Advanced Hydropower Technology

At the Wanapum Dam on the Columbia River, a fish-friendly turbine runner that helps salmon smolts pass through the turbine is under test.

The Advanced Hydropower Technology (AHT) activity supports the development of technologies that will enable existing hydropower projects to generate more electricity with less environmental impact. This will be done by: 1) developing new turbine systems that have improved overall performance, 2) developing new methods to optimize hydropower operations at the unit, plant, and reservoir system levels, and 3) conducting research to improve the effectiveness of the environmental mitigation practices required at hydropower projects.

Objectives

The main objective of DOE's research into Advanced Hydropower Technology is to develop new system designs and operation modes that will enable both better environmental performance and competitive generation of electricity. While DOE does not own or operate hydropower projects, the products of DOE's research will allow hydropower projects to generate cleaner electricity. DOE-sponsored projects will develop and demonstrate new equipment and operational techniques that will optimize water-use efficiency, increase generation, and improve environmental performance and mitigation practices at existing plants. Research efforts contributing to the success of these objectives include:

Testing a new generation of large turbines in the field to demonstrate that these turbines are commercially viable, compatible with today's environmental standards, capable of balancing environmental, technical, operational, and cost considerations.
Developing new tools to improve water use efficiency and operations optimization within hydropower units, plants and river systems with multiple hydropower facilities.
Identifying improved practices that can be applied at hydropower plants to mitigate for environmental effects of hydro development and operation.

When fully adopted, the products of DOE's research will enable up to a 10% increase in the hydropower generation at existing dams, with net benefits to the environmental quality of rivers in the U.S.

Technical Challenges

While the technology for generating hydropower exists, traditional hydropower is also associated with adverse environmental impacts, particularly with respect to fish passage and survival, water quality in reservoirs and downstream from dams, and altered flow regimes that may degrade physical habitat for fish below dams. Advanced research on new turbine designs has been supported jointly by DOE and industry for several years. The intent of that new design work was to improve environmental performance of turbines without sacrificing energy generation.

Environmental performance has been defined in terms of the survival of fish passing through the turbines, dissolved oxygen and other water quality parameters downstream of a dam, and downstream habitat conditions for fish. The advanced turbine research to date has produced two types of new conceptual designs: 1) modifications to existing Kaplan and Francis turbines, and 2) an innovative turbine runner with a helical screw shape, patterned after centrifugal pumps.

Biological design criteria have also been developed in laboratory tests of fish response to physical stresses such as hydraulic shear and pressure changes. Through the combination of laboratory, field, and computational studies, new solutions to environmental problems at hydropower projects are being found. Much of this work is cost-shared with the U.S. Army Corps of Engineers and with other industry partners.

Operational changes at hydropower projects can also improve energy and environmental performance. Operational changes to optimize hydropower projects range from better monitoring and control of individual turbine units and sets of units at a power plant up to coordination of total reservoir releases in a river basin. The specific actions needed for optimizing operations are highly project-specific, and the diagnostic technology, such as hydraulic measurements, remains fairly undeveloped, especially at the interface between engineering and environmental management.

Environmental mitigation is usually required at hydropower projects to overcome adverse impacts of project construction and operation. In 1990, DOE initiated a study of environmental mitigation practices, designed to provide better understanding of environmental problems at hydropower projects, and more importantly, of the solutions to these problems. One of the major conclusions was that there was a serious lack of appropriate data to evaluate mitigation effectiveness and costs. Based on this perspective and other interactions with industry and environmental groups, the DOE Program includes research on the effectiveness of mitigation measures.

Research Activities

Three sets of research projects are being supported under Advanced Hydropower Technology:

Large Turbine Testing

Evaluating a new generation of large turbines in the field to demonstrate that these turbines are commercially viable, compatible with today's environmental standards, and capable of balancing environmental, technical, operational, and cost considerations.
Water Use/Operations Optimization

Developing and demonstrating new tools to improve how available water is used within hydropower units, plants, and river systems with multiple hydropower facilities, to generate more electricity with less water and greater environmental benefits.
Improved Mitigation Practices

Studying the benefits, costs, and overall effectiveness of environmental mitigation practices and developing guidance that will enable best-available technology to be used in hydro development and operation.

Large Turbine Testing

The current program direction is moving from prototype testing of new turbine designs to the evaluation of full-scale systems in more realistic field settings. The Large Turbine Testing project will evaluate the environmental performance and operational efficiency of new generation turbines relative to older technology machines. In fiscal year 2002, DOE issued competitive solicitations for cost-shared field testing, and contracts were awarded to three projects. A fourth project was negotiated via an interagency agreement between DOE and the Corps of Engineers. DOE's portion of the cost for each project will cover efforts associated with performance testing that would not otherwise be conducted. Testing will determine environmental and engineering performance and estimate the incremental operations and maintenance (O&M) costs of new designs relative to existing technology.

The plan is to conduct extensive baseline engineering and biological tests at the sites with the old turbines in place and then conduct the same tests after the new turbines are in place and operating. The comparison of the before and after test results are designed to demonstrate that the new generation turbines:

Operate more efficiently and generate more electricity
Improve water quality during operation
Provide improved conditions within the turbine to safely pass increasing numbers of fish

The success of AHT research efforts will be measured in two respects: energy efficiency and environmental effects. The Large Turbine Testing project will be measured by:

Measurable improvements in environmental performance; for the ongoing activities, these would include improved dissolved oxygen conditions in waters downstream from the dam and improved survival of fish passing through the turbines
Measurable increase in generation

Water Use/Operations Optimization

The energy production from hydropower projects is determined by the type of hardware installed at a site (turbines, generators, etc.), the civil works configuration (dam structures, reservoir capacity, etc.), and the operation of the plant (timing and mode of water releases, hardware settings, etc.). While the Large Turbine Testing activities of DOE's Hydropower Program concentrate mostly on development of new hardware, the Water Use/Operations Optimization activities focus more on operational issues.

Generation can be increased at a given plant by optimizing a number of different aspects of plant operations. These include settings of individual units, multiple unit operations, and release patterns from multiple reservoirs. This is a new research direction that is responsive to requests from industry and environmental interests. There are significant technical challenges that need to be addressed in this effort, including improved hydraulic measurements. Also, an integrated approach to energy and environment will be applied in this research, to ensure that the multiple objectives of environmental quality and energy production are achieved together. The need to improve the scientific basis for decisions concerning water management at hydropower dams and reservoirs is becoming increasingly acute as competition over limited water resources escalates across the United States.

The Water Use/Operations Optimization project will be measured by:

Measurable improvements in plant operational efficiency and water use
Measurable increase in generation

Improved Mitigation Practices

The program is currently supporting several environmental mitigation studies, focused on instream flow issues and on fish passage requirements at hydropower projects.

Progress on mitigation studies has been limited in the last several years by Congressional appropriations and by the DOE program emphasis on advance turbine research. In FY 2003, a final report was published on non-structural approaches for addressing dissolved oxygen problems at hydropower facilities (PDF 507 KB). Download Adobe Reader. Recent licensing trends at nonfederal hydropower projects indicate that projects in the United States are experiencing a broad reduction in plant factors because of new flow requirements, such as a shift from peaking to base-load operation. This type of operational change to conform to regulatory requirements can have a substantial adverse affect on power generation and power values at individual projects. Therefore, the current mitigation research being conducted by the program is focusing on instream flow requirements that constrain peaking operations, such as ramping rates. Additional studies are planned on the effectiveness of fish passage technology at hydropower projects.

The Improved Mitigation Practices project will be measured by:

Identification of the costs, benefits, and effectiveness of instream flow requirements
Acceptance of recommendations for changes in instream flow needs at hydropower plants
Definition of ground water-surface water interaction on the timing of emergence of fall Chinook salmon from their spawning areas and acceptance of timing releases at upstream dams to maximize fall Chinook salmon survival.