For more technical news, check out the Technology and Equipment tab at Hydroworld.com
Snowy Hydro uses unmanned vehicle to inspect tunnels
Snowy Hydro is using an unmanned underwater vehicle (UUV) to inspect six unlined tunnels in its 3,950 MW Snowy Mountains Scheme in Australia's southern Alps.
The network for water transfer comprises 13 tunnels with a combined length of 135 km, featuring both tunnels lined with reinforced concrete and unlined tunnels. The unlined tunnels were constructed using different support techniques on the exposed rock face, including rock bolting. There have been two in-service failures of the unlined tunnels, resulting in lengthy, high-cost repair projects.
In the past, the unlined tunnels were dewatered for inspection at intervals ranging from five to 20 years, the company says. This involves considerable time and cost investment to reduce the risks associated with rock falls and ventilation to ensure personnel safety. Dewatering also shuts down several of the company's power stations. Removing water from the tunnel changes the pressure on the walls, which can cause weakness in the rock or even a collapse.
The UUV to be used measures 3,700 mm long by 700 mm wide and weighs about 650 kg. It will be inserted into each tunnel by a crane and directed via remote operation. The UUV will be outfitted with cameras, sensors and sonar technology. Data collected include a detailed profile of the entire wall circumference, as it travels up to 12 km. Each tunnel inspection is expected to take about 18 hours.
Use of this technology will save millions of dollars in terms of costs associated with dewatering and by maximizing generation capability, the company says.
The expenditure for this work was approved in April 2013.
Book available on small hydro engineering
CRC Press announces availability of Small Hydroelectric Engineering Practice, a reference book covering all aspects of identifying, building and operating hydroelectric schemes 500 kW to 50 MW in size.
The book is based on author Bryan Leyland's experience gained over 45 years working on the overall and detailed design, construction, commissioning and refurbishment of many small hydro schemes in New Zealand and other countries. It includes contributions from experts in the field of intakes, water diversion structures, geology, canals, painting, economics and environmental aspects of hydropower development.
A CD is included with some relevant papers, spreadsheet programs for analyzing aspects of small hydropower development, and many arrangement drawings and detailed designs for gates, penstocks, and electrical and control systems.
The book is broken into 12 sections, covering scheme identification; refining the design; detailed design of intake works, canals and penstocks; turbine selection; generators; electrical systems; auxiliary plant; specifications and contracts; powerhouse layout and design; construction and commissioning; operation; and lessons learned from failures.
— The book can be purchased for $159.95 at www.crcpress.com/product/isbn/ 9781138000988.
Alstom, EVN win honors for 2,400 MW Son La plant
Alstom Power and Electricity of Viet Nam (EVN) have won a trio of awards for their work on the 2,400 MW Son La plant. Son La's "Hydro Power Project of the Year," "Fast Track Power Plant of the Year" and "Power Utility of the Year" honors — presented at the Asian Power Awards 2013 ceremony in Bangkok, Thailand — were given based on the project's innovation, effectiveness and dynamism, Alstom said following the presentation.
"We are proud to be part of this great success," said Yves Rannou, general manager for Alstom's hydro business in China. "Winning the awards was made possible by the excellent teamwork and close cooperation between EVN, Alstom Hydro China, Alstom Vietnam and our partners."
The US$2.5 billion plant is on the Da River in Son La province and includes six units collectively producing about 10% of the country's total power, making it the largest hydro facility in southeast Asia. Work began in 2005, and its last turbine was put into operation in October 2012.
Handbook describes combining salmon needs, hydro generation
A handbook developed by the Centre for Environmental Design of Renewable Energy in Norway (CEDREN) describes what must be done to address the ecological needs of salmon while maintaining high generation from hydropower facilities.
Handbook of Environmental Design in Regulated Salmon Rivers is intended to show that, rather than suffering from electric power generation in regulated rivers, salmon numbers can even increase at the same time as hydroelectric power does. The methodology described is based on long-term research collaboration between the Norwegian Institute for Nature Research, Norwegian University of Science and Technology, Uni Research, University of Oslo and SINTEF Energy Research.
The book describes four procedures for ensuring simultaneous optimal salmon production and electricity generation:
— Make a diagnosis;
— Describe the generation system;
— Identify solutions for water use; and
— If necessary, implement physical measures in the river.
CEDREN also has computer models that simulate what happens to salmon when a regulated river is developed and environmentally friendly measures are used.
— For more information on the book, visit www.sintef.no/home/Press-Room/Research- News/More-salmon-and-more-hydropower-.