October 2017

alpha ventus surpassed 30 gigawatt hours in October

During October 2017, alpha ventus fed 30.178 gigawatt hours (GWh) of power into the German grid, equivalent to 503 full load hours or 21 days of continuous energy production at maximum load. With two European windstorms – Xavier and Herwart, both extratropical cyclones – October showed even for autumn an extreme amount of wind which is rarely recorded in the German Bight. Since the commissioning in April 2010 alpha ventus reached only during five winter months more than 30 GWh: December 2011, January 2012, January and December 2015. The record-holding month is December 2011 with 36.738 GWh generated power (612 full load hours or 25.5 days of continuous energy production at maximum load).

From 2011 to 2016, alpha ventus fed an annual average of 242.3 gigawatt hours of power into the grid (or 4,038 full load hours), equivalent to the annual power consumption of approximately 69,230 average households (3,500 kWh) in Germany.

The power generated from August 2009 (the first feed-in) to October 2017 accumulates to 1.84 terawatt-hours of electricity. Alpha ventus is expected to surpass the mark of 2 terawatt hours in 2018.

A joint project of the utilities EWE, E.ON and Vattenfall

alpha ventus - the first German offshore wind farm

alpha ventus was commissioned as the first German offshore wind farm in April 2010. The construction phase proper was a brief 12 months, a pioneering feat in a location with a water depth of about 30 metres and a distance from the coast of 60 kilometres.

Reflecting its role as offshore test site, alpha ventus operates two types of wind turbines with two different foundation designs. The rated output of the wind farm is 60 MW. Experience gained in construction and operation is an input into the further development and expansion of the German offshore wind power industry.

The alpha ventus offshore wind farm is a joint project of the utilities EWE, E.ON and Vattenfall. These three energy providers established the “Deutsche Offshore-Testfeld und Infrastructur GmbH & Co. KG” (DOTI) operator consortium specifically for this purpose in June 2006. The shares distribution is: EWE 47.5%; E.ON and Vattenfall each 26.25%. The total investment is Euro 250 million with the BMU (German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety) providing Euro 30 million of funds.

Number of units	12
Total capacity	60 MW
Energy yield 2011-2016	242.3 gigawatt hours per annum (= annual energy consumption of about 69,230 households)

Technical data Senvion 5M (REpower)

Rotor diameter	126 m
Height of hub	92 m
Total height above seabed	185 m
Rated output	5 MW
Speed	6.9 - 12.1 rpm
Cut-in wind speed	3.5 m/s (= force 3)
Rated wind speed	13.0 m/s (= force 6)
Cut-out wind speed	30 m/s (= force 11)
Weight of nacelle without rotor and hub	290 t
Weight of nacelle with rotor and hub	410 t
Jacket foundation	Weight of steel: 500 t
	tower: 210 t

Technical data Adwen AD 5-116 (AREVA Wind resp. Multibrid M5000)

Rotor diameter	116 m
Height of hub	90 m
Total height above seabed	178 m
Rated output	5 MW
Speed	5.9 – 14.8 rpm
Cut-in wind speed	3.5 m/s (= force 3)
Rated wind speed	12.5 m/s (= force 6)
Cut-out wind speed	25 m/s (= force 10)
Blade tip speed	90 m/s (= 300 km/h)
Weight of nacelle without rotor and hub	200 t
Weight of nacelle with rotor and hub	309 t
Weight of steel in tripod, tower, nacelle	1,000 t
Tripod	Weight of steel: 700 t; Height: 45 m; Piles: 35 – 45 m

Technical data transformer station

30 m	elevation of helipad
25 m	elevation of main deck with crane, substation control and protection (I&C) / switchgear plant / neutral earthing transformer, fire extinguishing system, MV and LV systems, emergency generating set, MVAr throttle / 110 kV GIS (gas-insulated switchgear) system (AREVA)
21 m	cable deck with workshop, equipment room, lounge, diesel tanks, emergency generating unit, cable bench and oil sump
Cable deck and main deck	110/30 kV transformator 75 MVA (AREVA)
Jacket foundation	approx. 750 t
Foundation piles	35 m long, 2.7 m diameter, 100 t apiece
Position	N 54°00', E 6°37.40'