Run-of-the-River As Alternative Run-of-the-river is a new application of old principles to generate low-head hydroelectric power. As in previous centuries, water is diverted from a river to the water turbines and then flows back into the river instead of being held in a reservoir. There may be a small weir, but the river is not completely blocked. In a run-ofthe-river system, the water is normally delivered via a canal, or conduit diverting the water from upstream of the power plant. Of course, there must be enough of a drop in height for the water to have sufficient kinetic energy to power the turbines. And the river must have a steady flow throughout the year. Run-of-the-river hydroelectric power facilities have minimal or no water storage, thus reducing the environmental impact. However, low-impact is not the same as no-impact. Water temperature changes and dissolved gasses downstream may impact fish. And in some instances, a ladder may be required for fish to help them swim upstream. Because the water is only diverted instead of dammed, there are many more suitable locations worldwide than with traditional hydropower. Run-of-the-river systems cost less than traditional hydroelectric systems to construct and may be completed in less time.
A disadvantage of run-of-the-river hydroelectric systems is that they have little or no energy storage capacity. All rivers have fluctuations in their flow. For example, the flow is relatively high in the spring but becomes low during the warm summers. And some rivers freeze in the winter. So run-of-the-river plants should be used in conjunction with other power generation sources in order to secure a steady supply of electricity. Simply removing traditional dams and replacing them with run-of-the-river isn’t a magic solution, of course. As with all power generation technologies, there are both pros and cons. And using new technology in old ways is often very inefficient. However, reinventing our power grid has the potential to be transformative. Small run-of-the-river projects in the right locations can be created with relatively little influence on the environment. Environmental issues are greater in larger projects. This includes projects where several smaller plants are clustered within a few miles of each other. Additionally, some adjustments must be made for the local flora and fauna, so as not to disrupt their life cycles.
Social Justice Aspect Many of the flooded lands are important to Native peoples. This includes both modern and ancient religious and cultural sites, many of which were destroyed in the process. Compare this to the Aswan Dam in Egypt. Many ancient Egyptian monuments were painstakingly disassembled and reassembled on higher ground. Yet the late 20th century superpowers, USSR, China, and the United States consistently disregarded the rights of their Indigenous peoples when planning their large hydropower projects. Decentralized or distributed generation often is touted as a new idea but Lewis Mumford presented this concept as far back as the 1930s. Mumford stated that technology must subject
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be subject to social democracy and wise regional planning. Otherwise, it could easily be misused, such as when Indigenous peoples are forced off their lands in order to build large projects. There must be prior, informed consent. Relatively small, local projects with more local control on the other hand can lead to more grassroots democracy. Indeed, by 1970, Mumford had concluded that the combination of smaller scales and community authority could counter the centralized power of the industrial megamachine. In his book, The Pentagon of Power, for instance, Mumford wrote: “The changes that have so far been effective, and that give promise of further success, are
