|Central by the Numbers:|
|239 million||megawatts of electricity generated at Central’s hydropower plants|
|92,000||people; Central’s four hydropower plants satisfy the residential needs of a city with a population of 92,000|
|100||percent renewable energy generated by Central’s hydropower project|
|113||megawatts generated when all four of Central’s hydro plants are generating electricity at capacity|
Senator George Norris, a powerful Senator from Nebraska, transformed the landscape and the economy of south central Nebraska when he hinged his support for the Central Nebraska Public Power & Irrigation District (CNPPID) on hydropower generation. Project engineers complied with his request, and in 1935 the U.S. Senate agreed to finance the project.
Generating and selling hydropower secured a more prosperous future for landowners and agri-businesses in Nebraska. Today, 79 years after the momentous day President Franklin D. Roosevelt officially signed approval of the $20 million loan to build the project, hydropower sales support the irrigation, research, repair and other components of Central’s project.
“Selling power generated at the hydro plants in the Central project paid off the original loan from the federal government,” said Don Kraus, Central’s general manager, “and today profits from generating hydro are key to financing the operation and maintenance costs of the Central project.”
Hydropower plants are designed and built to generate electricity from the flow and fall of water. From early history, people used falling water to power water wheels to grind grain and saw lumber. The world’s first hydroelectric power plant was built in Wisconsin in 1882 by a paper manufacturer, H.J. Rogers. The Appleton plant generated enough power to light his home, the plant, and a nearby building. (Source: National Hydropower Association)
The promise and production of hydropower rises and falls with the price of oil. In the 1950s and 1960s, low cost fossil fuels were available so power plants were designed using fossil fuels to power generators. But now the rising costs of fossil fuels and rising environmental concerns associated with the use of fossil fuels is renewing an interest in hydropower.
Central generates hydroelectric power
Central generates electricity for homes, farms and industry at four hydro plants, one at Kingsley Dam and three on Central’s supply canal.
|Johnson-1 (J-1)||20 megawatts|
|Johnson-2 (J-2)||23 megawatts|
The Hydro Division’s headquarters is located in Gothenburg, which also houses the control center. The control center is staffed 24 hours per day, every day of the year. Computers at each plant relay data to the Gothenburg Control Center. According to information from Central, if conditions at the plants deviate beyond certain limits, the computers alert control operators so corrections can be made, or if necessary, a technician can be sent to the plant. Control center personnel monitor and remotely operate Central’s four hydro plants, two diversion dams (one owned by the Nebraska Public Power District), all supply canal control structures and two major canal systems overseen by Central’s Irrigation Division. In the 1970s, the system was automated. This led to an increase in the generation of hydropower, better management of the system under high-water conditions, reduction in the incidence of spills, better control of flows that reduced the need for maintenance of the canals, and a reduction in operating costs. Central’s hydropower production may be studied in detail on their website, www.cnppid.com.
Advantages of hydropower
Hydropower may be ramped up or down quickly and at short notice. For example, when energy produced by wind turbines draws down due to less wind, the power load may pick up hydropower to maintain a continual flow of electricity when it is needed. The presence of hydropower in the mix of energy resources adds a capacity that is easily managed. Hydropower can be scheduled.
“We can adjust generation to match demand,” Kraus said. “We try as much as possible to operate at peak efficiency, and we achieve peak efficiency when all units are operating and gaining the most generation of power out of a unit of water. If demand for power is there, we will ramp up. Normal operation is at peak efficiency.”
Falling water turns the turbines that power the generators. Falling water plus a turbine and a generator form a unit. All units may be powered up when power is needed, or, if less power is required, a single unit may be powered down with a flip of a switch.
“In the 1940s, engineers didn’t have computers to synchronize the generation of hydropower with less demand on the grid,” Kraus said. “People adjusted the opening of the gates and the flow of water over the turbine, thereby changing production.”
In 2004 Central completed a four-year project to modernize the hydropower plants in their system. The engineers and technicians removed and replaced turbines and transformers.
“The efficiency of the four plants increased by 10 percent, and with the same acre feet of water, the plants generate 10 percent more power than in the 1990s,” Kraus said. “The renewal project increased capacity by 15 percent, and the improvements increased generation from 54 megawatts to 62 megawatts.”
Central’s hydropower plants were recently recertified by The Low Impact Hydropower Institute (LIHI), a non-profit 501(c)(3) organization dedicated to reducing the impacts of hydropower generation through certifying hydropower projects that have avoided or reduced their environmental impacts.
In 2013 Central contracted with Kansas City Power and Light to sell hydropower generated at Jeffrey, J-1 and J-2. Hydropower generated at Kingsley Dam is sold to Nebraska Public Power District.
The best science
More data and more information about the Central system improve the management of the water there, a limited resource. Groundwater development (wells that pump water from the Ogallala Aquifer for irrigation above Lake McConaughy) has reduced the flow of water in the North Platte River and diminished the supply of water available for irrigation and power generation.
“Our engineers and scientists look for the best science and latest models to understand the hydrology and use of water in the Central system,” Kraus said. “Our integrity as resource managers depends on our judgment. It’s fair to ask questions, and we have to answer using good reasons.”
Central hires staff with exceptional expertise. “We hire employees with technical backgrounds who are dedicated to look for and use the best science and with the best approaches,” Kraus said.
An often heard statement among Central engineers and managers is “We are incorporating the best science today, and today’s best science will change and improve tomorrow with more data and information.”
Central will continue to look at its practices for ways to improve efficiency, but Nebraskans must also ask themselves what they can do to insure our most precious resource, water, is used wisely so that is available for many different uses well into the future.