Statistics on wind turbines in Denmark

Photo by @thomasreaubourg on Unsplash

Here you'll find various statistics on wind turbines in Denmark. All figures below are interactive with data as of January, 2022. Most figures are updated regularly. Expect monthly updates with approximately one month delay. You can read about the open data sources here.

Contents

  1. Number of turbines and installed capacity over time
  2. Turbine age and survival rate
  3. Size of turbines: height and rotor radius
  4. Annual capacity factors
  5. Higher resolution capacity factors
  6. Wind power share of total power generation
  7. Municipality statistics: distances to and number of turbines

Turbines over time

In this section there are three figures showing data for onshore, offshore and all turbines:

  1. Number of installed turbines over time
  2. Installed capacity over time
  3. Capacity per turbine over time

The first onshore turbines was installed in 1977 and the first offshore turbine in 1999. Since then the number of turbines have grown significantly. Note that whenever a turbine is decommissioned it's subtracted from the numbers shown in the figures.

Today there are approximately 10 times more onshore turbines than offshore turbines. However, the difference in installed capacity (second figure) is now less than a factor of 3 because of the very high capacity per turbine for offshore turbines as you will see in the third figure.

We know the specific dates of commissioning/decommissioning for each turbine, so if you zoom in on the figures you'll notice there is a data point for every single day!

Turbine age

Here we look at the age distribution of all decommissioned turbines and for how long turbines survive after being installed.

The average age of the 3442 decommissioned turbines is 17.9 years. The longest serving turbine was in service for 40.07 years and the shortest was in service for just 24 hours.

The figure blow shows a histogram of the ages. Most turbines are in service for 15-20 years with a few lasting as long as 40 years! Note that these numbers represent decommissioned turbines and thus are not representative for the expected lifetime of currently active turbines.

The first turbine registered in Denmark was commissioned on December 15, 1977 and was in service for 25 years. The oldest turbine registered in Denmark was commissioned on February 14, 1980 and was in service for 40 years! Long lifetimes in both cases.

The figure below shows the survival rate of turbines for each year of installation. Each line starts at the number of turbines that were installed during that year and decreases over time as those turbines are decommissioned. The lines are colored by decade of installation. We see that most of the turbines installed in the late 80's were decommissioned rapidly during 2002 (orange lines). Many of the turbines from the early 90's have been decommissioned between 2000 and 2015, while most of the turbines from the late 90's are still active. Turbines that were installed in 2000 or later are mostly still active about 20 years later.

Tip: Double-click a decade in the legend on the left in the figure below for increased legibility.

Size of turbines: height and rotor radius

We saw in the first section that the capacity per turbine has increased over time. But how large are the turbines and how has their size increased over time?

The oldest turbine registered in Denmark was commissioned on February 14, 1980. It had a capacity of 22 kW, a hub height of 18 meters and a rotor diameter of 10 meters. In comparison the largest current turbine registered in Denmark was commissioned on December 9, 2021. It has a capacity of 14,000 kW, a hub height of 160 meters and a rotor diameter of 122 meters!

In the figure below we show the development of average hub height and rotor radius over time. For each year we show the average values of all turbines installed in that year. The hub height is the distance from the base of the turbine to the center of the rotor.

The numbers seem suspiciously low for the two turbines installed in 1977, but have since grown steadily. The two dips around 2007 and 2015 coincide with periods of low installation of offshore turbines, which tend to be significantly larger than onshore turbines.

For a detailed study of the development of turbine sizes and power rating, see this recent paper.

Annual capacity factors

A capacity factor, in some industries called load factor, is:

The ratio of the net electricity generated, for the time considered, to the energy that could have been generated at continuous full-power operation during the same period. (source)

In simple terms: an annual capacity factor of X% means a turbine is generating electricity at an average of X% of its capacity every hour of the year.

The capacity factor of a wind turbine is an important metric for investors: higher capacity factor means higher power output and higher return on investment. For a thorough study of power output and declining capacity factors over a turbine's lifetime, see this open source research article.

In this section there are four figures:

  1. Annual power production for onshore and offshore turbines
  2. Average annual capacity factor for onshore and offshore turbines
  3. Annual onshore capacity factors split by year of installation and colored by decade of installation
  4. Annual offshore capacity factors split by year of installation and colored by decade of installation

In all figures turbines are included for every whole year they have been producing. That means a turbine installed in one year is counted from the following year onwards and excluded for the year that it's decommissioned.

The first two figures show the annual power production and average capacity factor for onshore and offshore turbines separately. The capacity factor for onshore turbines have been fairly stable between 20-30% for several decades. For offshore turbines there was a significant jump in 2002 and since then it's been above 40% on average. Offshore wind turbines are expected to have higher capacity factors than onshore wind turbines for two main reasons: 1) typical wind speeds are higher at sea than on land (no trees and buildings to slow it down), and 2) they reach higher in the atmosphere where the wind tends to be more stable. In this figure it's not possible to distinguish the contribution to the average capacity factor from aging and new turbines. More on that in the following two figures.

The two figures below show the annual average capacity factor split by year of installation. In an attempt to make it easier to get an overview, each line is colored by the decade of installation. A general result for both figures is that more recently installed turbines initially have a higher capacity factor. For almost all of the lines shown the capacity factor decreases slowly over time. That is consistent with this open source research article (same as linked above), which, among other results, found that "performance decline with age is seen in all farms and all generations of turbines" and "onshore wind farm output falls 16% a decade, possibly due to availability and wear".

The numbers look suspicious for the onshore turbines installed in 1977 and 1978. All we can say is that's how the numbers were reported. Only whole years of production are included. So turbines installed throughout 2020 will appear in 2022 when production data for all of 2021 is reported.

Tip: Double-click a decade in the legend in the figures below for increased legibility.

Higher resolution capacity factors

In this section we explore average capacity factors in higher temporal resolution using production data from the ENTSO-E Transparency Platform together with the time series of installed capacity per day from the first section above. These figures are updated less frequently.

The four figures in this section show:

  1. Annual average capacity factor
  2. Monthly average capacity factor
  3. Daily average capacity factor
  4. Hourly average capacity factor

Not surprisingly the variation of the capacity factor increases with increasing temporal resolution. At an hourly resolution we see hours of close to zero production and hours at close to 90% capacity. This is a very different picture than the flat pattern of 20-30% for annual capacity factors. It highlights the challenge of keeping the electricity system in balance with increasing shares of variable renewable energy sources.

Tip: Remember that the figures are interactive, so you can zoom in on periods that interest you.

Wind power share of total power generation

Here we look into how much electricity is generated from wind power and how much it contributes to the total power generation.

The first of the three figures below shows how much power is produced from wind power per year from 6.6 TWh in 2005 to now more than 16 TWh.

The second figure shows the wind power share of the total annual electricity generation. In 2005 it was just below 20% and now it's well above 50%. The third figure shows the share of wind power on a monthly basis. Here we see a cyclic variation with lows during summer and highs during winter.

The data for these figures is updated less frequently than the turbine database.

Municipality statistics: distances to and number of turbines

In the table below you can compare between municipalities (every column can be sorted). We have calculated shortest, longest and average distance from turbines to addresses within each municipality. We also included number of turbines, installed capacity and number of inhabitants from here. Very small turbines with a capacity below 100 kW have been excluded as these are usually placed on a property.

The distance from a turbine to nearest house has to be at least four times the total height (hub height + rotor radius) as described here. Note that some of the distances in the table might not be accurate because not all addresses in the address database correspond to houses. The results have not been validated.

There are currently 21 municipalities with no turbines: Lyngby-Taarbæk, Furesø, Ballerup, Fredensborg, Rødovre, Frederiksberg, Vallensbæk, Rudersdal, Helsingør, Dragør, Gladsaxe, Herlev, Furesø, Egedal, Hørsholm, Brøndby, Ishøj, Tårnby, Glostrup, Gentofte, and Albertslund.

Kommune Shortest distance Average distance Longest distance Turbines Installed capacity [kW] Inhabitants
Skanderborg 339 698 1371 15 17010 61974
Herning 257 960 3782 101 126905 88917
Jammerbugt 204 920 2090 145 196660 38460
Horsens 263 493 720 5 3350 90370
Kalundborg 259 868 2149 68 81280 48681
Greve 729 842 1033 5 1260 50267
Tønder 290 1024 2849 226 161850 37587
Holbæk 335 1216 3147 60 59800 71297
Høje-Taastrup 323 323 323 1 850 50686
Læsø 1208 1208 1208 1 180 1806
Frederikssund 250 552 863 7 2800 45332
København 435 754 1164 12 10650 623404
Skive 197 639 1299 128 117615 46224
Norddjurs 272 993 2690 68 53860 37680
Stevns 292 1010 1492 19 11000 22782
Ærø 503 570 757 6 12000 6058
Viborg 249 951 2273 53 61410 97113
Nyborg 316 662 1136 37 28980 32042
Køge 272 619 1118 7 3950 60675
Fredericia 427 637 816 4 2250 51427
Ringkøbing-Skjern 286 1157 2751 241 484800 56930
Roskilde 290 646 1100 12 6233 87577
Haderslev 391 834 1929 54 39170 55857
Hedensted 274 630 1077 39 27630 46747
Faaborg-Midtfyn 269 775 2800 27 16480 51809
Solrød 280 342 403 2 600 23065
Favrskov 310 749 1676 50 34805 48374
Mariagerfjord 278 887 2226 53 74315 42055
Svendborg 177 680 1094 41 33680 58599
Brønderslev 171 1063 1869 44 91925 36370
Vordingborg 210 766 1870 38 17595 45816
Sønderborg 276 854 1505 18 13850 74561
Frederikshavn 264 750 1408 48 48360 59987
Randers 285 1095 3346 127 190500 97909
Halsnæs 367 546 732 7 4150 31271
Faxe 185 962 2171 31 32864 36513
Aalborg 294 1125 3460 151 157325 215312
Gribskov 575 575 575 1 600 41195
Lolland 207 872 1700 187 275045 41615
Odder 482 914 1666 12 15660 22675
Odense 453 814 1172 15 11130 204182
Thisted 178 741 2937 160 151760 43660
Næstved 195 949 2699 72 68610 82991
Varde 306 820 1645 78 96340 50129
Holstebro 316 1271 3020 131 211600 58504
Slagelse 212 701 1331 87 43570 79073
Samsø 243 735 1069 12 11150 3684
Syddjurs 190 867 1800 24 18600 42768
Sorø 383 652 1023 6 6800 29834
Lejre 220 862 1538 14 6375 27775
Hvidovre 269 340 389 3 1980 53416
Esbjerg 249 988 2290 49 79680 115652
Ringsted 461 771 1392 13 8990 34725
Guldborgsund 164 774 2182 108 58395 60930
Ikast-Brande 179 745 1595 46 67260 41282
Kerteminde 480 827 1624 16 24950 23773
Bornholm 348 765 1364 33 36580 39572
Middelfart 334 620 910 21 13470 38553
Aarhus 351 708 1168 19 11280 345332
Aabenraa 228 818 1622 79 83555 59035
Fanø 438 623 807 3 1980 3404
Allerød 582 1028 1267 3 2725 25646
Rebild 348 975 2687 35 48375 29916
Vejen 289 743 2087 77 55550 42863
Struer 240 792 1827 50 46815 21143
Odsherred 539 827 1370 11 4610 33122
Vejle 196 589 1261 53 53440 114830
Silkeborg 335 646 1449 18 15810 93054
Langeland 288 622 1419 49 43565 12560
Hillerød 360 704 991 6 3960 50998
Kolding 283 787 1767 39 34280 92893
Billund 379 817 1965 55 92425 26629
Assens 314 594 1169 44 31025 41212
Lemvig 283 924 2413 89 147300 19998
Morsø 202 811 1892 83 77785 20403
Hjørring 177 756 1541 121 121570 64665
Vesthimmerland 205 1007 5046 114 141685 37121