Voith in December announced it has completed the modernization of the Mucomir hydropower station in Scotland, and the 20-MW facility is again producing electricity for the Scottish grid. Voith was responsible for the new build, installation, and commissioning of the turbine unit. The company also installed a control system, circuit breaker, and hydraulic unit, and refurbished the generator.
SSE, a UK-based utility that primarily produces energy from renewable sources, said the upgrades will improve the Mucomir plant’s efficiency and also make it more environmentally friendly. “The modernization work was done during a shutdown, and because of the tight schedule, the fabrication and installation of the components were a major challenge,” Christian Merkl, project manager of Voith Hydro Germany, said in a news release. “However, thanks to our experience and our close cooperation with plant operator SSE, we were able to complete the project no less than three weeks ahead of schedule.”
Mucomir is a run-of-the-river hydro plant fed from Loch Lochy, as part of the Great Glen Hydro Group (Figure 1). It is one of about 70 SSE hydropower plants in Scotland.
Voith in the release said the design of the new turbine runner at the plant “reduces adverse effects on fish and makes it easier for them to pass through it. This means that SSE is taking regional fishery interests into account and acknowledging the importance of the power plant for migratory fish in the local catchment area. In addition, as part of the upgrade, oil and grease-free bearings were installed to avoid environmental damage.”
Peter Diver, programs manager at SSE, said in the release that “The modernization of the Mucomir hydropower plant ensures the commercial viability of the facility while taking account of ecological factors and using the most effective technological solution.”
Part of the improvements at the plant, which utilizes a Kaplan turbine driving a 3,300-V, 40-pole, 150-rpm AC synchronous generator, include the installation of a brushless AC exciter by Quartzelec to replace the DC exciter. In a news release, David Swaffield, Quartzelec’s lead electrical engineer on the Mucomir project, said, “Each project comes with its own unique requirements. The slow 150-rpm shaft speed of this turbine, presents its own challenge for the electrical machine design which, when combined with the limited access and available footprint along with the available cooling and the limited envelope, meant this project necessitated some significant engineering and a high pole count—but we were more than up to the task.”
The Mucomir plant began operating in 1962. With the upgrades, it now qualifies for a feed-in tariff program, which was part of the business case for the improvements. The plant also now can be controlled remotely.
—Darrell Proctor is a POWER associate editor.