Dispatchable renewable power supply

Abstract

A dispatchable power supply is disclosed, more particularly an off-grid power supply, more particularly an off-grid electric vehicle charge station, more particularly to an off-grid renewable energy powered electric vehicle charge station.

Claims

1. A dispatchable renewable power supply having a total dispatchable power output (P.sub.D) of at least 25 kW, the dispatchable power supply comprising: (i) a base power generator selected from at least one of the group consisting of: a hydroelectric power generator, and a geothermal power generator; (ii) a secondary power generator comprising at least one renewable power generator; (iii) a battery; and (iv) power transmission means for communicating the generated power to an at least one consumer, wherein each of the power generators is non-dispatchable, and (a) the dispatchable power supply has a peak instantaneous non-base required power output (P.sub.M-Peak), (b) the secondary power generator has a capacity factor (CF.sub.secondary), and (c) the total installed power generating capacity of the secondary power generator (P.sub.Secondary-Installed) is equal to P.sub.M-Peak×(1/CF.sub.Secondary).

2. A The dispatchable renewable power supply according to claim 1, wherein the base power generator has a maximum power output (P.sub.B-Installed) equal to or greater than the total dispatchable power output (P.sub.D).

3. The dispatchable renewable power supply according to claim 2, wherein the base power generator has a maximum power output (P.sub.B-Installed) equal to the total dispatchable power output (P.sub.D).

4. The dispatchable renewable power supply according to claim 1, wherein the base power generator has an annualised capacity factor (CF.sub.B) of at least 50%.

5. The dispatchable renewable power supply according to claim 1, wherein the battery has a total installed power rating (PR.sub.Installed) of the greater of PR.sub.B and PR.sub.Secondary, wherein: PR.sub.B is the power rating requirement from the base power generator and which is equal to or greater than the base power generator maximum power output (P.sub.B-Installed); and PR.sub.Secondary is the power rating requirement from the secondary power generator and which is equal to or greater than P.sub.secondary-Installed×CF.sub.Secondary-Peak, wherein CF.sub.Secondary-Peak is the instantaneous peak capacity factor of the secondary power generator.

6. The dispatchable renewable power supply according to claim 5, wherein the secondary power generator is not a hydroelectric power generator or a geothermal power generator, wherein the battery has a storage capacity (ES.sub.Generators) equal to or greater than ES.sub.B+ES.sub.Secondary, wherein ES.sub.B is the minimum required energy storage for the base power generator, and ES.sub.secondary is the minimum required energy storage capacity for the secondary power generator.

7. The dispatchable renewable power supply according to claim 1, wherein the secondary power generator is not a hydroelectric power generator or a geothermal power generator.

8. The dispatchable renewable power supply according to claim 1, wherein the secondary power generator is selected from at least one of the group consisting of: a solar power generator, and a wind power generator.

9. The dispatchable renewable power supply according to claim 8, wherein the secondary power generator comprises a solar power generator and a wind power generator.

10. The dispatchable renewable power supply according to claim 1, wherein it has a total dispatchable power output (P.sub.T) of at least 50, 75, 100, 200, 250, 300, 400, 500, 750 or 1000 kW.

11. The dispatchable renewable power supply according to claim 1, wherein the base power generator is a hydroelectric power generator.

12. The dispatchable renewable power supply according to claim 11, wherein the hydroelectric power generator is in fluid flow communication with a water source.

13. The dispatchable renewable power supply according to claim 1, wherein it is an off-grid power supply.

14. The dispatchable renewable power supply according to claim 13, wherein it is an off-grid electric vehicle charge station.

15. A dispatchable renewable power supply according to claim 14, wherein the power transmission means comprises an at least one electric vehicle charge point.

16. The dispatchable renewable power supply according to claim 15, wherein the at least one electric vehicle charge point has a power output of at least 7 kW.

17. A dispatchable renewable power supply having a total dispatchable power output (P.sub.T) of at least 25 kW, the dispatchable power supply comprising: (i) a base power generator selected from at least one of the group consisting of: a hydroelectric power generator, and a geothermal power generator; (ii) a battery; and (iii) power transmission means for communicating the generated power to an at least one consumer, wherein each of the power generators is non-dispatchable, and (a) the dispatchable power supply has a peak instantaneous non-base required power output (P.sub.M-Peak), (b) the secondary power generator has a capacity factor (CF.sub.Secondary), and (c) the total installed power generating capacity of the secondary power generator (P.sub.Secondary-Installed) is equal to P.sub.M-Peak×(1/CF.sub.Secondary).

18. The dispatchable renewable power supply according to claim 17, wherein the base power generator is a hydroelectric power generator.

Description

EMBODIMENTS

(1) Unless the context dictates otherwise, the words “comprise”, “comprises”, “comprising” and the like are to be interpreted in an inclusive, rather than exhaustive sense i.e. the sense of “including, but not limited to”. The terms do include embodiments in which no further components are present.

(2) Particular and preferred aspects of the invention are set out in the accompanying independent claims. Features from the dependent claims may be combined with features of the independent claims as desired and appropriate and not merely as explicitly set out in the claims.

(3) An enabling disclosure of the present invention, to one of ordinary skill in the art, is provided herein. Reference now will be made in detail to embodiments of the invention, one or more examples of which are set forth below. Each example is provided by way of explanation of the invention, not limitation of the invention. Of the figures:

(4) FIG. 1 is a graphical representation of the power generated by a wind farm illustrating the day-to-day variation over a period of 4 days in two years;

(5) FIG. 2 is a graphical representation of the power generated by a wind turbine against wind speed;

(6) FIG. 3 is a graphical representation of the solar radiation in California given monthly over 2013/2014 (www.eia.gov/todayinenergy/detail.php?id=16851; perma.cc/K7HC-HPW8);

(7) FIG. 4 is a schematic diagram of an off-grid charging system according to at least one exemplary embodiment of the present invention;

(8) FIG. 5 is a graph showing the exceedance flow curve for a hydrological site in Scotland; and

(9) FIG. 6 is a schematic diagram of a dispatchable grid-connected power supply as per Embodiments 4-7.

(10) A list of the reference signs used herein is given at the end of the specific embodiments. Repeat use of reference symbols in the present specification and drawings is intended to represent the same or analogous features or elements.

Embodiment 1

(11) In a first embodiment, and with reference to FIG. 4 of the drawings, there is provided an off-grid electric vehicle (EV) charge station (10) capable of providing 100 kW dispatchable power output (P.sub.D). The off-grid electric vehicle charge station (10) comprises a base power generator (11) (also referred to as a primary power generator) in the form of a hydroelectric power generator. The hydroelectric power generator is in fluid flow communication with a water source, and comprises a turbine and generator.

(12) The off-grid electric vehicle charge station (10) further comprises storage capacity in the form of a battery (12) (“grid battery”) electrically coupled to the base power generator (11). A secondary power generator (13) in the form of a solar power generator (comprising photovoltaic cells) is also coupled to the battery (12), and both power generators (11, 13) are configurable to generate power from their respective renewable energy sources and send the power to the battery (12).

(13) Connections between components of the invention are illustrated schematically as lines going between each part. However, it will be apparent to the person skilled in the art that such connections could be any suitable connection such as wires, cables, RF communication, etc., which is configured to transmit power on demand.

(14) A control module (14) is coupled to the power generators (11, 13) the battery (12) and the four charge points (15). The control module (14) is a computer located at the site. The control module (14) is configured to communicate with each relevant component using a separate control network and send power upon receipt of a charge signal from the electric vehicle charge points (15), and transmit the energy to the charge points (15) with load. The control module (14) is also configured to ensure that each EV charge point (15) has the required power output of at least 7 kW at any given time. Control module (14) is provided with secure VPN remote access.

(15) For example

(16) Location: Scotland, National Park Area

(17) User Profile: park, walk and slow-charge

(18) TABLE-US-00009 Inputs Nomenclature Input EV charge station dispatchable P.sub.D 100 kW power base power generator (hydro) P.sub.B-Oversize  0 kW oversize average annual capacity factor CF.sub.B  80% (base) lowest base generation P.sub.B-Low  0 kW secondary power generator S.sub.S 100% solar component capacity factor solar CF.sub.S  12% capacity factor wind CF.sub.W n/a peak capacity factor solar CF.sub.S-Peak  50% peak capacity factor wind CF.sub.W-Peak n/a operational hours (per day) T 24 hours Specifications Nomenclature Design Size base power generator - P.sub.B-Installed 100 kW hydro (11) grid-battery (12) power rating PR.sub.Installed 417 kW grid-battery (12) Capacity ES.sub.Installed 1.3 MWh secondary power generator - P.sub.S-Installed 833 kW solar (13) (i.e. P.sub.Secondary-Installed)

(19) As illustrated in FIG. 4, in this embodiment four 25 kW charge points are provided. The 100 kW dispatchable power can be distributed with other configurations of charge points, as illustrated below:

(20) TABLE-US-00010 Charge per EV vehicle Simulta- Charges charge point(s) (15) per neous per Example Usage Scenarios Power hour Charges hour slow charging (>1 hour)  7 kW  7 kWh 14 14 medium charging (>1 hour)  25 kW 25 kWh  4  4 fast charging (30 minutes)  50 kW 25 kWh  2  4 Super-Fast charging 100 kW 25 kWh  1  4 (15 minutes)

Embodiment 2

(21) A second exemplary embodiment of the invention comprises the base power generator (11), the battery (12), the control module (14) and the EV charge point (15) as described above.

(22) Where a reliable energy source is known, it is not necessary to provide a secondary power generator. For example, dams may often have a minimum water flow or spill from the reservoir in order to allow water to flow downstream, reducing the environmental impact of the dam. Therefore, there is a guaranteed water flow at all times of the year. Therefore, the base power generator (11) can be built to specification for the exact amount of water flow, and the battery (12) sized appropriately so as to provide the “off-grid”, always on, EV charging station of the present invention.

(23) In use, the electric vehicle charge station (10) provides an off-grid, always on power source for EV vehicles and is powered entirely by renewable energy sources. The battery (12) and base power generator (11) combine to provide dispatchable power so that the EV charge point (15) is always available to the user. Where necessary, and depending on the site, a secondary power generator (13) may be used to supplement the missing capacity factor if the base power generator (11) is not operating at the preferred capacity factor. The base power generator (11) is capable of limiting the water intake (as it is preferably a hydroelectric power generation system) so as not to generate excess energy. This allows the storage capacity, or battery (12), to be small and therefore significantly reduces the cost and environmental impact of building the electric vehicle charge station (10). The electric vehicle charge station (10) is entirely “off-grid” therefore may be located in areas which are not yet connected to the local power grid.

Embodiment 3

(24) A third exemplary embodiment comprises commercial premises having a typical power demand during operation hours (8 am-6 pm) of 75 kW, and a maximum power demand of 95 kW. A dispatchable off-grid power supply is provided as per Embodiment 1, capable of providing 100 kW of dispatchable power.

Embodiment 4

(25) A fourth example embodiment in the form of an on-grid dispatchable power supply (18) is illustrated in FIG. 6 and comprises the base power generator (11), the battery (12), and the control module (14) as described above. A dispatchable power supply is provided as per Embodiment 1, capable of providing dispatchable power. Rather than having an EV charge point (15), a consumer is provided in the form of a grid connection (17). Generated power from the base power generator (11) is transmitted to inverter and transformer (16) and then to battery 12 which is located adjacent grid connection (17). Additional non-dispatchable generation can be sold onto the grid (for example at times of system peaking).

Embodiment 5

(26) In an 8-hour 3 MW storage discharge configuration, a dispatchable power supply is provided as per Embodiment 4. 1 MW dispatchable generation is provided by the base power generator (11) and the secondary power generator (13). Battery (12) has a capacity of 16 MWh This provides 8 hours of dispatchable power at 3 MW, compliant with requirements for the capacity market. As for Embodiment 4, generated power from the base power generator (11) is transmitted to inverter and transformer (16) and then to battery 12 which is located adjacent grid connection (17).

Embodiment 6

(27) In a 16-hour 1.5 MW storage discharge configuration (for example, “black start”), a dispatchable power supply is provided as per Embodiment 4. 1 MW dispatchable generation is provided by the base power generator (11) and the secondary power generator (13). Battery (12) has a capacity of 8 MWh. This provides 16 hours of dispatchable power at 1.5 MW, compliant with requirements for a “black start” service in the PJM market. As for Embodiment 4, generated power from the base power generator (11) is transmitted to inverter and transformer (16) and then to battery 12 which is located adjacent grid connection (17).

Embodiment 7

(28) In a 12-minute 120 MW storage discharge configuration, a dispatchable power supply is provided as per Embodiment 4. 1 MW dispatchable generation is provided by the base power generator (11) and the secondary power generator (13). Battery (12) has a capacity of 24 MWh. This provides 12 minutes of dispatchable power at 120 MW, available every 24 hours. This is sufficient to substitute for always on gas-plant spinning reserve. Instead of running the gas plants always on during peak times, this invention will carry a 120 MW load while the gas plant is warmed up. As for Embodiment 4, generated power from the base power generator (11) is transmitted to inverter and transformer (16) and then to battery 12 which is located adjacent grid connection (17).

Embodiment 8

(29) A dispatchable power supply is provided as per Embodiment 4. Grid connection (17) is replaced with a local consumer and a local grid, e.g. an industrial facility. Thus, a UPS (uninterruptable power supply) service can be provided for a local consumer, bridging short gaps in grid supplied power where necessary, and providing power in critical situations so as to allow for a graceful shutdown of services.

(30) Reference signs are incorporated in the claims solely to ease their understanding, and do not limit the scope of the claims. The present invention is not limited to the above embodiments only, and other embodiments will be readily apparent to one of ordinary skill in the art without departing from the scope of the appended claims.

REFERENCE SIGNS

(31) 10—Electric vehicle charge station 11—Base power generator 12—Battery 13—Secondary power generator 14—Control module 15—EV charge point(s) 16—Inverter and transformer 17—Grid connection 18—On-grid dispatchable power supply