Yangyang Pumped Storage Power Station
{{Infobox dam
| name = Yangyang Pumped Storage Power Station
| name_official =
| image =
| image_caption =
| image_alt =
| coordinates = {{coord|38|00|37|N|128|32|34|E|type:landmark|display=inline,title}}
| country = South Korea
| location = Yangyang
| status = O
| construction_began = 1996
| opening = 2006
| demolished =
| cost = ₩1.1 trillion won (US$1.4 billion).
| owner = Korea Hydro & Nuclear Power
| operator =
| res_name = Inje-gun
| res_capacity_total = {{Convert|4568000|m3|acre.ft|0|abbr=on|lk=out}}
| lower_res_name = Yangyang-gun
| lower_res_capacity_total = {{Convert|19982000|m3|acre.ft|0|abbr=on|lk=out}}
| plant_pumpgenerators =
| plant_turbines = 4 x {{convert|250|MW|abbr=on}} reversible Francis-type
| plant_pumps =
| plant_hydraulic_head = {{Convert|817|m|abbr=on}} (maximum)
| plant_capacity = {{convert|1000|MW|abbr=on}}
| plant_capacity_factor =
| website =
| extra =
}}
The Yangyang Pumped Storage Power Station uses the water of the Namdae-Chun River to operate a {{convert|1000|MW|adj=on}} pumped storage hydroelectric power scheme, about {{Convert|10|km}} west of Yangyang in Gangwon Province, South Korea. The lower reservoir is created by the Yangyang Dam on the Namdae and the upper reservoir by the Inje Dam is located {{Convert|937|m}} above the power plant. Construction on the power plant began in 1996 and it was completed and dedicated on September 13, 2006. It is operated by Korean Midland Power Co., a subsidiary of Korea Electric Power Company and was completed at a cost of ₩1.1 trillion won (US$1.4 billion).{{cite web|title=Korea dedicates 1,000-MW Yangyang pumped-storage|url=http://www.hydroworld.com/index/display/article-display/articles/hrhrw/News/Korea_dedicates_1000-MW_Yangyang_pumped-storage.html|publisher=HydroWorld|access-date=5 August 2011|date=13 September 2006}} The first generator was operational on February 23, 2006 and the last August 10, 2006.{{cite web|title=Pumped-Storage Plants|url=http://www.khnp.co.kr/en/030402|publisher=Korea Hydro & Nuclear Power|access-date=5 August 2011}}
Design and operation
The operation of the power plant begins on the Namdae-Chun River where it is dammed by the Yangsang (Sangbu) Dam at {{Coord|38|01|15|N|128|33|15|E|name=Yangyang Dam}}, creating the lower reservoir. This dam is {{Convert|61.5|m}} tall and {{Convert|275|m}} long concrete gravity dam. Water from a {{Convert|124.9|km2|sqmi|0|abbr=on}} catchment area collects into the lower reservoir which has a {{Convert|19982000|m3|acre.ft|0|abbr=on|lk=out}} capacity, of which {{Convert|4200000|m3|acre.ft|0|abbr=on|lk=out}} is active (or "useful") capacity for the power station. The lower reservoir has a surface area of {{Convert|1.1|km2|acre|0|abbr=on}} and operates at storage levels between {{Convert|127|and|131|m}} above sea level.{{cite web|title=Environmental Impact Assessment of the Yangyang Pumped Storage Power Plant Construction on the Namdae-Chun River, Korea|url=http://210.101.116.28/W_kiss5/23300112_pv.pdf|publisher=Korea Electric Power Co.|access-date=5 August 2011|date=1 June 1997}}
During low electricity demand periods, such as the night time, water from the lower reservoir is pumped {{Convert|937|m}} above the valley to the upper reservoir in the mountains. The upper reservoir is created by the Inje Dam, located {{Convert|5.3|km2|sqmi|0|abbr=on}} west of the Yangyang Dam at {{Coord|38|01|08|N|128|29|47|E|name=Yangyang Dam}}. The Inje is a {{Convert|84|m|ft|0|abbr=on}} tall and {{Convert|415|m}} long rock-fill embankment dam. The capacity of the upper reservoir is {{Convert|4200000|m3|acre.ft|0|abbr=on|lk=out}} and it has a surface area of {{Convert|190|m2|acre ha}}. When electricity demand rises and the power plant begins to operate, water is released from the upper reservoir back towards the underground power plant, at the western edge of the lower reservoir. Water fluctuations in the upper reservoir range from {{Convert|900|m}} and {{Convert|936|m}} above sea level. The power plant contains four 250 MW reversible Francis turbine-generators for an installed capacity of 1,000 MW. The drop in elevation affords a maximum hydraulic head (drop) of {{Convert|817|m}} and effective head of {{Convert|776|m}}.
Additionally, there are 2 x {{convert|1.5|MW}} Wind turbines installed at the upper reservoir and a 1.5 MW small hydro turbine on the Yangsang Dam.{{cite web|title=Yangyang Pumped Storage Power Plant South Korea|url=http://globalenergyobservatory.org/form.php?pid=6182|publisher=Global Energy Observatory|access-date=5 August 2011}}{{cite web|title=Status of Power Generation Equipment|url=http://www.komipo.co.kr/english/|publisher=Korean Midland Power Co.|access-date=5 August 2011}}
See also
{{stack|{{Portal|South Korea|Water|Renewable energy}}}}