System for distribution of electricity

Abstract

A system for distributing energy from an electrical power source to electrical loads, the system comprising: electrical storage tanks, each tank being transportable and having an electrical energy storage (ESS) facility, an inlet port, a DC-to-DC converter, an outlet cable and a coupler, the inlet being adapted to transfer DC power from the inlet port to the electrical energy storage facility, the DC-to-DC converter being adapted to deliver DC power from the electrical energy storage facility through the DC outlet cable and coupler; tank charging stations, each charging station having an AC to DC inverter, an outlet cable and a coupler, the inverter being coupled to the source in use to receive AC power therefrom and produce DC power and the cable being adapted to transfer DC power from the inverter to the outlet coupler; and load centers, each center having an electrical energy storage facility, an inlet port, a DC to AC inverter, and power distribution gear being operatively electrically coupled, in use, to one or more loads, the inlet port being adapted to transfer DC power from the outlet of an electrical storage tank to the load center's ESS facility.

Description

SYSTEM FOR DISTRIBUTION OF ELECTRICITYCross-Reference to Related Applications

[0001] This invention claims the benefit of United States Provisional Application Serial Nos. 63 / 662773 and 63 / 720212 filed June 21, 2024 and November 14, 2024, respectively.Field

[0002] The invention relates to the field of energy distribution.Background:

[0003] The adoption of electric vehicles and other electromobility carriers is rapidly increasing. One of the challenges in continuing this trend is the build-out of the electrical transmission and distribution systems of the electrical grid to support electric vehicle ("EV") charging stations.State of the Art:

[0004] EV charging stations are coupled via intermediate transformers to the electrical grid. To support the coupling and level power demand, increasingly electrical energy storage (EES) systems are located at points on the electric grid requiring power flow management / support, including at the point of EV charging station coupling. The EV charging stations are located at convenient charging locations, such as a shopping mall or fueling station. While this strategy works to a degree, it is limited by the capacity of the power lines and network equipment. In many cases, EV charging stations cannot be installed due to constrained electrical delivery capacity.

[0005] Typically, stationary EES systems utilize batteries for the storage of electrical energy. A conventional, stationary, battery EES ("BEES") system consists of: Battery modules are typically mounted in racks that are electrically connected in a series string and with multiple strings connected in parallel;DC switchgear and protections; power electronics to convert and control power flow; cooling / heating system; fire detection and suppression system, and controls.

[0006] To address constrained electrical energy delivery capacity on the grid, one recently deployed solution is portable BEES Systems, where the BEES is charged at a centralized substation and then transported to the location (site) of need. This solution, however, is limited by the logistics of unloading fully charged BEES systems at the site and reloading discharged BEES systems for charging at the centralized location. This is analogous to unloading full tanks of fossil fuels and reloading empty tanks for refilling. This, of course, is not done in the fossil fuel industry.

[0007] To address this drawback, two prior art solutions, are noteworthy.

[0008] The first solution is described in US10946762 and utilizes a DC microgrid for charging an "electric-tanker" that transports electrical energy to a DC charging station. The electric tanker comprises multiple discharge ports, one for each EV charging station, as illustrated in Figure 4. Each EV charging port is controlled by a DC-to-DC converter, as illustrated in Figure 5. The DC-to-DC converters are fed from a common DC interconnection to the battery energy storage (referred to as a "BES" in the patent) onboard the electric tanker. The BES is divided into multiple battery units, each unit controlled by a DC-to-DC converter. Other power sources, such as solar PV can be connected to the common DC interconnection to complement the energy stored in the BES system. In addition, the common DC interconnection can be used to power the electric tanker's tractor, subject to its electrical propulsion configuration. Charging of the electric tanker is performed by a DC microgrid with a DC-to-DC converter interface, as illustrated in Figures 6 and 7.

[0009] The second solution is described in US20220281346 and utilizes AC charging and discharging of an electric tanker (referred to as a "mobile BESS"). "BESS" is defined in the patent as a battery energy storage system. The mobile BESS delivers electrical energy in the form of AC power to a stationary battery energy storage system (referred to as a "stationary BESS") and AC power is distributed to EV charging stations (in the preceding patent an "outlet") from the stationary BESS, as shown in the single- line diagram of Figure 7. The power for the AC charging station is sourced from solar PV, the electric grid, or both. Electrical energy in the form of AC power is directly delivered to the mobile BESS, and power flow is controlled by an AC to DC converter ("Inverter") onboard the mobile BESS, as shown in the single- line diagram of Figure 8.

[0010] The preceding solutions are not ideal. The first solution adds unnecessary complexity by using multiple ports to directly charge each EV charger station, and the electrical tanker must remain at the delivery site until empty, which unnecessarily ties up capital in the form of truck assets. The second solution, with both AC charging and discharging of the electric tanker (mobile BESS), has impractically large cables and connectors. For example, an electric tanker with 1.8MWh is estimated to have 14 AC cables, enabling a charge in 2.7 hours.Summary of the Invention

[0011] Forming one aspect of the invention is a system for distributing electrical energy by transporting stored electrical energy from an alternating current (AC) electrical energy source, such as the electrical grid, to an AC or direct current (DC) load center comprising one or more loads, such as an EV charging station load (a "Load Center"). The transportation means being a transportable DC EES system (an "electrical tanker" or "eTanker") transported by road, waterway, or airway using a vehicle. Therefore, the system encompasses eTankers, a means of charging eTankers (each means being an "eTanker Charging Station"), and Load Centers that receive deliveries of electrical energy from the eTankers.

[0012] Each eTanker Charging Station has an AC to DC inverter, a cable and a coupler, the inverter being coupled to the electrical grid or other AC electrical source to receive AC power therefrom and produce DC power, and the outlet cable being used to transfer DC power from the inverter to the coupler to charge the eTanker's ESS facility with electrical energy.

[0013] Each eTanker is transportable and having an EES facility, an inlet port (mating end of a coupler), a DC-DC converter, an outlet cable and coupler, the inlet port used to transfer DC power from the eTanker Charging Station coupler to the eTanker's EES facility, and the DC-DC converter being adapted to deliver DC electrical power from the eTanker through the outlet cable and coupler to an inlet port on the Load Center; and

[0014] Each Load Center having an ESS facility an input port to charge the ESS, and being operatively electrically coupled through an DC to AC inverter, in use, to one or more loads, including EV charging stations, the inlet port being adapted to transfer DC power from the outlet coupler to the ESS facility.

[0015] According other aspects of the invention, the Load Centers can be coupled in use to the electrical grid or other power sources to receive electrical power therefrom in support of electrical energy deliveries from eTankers.

[0016] According to other aspects of the invention, an eTanker can remain coupled to a Load Center to act as its ESS facility to deliver electrical power on demand from the loads.

[0017] According to other aspects of the invention, in addition to the electrical grid, AC electrical energy sources to power the eTanker Charging Station include fuel cells, combustion engine generators, solar photovoltaic, wind turbines, thermoelectric generators, and any other means of generating electrical power, or any combination thereof.

[0018] According to other aspects of the invention, each eTanker can comply with ISO 668, each eTanker Charging Station can comply with ISO 668, and each Load Center can comply with ISO 668.

[0019] According to another aspect of the invention, the vehicle transporting the eTanker can further comprise of a propulsion system adapted to be charged with electrical energy from the eTanker Charging Station, or a portion thereof, or adapted to be charged with chemical energy, for example, hydrogen, produced using electrical energy, or a portion thereof, from the eTanker Charging Station.

[0020] Advantages, features and characteristics of the present invention will become apparent upon review of the following detailed description, with reference to the appended claims, the latter being briefly described hereinafter.BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Throughout the drawings, the EES is drawn as a battery. However, the EES can be a battery, supercapacitor, or another medium that stores electrical energy.

[0022] In the drawings:Figure 1 is a schematic view of a system according to an example embodiment of the invention where the electrical energy transported is derived an electrical grid;Figure 2 is a schematic view of a system according to an example embodiment of the invention where the electrical energy transported is derived an renewable power sources;Figure 3 is a single line diagram of an eTanker concept with the eTanker Charging Station and Load Center simultaneously coupled to the eTanker for illustration purposes;Figure 4 is a single-line diagram of an example eTanker Charge Station powered from the electrical grid;Figure 5 single-line diagram of an example eTanker Charge Station with renewable energy power sources and an EES system;Figure 6 single-line diagram of an example eTanker Charge Station with renewable energy power sources and an EES system replacing the grid to form the AC voltage;Figure 7 single-line Diagram of an example eTanker Charge Station charging a tractor having an electrical propulsion system with electrical energy;Figure 8 single-line diagram of an example eTanker Charge Station fueling a tractor with hydrogen fuel generated from electrical energy;Figure 9 single-line diagram of an example Load Center with EV charging station loads;Figure 10 single-line diagram of an example Load Center where the eTanker and electrical grid supplement each otherFigure 11 single-line Diagram of an example Load Center where an eTanker, electrical grid, and renewable electrical power sources supplement each other;Figure 12 single-line Diagram of an example Load Center where the eTanker provides electrical power on demand without an EES system present in the Load Center;Figure 13 single-line diagram of a Load Center where the eTanker supplements power from the grid without an EES system present in the Load Center, including management of power flow by the eTanker's ESS system;Figure 14 example ratings for a eTanker Charging Station discharging into an eTanker with an ESS facility utilizing lithium-ion batteries with a Nickel-Magnesium-Cobalt (NMC) cathode;Figure 15 example ratings of an eTanker discharging into a Load Center with an integrated ESS facility utilizing lithium-ion batteries with a Nickel-Magnesium-Cobalt (NMC) cathode, and alternatively, lithium-ion batteries with a Lithium-lron-Phosphate (LFP) cathode;Figure 16 example ratings of an eTanker discharging into a Load Center with a segregated ESS facility (ie a dedicated enclosure) utilizing lithium-ion batteries with a Nickel-Magnesium- Cobalt (NMC) cathode, and alternatively, lithium-ion batteries with a Lithium-lron- Phosphate (LFP) cathode; andFigure 17 is a glossary of symbols shown in the drawingsDetailed Description

[0023] According to one aspect, the invention entails designing an electric tanker with an electric energy storage (EES) facility utilizing one or more input ports for DC charging and a single output cable and coupler for DC discharging, referred to as an "eTanker". The eTanker is charged (filled) by an "eTanker Charge Station" powered by an electrical grid connection with an AC to DC inverter to convert and control the flow of charge power to the eTanker. The eTanker discharges its stored electrical energy to a stationary "Load Center" incorporating an EES and power distribution gear to power loads such as EV charging stations (or other loads). A DC-to-DC converter ("DC Converter") onboard the eTanker converts and controls the flow of discharge power to the stationary Load Center. This is illustrated in the single-line diagram of Figure 1.

[0024] In Figure 2, the electrical grid is replaced by renewable power sources and an EES to form an AC microgrid. The power from the AC microgrid then charges the eTanker utilizing the AC to DC inverter and its charging coupler. The AC microgrid can also incorporate fuel cells or combustion engine generators or other alternative power sources or combinations thereof.

[0025] Figure 3 is a single-line diagram of an example eTanker concept, which, for understanding purposes, includes the eTanker Charging Station and the Load Center connected to the eTanker simultaneously. Of course, this would not be the case in reality - it would be one or none.

[0026] As mentioned above, at minimum, the eTanker Charging Station has an electrical power source, AC to DC Inverter, and a DC cable with a coupler for plugging into the eTanker's input port. The power source for a basic design would include a connection to the electric grid and a transformer for isolation, which may not be required depending on the specifics of a solution. Other configurations are described further herein.

[0027] Electrical energy from the eTanker Charging Station is delivered directly to the EES facility within the eTanker through a diode to prevent back feed through the coupler of the eTanker Charge Station. However, other means of backfeed protection may be used, such as a reverse power flow relay with a high-speed DC breaker. Similarly, the eTanker directly delivers electrical energy to the Load Center's ESS facility through a diode or other means to prevent backfeed.eTanker:

[0028] For ease of logistics and transportation, an ideal enclosure for an eTanker is a 20' modified ISO 668 container transported on an intermodal trailer. However, the invention covers any type and size of a trailer and any enclosure / shelter for the EES suitable for truck transportation.

[0029] The transportation of an eTanker is not limited to transportation by overland trailer, but can be by a vessel or carrier using a waterway or airway

[0030] Expanding on the preceding descriptions, the eTanker includes the mobile EES for transporting electrical energy, associated safeties and environmental controls, a DC port for direct charging the ESS, a diode to prevent backfeed through the inlet port, a DC to DC converter (DC Converter), cable and coupler for discharging the ESS, and electrical protections and safeties. In the figures, the eTanker's EES facility is represented by a battery, but it does not necessarily need to be a battery. For example, the EES system could use supercapacitor or a mechanical or thermal means of storage,

[0031] The propulsion system for an eTanker's tractor, vessel or carrier can be mechanical, using a combustion engine with a variety of fuels, or electro-mechanical, using a fuel cell with a variety of fuels, or EES to store electricity, or any other means of propulsion. eTanker Charging Station

[0033] As mentioned, a basic eTanker Charging Station includes an electrical grid connection, an AC to DC Inverter, likely a transformer in between the two, and DC cable and coupler to plug into the eTanker's charge port. This configuration is shown in Figure 4.

[0034] In Figure 5, the eTanker Charge Station includes renewable energy power sources in addition to an electrical grid connection, which may or may not include an EES facility to manage power flow and store intermittent renewable energy. In the figure, the EES facility is represented by a battery, but it does not necessarily need to be a battery. For example, the EES facility could use supercapacitors or a mechanical or thermal means of electrical storage.

[0035] In Figure 6, there is no grid connection and the EES system forms the AC voltage, referred to as a "standalone" or "islanded" AC microgrid. In the figure, the eTanker is charged purely from renewable energy sources. However, the energy sources do not necessarily need to be from renewables, for example, a fuel cell, combustion engine, or other alternative power source.

[0036] In addition to charging the eTanker's ESS facility, the eTanker Charging Station can also charge its tractor used to transport the eTanker. Figure 7 illustrates charging a battery-powered eTanker, and Figure 7 illustrates charging a hydrogen-powered eTanker's tractor. The invention includes use of tractors with stored energy in any form derived from the electricity available in the eTanker Charging Station and useable as a power source to propel an eTanker's tractor. Similarly, the eTanker Charge Station can also charge a vessel or carrier for transporting eTankers using a waterway or airway.Load Center

[0037] As mentioned, a basic Load Center includes a DC port for direct charging of the ESS facility, a diode to prevent backfeed through the coupler, an EES facility for storing electrical energy and dispensing it on demand, associated safeties and environmental controls, a DC to AC inverter, a power distribution panel or cabinet to deliver power to each connected load, such as an EV charging station, and electrical protections and safeties. This configuration is shown in Figure 9. As a further example of a load, the Load Center could power the loads of a temporary event.

[0038] In Figure 10, energy delivered by the eTanker is supplemented with energy from the electrical grid, and vice versa. In Figure 11, energy delivered by the eTanker is supplemented with energy from the electrical grid and renewable power sources, and vice versa.

[0039] In Figure 12, the eTanker is connected to the Load Center as the only power source, eliminating the EES system within the Load Center. Similarly, in Figure 13, the eTanker can also be connected in parallel to the electric grid to supplement the grid during high demand. For example, this configuration could supplement an electrical grid connection during special occasions demanding higher power.Controls

[0040] The ideal means of control for charging and discharging the eTanker is a power regulator with voltage and current limit control. Another advantage of the invention is that voltage, current, and power feedback for the controls are available at the terminals of the Inverter in the eTanker Charge Station or the DC Converter onboard the eTanker. To supplement this feedback, the state-of-charge or state-of- stress of the ESS facility or other ESS state could also be fed back to the Inverter or DC Converter controlling power flow. This feedback from the battery could be wireless or hardwired using analog feedback or a digital signal plugged in while charging and used to optimize the charging / discharging profile.Example:

[0041] A specification of the eTanker system illustrated in Figures 1 and 2 follows. The eTanker requirements / constraints used in the example include:Use of a 20' ISO container as the envelope of the eTanker;Use of a battery as the storage medium of the ESS facilities (a battery energy storage system or "BESS");Safety as the first design constraint for the eTanker's BEES;An AC to DC unidirectional inverter, within the eTanker Charging Station, to charge the eTanker; A boost chopper DC converter, onboard eTanker, for discharging the eTanker;Active liquid cooling onboard the eTanker using a chiller to chill the battery modules, DC converter, power diodes, and DC cable and coupler for eTanker discharging;NMC lithium-ion battery modules onboard the eTanker for high-energy density, including thermal runaway protections, and compatibility with inert gas fire suppression;Inert gas fire alarm and suppression system; and Compliance with NFPA 855 for locations near exposures.

[0042] The foregoing eTanker requirements / constraints balance energy density with safety. Of the two, safety is the most important for an eTanker. Note that LFP and NMC lithium-ion batteries have very different attributes, and both can be designed to ensure a high degree of safety. Therefore, NMC was selected for the eTanker due to its higher energy density.

[0043] Figures 14, 15, and 16 illustrate typical ratings of an eTanker system using readily available equipment. eTanker Charging

[0044] Figure 14 is an example set of ratings for the eTanker being charged by an eTanker Charging Station. It utilizes a 1000V, 3000A DC charge coupler supplied and controlled by a unidirectional AC to DC inverter in the stationary eTanker Charging Station. REMA announced the availability of such a DC coupler in a press release dated June 12, 2023. Inverters of this rating are readily available from companies such as Dynapower, for example, its CPS-3000, with a DC voltage range of 550-1500 V and a maximum DC current of 3400 A.

[0041] The NMC lithium-ion battery onboard the eTanker must fit within the Charging Station's DC voltage and current rating of both the Inverter and the DC coupler. Such an NMC battery is composed of strings with groups of parallel-connected cells, each with 182 cell groups connected in series for a voltage range of 546V when fully discharged and 765V when fully charged. This is a good fit with the CPS-3000 inverter, stays below the preferred 800 V level for electric transportation systems, and the 3000 A current rating of the REMA DC coupler.

[0042] The described string configuration for the eTanker's battery, based on standard cargo door openings for a 20' ISO container, a typical prismatic NMC cell, and spacing for barriers and fire suppressant diffusion, has an estimated storage capacity of 1700 kWh. The foregoing charge rating supports a charge time of just over 1 hour with a constant power of 1700 kW tapered to 1638 kW once the DC charging current reaches 3000 A.eTanker Discharging

[0043] Figures 15 and 16 illustrate the eTanker being discharged into a Load Cener's BESS. The BESS acts as the "holding tank" to dispense electrical energy on demand. There are two physical arrangements.The one illustrated in Figure 15 where the BESS is integrated with the load power distribution equipment (the "Integrated Load Center"), and the other illustrated in Figure 16 where the BESS is in a dedicated container interconnected to a second container enclosing the load power distribution equipment (the "Segregated Load Center"). One of the advantages of the Segregated version is its additional energy storage capacity.

[0044] In this example, the DC converter onboard the eTanker uses a boost chopper typology requiring that the difference in voltage under all conditions between the eTanker's BESS and the Load Center's BESS be greater than 50 V. This condition with the minimum voltage difference occurs when the eTanker's BESS is fully charged and the Load Center's BESS is fully discharged. Therefore, the minimum voltage of the Load Center's BESS must be 765 V plus 50 V, or 815 V.

[0045] Using NMC lithium-ion cells, a battery using strings of 336 cell groups connected in series has a voltage range of 1010 V to 1410 V, which meets the foregoing criteria while limiting the voltage to less than 1500V within the rating of readily available equipment. Using LFP lithium-ion cells, a battery using strings of 416 cell groups connected in series has a voltage range of 835 V to 1330 V, which also meets the criteria.

[0046] For the Integrated Load Center, an NMC lithium-ion battery has an estimated capacity of 820 kWh, and for LFP, 720 kWh. One advantage of LFP is its higher charge rate. While NMC has a typical charge rate (the power to energy ratio) of 1, whereas an LFP-based battery can easily achieve charge rates of 2. Therefore, the NMC example for the Load Center's BESS has a charge time of 1 hour with a constant power of 820 kW with a maximum current of 813 A and no power tapering. For the LFP example, it has a charge time of just over 2 hour with a constant power of 1440 kW tapered to 1250 kW once the DC charging current reaches 1500 A. The 1500 A limit is imposed by the readily available rating of DC couplers within the charge rating.

[0047] For the Segregated Load Center, an NMC-based battery has an estimated capacity of 1635 kWh, and for LFP, 1380 kWh. For the NMC example with a charge rate of 1, the charge time is just over 1 hour with a constant power of 1635 kW tapered to 1575 kW once the DC charging current reaches 1500 A, which is the rating of the DC coupler. For the LFP example with a charge rate of 2, the charge time is just over J4 hour with a constant power of 2760 kW tapered to 2495 kW once the DC charging current reaches 3000 A, the next rating up for the DC coupler.

[0048] Note that practically, the eTanker would have one size of DC coupler. If the population of Load Centers has a Segregated Load Center utilizing an LFP BESS with a charge rate of 2, then all Load Centers would need to have a DC port rated 3000 A, even if 1500 A is only required on most of them.Load Center Recharge Intervals:

[0049] The Load Centers depicted in Figures 15 and 16 have EV charging station loads. However, the load can be of any type. For this example, however, Level 2 EV charging stations are used, each with a rating of 19kW. Using these loads and an effective utilization factor, the interval between recharging the Load Center's BESS is calculated to check its reasonableness. Further, as illustrated in Figure 10, the electric grid can complement Load Center's BESS, which would increase the recharge interval by the eTanker. Tables 1 and 2 list the recharge intervals for an effective utilization of 10 and 12 hours per day, and different grid connection amperage, where Table 1 is for an Integrated Load Center with 3 x Level 2 EV charge stations, and Table 2 for a Segregated Load Center with 6 x Level 2 EV charge stations. In each table, the first amperage is nil (i.e., no grid connection) and the last is 200 A with an AC grid interconnection of 480 V, 3-phase. For the Integrated Load Center example, a BESS with eTanker recharging is not required with a 100 A grid connection, and for the Segregated Load Center example, a BESS with eTanker recharging is not required with a 200 A grid connection.Table 1: Example eTanker recharge intervals for an Integrated Load Center with 3 x EV Level 2Charge Stations under different scenarios.Table 2: Example eTanker recharge intervals for a Segregated Load Center with 6x EV Level 2 Charge Stations under different scenarios.

[0050] Whereas specific embodiments are herein shown and described, further variations are possible. Accordingly, the invention should be understood to be limited only by the accompanying claims, purposively construed.

Claims

CLAIMS1. A system for distributing energy from an electrical power source to electrical loads, the system comprising: electrical storage tanks, each tank being transportable and having an electrical energy storage (ESS) facility, an inlet port, a DC-to-DC converter, an outlet cable and a coupler, the inlet being adapted to transfer DC power from the inlet port to the electrical energy storage facility, the DC- to-DC converter being adapted to deliver DC power from the electrical energy storage facility through the DC outlet cable and coupler; tank charging stations, each charging station having an AC to DC inverter, an outlet cable and a coupler, the inverter being coupled to the source in use to receive AC power therefrom and produce DC power and the cable being adapted to transfer DC power from the inverter to the outlet coupler; and load centers, each center having an electrical energy storage facility, an inlet port, a DC to AC inverter, and power distribution gear being operatively electrically coupled, in use, to one or more loads, the inlet port being adapted to transfer DC power from the outlet of an electrical storage tank to the load center's ESS facility.

2. The system according to claim 1, wherein the load centers are coupled in use to the electrical grid to receive AC power therefrom, in addition to the electrical energy delivered by electrical storage tanks.

3. The system according to claims 1, wherein the load centers are coupled in use to renewable, fuel cell, combustion engine, or other alternative power sources to receive AC power therefrom, in addition to the electrical energy delivered by electrical storage tanks.

4. The system according to claims 2, wherein the load centers are coupled in use to renewable, fuel cell, combustion engine, or other alternative power sources to receive AC power therefrom, in addition to the electrical energy delivered by electrical storage tanks.

5. The system according to claim 1, wherein a load center is coupled in use to an electrical storage tank.

6. The system according to claim 1, wherein a load center powers DC loads from the energy storage facility using a DC-to-DC converter.

7. The system according to claim 1, wherein a tank charging station is coupled to renewable, fuel cell, combustion engine, or other alternative power sources, with or without an electrical energy storage facility, to receive AC power therefrom.

8. The system according to claim 1, wherein a tank charging station is coupled to both the electrical grid and to renewable, fuel cell, combustion engine, or other alternative power sources, with or without an electrical energy storage facility, to receive AC power therefrom.

9. The system according to claim 1, wherein each electrical storage tank complies with ISO 668.

10. The system according to claim 1, wherein each load center enclosure complies with ISO 668.

11. The system according to claim 1, wherein each tank charging station enclosure complies with ISO668.

12. The system according to claim 1, further comprising tractors adapted to transport an electrical storage tank with energy for propulsion derived from a tank charging station.

13. The system according to claim 1, where the means of transporting the electrical storage tanks are by vessel or carrier using a waterway or airway.

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