The relevance of energy storages for an autarky of electricity supply ...
The relevance of energy storages for an autarky of electricity supply ...
The relevance of energy storages for an autarky of electricity supply ...
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A disadv<strong>an</strong>tage <strong>of</strong> Pumped Hydroelectric Storage is that it is dependent from<br />
topographic circumst<strong>an</strong>ces to have enough head. This me<strong>an</strong>s, that the location is<br />
currently restricted to mountainous regions, where m<strong>an</strong>y countries do not have much<br />
potential left. <strong>The</strong>re<strong>for</strong>e the main focus nowadays is to improve existing pl<strong>an</strong>ts. In<br />
the future, pl<strong>an</strong>ts with the lower reservoir underground could be constructed (e.g.<br />
from caves, <strong>for</strong>mer mines or artificial holes). <strong>The</strong> upper reservoir could be a natural<br />
or artificial lake. With this technology, the l<strong>an</strong>dscape would not be that drastically<br />
ch<strong>an</strong>ged <strong>an</strong>d the storage pl<strong>an</strong>t could be built more closely to the place, where the<br />
<strong>electricity</strong> is produced or consumed. Furthermore, the need <strong>for</strong> tr<strong>an</strong>smission, which<br />
c<strong>an</strong> cause losses, would be decreased. At the moment investment costs <strong>for</strong> such<br />
storage pl<strong>an</strong>ts are very high – thus is not likely that such pl<strong>an</strong>ts are realized within<br />
the next ten years. (Neupert, 2009)<br />
Pumped Hydroelectric Storage is useful <strong>for</strong> daily peak shaving, load levelling <strong>an</strong>d <strong>for</strong><br />
weekly <strong>an</strong>d seasonal variations in the <strong>energy</strong> dem<strong>an</strong>d. Electricity is available very<br />
fast, which is one major adv<strong>an</strong>tage <strong>of</strong> this system. <strong>The</strong> full power <strong>of</strong> the pl<strong>an</strong>t is<br />
available only after about one minute <strong>an</strong>d it only takes several minutes to get<br />
pumping into operation. Furthermore, power c<strong>an</strong> be adjusted flexible to the dem<strong>an</strong>d.<br />
Pumped hydro is available at almost <strong>an</strong>y scale with discharge times r<strong>an</strong>ging from<br />
several hours to a few days. (Huggins, 2010; Neupert, 2009)<br />
4.4.2 Key figures<br />
Rated power<br />
<strong>The</strong> rated power from Pumped Hydroelectric Storage r<strong>an</strong>ges from 20 – 2100 MW.<br />
(Alamri, 2009) <strong>The</strong> power <strong>of</strong> such pl<strong>an</strong>ts in Austria currently r<strong>an</strong>ges up to 750 MW.<br />
Energy content <strong>of</strong> the storage<br />
<strong>The</strong> stored <strong>energy</strong> <strong>of</strong> Pumped Hydroelectric Storage is proportional to the volume <strong>of</strong><br />
the higher reservoir <strong>an</strong>d the head. In Austria head is between 340 m <strong>an</strong>d 1250 m 5,6,7 .<br />
Equation (1) <strong>an</strong>d Equation (2) show how <strong>energy</strong> content <strong>an</strong>d power c<strong>an</strong> be calculated<br />
5 http://www.verbund.com/cc/de/ueber-uns/unserekraftwerke/kraftwerkstypen/pumpspeicherkraftwerk,<br />
07.10.2011<br />
20
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