- Noises are temporary and will not be heard during normal operation -

Essential testing at the new power station at Uskmouth is reaching a climax this week, according to owners Severn Power Limited. The twin gas turbines were fired successfully for the first time earlier this year, and now the company is testing the boilers which will generate steam to create electricity and test vital safety systems.

Severn Power Limited anticipates that the most intensive period of testing and temporary use of the bypass system will be completed by the end of this weekend. However, the overall boiler testing regime is likely to run for about another three weeks, during which time there may be occasional peaks of noise. These are unlikely to last for more than an hour or so and should only occur between 6am and 10pm at night.

The Severn Power Station is scheduled for completion by the end of 2010. When commissioned, it will be one of the most advanced and energy efficient gas-fired power stations in the UK and will be capable of generating up to 842 megawatts – enough electricity to meet the average needs of up to 1.5 million homes.

Ian Crummack, Director of Severn Power Limited, explained: “There are three main reasons for the testing that is currently under way. First and foremost is safety. We need to make sure that the plant and equipment will withstand the pressures and operate safely for the power station’s lifetime. This leads to the second reason, which is to protect our employees and visitors by making the site as safe an environment as possible.”

“Thirdly, we are assessing noise levels very closely so that we can identify exactly where we need to apply attenuation measures, so that the plant will not disturb local residents when it is operating under normal conditions. The company intends to invest approximately £2 million in noise abatement to make sure that the power station will be a good – and considerate – neighbour during its lifetime.”

In order to test the boilers, steam levels are being cycled from low to high pressure flow rates. There is some noise associated with these tests – mainly loud hissing noises – which reached a peak this week because both boilers were being tested at high pressure at the same time.

Says Mr Crummack: “We are aware that these peak noise periods may be a cause of disturbance or concern for some local residents. While we are taking every step possible to minimise any nuisance during this period, we must emphasise that the tests are absolutely critical to ensuring the safe and efficient operation of the power station and to making sure that noise is not an issue in the longer term. We would like to reassure everyone that the current noise levels are temporary and will not occur during normal operation of the plant.”

The technology being used at the Severn Power Station is known as a Combined Cycle Gas Turbine, or CCGT. This energy generating equipment is designed to be highly efficient because it uses a combination of heat from the gas turbines and steam (made using the hot exhaust gases from the same gas turbines) to drive the generator from both ends. Effectively, this creates a turbo-charging effect.

This equipment must be carefully tested before the power station can be brought into full operation. At present, the boilers are being tested to check that they can generate high pressure steam at the right quality to use in the steam turbines. Any impurities in the steam could seriously damage the steam turbines; so when the testing begins, the steam is initially fed through a bypass system until it is clean enough to use. Noise is caused during these tests by the steam rushing through the bypass system and into an air cooled condenser, which cools the steam to water for reuse in the boiler.

People with concerns about the plant can call 0845 544 0967 for further information.