An overwhelming statistical fact throws light on the evolution of wind turbines, according to the Danish Energy Agency Energistyrelsen (and its associated 4 decades of statistical data), in charge of following up on the development of the energy and supply sectors in the country, and its survey of turbine inventory.
Denmark was a pioneer in developing commercial wind power during the 1970s, and today a substantial share of the wind turbines around the world are produced by Danish manufacturers such as Vestas and Siemens Wind Power along with many component suppliers. So, it is not by chance that old-tech turbines have shown such reliability through almost 4 decades, with the oldest 48 still going strong from the late 1070s despite having a combined capacity of only 2 megawatts. Compare that to the standard Vestas V164 turbine introduced in 2013 with a capacity of 7 — 9 megawatts (MW). That’s a 200-fold improvement!
With the advent of the updated turbines, the older ones are meant to be decommissioned in larger numbers should the tendency continue. In 2017, a total of 220 turbines were connected to the grid with a combined capacity of 373 MW, while a total 174 turbines with a total capacity of 98 MW we deactivated. It means with the added 46 turbines an overall 275 MW was produced. That’s an average of 6 MW per turbine accomplished nowadays versus the 1970s´pioneers 25 kW.
By the end of 2017, Denmark had a total of 6,157 turbines operational with a total capacity of 5.5 GW generating a total of 14,772 GWh of electricity. With no further technological update, and maintaining the average of 6 MW per turbine, it would mean that a total of 917 turbines would suffice to preserve 5.5 GW of capacity. It is assumed that 10 GW of total capacity will be the goal in the country, which means some 2,000 turbines is enough, or one-third of today’s number.
According to chief consultant Kristine Grunnet from Danish Energy, as per an article in DR News on behalf of the energy companies in Denmark, more than half of the wind capacity on land will be decommissioned by 2030. She states:
“While many want to have the turbines placed far out to sea, it is still important to have turbines on land. We need a lot of renewable energy, and wind turbines [on land] are simply the cheapest right now, supplying the cleanest energy for our money. We actually believe that we can restore the beauty of the Danish landscape by replacing a lot of turbines with fewer, slightly bigger, but also more efficient ones. When we set up one new turbine, it can replace up to six of the old ones.”
With fewer and more efficient turbines, wind power units can be placed at chosen locations where nature blows steadily and strong, away from residential areas, thus avoiding long-standing claims about turbines changing the surrounding natural landscape and introducing low-frequency noise.
Since 1977, 9.387 turbines have been installed in Denmark and 3.230 decommissioned. Of the 6.157 turbines left 23.6% are on land (5.649), and 8.6% at sea (508).
For Denmark wind power at sea started back in 1991, with just 11 turbines each of 500 KW capacity, delivering 26 years of work before being dismantled just last year. Most importantly is the fact that the first turbines manufactured for operation at sea were twenty times more robust than the first turbines built for use on land in 1977.
The evolution of wind power in the last few decades has been impressive; however, a factor that will shape the energy market in Denmark and most everywhere else is the potential for cheaper solar power. Notwithstanding, wind power continues to be the energy choice for countries with high winds, such as Denmark. How well other alternative energies will ensure a smooth transition from fossil-fueled economies to green energies remains to be seen.