Tech Notes

Snowy Hydro tests flushing flows to improve river environment

Snowy Hydro Ltd. has performed a flushing flow trial at Jindabyne Dam designed to better mimic the natural flow characteristics seen in the Snowy Montane rivers. According to the Department of Primary Industries Office of Water in New South Wales, this flow variability technique, known as hydro-scaling, has three objectives:

– To better reflect the hydrology of a Snowy Montane river, including increasing the daily, seasonal and annual flow variability;

– To provide multiple high-flow events to meet the primary ecological objective of habitat improvement; and

– To fully test the infrastructure capability of Jindabyne Dam to provide variable flow rates.

The release that took place October 8, 2013, involved opening the spillway gates at Jindabyne Dam and providing a peak flow that exceeds the capacity of the cone valves. The remaining releases will occur through the cone valves and other infrastructure below the spillway. This new release pattern included 96.6 gigaliters (Gl) of water released during spring 2013, with five flood events occurring between September and November, and a total of 190.6 Gl released over the course of the water year.

Five of these events, including the flushing flow, will involve an eight-hour peak through the day that will cause the river level downstream to fluctuate substantially, much like a natural high-flow event in an unregulated catchment, Snowy Hydro says. The high flows facilitate the improvement of the physical condition of the in-stream habitat by scouring and transporting sediment, the Office of Water says.

The Increased Flows program under which this work is being conducted is part of the Snowy Initiative established in 2002 to achieve significant improvements in river health. Flushing flows began to be tested in 2002, with the program in its fourth stage.

Snowy Hydro owns and operates the Snowy Mountains Scheme, which consists of nine major hydropower stations with a total capacity of 3,950 MW and two small stations.

IEA offers world energy statistics app

The International Energy Agency’s Key World Energy Statistics 2013 is now available for use in an iPhone, iPad or iPod Touch.

Just like the pdf version on the IEA website, the mobile app lists 16 headline statistics for more than 140 countries, from total energy supply to electricity consumption per capita to CO2 emissions per unit of gross domestic product. In addition, the app features a customizable favorites function for fast access to each user’s most relevant energy topics. Users can also rank countries in ascending and descending orders using multiple indicators.

The online summary of key energy data has been produced every year since 1997.

The IEA Key World Energy Statistics app version 2.0 can be downloaded from iTunes. An android app is in development.

Hydroelectric training center being built in Pakistan

Officials from the French Development Agency, European Union and French government have signed an agreement to establish a hydroelectric training center in Pakistan.

The project, called the Pakistan Hydropower Training Institute (HPTI), will be located at the country’s 1,000 MW Mangla hydroelectric plant with the purpose of increasing “the capacity of both public and private hydropower operators,” according to the French Embassy in Pakistan. Mangla is already home to a training center, which is being rehabilitated and expanded using grants delegated to the French Development Agency (AFD) by the EU.

The French Embassy said HPTI will help Pakistan work toward a number of goals, including:

– Safeguarding large dam and infrastructure projects against climate change;

– Improving the safety and efficiency of hydropower projects;

– Preparing eligible projects for qualification under the United Nations’ Clean Development Mechanism; and

– Making sure projects and proposals comply with international environmental and social practices in order to make them more attractive to international funding.

Officials said the center will be the only one of its kind in Pakistan once it is complete.

Authority to perform hydrological studies of African basin

L’Autorite du Bassin de la Volta (ABV) plans to hire a company to review and recommend a hydrological management system for the six-nation Volta Basin of Africa.

ABV was created to manage the basin and promote strategic water resources development, including hydropower. Hydro projects in the Volta Basin include 400 MW Bui, 1,020 MW Akosombo and 48 MW Pwalugu.

The authority will hire a consultant to review relevant reports on the current situation and projected operational hydrology in ABV member states Burkina Faso, Ghana, Cote d’Ivoire, Togo, Benin and Mali. This phase of study is to be based on results of an earlier study of hydrological conditions in the basin, including the state of hydrometric stations, organization of hydrological monitoring, management of hydrological data and the means of financing data collection activity. The consultant is to propose an operational network for maintenance of a system in the sub-region.

Bank to develop atlas of hydro development sites in Guinea

The World Bank plans to hire a consultant to develop an atlas of hydropower development sites in Guinea.

Work to be performed includes conducting an inventory and developing a map of all potential sites for large and small (minimum 1 MW) hydropower projects throughout Guinea. Work is to include assessment of all available documentation, site visits and collection of information, data analysis and development of the atlas of hydro potential, creation of an Internet viewer, training on models developed, and drafting of terms of reference for subsequent hydro master plan assignment for Guinea.

Bearings pass tests simulating conditions at Brazil’s Belo Monte

HPM bearings manufactured by GGB Bearing Technology underwent laboratory testing to determine their suitability for extended wicket gate service at Brazil’s 11.2 GW Belo Monte project. Testing was conducted by Powertech Labs in British Columbia, Canada, in accordance with U.S. Army Corps of Engineers specifications, with modifications made to simulate 30 years of operation.

The study simulated operating conditions at Belo Monte and used water from the Xingu River where the project will be located. GGB said its bearings were subjected to a static load with rotary and oscillating motion under wet and dry conditions. They then underwent accelerated wear testing with a dynamic radial load on a journal moving continuously +/- 1 degree. Static load remained constant, but dynamic load was paused every 15 minutes to simulate a wicket gate opening +/- 15 degrees.

“The bearings performed well, with little evidence of operating stress,” GGB said. “Significantly, it was demonstrated that their coefficient of friction and wear rate decrease as running time increases.”

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