A pump-fed power station (briefly "pumped storage power station" (PSW) mentioned) is a special form of a storage power station and serves the storage of electricity by means of water.

Function mode

Storage

At times, in which a "surplus" is present at electricity (usually at night), water by pipings into a high-altitude storage basin (upper reservoir) pumped. This lake is either natural origin or develops by accumulating by a concrete dam or a dam. There are upper reservoirs, which are filled exclusively by pumps and such, which are fed also by natural supply.

The height of the storage capacity depends in principle on the storable quantity of water and the usable difference in height between upper reservoirs and the turbine. Distances underneath the turbine up to the discharge, also verrohrte, are usable for the turbine. With pure pumped storage power stations the storage capacity is usually in such a way laid out that the generators can produce approx. 4 to 8 hours under full load river.

Energy conversion

Characteristic of a pump-fed power station is the reversible plant enterprise. A turbine, a motor generator and a pump are installed on a wave and form a unit, which functions in double way. The motor generator produces on the one hand, from the turbine propelled, electric current. On the other hand it than electrical engine functions and propels the pump, which pumps the water now to the upper reservoir.

Apart from this classical building method a pumping turbine power station is today usually equipped with a so-called pumping turbine in place of the turbine and the pump. With the pumping turbine it concerns a fluid-flow machine, which can be flowed through in both directions, and depending upon drive direction as pump or turbine works.

Energy-industry meaning

The ability of the pump-fed power stations will deliver to take up energy and for the regulation of electricity mains used. In Germany a pump storage achievement of 4215 MW is installed, which supply a generation of current of 6,1 TWh with a course of the year time of 1070h as so-called "rule energy".

The achievement is available if necessary within minutes and can be flexibly regulated within a wide range. This is an advantage opposite conventional thermal power stations, whose achievement can be adapted only within the range of several hours. This rule energy is used both to interception of need points and to interception of sudden consumption break-downs.

Strong load times, which are served by pump-fed power stations, are in particular at noon, with certain medialen events such as soccer games or with tempests, which are connected with sudden cold weather or darkness.

Owing to their "black starting ability in such a way specified" pump-fed power stations can be used with total power failures for starting other power stations.

In small yardstick pump-fed power stations were realized for the first time into the 1920ern. One of German engineers, who developed the technology for largely dimensioned pump-fed power stations as world-wide pioneer achievement, was Arthur Koepchen. After it that was designated 1930 in enterprise taken PSW Koepchenwerk of the RWE AG in stove corner at the Ruhr.

Economics

With low general power requirement and therefore cheap electricity tariffs functions the generator as current consumption that engine and pumps water highly. With this water in point times of the current consumption river is produced, which is expensively sold. To that extent pump-fed power stations essentially use the difference in prices between reason and crest current and operate the "current refinement in such a way specified".

By thermal power stations, like nuclear power, certain types of coal-fired power stations and run hydro-electric power plants, the nearly constant quantities of electricity supply and at the same time the general current consumption varying strongly in the course of the day, are economically quite meaningful the enterprise of pump-fed power stations. They offer a possibility of converting "blindly" the river, which is at paragraph-weak times of day either quasi free of charge (with same operator) or at comparatively favourable prices available, fed into the net, temporally transferred in river which can be sold clearly more expensively for need points. Usually the selling price reaches a multiple of the purchase price with this business.

Pump-fed power stations remove usually daily a remaining alike quantity of electricity for the pumping enterprise. Their existence secures thereby also a part of the economic risks of thermal power stations, which feed at night practically necessary river at all only into the net. On the assumption of a further rise of current production from wind energy also on a meaning of pump-fed power stations, rising in the future, one counts, since wind energy is subject mostly to strong temporal fluctuations and therefore effective memory possibilities necessarily.

Ecology

Under the fact that with this power station form and current-intensive pumping a "invisible energy destruction" accompanies, it is however energy-politically and ecologically disputed pump-fed power stations. They represent at present however the only industrial procedure to store not in principle storable electric current temporarily on fluctuations of the demand and the offer. In principle purely physically in each pump-fed power station more energy for the inflation needed than by the water drain to be again recovered can (see principle of conservation of energy ). With modern works nearly 80% of the supplied river are nevertheless recovered again. However the line losses for and return motion of the electricity double themselves.

With the high efficiencies indicated by the operator companies (often 70 80%) it should be considered that these refer exclusively to the efficiency of the plants as energy stores. Logical way would have to be considered for the computation of an overall efficiency the memory use as efficiency-reducing factor for the efficiency of the pumping Rome supplier (for example coal-fired power stations).

The building of pump-fed power stations represents a partial substantial interference in nature and landscape.

List of pump-fed power stations

The power stations are sorted in the order of their MW-achievement. The respective construction period or start-up is to be read off from the years.

Articles in category "Pump-fed power station"

We found here 42 articles.