You may not realize it, but a rush of water likely helps keep your lights on every day. Like many electric cooperatives around the country, Access Energy Cooperative draws on hydroelectric power to keep electricity reliable, safe, and affordable.
Energy from flowing water has been harnessed and used for more than 2,000 years; ancient Greeks thought up the first water wheels and used them to grind wheat into flour. In the 1880s, converting a rush of water into electricity became a reality in the United States. The breakthrough quickly swept the nation, and within a decade 200 U.S. plants were using water power for some or all generation.
Today, hydropower provides about 80,000 MW of capacity in the United States and accounts for 86 percent of all renewable, carbon-free electricity used by co-ops. It’s inexpensive, pollution-free, and has been supplying electricity to rural areas since the inception of electric co-ops in the mid-1930s.
But how does it work? Simply, hydropower converts the natural energy in moving water to mechanical energy. A water wheel, which can be attached to a mill, becomes a basic means to that end. If that water wheel (or its modern-day equivalent, a turbine) is attached to a generator, electricity results.
With highly efficient turbine-generators doing the job formerly performed by water wheels, electricity can be turned out in a number of ways:
• Impoundment: When most people think of hydropower, dams come to mind. By plugging a river and amassing water in a reservoir, its flow (and the resulting electricity) can be better controlled and generated as needed.
• Diversion: Water is channeled away from a river, typically near natural falls, down to generators at the falls’ base. This can be done without any visible impact to the natural course of a river. In fact, this kind of generation was used to bring electricity to Buffalo, New York, from Niagara Falls in the late 1800s.
• Pumped Storage: This method essentially uses off-peak electricity to make electricity for use during times of high consumption. Two reservoirs are filled, one typically uphill from the other, with an electric pump/generator in between. At night, when demand is low and electricity is less expensive, water from the lower reservoir gets pumped uphill. During the day, when demand for power increases, that water is released down through the generator to make electricity.
More than 600 electric co-ops across the country purchase power from 134 federally owned and operated dams, most of which were built between the late 1930s and early 1960s. Despite the incredible importance of these resources, maintenance of the old-timers has lagged in recent years and created room for improvement.
Electric co-ops are making efforts to address this problem, advocating that the government set aside funds to repair and maintain dams and the turbines inside them. Researchers are also looking to create more efficient and environmentally sound (i.e. fish-friendly) ways of generating hydropower. Careful studies of aquatic environments have given dam operators a better idea of how to simulate a natural river downstream. More unique environmental protection solutions, such as fish ladders (a concept first developed in the 1600s), are also being researched and put into action.
This push for increased maintenance and technology development will ensure that hydropower remains a reliable and affordable renewable resource for decades to come.