2008-09-04 - Innovative PASS MO switchgear will provide a temporary space-saving solution at Reading 132 kV substation
Iver Heath 66 kV substation will be constructed on stilts to ensure flood protection
Scottish and Southern Energy (SSE) has awarded two substation contracts worth a total of £24 million to an ABB and Balfour Beatty consortium. The consortium will design and construct two new indoor state-of-the-art GIS (gas insulated switchgear) distribution substations at Reading and Iver Heath, Buckinghamshire to replace existing outdoor AIS (air insulated switchgear) substations that are approaching the end of their service-life.
Building on the global success of ABB’s ENA approved PASS M0 hybrid switchgear, the Reading project will use this innovative approach to provide a temporary space-saving solution. This will free up substantial construction space so that the new GIS substation can be built within the very restricted space available within the existing site footprint.
Over 11km of 66kV and 132kV cables are to be installed at the two sites. The jointing work includes a number of XLPE to fluid cable transition joints to existing circuits which will draw on Balfour Beatty’s in-house capability and expertise in fluid-filled cable laying and jointing, together with associated civils works. The consortium’s planning and logistics capabilities will also play a key role during both schemes due to time and available working area restrictions.
These projects play a vital role in SSE’s plans to reinforce its distribution network in the south of England to ensure security of supply and provide additional capacity. SSE regards both sites as flagship projects and asked the consortium to deploy innovative, cost-effective solutions that will enable the new GIS substations to be constructed within the confines of the existing AIS sites.
PASS MO to provide vital construction space at Reading
The Reading site presents a particular challenge as it is already completely full with AIS switchgear that has to remain in service until the circuits can be transferred to the new substation. At first, it appeared that the only possibility would be to extend the site onto the local, heavily wooded, green space to offer the additional room needed for the construction of the new indoor GIS building. However, extending the site would have involved considerable planning time and expense and significant project delays.
ABB has developed an innovative alternative solution that uses its modular PASS MO switchgear as a temporary measure to provide additional space to enable the new GIS building to be built within the existing site footprint. Firstly, ABB will dismantle the generator circuit breakers that used to serve the old North Earley power station, which was demolished some years ago. This will free up just enough space for ABB to install its PASS MO modules which will take over the operation of the AIS circuits at the far end of the site.
Once Balfour Beatty has installed all the new cable circuits and the AIS circuits have been transferred, ABB will dismantle the AIS switchgear and that will make room for the new GIS building. When complete, the new 132 kV substation will comprise 13 bays with space for four future circuits. After all the circuits have been transferred to the new substation the PASS MO modules will be removed.
Work on the Reading site has already started and it is due for completion in December 2010.
Fast-track project for Iver Heath
The construction of the new 66 kV substation at Iver Heath is more straightforward, since there is already room available within the existing site area. In this case the challenge is that SSE needs the new GIS substation on-line as quickly as possibly, so the ABB and Balfour Beatty consortium is placing a major emphasis on planning and logistics.
The key feature of the Iver Heath project is that the site is on the floodplain of the River Colne, so the building has been constructed on stilts to ensure protection against the predicted level of a once in 100 years flood. When complete, the new substation will provide 19 bays, with space for six additional future circuits.
ABB Background
ABB (www.abb.com) is a leader in power and automation technologies that enable utility and industry customers to improve their performance while lowering environmental impact. The ABB Group of companies operates in around 100 countries and employs about 115,000 people.