That seems like a long time ago, but today, the aging plant is still an important source of electricity and heat for Hamburg, Germany. Time has not been kind to Wedel. When the German newspaper Der Spiegel visited Wedel eight years ago, it noted that the plant was due for an update. Wedel was operating at a 37 percent efficiency, almost 10 percent less than the industry norm.
But rather than give the plant a burial and go through the long and costly process of building a new plant, Vattenfall, the German utility that owns Wedel, has decided to give it a second life. The company recently tapped GE Power Services to refurbish and extend the life of two Siemens steam turbines inside—the beating heart of the power plant.
GE has been refurbishing equipment for Vattenfall’s power plants in Germany for 25 years, but Wedel will be one of its most significant renovations to date. “It’s one of the biggest contracts we ever won in this business for Germany,” says Christian Pohle, a manager of power-plant services for GE Power.
Upgrading a pair of decades-old turbines is no easy task. First, you have to strip everything away, Pohle says. “The rotors get removed, the bearings, the ceilings, the control units. The machine gets naked at the end.”
By taking the 4-meter-long turbines apart, GE can find any hidden issues that need to be addressed to ensure the turbines continue to work optimally for years to come.
Understanding the complexities of steam turbines is an art in itself. These powerful machines—which can be as long as four cars—are modern equivalents of the piston-pushing steam engines of the 1800s and are still based on the principles laid out in the first 1884 blueprints of inventor Sir Charles Patterson: Steam turns blades at incredibly high speeds in order to generate electricity.
GE will be building new blades for the turbines that will perfectly fit the demands of the refurbished Wedel. “These are forged blades,” Pohle says. “You cannot buy them in a supermarket.” Around 60 people from GE will be working on the refurbishment project at Wedel, Pohle adds.
So why go through the trouble to upgrade such old steam turbines? There are plenty of reasons. For one, new power stations (such as Vattenfall’s new plant in Hamburg’s Moorburg neighborhood) can cost more than €2 billion to build. Refurbishing Vattenfall will cost significantly less, according to Pohle.
The process of “re-powering” older power plants also means large parts of the station can continue running and generating heat or electricity during the upgrades. There’s no need for tearing the old structure down, and getting work permits is also easier.
Wedel is one of a series of European plants that GE is refurbishing this year. In June, the company used software and new equipment to bring online a decommissioned power plant near Turin, Italy. GE says the technology now allows managers to respond to the grid when it needs more power, simulate grid conditions, make the plant available and respond quickly in a profitable way.