An underground power station is a type of hydroelectric power station constructed by excavating the major components (e.g. machine hall, penstocks, and tailrace) from rock, rather than the more common surface-based construction methods.
One or more conditions impact whether a power station is constructed underground. The terrain or geology around a dam is taken into consideration, as gorges or steep valleys may not accommodate a surface power station. A power station within bedrock may be less expensive to construct than a surface power station on loose soil. Avalanche-prone valleys often make a surface station unfeasible as well.[1] After World War II, large hydroelectric power stations were placed underground more often in order to protect them from airstrikes.[2]
Often underground power stations form part of pumped storage hydroelectricity schemes, whose basic function is to level load: they use cheap or surplus off-peak power to pump water from a lower lake to an upper lake. During peak periods (when electricity prices are often high), the power station generates power from the water held in the upper lake.
- ^ A K Raja, Amit Prakash Shriwastava, Manish Dwivedi. Power Plant Engineering. Digital Designs. pp. 358–359. Retrieved 25 January 2015.
{{cite book}}: CS1 maint: multiple names: authors list (link) - ^ Dandekar, M. M.; Sharma, K. N. (2010). Water power engineering. Noida: Vikas Publishing House. p. 381. ISBN 978-0706986365. Retrieved 25 January 2015.