A £13 million project to improve electrical efficiency at Vale Power Station, Guernsey is currently underway.
The project comprises the installation of a Wärtsilä 18V46 engine diesel generator to supplement the existing diesel generators which are currently in use at the power station. The project is being implemented and funded by Guernsey Electricity Ltd and is currently scheduled for completion in February 2013.
Work began on the site in June 2012, with Wärtsilä Finland OY as the main contractor and Tom Woodford of Guernsey Electricity Ltd as Project Manager.
Commenting on the implementation of the project, Tom Woodford said:
“At Vale Power Station we currently have five slow-speed engines and three gas turbines and we are adding to this capacity with the installation of a new 17MW Wärtsilä generator. The generator is being installed in order to cope with increasing demand on the island and also to prepare for the eventual retirement of the site’s existing engine fleet.
“There is a large civil works programme to this project and this is something which makes this project a little more complicated than it would first appear. Although the power station was designed to accommodate two slow-speed engines the facility wasn’t designed to accommodate an engine of this shape, so we had to modify the foundations to fit this new generator and potentially fit another generator in the future.
“In effect, we had a foundation designed for a 14MW engine, but now we are able to accommodate two Wärtsilä 17MW engines, meaning we have a much larger capacity on the exact same footprint.
“It was always part of the plan to install another engine should it be needed. The second engine will arrive in the foreseeable future, quite possibly within the next five years.”
To date work on modifying the new foundations has been completed, which involved the use of approximately 600 tonnes of concrete and 35 tonnes of steel. Mechanical and auxiliary equipment has also been erected on the site and the new diesel generator has been installed.
“There are quite a few interesting features about the project, but one of the most interesting aspects for me was the delivery of the new diesel engine. When the engine was delivered it arrived as a 300 tonne, fully assembled engine, which we believe made it the heaviest single load ever shipped to Guernsey.
“The engine was manufactured at Wärtsilä’s factory in Trieste, Italy and was transported to us by heavy lifting and transport company Mammoet. The engine was loaded onto a special variable deck barge for delivery directly into St Sampsons harbour – which is not normally used for this type of cargo. Once it arrived the deck of the barge was raised to match the height of the quayside so that the engine could be driven off. The quayside needed to be strengthened to take the weight of the engine, using a temporary structure designed by Mammoet and our own structural consultants Dorey, Lyle and Ashman. The delivery of the machine was certainly quite unusual.”
“This project is extremely important for Guernsey Electricity Ltd. We maintain a fleet of diesel generating plant to supply part of the island’s electricity demand and this work will allow this to continue.
“The diesel plant has a vital role to play on the island of Guernsey as the demand for electricity is met either by our own generating plant or by importing power through a submarine cable from France.
“We see this project as the best way to maintain the security of our electricity supply for all of the residents of Guernsey.”
This major project for Guernsey is being undertaken with the support of several local contractors including Geomarine, Guernsey Electricity Contracting, Marine and General Engineers and Scaffolding Services.
Guernsey Electricity Ltd Commercial Contracting Manager, Vincent Smith, said:
“Guernsey Electricity Ltd is a commercial division which operates on commercial terms so this project is very important. Not only does this project highlight that our own commercial division is able to compete with similar companies for bidding on a project of this size, but also our involvement has secured work for ten members of staff.
“Work in Guernsey is a bit tough at the moment, so it is great that local people can be involved with what is in essence a very complicated project for the island.
“The work is also quite challenging, as this is an existing power station site where there are live cables, pumps and an engine that is already in operation.”
“In addition, not only is Guernsey Electricity Ltd a local company but we are also employing a number of other local companies to help us complete some aspects of the project, such as welding and transportation. We can’t solely use local resources, but we are attempting to use as many as possible to keep this as a local project.”