U.S. patent application number 12/935925 was filed with the patent office on 2011-02-03 for power plant, method for producing power, and application of said power plant.
This patent application is currently assigned to STATOIL ASA. Invention is credited to Bjorn Bekken.
Application Number | 20110027107 12/935925 |
Document ID | / |
Family ID | 41135755 |
Filed Date | 2011-02-03 |
United States Patent
Application |
20110027107 |
Kind Code |
A1 |
Bekken; Bjorn |
February 3, 2011 |
POWER PLANT, METHOD FOR PRODUCING POWER, AND APPLICATION OF SAID
POWER PLANT
Abstract
Power plant comprising: a lower level reservoir, a feed-through
(line, hose, pipe, channel) for fluid communication from the lower
level reservoir to a higher level reservoir, characterised by a
pump arranged in connection with the feed-through in order to pump
water from the lower level reservoir to the higher level reservoir
in order to store energy by emptying the lower level reservoir, and
a turbine/generator for power production arranged in or at the
lower level reservoir in connection with said feed-through, or
additional feed-through, for fluid communication between the lower
level reservoir and the higher level reservoir for power production
during flow of water from the higher level reservoir to the lower
level reservoir. A method for power production. Use of the power
plant.
Inventors: |
Bekken; Bjorn; (Stavanger,
NO) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
STATOIL ASA
Stavanger
NO
|
Family ID: |
41135755 |
Appl. No.: |
12/935925 |
Filed: |
March 26, 2009 |
PCT Filed: |
March 26, 2009 |
PCT NO: |
PCT/NO2009/000111 |
371 Date: |
October 22, 2010 |
Current U.S.
Class: |
417/330 |
Current CPC
Class: |
Y02E 60/17 20130101;
F03B 13/06 20130101; Y02E 60/16 20130101; Y02E 10/22 20130101; Y02E
10/20 20130101; Y02P 90/50 20151101 |
Class at
Publication: |
417/330 |
International
Class: |
F04B 35/00 20060101
F04B035/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 2, 2008 |
NO |
2008 1642 |
Claims
1.-7. (canceled)
8. Power plant, comprising: a lower level reservoir, a feed-through
(line, hose, pipe, channel) for fluid communication from the lower
level reservoir to a higher level reservoir, a pump arranged in
connection to the feed-through for pumping water from the lower
level reservoir to the higher level reservoir in order to store
energy by emptying the lower level reservoir, and a
turbine/generator for power production arranged in or at the lower
level reservoir in connection with said feed-through, or additional
feed-through, for fluid communication between the lower level
reservoir and the higher level reservoir, for power production
during flow of water from the higher level reservoir to the lower
level reservoir, wherein the sea constitutes the higher level
reservoir.
9. Power plant according to claim 8, wherein the turbine/generator
is arranged at the bottom level in the lower level reservoir.
10. Power plant according to claim 8, wherein the pump is arranged
at the bottom level in the lower level reservoir.
11. Power plant according to claim 8, wherein the lower level
reservoir is arranged at or below a sea level.
12. Power plant according to claim 8, wherein the lower level
reservoir is arranged in tanks and/or in the shaft of a gravity
based structure installation or a seabed positioned tank previously
used for storage of fluid such as oil.
13. Power plant according to claim 8, wherein the lower level
reservoir is a hollow space onshore, which is close to the sea, and
in a level below the sea surface, such as a cave or a hollow space
from a terminated mining operation.
14. Method for power production by using the power plant according
to claim 8, which method comprises: pumping out water with the pump
from the lower level reservoir by means of surplus power or cheap
power in periods of the time when such power is available, and
introducing water from the higher level reservoir to the lower
level reservoir in periods of time when the price of power is high,
or when there is need for the thus stored power, in order to
produce power in the turbine/generator.
15. A method of using the power plant according to claim 8,
comprising the step of storing surplus power or cheap power, when
such power is available, for subsequent production.
16. Power plant according to claim 9, wherein the pump is arranged
at the bottom level in the lower level reservoir.
17. Method for power production by using the power plant according
to claim 9, which method comprises: pumping out water with the pump
from the lower level reservoir by means of surplus power or cheap
power in periods of the time when such power is available, and
introducing water from the higher level reservoir to the lower
level reservoir in periods of time when the price of power is high,
or when there is need for the thus stored power, in order to
produce power in the turbine/generator.
18. Method for power production by using the power plant according
to claim 10, which method comprises: pumping out water with the
pump from the lower level reservoir by means of surplus power or
cheap power in periods of the time when such power is available,
and introducing water from the higher level reservoir to the lower
level reservoir in periods of time when the price of power is high,
or when there is need for the thus stored power, in order to
produce power in the turbine/generator.
19. Method for power production by using the power plant according
to claim 11, which method comprises: pumping out water with the
pump from the lower level reservoir by means of surplus power or
cheap power in periods of the time when such power is available,
and introducing water from the higher level reservoir to the lower
level reservoir in periods of time when the price of power is high,
or when there is need for the thus stored power, in order to
produce power in the turbine/generator.
20. Method for power production by using the power plant according
to claim 12, which method comprises: pumping out water with the
pump from the lower level reservoir by means of surplus power or
cheap power in periods of the time when such power is available,
and introducing water from the higher level reservoir to the lower
level reservoir in periods of time when the price of power is high,
or when there is need for the thus stored power, in order to
produce power in the turbine/generator.
21. Method for power production by using the power plant according
to claim 13, which method comprises: pumping out water with the
pump from the lower level reservoir by means of surplus power or
cheap power in periods of the time when such power is available,
and introducing water from the higher level reservoir to the lower
level reservoir in periods of time when the price of power is high,
or when there is need for the thus stored power, in order to
produce power in the turbine/generator.
22. A method of using the power plant according to claim 9,
comprising the step of storing surplus power or cheap power, when
such power is available, for subsequent production.
23. A method of using the power plant according to claim 10,
comprising the step of storing surplus power or cheap power, when
such power is available, for subsequent production.
24. A method of using the power plant according to claim 11,
comprising the step of storing surplus power or cheap power, when
such power is available, for subsequent production.
25. A method of using the power plant according to claim 12,
comprising the step of storing surplus power or cheap power, when
such power is available, for subsequent production.
26. A method of using the power plant according to claim 13,
comprising the step of storing surplus power or cheap power, when
such power is available, for subsequent production.
Description
SCOPE OF THIS INVENTION
[0001] This invention relates to production of energy. Furthermore,
the invention relates to a power plant, a method for power
production and utilization of the power plant according to the
invention. The power plant according to the invention is
particularly suitable for storage of surplus power or cheap power
for subsequent power production.
BACKGROUND AND PRIOR ART OF THE INVENTION
[0002] Stable access to energy is necessary for the modern society.
Out of consideration to the environment, many are today concerned
about sustainable energy, for instance obtained from wind, waves,
tidal currencies, sea currencies, geothermal deposits or salt-water
gradients. Utilization of a number of such energy sources can for
instance be combined in marine energy parks, and since different
energy sources partly can be utilized complimentary, uniform
production and savings with regard to developing and operating
costs can be obtained. Still, the energy production tends to vary,
and there is a need to store surplus energy. Similarly, there is a
need for a simple way to store cheap energy from energy sources or
power plants of any known type, including surplus energy from
industrial plants. Different power plants and industrial plants
attend to have an uneven energy production which is not correlated
with the consumption.
[0003] A pumping storage power plant is known as technology, and is
the method of storage of energy that presently give the highest
efficiency. In a pumping storage power plant water is pumped to an
elevated reservoir in periods with surplus production or in periods
with low energy prices, whereupon energy is produced by letting
water escape from the elevated reservoir through turbines located
at a lower level. Furthermore, there are means to dam up water at
flood tide and to let out water through turbines at low tide.
Examples of known devices may be found in the patent publications
U.S. Pat. No. 3,487,228 and BE 903837.
[0004] There is a need for alternative power plants, methods and
uses of power plants having advantageous properties compared to
prior art devices. There is particularly a need for pumping storage
power plants which are particularly suitable in marine
environments.
SUMMARY OF THE INVENTION
[0005] The above mentioned needs are met by the present invention,
where the invention provides a power plant comprising: [0006] a low
level or low-lying reservoir [0007] a feed through (line, hose,
pipe, channel) for fluid communication from the low level reservoir
to a high level or high-lying reservoir, [0008] characterised by a
pump arranged in connection with the feed through in order to pump
water from the low level reservoir to the high level reservoir in
order to store energy by emptying the low level reservoir, and
[0009] a turbine/generator for power production arranged in or at
the low level reservoir in connection with the mentioned feed
through or an additional feed through for fluid communication
between the low level reservoir and the high level reservoir for
power production during flow of water from the high level reservoir
to the low level reservoir.
[0010] By the term low level reservoir is meant a reservoir where
the water level at any time is lower than the water level in the
high level reservoir or a reservoir where the highest possible
water level equals the water level in a high level reservoir, such
as a volume delimited from an external sea level.
[0011] The invention also provides a method for power production by
using the power plant according to the invention, characterised by
pumping out the water with the pump from the low level reservoir by
means of surplus power or cheap power during periods of time when
such power is available, and introduce water from the higher level
reservoir to the lower level reservoir in periods of time when the
price of power is high or when there is a need for the thus stored
power for producing power in the turbine/generator.
[0012] Furthermore, the invention provides for the use of a power
plant according to the invention for storing surplus power or cheap
power for subsequent power production according to the need.
FIGURE
[0013] The present invention is illustrated by means of FIG. 1 that
illustrates the power plant according to the present invention.
DETAILED DESCRIPTION
[0014] Reference is made to FIG. 1 which illustrates the power
plant according to the invention, as well as the method and the use
according to the invention.
[0015] Specifically, 1 illustrates the power plant in storage mode,
meaning that the water level in the lower level reservoir is
lowered due to use of surplus energy or cheap energy for pumping
water from the reservoir, while 2 illustrates the plant in
production mode, that is when water is introduced via a turbine for
thus to produce energy. In the FIGURE A indicates the lower level
reservoir, B indicates both pump and turbine/generator for power
production, while C indicates a valve. The higher level reservoir
is situated outside the lower level reservoir. The higher level
reservoir is preferably the sea while the lower level reservoir
preferably a tank positioned at the seabed, which typically has
previously been used for another purpose. In the illustrated
embodiment only one feed-through (line, hose, pipe, channel) is
present which is thus used to pump out water from the lower level
reservoir and feed water from the higher level reservoir during
subsequent power production. Alternatively separate feed throughs
or lines for alternatively pumping out water and introducing water
is arranged, having a pump in a connection with the feed-through
for out-pumping, and turbine/generator in connection with the
feed-through for introducing water from the higher level reservoir.
In the illustrated embodiment the valve C is arranged in a
branch-line from the feed-through. In storage mode, illustrated by
1, the valve C is closed while the valve, in production mode 2, is
open to introduce water from the higher level reservoir. When using
one feed-through the pump can likewise be separated in a dedicated
branch-line from the turbine/generator, as convenient. The outlet
for out-pumped water is preferably just above the water surface in
the higher level reservoir in order to minimize the pumping effort.
The outlet from the turbine is preferably at a bottom level in the
lower level reservoir in order to maximize the height of fall of
water, independent of degree of filling in the lower level
reservoir, and in order to reduce any problems with cavitation. The
energy which can be stored is proportional with the product of
out-pumped water volume and the obtained height of fall of water in
production mode. In order to maximize the stored amount of energy,
the cross-section of the lower level reservoir may be larger at to
the bottom than at the top, which will create a large height of
fall of water for larger volumes. Several lower level reservoirs
can be interconnected, which may be advantageous in connection with
building work and mechanical loads. In a preferable embodiment the
entire lower level reservoir is at a level below the water surface.
In one embodiment the lower level reservoir is preferably a part of
a foundation for a field centre, or anchoring or foundation for
other energy producing devices. In a preferred embodiment the lower
level reservoir is a re-use of previous, differently used devices,
for example former storage tanks for oil, storage tanks or shafts
for oil- and gas platforms or even pipe lines. A particularly
advantageous embodiment is to arrange the lower level reservoir in
tanks and perhaps also on the shaft on one or several
interconnected gravity based structure-platforms such as concrete
tanks and one or several hollow concrete shafts in a seabed
positioned platform. One embodiment, which particularly can be
suitable along coasts with suitable topography, is to dam up in an
area, wherein the area constitutes the lower level reservoir.
Another preferred embodiment is to operate the lower level
reservoir to also function as wharf or an area for other
applications, where a cover with ventilation preferably is arranged
at the upper part of the lower level reservoir. A further
advantageous embodiment is to apply hollow spaces onshore, which is
close to the sea, and in a level below the sea surface, as the
lower level reservoir, for example cave, caverns or hollow spaces
from a terminated mining operation.
[0016] The pump is preferably also arranged in a bottom level in
the lower reservoir since such a location will provide a certain
inlet pressure and reduction of any cavitation problems. Increased
pump head is compensated by increased inlet pressure.
[0017] For a turbine arranged at the bottom level, or at the bottom
of the lower level reservoir, increased pressure at the outlet side
is compensated by increased height of fall of water.
[0018] The turbine/generator may however be arranged on a floating
body, where water supply preferably is provided via flexible pipes
such as in the form of hoses or telescopic pipes. The pump may also
be arranged on or attached to such floating body, having attached
feed-throughs in the form of flexible pipes. Structural benefits,
and advantages with regard to access and maintenance, may thus be
achieved.
[0019] The pumps may be chosen among pumps that are driven
electrical, directly mechanical, or mechanical via gear connections
or hydraulic, as the available surplus energy or cheap power will
determine which choice is suitable to achieve a high efficiency,
low investment costs, good operation safety and simple maintenance
and replacement according to good engineering practice. In order to
reduce loss of efficiency, the pump may be driven mechanically,
directly or hydraulic, by wind power, wave power and/or sea current
power. Pumps, turbines, generators, valves and types of pipes or
similar will not be further described herein since it is considered
within prior art and good engineering practice to undertake
suitable choices and arrangement of such known equipment within the
framework of the description and attached claims.
[0020] The power plant according to the invention can both store
and produce energy and is particularly advantageous if it is
arranged as part of a large energy plant. For example the transfer
capacity in cables from a plant for offshore power production may
be reduced by storing the peak production as energy in a power
plant according to the invention. In such an offshore plant, water,
waves and current in the sea can generate energy under normal
operational conditions, However, during high regular production a
part of the produced energy will be stored in a power plant
according to the invention, while at low regular production the
power plant according to the invention can be put in operational
mode for production of the storage energy.
* * * * *