Particularly in the West, hydropower long has provided a significant portion of the energy required to meet the needs of a growing population. Increasingly, however, the circumstances that led to the dominant role played by hydropower generation in providing nearly boundless energy supplies in many parts of the country are changing. Factors that were not known about or anticipated in the decades when much of our existing hydropower infrastructure was constructed are creating challenges both to the long-term reliability and continued cost-effectiveness of traditional hydropower. Climate change and other factors are predicted to alter both the timing and pattern of precipitation and associated runoff that largely determines the availability and amount of hydropower.
The magnitude of the contribution that hydropower historically has made to our Nation’s energy abundance can be seen in the statistics maintained the U.S. Bureau of Reclamation, which has shared jurisdiction over federal hydropower generation. The Bureau is the Nation’s second largest producer of hydroelectric power, with roughly 58 power plants and 194 generating units in operation accounting for an installed capacity of more than 14 million kilowatts.
However, the large-scale dams that historically have supplied enormous amounts of hydroelectric power, particularly in the Colorado River Basin and the Pacific Rim states, are no longer being built. Although they continue to operate, and some have been retrofitted with more efficient turbines resulting in marginal increases in output, our traditional reliance on hydroelectric generation no longer is sustainable. Water supply availability increasingly is being limited by the effects of climate change and other factors, while increased water demand for energy production, agricultural production, and municipal development continues unabated.
Efforts to secure the future sustainability of our energy and water resources are leading to dramatic changes in how we address what has come to be known as the “water/energy nexus.” These changes range from the adoption of alternative cooling technologies for thermoelectric power plants to greater emphasis on energy efficiency and increased use of non-traditional energy and water resources.
The impacts of climate change and other factors on the availability of traditional water supplies have posed some unique challenges with respect to the continued use of hydropower for energy generation. Reservoirs, particularly large ones, are increasingly susceptible to evaporation due to warming, with the result that less water is available for all uses, including hydropower.
The implications of reduced water levels in many of the reservoirs on which we rely for the generation of hydropower has spurred, at least in part, an entirely new technological approach to hydropower generation which is largely immune to the increasing variability of reservoir water levels. The trailblazer of this new approach has been a Portland, Oregon-based startup, Lucid Energy. Several years ago, Lucid conceived an alternative, highly sustainable model of hydropower generation that is in the process of being adopted in communities across the country. The system pioneered by Lucid involves the installation of small turbines in water distribution systems (i.e., pipes) which generate energy when the turbines spin in the flowing water.
The power generated by the turbines either can be used to off-set a utility’s own power demands, or be sold into the grid as a separate source of revenue for the utility. Portland’s local water utility was the first to install the new technology into its water distribution system, but a number of other cities, including San Antonio and Riverside California, quickly followed suit.
In addition to addressing challenges to our domestic hydropower industry posed by climate change and other factors, the Lucid technology also would seem to offer a promising model for power generation in developing countries, many areas of which often do not have access to an established electricity grid.