Top 5 overall multiannual capacity factor
- Horns Rev 2: 48.18% (2010+2011)
- Rønland: 44.07% (2002-2011)
- Hywind Demonstration: 43.43% (2010+2011)
- Horns Rev 1: 40.88% (2003-2011)
- Samsø: 39.88% (2003-2011)
Global offshore wind production data is now accessible at LORC Knowledge. Last year, offshore wind farms exceeded the commonly expected capacity factor of 40%, as shown by newly released production data.
By Mads Kromann Larsen and Tea Tramontana
The online resource LORC Knowledge now provides data on the actual energy generation output and capacity factors from 70% of all global offshore wind farms. The world premiere is part of a greater update of the online knowledge center and shows that 2011 was a great year for offshore wind.
In terms of production, Horns Rev 2 in Denmark came in as number one in 2011 with an actual production of 911.03 GWh from the installed 209.3 MW, yielding a capacity factor of 49,69 %. Rødsand 2 also in Denmark generated 833.47 GWh from its capacity of 207 MW, while Thanet in England “only” managed 823.88 GWh despite it having an installed capacity of 300 MW. Some people might ask: “what about Walney?”, being one of the biggest sites in the world with 2 x 183.6 MW. But Walney 2 did not produce during the entire year of 2011 – and LORC Knowledge actually also counts Walney 1 and 2 as two individual sites, each having its own substation.
12 sites performed excellently
Looking into the capacity factor, which is the ratio of the actual output and the maximum potential production (assuming that the wind turbines were generating at full capacity 24 hours and 365 days a year), the data shows that two sites had an impressive capacity factor of over 50%. These were Alpha Ventus with a capacity factor of 50.8% and the floating test turbine in Norway, the Hywind Demonstration, with a capacity factor of 50.13%. Ten other sites had capacity factors over 40% in 2011. The European Wind Energy Association, EWEA, uses an expected capacity factor of 40% for offshore wind farms, which is a commonly accepted target when calculating cost of energy. Looking into the historical data you will find that offshore wind farms have had an overall capacity factor of 34% since the first offshore turbine was installed in Vindeby in Denmark back in 1991. The average capacity factor of 2011 was 36.33%. The main explanation for this increase is the fact that newer generations of wind turbines have larger swept areas compared to the rated power which allow them to make efficient use of weaker winds.
LORC Knowledge is the first online site in the world to present production data which is gathered from a wide range of primary sources in the energy sector. The countries covered by LORC Knowledge in relation to production data are currently: Denmark, Finland, Germany (with the exception of two single test turbines at Hooksiel and Breitling, which both lack production data), Ireland, Norway, Sweden and United Kingdom. LORC Knowledge is trying to collect the remaining data from Belgium, China, Japan, Netherlands (where Egmond aan Zee is currently covered with historical data but no production data from 2011), Portugal and South Korea.
All data is presented in the Offshore Wind Farms Map on LORC Knowledge: http://www.lorc.dk/offshore-wind-farms-map
Offshore Wind Farms Map, the updated version
The online Offshore Wind Farms Map covers all offshore wind farms in commission and under installation. Approved projects will be added in a future release. A new ‘submit project feature’ also allows you to add new projects as a user.
The new version 2.0 of the Offshore Wind Farms Map has more data of a better quality and optimized usability. Among other things, you will experience the addition of graphic elements showing the layout of each wind farm and a brand new datasheet layout. Up to seven images and graphics are added to each datasheet, including wind farm photos, turbine layouts, inter-array and export cabling, turbine image and power curve, and foundation image.
When you make a search, the system will guide you from the search query to the exact match in the datasheets. The system will automatically expand the categories and highlight the entered search term(s). The enhanced use of dropdowns in normal search options will allow you to quickly gather lists of all sites by countries and with a specific turbine model, drive train or support structure. The feature can be used in combination or individually as you prefer.
A lot of new information has been added and the level of detail has been enhanced for higher relevancy and precision, such as the possibility of getting an overview of the electrical transmission from the offshore wind turbine to the onshore grid. You can discover the voltage levels, AC and DC, and get information about the cables used. The addition of power curve data for Siemens wind turbines is another example.
A new feature provides instant overview with the current development of offshore wind farms worldwide. It provides a simple entry to key statistics such as: “how many sites are commissioned and under construction”, “how many MWs are installed in each country” or “what are the leading turbine manufacturers and most installed turbine models”.