On the North Shore of Kauai, GE Energy’s Control Solutions business recently upgraded two 1906-era Pelton hydro turbines with Mark VIe digital controls and a new hydraulic system. This upgrade brought increased efficiency and reliability to the first hydroelectric plant ever built in Hawaii and still in operation today.
Kauai Coffee Company, owner and operator of the Wainiha hydro power plant, required a solution that could modernize the over 100-year-old mechanical fly-ball governors to a modern digital control while also supporting the continued life and maintainability of this essential power generator as a clean, renewable energy source for this western-most Hawaiian island. The plant was originally built to support the company’s prior sugarcane operations on the island.
“The new digital control system and its simple-to-use ToolboxST software tools are more accurate and dependable, easier to maintain, and – best of all – more efficient, allowing additional kilowatt hours of electricity to be generated each year,” explained Kauai Coffee Company’s project manager Dan Sargent. “The system and software ushers in a new era of power generation for this valuable company asset.”
The original 25-hertz generators were used to power irrigation pumps on the dry side of the island for sugarcane irrigation until GE converted them to 60-hertz generators in 1929 for connection to the electrical grid. Maintaining the 100-year-old governors to run efficiently and correctly was difficult with malfunctions resulting in costly repairs and downtime. GE Energy with its long-time expertise in servicing the worldwide installed base of hydro plants, partnered with Kauai Coffee’s experienced and skilled team to overcome these control challenges.
The entire harmonics and operation of the installation have now changed. Legacy controls on the dual needle impulse turbines created an imbalance on needle position that resulted in lost efficiency and continuous vibration and wear. The new control system achieved accurate balancing of the needles, which resulted in increased power production during lower water levels, less parasitic power consumption and smoother operations.
Start up time for the plant decreased from an average of four hours to less than 10 minutes. The Wainiha plant staff also benefits from the ability to monitor and easily troubleshoot its system in real-time, both on-site and remotely, contributing to plant productivity, maintainability and ease of operator training.
“This project highlights GE’s continued service support of the hydropower segment,” said Brian Palmer, vice president for optimization and control, GE Energy. “Our solutions can deliver increased efficiency and productivity for the installed base of hydro power plants around the world.”
Upgrading this plant is part of the Aloha state’s efforts to implement a progressive clean energy initiative. As part of a bill signed into law on June 25, 2009 (Link to Bill HB1464), utilities must generate 40 percent of their electricity from renewable sources by 2030. The Wainiha station generates four MW, enough power to supply its coffee processing factory, visitor center complex and main offices, while also producing six percent of the island’s total power generation.
Hawaii’s natural power-generating resources are primarily hydro, wind and geothermal, with other energy sources such as liquid fuels, gas and coal imported at high cost. With more than 40 feet of rain per year, the Wainiha plant’s water source, Mt. Waialeale, helps ensure that this project will provide consistent, reliable hydropower to help offset the rising costs of generating power from imported fuel.
In accordance with local customs, a traditional Hawaiian blessing complete with adorning native flowers and plants, was held on June 5, 2009, for the new control system inside the powerhouse. The ceremony fed positive energy into the system and honored the rich legacy of the original installation and its future contributions to hydropower supply for the Island of Kauai.