ISO 55001, 45001 and 27001

The success of this story lies on strong involvement of both the management team and the team of Gemini that embraced this target. The result is a QMS system that helps the Gemini team to stay focused on the most important aspects of Gemini business and prioritize the day-to-day business accordingly. It helps Gemini to be on top of potential risks and opportunities following a risk-based decision-making approach, which leads to making better-informed decisions.
After the successful implementation of the QMS system under ISO 55001 in June 2018 and pushed by the ethos of continual improvement at Gemini and their “safe by choice” culture, the team successfully implemented an ISO 45001 certification for Health and Safety, fully aligned with the ISO 550001 systems. Gemini received ISO 45001 accreditation in November 2019. Both systems are now integrated into a full Integrated Management System (IMS).


‘First single purpose offshore wind park project

to achieve this accreditation.’

Driven by the aim to continuously improve the organization and its integrated management system, Gemini prepared and applied for ISO 27001 certification at the beginning of 2023. After the successful certification for ISO 55001 and 45001 in 2018
and 2019, the certification for Information Security was approved by LRQA on
16 March 2023. Gemini’s commitment to “Safe by choice” is thus also reflected
in the secure and safe management of information.

On this page you find information on the key elements of the Gemini Wind Park. Some general facts are introduced, as well as a sum-up of the main figures of the project. The introduction concludes with an important aspect of Gemini: the ecological monitoring. At Gemini, preserving the flora and fauna in the North Sea and the Waddenzee is highly valued. The monitoring helps in keeping this aspect under close scrutiny.



General facts

To get an idea of the size of Gemini

we have made a drawing of the wind

park and projected it on a map of the Amsterdam city centre.


Gemini is one of the world’s largest offshore wind parks, both in terms of size and production.
Gemini is located in the Dutch North Sea, 85 kilometres north of the Dutch coast
and is not visible from the shore. This location offers some of the highest and most
constant wind speeds on the Dutch part of the North Sea.
The construction of the Gemini Wind Park took place between 2014 and 2017.
The project was fully operational by 2017.
Four companies joined forces to create Gemini: Northland Power,
Siemens, Van Oord and HVC. To learn more about our current shareholders, visit
The Shareholders page.
The project provided over 500 jobs during development and construction, as well as an additional 75 to 100 operational jobs over the coming years.




Gemini in figures

600 megawatt production capacity

2.6 terawatt hour electricity generated per year

€ 2.8 billion project financing (loan capital and equity) pooled in record time

6 months to Financial Close - an unprecedented timescale for a project of this size

36 kilometres per hour - the average wind speed in the area

85 kilometres from the Groningen coast

68 square kilometres of wind park in the North Sea

28-36 metre water depth at the site of the wind park

5 years between obtaining the Water Act licence and the financial close in May 2014

24-36 months needed to complete the environmental surveys and obtain the required project licences

1.25 million fewer tons of CO₂ emissions per year because of Gemini

500 local jobs to be created during construction

1 land station has been constructed in Eemshaven

59-73 metres - length of the monopiles; each monopile has been adjusted to the installation depth required by the conditions at the various locations

7-11 centimetres - wall thickness of the monopiles; this varies to give additional support to the construction in areas in which the sea exerts most pressure

5-13 revolutions per minute - range of the nominal rotor speed

88.5 metres - height of the turbine hub above sea level

990 tons - lifting capacity of the crane on offshore installation vessel Aeolus

2 offshore high-voltage substations

5,000 tons - weight of a full cable carousel on installation ship Nexus

110 kilometres of export cable from each offshore substation to land (approximately)

33 - nominal kilovoltage of the thinnest infield cable (108 mm diameter) that connects the

turbines with the substations

230 - nominal kilovoltage of the thickest export cables (267 mm diameter) that can each

transport up to 75% of the electricity that Gemini generates.

450 turbine blades, each weighing 18 tonnes, to complete the wind park

1,347 tons - total weight of the heaviest installed turbine (including monopile, transition piece,

nacelle and rotor with blades)



Ecological monitoring

Gemini executes a research program which is aimed at monitoring possible ecological effects on marine life. This program started a few years before construction of the wind park and continues during construction and a number of years into operations. This monitoring program is specifically aimed at determining distributions and behavorial responses of birds, fish, seals and harbor porpoises in the area of the wind park site.



Offshore wind

A wind park needs wind in order to perform. This illustration shows where that wind can be found in the North Sea area. It makes sense: the further away from shore, the higher the average wind speed. The countervailing factor is the length of the export cables needed to convey the energy from the wind park onshore. The optimum for Gemini in this case was found in the area where winds reach an average speed of 10.2 to 10.4 metres per second.