American Hydro, a Wärtsilä company, as well as the owners and operators of hydropower plants know that the plant is only as powerful as the components within it. The output of any hydropower plant depends on the optimum performance of every single component. From the smallest seal to the largest runner, everything must work reliably and to its maximum capability. But nothing is eternal, and components wear and tear. New technical innovations enable more efficient and environmentally sustainable ways of operating the hydropower plant.
Keeping the components of a hydropower plant up to date with upgrade and refurbishment projects ensures that the owners and operators are getting everything out of their plants. This enables them to maximise the uptime of the plants, increase efficiency and reduce maintenance costs during the whole lifecycle of the plant. “Especially in the US, the ever-increasing average age of the hydro fleet and the price of electricity are driving the demand for upgrades and refurbishments of hydropower plants,” says Jason Heilman, Director, Proposals and Marketing at American Hydro.
Substantial financial and operational benefits
Typical reasons for a hydropower plant’s upgrade and refurbishment include increased unit output and efficiency, extension of the machine’s lifetime or better matching of unit design to the plant operator’s current operational goals. “Sometimes an unplanned unit failure can also trigger an upgrade and refurbishment project. No matter what the reason for the project may be, the financial and operational benefits of these projects are substantial,” says Heilman.
Upgrade and refurbishment projects generally take 10 to 18 months. “This includes 10 to 12 months of new component manufacture and 4 to 6 months of field work and existing component rehabilitation. To ensure a successful project, enough contingency should be allowed in the schedule or budget to account for unknown factors discovered during the project,” Heilman says.
The exact scope of upgrade and refurbishment projects varies greatly. A turbine upgrade project can include the installation of a new runner, the rehabilitation of existing turbine components, the disassembly of the unit on site, field machining of embedded components, the reassembly of new and rehabilitated components and even the commissioning of the unit. Sometimes also the cleaning, upgrading, or even the installing of a new generator or new thrust bearings is included in the project.
Expanding lifespan and improving reliability
One example of a refurbishment project carried out by American Hydro is a comprehensive rehabilitation and installation of the turbine and auxiliary components for Unit 2 of NB Power’s Beechwood hydropower plant, located on the Saint John River in New Brunswick, Canada.
A vertical Kaplan generating unit, often used at sites with limited water storage and supply, will be modernised to incorporate a new and more environmentally efficient, self-lubricating wicket gate operating system. “Greaseless, water-lubricated bearing surfaces offer a low coefficient of friction while eliminating the need for a greasing system. These self-lubricating bearings provide a maintenance-free solution without introducing grease into the waterway,” says Joe Druck, Chief Design Engineer at American Hydro.
“We selected American Hydro through a competitive process as our partner for this major rehabilitation project because of their experience and cost competitiveness for this kind of challenging project. Thanks to this project, the lifespan of our unit will be extended and its reliability improved,” says Liam O’Dell at NB Power.
Image caption: NB Power’s Beechwood Hydroelectric Plant, located on the Saint John River between Bath and Pert-Andover, approximately 160 kilometres north of Fredericton, New Brunswick, Canada.
Date: Jul 5, 2018