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Case Study Photos
  • Greater Gabbard windfarm, Suffolk
  • The housing ready to dispatch in our internal installation bay
  • The housing on its substructure on site
  • Internal view of the housing prior to the switchgear being installed
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Location: Greater Gabbard windfarm, Suffolk

Storage Use: Housing for 3 switchgear and transformers


A huge new windfarm is being constructed off the coast of Suffolk in a joint venture between Scottish and Southern Energy and RWE npower renewables. The 140 wind turbines that will make up the Greater Gabbard windfarm are being manufactured by Siemens and will generate around 1,900GWh of electricity per year – that’s enough to power more than half a million homes.

As part of the onshore facility that will receive the electricity generated by the turbines, Siemens needed to install switchgear that would convert the electricity to 33kVA for transfer to the National Grid. It also needed to provide transformers to supply low-voltage power to other equipment on the site. To house this equipment in three areas of the site, Siemens
needed to source three high-quality, robust and secure equipment housings.


Barry Greenwood, Senior Project Engineer at Siemens, says: “The timescales we were working to meant that bricks and mortar construction was not an option, so we investigated suppliers of modular equipment housings. We chose Portastor to supply our buildings because of the quality of its products and the excellent testing facilities at its manufacturing site. These meant we could comfortably and conveniently test all of our installed equipment in the Portastor buildings away from the operational site, before they were despatched.”

Portastor provided a full turnkey package for Siemens, from design to installation. The company began by working with Siemens to develop the optimum design and layout for the equipment housings. The buildings were then manufactured under carefully controlled conditions at the dedicated Portastor manufacturing facility and fitted out to Siemens’ specifications. Once installed, the equipment was tested by Siemens before the complete integrated buildings were released for delivery to site.

Each of the three 11 x 3.2 metre buildings houses six switchgear panels, a transformer and an automatic voltage regulator. The switchgear and transformers are separated by special IP-rated mesh enclosures. To accommodate the large equipment, the buildings

feature wide high-security double doors with a sealed seven-point locking mechanism, which can only be opened from within the building. Additional smaller double and single access doors on each building are also designed for enhanced security, with anti-jemmy bars to prevent forced entry.

Portastor installed the galvanised steel substructures for each building at the Greater Gabbard site. The substructures raise the buildings 1.5 metres above the ground, enabling incoming cables to be fed easily into the building without the need for time-consuming and expensive excavations. The 1.5 metre clearance also allows easy access underneath the buildings and protects the sensitive equipment from flooding. The substructure is enclosed by steel panels and a door to prevent unauthorised access.

The buildings are fitted with ventilation systems to maintain a constant airflow and prevent the equipment from overheating. Portastor even provided steel platforms and steps for safe and easy access to the buildings. All three buildings were installed at the Suffolk site by experienced Portastor teams on the agreed dates.

Barry adds: “We are very happy with the new buildings, which meet our requirements exactly. Portastor took responsibility for the whole project, and managed everything expertly on our behalf. The service we received throughout the project was very good and Portastor was always very quick to respond to any queries or modification requests from us.”

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Telephone: +44 (0)845 60 41 443

“We are very happy with the new buildings, which meet our requirements exactly. Portastor took responsibility for the whole project, and managed everything expertly on our behalf. ”
Barry Greenwood,
Senior Project Engineer,