark decommissioned 174 turbines with a total capacity of 98 megawatts while 220 new ones generating 373 megawatts were connected, according to the Danish energy agency. By mid-2017, Germany had a total of about 28,000 onshore wind towers, according to the country’s wind lobby.
Meanwhile, E.ON UK Renewables has announced plans to decommission two offshore wind turbines at its Blyth Offshore Wind Farm, in the coming months. The wind farm was installed in 2000 and during operation was able to generate enough power to supply around 2,000 homes. They also helped to establish the Port of Blyth’s reputation in the offshore energy sector as well as highlighting the ORE Catapult‘s value as a testing ground for offshore construction.
The number of towers being decommissioned could rise after generous government support programs for the first wave of wind farms end in 2020. Rising maintenance costs and lower power output increase arguments to take them out of service and replace them with newer, more effective turbines.
According to Jonas Pagh Jensen of Siemens Gamesa Renewable Energy, which produces wind turbines and constructs wind farms, said, “Every customer is obliged to make a plan [for] what they intend to do in 20-25 years’ time when the turbine is expected to come down.”
For wind farm operators, there are several options as to what to do with the particular site and redundant equipment.
UPGRADE EXISTING SITE
In the case of the site, they can replace existing equipment with more modern devices, since they already have the required operating and planning approvals, including being connected to the grid. Since a modern wind turbine produces 180 times the electricity at half the cost of one built 20 years ago, according to the New Zealand Wind Association. The turbines themselves have also changed. In the 1980s, a wind tower stood about 20 meters tall, its blades spanned about 17 meters, and it had a capacity of about 75 kilowatts of electricity. A modern tower can stretch more than 100 meters tall, with blades that span 126 meters and a capacity of 7.5 megawatts — enough to power about 3,000 households. One of the world’s largest rotors has a diameter of 164 meters. Its 82-meter blades correspond to the wingspan of an A380 airplane and it produces some 9.5 megawatts of power.
SELL REDUNDANT EQUIPMENT
As for the redundant equipment there are two main options, these are placing the equipment on the second hand refurbished market. There is a well-established market, in former Soviet Union countries, southeast Europe, Latin America and Asia. For instance Dutch wind BV, a Dutch company based in Amsterdam, are brokers who specialise in selling used wind turbines. They source the wind turbines from around the globe. They sell a whole range of refurbished second hand wind turbines range from 80 kW to 3.6MW including popular brands such as Vestas, Enercon, Nordex, GE, Gamesa, NEG Micon, Lagerwey, AN Bonus / Siemens, Micon, Nordtank and many more. Currently most used wind turbines for sale are found in Germany, Denmark, the UK, Italy, the USA and The Netherlands. Amongst the brokers involved in the buying and selling of second-hand wind turbines are companies like Green Energy Wind in the UK, Dutchwind in Holland, and Sukumar Trading And Service Company in India. Often such brokers will work with purchasers of second-hand equipment to refurbish, service, re-install and start-up (commissioning) used wind turbines.
DUMP REDUNDANT EQUIPMENT
But resale market options for outdated wind generating equipment could change thanks to rapid technological improvement and as more wind power is added. “From year to year, more wind plants are being dismantled, and not every plant finds a secondary market,” German wind association BWE said in a paper last year.
Burying the blades in landfills is increasingly difficult thanks to toughening EU waste rules. Countries should resort to waste disposal, including landfills and incineration only as “the least preferred option.” New rules agreed to last year are meant to boost recycling rates and reduce landfilling.
Europe’s wind industry says it’s unclear how a 10 percent landfill cap on municipal waste by 2030 will affect industrial and construction waste but concedes that disposing waste through landfills or incineration without energy recovery are the “least favoured” waste treatment methods. Everything, except for rotor blades, is very well recyclable” — Michael Schneider, spokesman for Remondis.
Wind tower foundations are made of concrete and steel. Towers tend to be steel. The nacelle — the casing atop the tower — contains gears, the drive shaft, generator and transformer (containing oils and lubricants) made of a mix of steel, iron, copper and silica. In total, about 80 percent of the complete installation can be recycled, according to the German industry lobby group Bundesverband WindEnergie.
The turbine blades, however, are another matter. They are designed to be very light and very strong, able to withstand enormous forces without bending and breaking. To do that, blades are made from either reinforced carbon or glass fibre, combined with polyesters and thermoplastics. That strength comes at a price — such materials aren’t designed to be easily recycled.