Meg Cichon and Jennifer Runyon, RenewableEnergyWorld.com
December 11, 2012 | 2 Comments
Best Hydro Project of the Year: The Chacayes Hydroelectric Station, owned by Pacific Hydro Chile in Chile
Pacific Hydro Chile (PHC) saw an opportunity to develop run-of-river hydroelectric plants in the Cachapoal Basin to feed into the national grid and achieve attractive returns, especially considering the expected 6 percent annual growth in electrical demand in the country.
In 2005, PHC commissioned a feasibility study of the Cachapoal River basin, which resulted in the recommendation for six run-of-river projects. The 111 MW Chacayes hydroelectric project is the first in a series of planned developments on the river to be undertaken by PHC and co-owned by Astaldi Concessions. The project includes diversion weirs, a daily regulation pond, a desander, canals, tunnels and a surface powerhouse.
Hatch, formerly Acres International, provided consulting services for the basic and definition engineering and the preparation of tender documents for an Engineering, Procurement and Construction Management (EPCM) contract for the 111 MW Chacayes project.
The project was built under an EPC contract with Constructora Astaldi Fe Grande Cachapoal Ltda, a consortium made up of Astaldi SPa from Italy and Fe Grande, a Chilean construction company. Hatch was responsible for reviewing the EPC contractor’s detailed design documentation and drawings for civil works, mechanical and electrical systems and equipment supply.
The project posed a number of logistical challenges. The development is in a seismically active region of Chile, and one of the two diversion intakes is located in a national reserve. Careful attention had to be given to the visual impacts on the unique development.
Chacayes, which came online in September 2011, is the first of six hydropower projects in the $2 billion development pipeline in the valley. Together, the six projects will add more than 600 MW of renewable energy capacity to Chile’s national grid.
Clean energy generated at Chacayes is supplied to Chilectra, the largest electricity distributor in the country, under a long-term power purchase agreement.
Best Hydro Project Runner-Up: Jordan Hydroelectric Project, owned by the U.S. Army Corps of Engineers, North Carolina
The 4.4 MW Jordan Hydroelectric Project is located on the New Hope River in North Carolina at a 115-foot-high flood storage dam operated by the U.S. Army Corps of Engineers. This small hydro project, developed by an independent power producer, consists of two 2.2 MW vertical Kaplan turbines. Each turbine-generator unit is located inside of a 13-foot square by 100-foot-high steel box, or module, installed on the upstream side of the dam’s intake tower. The module supports the turbine, generator, and houses the equipment’s hydraulic power unit, ventilation and water filter systems, oil coolers, governors, and controls.
Kleinschmidt and North Fork Electric Inc., the module designer, fabricator, and installer, worked closely on the development of the innovative concept for the project, its layout, final design, fabrication and construction. Kleinschmidt designed the structural support system to allow a 90-ton rough terrain crane to be located on the intake tower roof for the assembly and installation of the modules and equipment.
The project is also unique in that it used existing, proven hydropower technology in a location that has historically been overlooked as a potential power source. The unique design allows the modules to be raised up to 7 feet when flow releases are between 3,000 and 12,000 cfs, allowing power generation to occur 95 percent of the time.
The project was completed at an installed cost of approximately $2,300 per kW, inclusive of all development, design, equipment, and construction costs. Construction costs of a hydroelectric project in a new powerhouse at an existing dam typically have an installed cost of $4,000 to $5,000 per kW. The installed cost of the project was kept low because there was no need to construct significant civil works to house the power generating equipment.
The first turbine became commercially operational in January 2012 and the second unit was operational in July 2012. Many design features implemented in the Jordan Hydroelectric Project could be utilized at other dams that contain a similar discharge tower and, as a result, produce clean, renewable energy from a previously untapped source.