Systems and methods for integrated power management

Abstract

Disclosed herein are systems and methods for integrated power management, which can draw seamlessly on multiple sources to provide uninterrupted power, and can harness heat and water byproducts to maximise efficiency within their ecosystems. A hydrogen powered fuel cell can provide range extension for a direct coupled battery within the system, and the different power inputs can be prioritised and tuned based on programmable criteria such as user preference, availability, time of day, and cost.

Description

[0001] SYSTEMS AND METHODS FOR INTEGRATED POWER MANAGEMENT

[0002] BACKGROUND

[0003] In the past century, fossil fuels, such as coal, oil, and natural gas, have traditionally served as the major sources of energy to generate electricity. However, these non-renewable resources can take millions of years to form and have to be extracted from the earth and burned to produce energy. The burning emits harmful greenhouse gases, such as carbon dioxide.

[0004] Renewable energy is energy derived from sources that are naturally replenishing. Types of renewable energy include bioenergy, geothermal energy, hydropower, marine energy, solar energy, and wind energy. Renewable energy sources are much more plentiful, as compared to fossil fuels, and produce little or no harmful emissions when used. Renewable energy sources are increasingly cost-competitive with traditional energy sources, and can provide clean energy for numerous applications, including in communities and locations where the grid is inaccessible or unreliable and has prolonged periods of blackouts.

[0005] SUMMARY

[0006] Renewable energy is intermittent and the storage and the ability to decouple the time of creation / production from the time of demand on the existing electrical grid is an area needing improvements.

[0007] Existing electrical grids are commonly congested and limited in capacity and therefore renewable and storage systems that are not co-located have difficulties or are unable to be fully utilised and present a situation where two sets of grid connection fees are required.

[0008] Embodiments of the present invention address these issues and provide a single point to aggregate, store and dispatch renewable and traditional energy sources providing off-grid power or connecting to existing electrical grid infrastructure.

[0009] Various embodiments of a power system are described herein, which provide fully integrated power management for the end user (such as agriculture, industrial, tourism and large real estates / buildings). Current solutions typically come from different providers, leading to duplication and a lack of overall integrated control and differing maintenance / ownership contracts for the end user. The integration that the described embodiments afford provides an improved solution with a single point of ownership.

[0010] The systems are flexible, and can be configured to accept a range of established renewable power provisions, as well as legacy grid-supplied power. The final power balance is under software control and allows the end user to tailor their power profile depending on their application.

[0011] The embodiments also can function as an uninterruptible power supply (UPS) with no dropout due to the DC bus. Existing hybridised systems are not commonly managed at this power level, providing breakerless failover for the end user.

[0012] In some embodiments, the system may incorporate combined liquid and ambient air cooling to prevent system overheating. Furthermore, heat derived from such cooling can be aggregated and utilised (e.g., input into a customer’s hot water system), rather than being lost to the atmosphere.

[0013] In some embodiments, the system may be associated with an electrolyser. In such arrangements, combined heat and water recovery can increase the efficiency of the photovoltaic panels and the electrolysis process whilst reducing the overall volume of water required.

[0014] In some embodiments, hydrogen management is structured to provide the most robust power provision. The electrolyser may be configured to prepare trailers for distribution as promptly as possible. Similarly, the power system may be configured to free up (empty) its emptiest trailer preferentially to allow it to be returned for re-filling whilst leaving a full reserve in place, if required.

[0015] In some embodiments, an ecosystem is formed in which multiple power systems (the same or different) as described herein are installed in clusters around a larger electrolyser site. This configuration provides benefits of scale and allows for larger solar or other renewable sources to be located away from the desired points of consumption. In some embodiments, the invention provides an integrated power system providing uninterrupted power, comprising: a DC bus configured to accept DC and AC power inputs from a plurality of power input sub-systems, including grid, one or more renewable energy sources, and a hydrogen fuel cell, the DC bus including one or more voltage or current sensors; a battery sub-system directly coupled to the DC bus; a micro-grid inverter configured to provide power from the DC bus in a single uninterruptible system output; and a system controller configured in accordance with computer readable instructions to perform functions, including to: (i) monitor energy flow onto and from the DC bus via the one or more voltage or current sensors, (ii) direct energy to the battery sub-system, thereby charging the battery sub-system, when energy flow onto the DC bus is greater than energy flow from the DC bus, and (iii) select as an active power input the input from at least one of the plurality of power input sub-systems and the battery subsystem based on one or more programmable prioritisation criteria, where the active power input changes based on the one or more programmable prioritisation criteria.

[0016] In some embodiments, the programmable prioritisation criteria include at least one of end user preference, availability, time of day, and cost.

[0017] In some embodiments, each power input sub-system is configured to track variations in voltage of the DC bus.

[0018] In some embodiments, the system output is 3-phase+N+PE.

[0019] In some embodiments, the system is operated stand-alone.

[0020] In some embodiments, the system is operated in a co-operative mode, connected in parallel to at least one additional integrated power system as described above.

[0021] In some embodiments, the system further includes the hydrogen fuel cell, wherein the hydrogen fuel cell includes low temperature and high temperature cooling loops combined and utilised with a temperature-controlled cooling fan to safeguard against system overheating.

[0022] In some embodiments, heat from the combined cooling loops is aggregated and input into a customer's hot water system or an absorption HVAC system. In some embodiments, heat and water produced by the system are collected and input into an electrolyser.

[0023] In some embodiments, the system further includes the hydrogen fuel cell, and includes one or more trailers supplying hydrogen for the fuel cell, each trailer including a local controller configured to be interrogated both by the system and by an electrolyser filling the trailer, providing a logged audit trail.

[0024] In some embodiments, the system includes at least two trailers, and is configured to use the emptiest trailer preferentially, and to switch to the next trailer automatically via an automatic valve controlled by the system controller based on pressure sensor feedback.

[0025] In some embodiments, the system controller is configured to select the battery subsystem and the hydrogen fuel cell as the active power input, in a predetermined battery to fuel cell ratio.

[0026] In some embodiments, the system controller is configured to adjust the battery to fuel cell ratio based on availability of the one or more renewable energy sources.

[0027] In some embodiments, the system controller is configured to select the hydrogen fuel cell as the active power input when the battery sub-system charge is below a predetermined threshold and no renewable energy sources are detected.

[0028] In some embodiments, the system is configured to provide power to an electrolyser comprising a plurality of clusters.

[0029] In some embodiments, the electrolyser includes a field controller, the field controller configured and adapted to communicate with the system controller, receive an indication of available power, and limit hydrogen production to match the available power.

[0030] In some embodiments, the field controller in communication with the system controller is configured to power a portion of the clusters proportional to the power available from the one or more power input sub-systems. In some embodiments, the one or more power input sub-systems include solar and the system is configured to use source water for the electrolyser to cool one or more photovoltaic panels connected to the DC bus.

[0031] In some embodiments, the system and the electrolyser each include a wireless communication channel.

[0032] In some embodiments, the system includes a wireless communication channel.

[0033] In some embodiments, each trailer includes a pressure regulator and is configured to be filled at a high pressure and to provide a lower pressure hydrogen feed to the system.

[0034] In some embodiments, the electrolyser includes a field controller in communication with the system controller and the field controller and the system controller are configured to implement power matching, whereby the amount of power drawn by the electrolyser does not exceed the amount of power available from the system.

[0035] In some embodiments, the invention provides a method of providing uninterrupted power, comprising: providing a DC bus directly coupled to a battery sub-system, the DC bus configured to accept DC and AC power inputs from a plurality of power input sub-systems, including grid, one or more renewable energy sources, and a hydrogen fuel cell, the DC bus including one or more voltage or current sensors; monitoring energy flow onto and from the DC bus via the one or more voltage or current sensors; directing energy to the battery sub-system, thereby charging the battery sub-system, when energy flow onto the DC bus is greater than energy flow from the DC bus; selecting as an active power input the input from at least one of the plurality of power input sub-systems and the battery sub-system based on one or more programmable prioritisation criteria, where the active power input changes based on the one or more programmable prioritisation criteria; and providing power from the DC bus in a single uninterruptible system output.

[0036] In some embodiments, the programmable prioritisation criteria include at least one of end user preference, availability, time of day, and cost.

[0037] In some embodiments, the system output is 3-phase+N+PE. In some embodiments, the system output is DC.

[0038] In some embodiments, the method further comprises aggregating heat produced by the system and providing the aggregated heat as input into a customer's hot water system or an absorption HVAC system.

[0039] In some embodiments, the method further comprises collecting heat and water produced by the system and providing the collected heat and water as input into an electrolyser.

[0040] In some embodiments, the method further comprises using the system output to power an electrolyser comprising a plurality of clusters.

[0041] In some embodiments, the method further comprises using the system output to power a portion of the clusters proportional to the power available from the one or more power input subsystems.

[0042] In some embodiments, the one or more power input sub-systems include solar and the method further comprises using source water for the electrolyser to cool one or more photovoltaic panels connected to the DC bus.

[0043] In some embodiments, the method further comprises matching the power used by the electrolyser to the power available from the DC bus.

[0044] In some embodiments, the selecting comprises selecting the battery sub-system and the hydrogen fuel cell as the active power input, in a predetermined battery to fuel cell ratio.

[0045] In some embodiments, the method further comprises adjusting the battery to fuel cell ratio based on availability of the one or more renewable energy sources.

[0046] In some embodiments, the selecting comprises selecting the hydrogen fuel cell as the active power input when the battery sub-system charge is below a predetermined threshold and no renewable energy sources are detected.

[0047] Additional features and advantages of embodiments of the present invention are described further below. This summary section is meant merely to illustrate certain features of embodiments of the invention, and is not meant to limit the scope of the invention in any way. The failure to discuss a specific feature or embodiment of the invention, or the inclusion of one or more features in this summary section, should not be construed to limit the invention as claimed.

[0048] BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The foregoing summary, as well as the following detailed description of certain embodiments of the application, will be better understood when read in conjunction with the appended drawings. For the purposes of illustrating the systems and methods of the present application, there are shown in the drawings certain embodiments. It should be understood, however, that the application is not limited to the precise arrangements and instrumentalities shown. In the drawings:

[0050] FIG. l is a diagram showing an example of a power system according to various embodiments of the invention;

[0051] FIG. 2A is a diagram showing an example of thermal management according to various embodiments of the invention;

[0052] FIG. 2B is a diagram showing an alternate use for aggregated heat from the system;

[0053] FIG. 3 is a schematic of a power system-electrolyser ecosystem according to various embodiments of the invention; and

[0054] FIG. 4 is a diagram showing another example of thermal management according to various embodiments of the invention.

[0055] DETAILED DESCRIPTION

[0056] Certain illustrative embodiments of the present invention will now be described with reference to the drawings. In general, such embodiments relate to systems and methods for integrated power management, which can draw seamlessly on multiple sources to provide uninterrupted power, and can harness heat and water byproducts to maximise efficiency within their ecosystems. A hydrogen powered fuel cell can provide range extension for a direct coupled battery within the system, and the different power inputs can be prioritised (ordered for drawing power) and tuned in their relative (to each other) or absolute levels of power, for example based on one or more parameters (programmable prioritisation criteria), such as preference, availability (including level), time of day, and cost.

[0057] System Overview

[0058] A system according to embodiments of the present invention supports the aggregation of multiple power sources (any number of AC and DC sources) into a single effective power source, to output an improved stationary uninterruptible power supply (UPS) / power generator / power module. This allows a user-configured balance of renewable and grid supplied energy to be combined with a hydrogen powered fuel cell to meet power needs, including continuous power needs.

[0059] Electrical inputs may be directly cable lugged into the system through a dedicated isolator for each input path. These may be co-located on one side of the system for ease of customer use and can be in DC form (as is typical from solar / photovoltaic) or single / 3-phase (as is typical from grid and some wind turbines).

[0060] Internally, the system converts these inputs onto a common DC bus, and this bus is directly coupled to a high voltage (HV) battery sub-system (the bus bar may be functionally considered as an extension of the battery). In some embodiments, the given battery sub-system may be of a more modest size than what would be usually installed at the proposed site due to the range extending functionality of the hydrogen fuel cell providing a de-coupled, variable and long term storage energy input from the hydrogen. A micro-grid inverter takes power from this DC core / bus and generates the 3 -phase output.

[0061] The micro-grid inverter output can operate both fully standalone, as well as in a cooperative mode. This allows multiple power modules to be seamlessly connected in parallel through independent analog feedback of the grid back to each inverter downstream of a master breaker that connects the multiple module power units to the external grid to allow larger power requirements to be readily met by clustering power modules. As an example, ten individual 100 kW systems as described herein could be connected in a co-operative synchronised relationship to effectively form a one-megawatt system. Any of the individual systems can be removed (e g., for maintenance) without interrupting the power provided by the cluster.

[0062] By routing all power inputs through the common DC core, the system can maintain an “always on” micro-grid inverter output. Should any of the power input provisions cease to provide energy, the software controlling layer and core hardware is configured to make it up from remaining supply options without any end user loss of service. More specifically, the control layer may receive an input signal that a power input has ceased or is about to cease (e.g., drops below a threshold level of monitored voltage), in response to which the control layer causes the changeover to an alternate power input or reduces the power draw from the given input. Such alternate power input may be selected based on one or more factors, such as preference, availability (including level), time of day, and cost. In a traditional generator system, power is lost for a number of seconds before changeover occurs and power from a generator is actually supplied. With the direct coupled battery of the present embodiments, this hybridised approach provides the true UPS functionality.

[0063] Internal Building Blocks

[0064] FIG. 1 is a diagram showing an example of a power system 100 according to various embodiments of the invention, combining renewable and grid supplies with a hydrogen powered fuel cell and a direct coupled battery.

[0065] DC Core: In this system, each power input sub-system has its own power management allowing it to track variations in external input voltage and voltage of the internal DC core / bus 104. As well as providing implicit maximum power point tracking (MPPT) as required, this DC core 104 forms an extension of the direct coupled battery sub-system 105, allowing the connected micro-grid inverter 106 to instantaneously react to end customer load changes without the delays and losses of battery DC-DC direction arbitration. Voltage, temperature and current clamps / probes within the system 100 are able to monitor the energy flow both onto and from the DC bus 104. This allows a base load balance to be maintained under software control by system controller 110 to ensure the battery state of charge (SoC) is maintained within operational limits through the method of coulomb counting and voltage sensing. When the system determines an energy surplus - for example, when the energy that is able to flow onto the DC bus is greater than the energy draw from the DC bus - the system may divert energy to the battery sub-system 105, which has the benefit of allowing energy storage when there is a surplus whilst also maximising the lifetime of the battery subsystem 105.

[0066] Micro-Grid Inverter: The system 100 output 114 is typically 3-phase+N+PE, as is typical of traditional generators used today for power backup. This way existing installations can be directly transitioned with little or no additional infrastructure burden. The electrical micro-grid inverter drive 106 coupled with the isolation transformer 107 (incorporating sine filter) converting from a delta to centre tap provides the neutral reference. This provides safety isolation as well as direct support for single phase operation. The micro-grid inverter 106 output does not require load balance across the phases, as one would typically aim to achieve in a grid supply; in certain embodiments just a single phase could be loaded providing significant scope for end user usage models. The isolator 109 allows the system to be disconnected from the end user’s grid. Also associated with isolator 109 in the present embodiment is a breaker that will detect, and trip in response to, an overcurrent (short circuit) either on the system or the customer’s end, thereby protecting the system’s or user’s hardware. As indicated in dashed lines, pre- and / or post-breaker sensing can be incorporated to allow synchronisation of outputs and accurate power metering for the end user. The pre / post breaker sensors are coupled to the controller 110. Such sensing allows the system to know whether the breaker is engaged or not, and what may have caused it to trip if it has (e.g., an internal short circuit), and to phase and voltage align the power downstream of the breaker with either the grid or other system(s) connected in parallel. The system would start up and be ready to deploy power and then would sense and then align with the voltage and phase downstream of the breaker before it engages / closes the breaker; otherwise it may cause a grid imbalance. A power meter (not shown) may be installed to facilitate billing customers for the amount of energy used and for internal statistics. In certain alternative embodiments, the system output 114 includes DC output (either solely or in conjunction with an AC output). In these embodiments, the DC output includes a DC-DC converter instead of the micro-grid inverter 106 and isolation transformer 107 and the isolator and breaker 109 is changed accordingly for compatibility.

[0067] DC Input (Solar / Photovoltaic (PV)): The DC input to the system allows direct connection to any available DC source. Typically this would be used to interface to solar / photovoltaic arrays 101. As with many renewable energy sources, the power available varies with prevailing conditions. MPPT is provided for DC input, as detailed below.

[0068] AC Input (Single / 3-Phase): The AC input allows connection to both grid 102 and inverter output based renewables, such as wind 103 and hydroelectric. System control software implemented by controller 110 allows peak limits to be set for all sources (for example, by setting and storing a threshold for each source). In addition, when renewables are present, advanced AC MPPT can be deployed utilising voltage, frequency and phase characteristics sensed on the input and fed back to the controller 110 to maximise power transfer when not at the peak limit.

[0069] Hydrogen Fuel Cell: The system 100 is also fitted with a hydrogen powered fuel cell 108 connected via manifold 111 to one or more hydrogen storage trailers 112, 113. When all of the renewable or external power options are at low or no availability (e.g., as set in the control system), the system can bring the fuel cell 108 online to provide locally generated power to maintain the output power levels required by the end user. The fuel cell 108 provides a DC output and the system control software implemented by controller 110 can manage the power requested from the fuel cell 108 both to provide base load and also to be able to react to the dynamic nature of micro-grid operation. This allows the system to manage both the fuel cell 108 and battery 105 for longevity whilst simultaneously optimising hydrogen fuel consumption. System Controller: Managing various components of the system 100 is a system controller 110, which is based on industrial Programable Logic Controller (PLC), dedicated Safety Controller (SC) and Human Machine Interface (HMI) 120. Each part of the system controller 110 includes a computer readable medium with software (or firmware) configured and implemented to provide the power management functions described herein.

[0070] The PLC controls the overall function of the system, such as switching between inputs based on the customer / end user preferences, such as a priority list for energy (e.g., 1-solar, 2- grid, 3-wind, 4-hydrogen). It also monitors the battery’s voltage / state of charge to reduce incoming power from its energy sources as the battery sub-system 105 approaches a peak charge level (e g., 80%). The PLC also collects telemetry and performance data that is used to perform preventative maintenance of the system (e.g., identifying when a fan may be requiring replacement or there is a coolant leak).

[0071] The SC is dedicated to performing safety critical tasks such as monitoring for hydrogen leaks or power faults as well as ensuring that in the event of the system requiring a shutdown that the shutdown will be successful. Inputs to the SC such as hydrogen detection are supplied by redundant sensors while inputs such as hydrogen are switched by two solenoids in series with proof testing located at the boundary of the system.

[0072] The HMI 120 provides customer / end user feedback on the status of the system as well as detailed diagnostics information for service personnel.

[0073] In some embodiments, a cellular / Wi-Fi data return channel 115 may be provided in connection with controller 110. Data return channel 115 enables the system 100 to self audit at power-up and to transmit (e.g., to a back office) key parameters (e.g., periodically, on significant state change, or both). The data / parameters transmitted via channel 115 may include, for example, state changes (e.g., fuel cell on / off), power delivered, key temperatures, and fault codes. This data transmission capability facilitates a centralised global status cloud based dashboard to be viewed from any location, providing fleet wide situational awareness. It can be used to facilitate timely preventive maintenance, and can also allow customers access to the status of their own installations.

[0074] Examples

[0075] In one example, system software of controller 110 may implement (e.g., in software residing in computer readable medium or in firmware) a priority setting for power input as follows.

[0076] (1) First priority for power input may be a renewable energy source, such as solar or wind (used when available and not curtailed). The system will use what is required for the end user / customer and then, when the voltage and / or current sensors 117 indicate a surplus (availability beyond what is needed by the end user / customer), charge the battery 105 until full. If the battery is full (as indicated by a signal to the system controller 110), the system can run heating elements in hot water storage (e.g., for use in external hot water systems 206 as described below). It can also (or alternatively) redirect the excess power to create hydrogen in embodiments where electrolysers are connected. Lastly, if fuel cell, battery storage and hydrogen storage are all full, the system controller 110 may curtail input. The system controller 110 can monitor how often this happens and flexibly either add more battery storage or hydrogen if it is not sufficient.

[0077] (2) Second priority for power input may be grid during off-peak times. In some cases this input may be after the third priority (below), depending on local electricity costs or customer preference, and may not exist at all for systems installed at sites that are off grid.

[0078] (3) Third priority for power input may be a fuel cell and battery power ratio (which, in turn, may have its own priority / may be tuned, for example, based on battery state of charge and / or time of day). For this input, the system has a baseline ratio for normal use (e.g., 40 / 60). The system controller 110 is configured to adjust the battery to fuel cell ratio to maximise power transfer to the battery with a view to minimising curtailment from renewable sources when available. For example, in some embodiments, if the system controller 110 detects power on the PV input / leg, it will increase the battery to fuel cell ratio if the battery charge is not below a threshold (e.g., 20% SOC), such that the battery is discharged enough so it can be fully charged by cheap renewables and not have to curtail them. If the battery is low (e.g., below about 20% SOC) and no renewables are detected, it will switch to fuel cell only (in some embodiments, it may be preferable to avoid charging the battery with hydrogen). If the temperatures of the hot water storage units used for external hot water systems 206 (as measured by temperature sensors coupled to the controller 110) begin to dip and there are no renewables available, it will shift to using more hydrogen versus battery to heat the water.

[0079] (4) Fourth priority for power input may be grid at peak times, which is preferably only used as a fall back option.

[0080] FIG. 1 shows an example DC bus 104, which includes a number of inputs (legs) 101, 102, 103, 105, 108 and one output 116. Each of the inputs / legs has at least one voltage and / or current sensor 117 and at least one contactor (software controlled switch) 118. The controller 110 monitors all the voltages and currents going in and out of each leg via sensors 117 to understand what is available on the main bus 104 and the various legs. Each sensor 117 can monitor up to three sensing points. The controller 110 can turn on and off each leg with the contactors 118 depending on the above logic or presence of available energy at the leg (or other priority setting). Three sensing points (long dashed lines) are illustrated in FIG. 1 and, for simplicity, are shown for only one example sensor 117 (on the solar / PV input 101). The sensors 117 sit on the negative leg (shown in gray) of the respective input feeds and they monitor the positive (shown in black) too. One voltage reference will go to the positive leg measuring input voltage to the power track; a second voltage reference monitors the ground / earth to monitor the difference between the voltage of the negative and earth to detect an earth fault without using expensive equipment. Voltage may be monitored via the sensors 117 before and after the input converters to monitor the difference. For example, with DC inputs the controller 110 monitors the voltage external to the system before closing the contactors to join the external DC input to the system. The system will precharge the DC bus 104 from the battery 105, such that other devices on the bus 104 (e.g., micro grid inverter 106) are not subjected large inrush currents as their input capacitors are charged. Precharging involves routing power from the battery through resistors slowly over a period of time such that the bus voltage equals the battery voltage before engaging the contactors for the other devices on the bus. The sensors 117 on the battery 105 and fuel cell 108 legs assist the precharge function.

[0081] The software of controller 110 is configured to coulomb count the battery 105 using the respective sensor 117 without an external device, thereby creating a mini BMS (battery management system) configured in the software. As mentioned above, the logic implemented in the controller software permits the controller 110 to monitor the state of charge within operating limits to decide various operating states, to increase efficiency and save money as compared to using a battery converter.

[0082] Maximum power point tracking (MPPT) is provided for both the DC and AC inputs.

[0083] Certain converters (e.g., standard household PV inverters) may include such functionality, but not for the operating conditions of the systems described herein (power, size, packaging, etc.). Therefore, the controller 110 is preferably configured in software to implement MPPT itself using the voltage and / or current sensors 117 on the DC bus 104. To do so, the controller 110 pulls as much power as possible until it detects a voltage drop and then will back off the power / current draw (e.g., such that the voltage drop is removed) to maintain the highest power point achievable.

[0084] Additional sensors may also be included in system 100, for example, monitoring temperature and flow rates to turn off and on fans and bypass valves, hydrogen valves, etc.

[0085] System Cooling

[0086] FIG. 2A is a diagram showing an example of a thermal management configuration 200 according to various embodiments of the invention, which provides combined liquid and ambient air cooling of a fuel cell powered stationary uninterruptible power supply / power generator / power module, such as system 100. As will be understood by those of skill in the art, such configuration 200 may be used with the various embodiments described herein, as well as others.

[0087] A PEM (polymer electrolyte membrane / proton exchange membrane) fuel cell system, such as fuel cell 108, has a high temperature (HT) cooling loop 203 that cools down the fuel cell stack 204 itself (via liquid-liquid heat exchange (HX)) and is temperature controlled, and a second, low temperature (LT) cooling loop 202 that cools the accessories (generating relatively small amounts of heat that is hard to use). These loops usually run independently but need not.

[0088] In some embodiments, these two cooling loops 202, 203 may be reconfigured into a single cooling loop (e.g., where the low temperature loop 202 is fed as an input to the high temperature cooling loop 203) and combined with a pump 201 and a temperature controlled cooling fan 207 (with temperature sensor 208) to safeguard against system overheating. In such an embodiment, the low temperature loop 202 is used to cool both the fuel cell 108 components and other system 100 components (inverter 106, etc.). It also then cools the high temperature loop 203 to perform a heat aggregation function such that all the waste heat 205 of the system 100 (combined via liquid-liquid HX) can be utilised in an external hot water system 206, for example, to either input into a customer's hot water system’s heat exchanger as shown in FIG. 2A or run an HVAC system as shown in FIG. 2B and detailed below. This heat aggregation allows for the customer to be provided with an efficient system 100 such that little or no energy input is lost in the form of heat to the atmosphere.

[0089] FIG. 2B is a diagram showing an alternate use for aggregated heat 205. Instead of being input into a customer's hot water system’s heat exchanger (as shown in FIG. 2A), aggregated heat 205 can be input into an absorption HVAC system, which uses either lithium bromide (air conditioning) or water-ammonium (refrigerator / freezer) solutions. The heat provided is transferred to the lithium bromide or ammonium solution, reducing the temperature of the cooling loop that is then returned to the system. Absorption cooling / refrigerant systems use heat from an external source to drive the refrigeration system as opposed to an electrical compressor. Use of aggregated heat 205 from system 100 removes a large electrical burden of the absorption HVAC system and replaces it with heat that would have otherwise been wasted.

[0090] Modified System

[0091] In some embodiments, a modified power system may be provided, which uses the same technology building blocks as system 100 described above (including battery 105 and controller 110), but does not include the fuel cell 108 and its support functions. Such a system, which can be thought of as a simplified version of the system 100 described above, can provide 3 -phase UPS support for critical functions.

[0092] FIG. 3 is a schematic of an ecosystem according to various embodiments of the invention, showing an example of one such modified power system 300 having solar / PV 101 and grid 102 inputs. Power system 300 is coupled to an electrolyser, such as electrolyser system 500 (with local controller 510 and cellular / Wi-Fi data return channel 515), which produces hydrogen to fill trailers 112, 113 (each of which may have a local controller 121, as detailed further below). In this example, the electrolyser is made up from sub module clusters 520. The air- driven boosters 521, which are connected to electrolyser clusters 520 and air compressor 522, comprise an internal manifold that controls filling of individual trailers. The filled trailers are then relocated to points of consumption as needed, for example, to a site where a system 100 (see also FIG. 1) is installed. Two trailers are shown, but other embodiments may include different numbers of trailers (i.e., as little as one or greater than two) according to the application. Like data return channel 115, data return channel 515 enables the electrolyser 500 to self audit at power-up and to transmit (e.g., to a back office) key data / parameters (e.g., periodically, on significant state change, or both), which can facilitate remote monitoring of status and / or timely preventive maintenance. FIG. 3 shows a modified power system 300 providing power to electrolyser system 500, but in other embodiments a power system 100 may be used (which may be operated, e.g., with a larger solar / PV input 101 and / or with the fuel cell 108 turned off). Local controller (field controller) 510 is an internal controller that, in various embodiments of the present invention, is added to a commercial electrolyser system and is configured to be in communication with system controller 110 to provide steady power management. Field controller 510 controls the electrolyser 520 and booster system 521. System controller 110 can communicate to field controller 510 the amount of power available to the electrolyser system 500 from the power system (100 or 300), and field controller 510 can communicate to system controller 110 the amount of power needed. For example, field controller 510 may set the hydrogen production rate or level required (e.g., based on input from local controller(s) 121 on trailer(s) 112, 113), then query (or otherwise use data from) controller 110 to determine if sufficient power exists to satisfy the desired production rate or level. Field controller 510 may receive an indication of available power from controller 110, and if sufficient power to meet the desired production rate does not exist, field controller 510 may scale back (decrease) the desired production rate / level such that only the available power would be used. Field controller 510 may then initiate such scaled-back production, thereby limiting the hydrogen production to the available power. If the indication of available power is sufficient to meet the desired production rate / level, then field controller 510 initiates it. Thus, the electrolyser system and the power system can match the power used to the power available, and avoid a situation where the electrolyser draws more power than is available, which could be destructive.

[0093] Increased Efficiency of Electrolyser Operation

[0094] Power systems according to embodiments of the present invention can be configured to provide efficient electrolyser operation when powered from a partially available supply. For example, when partial power is available, the systems can be configured to power a smaller number of electrolyser clusters within a larger system, instead of being limited to powering either all or none. In such embodiments, controller 510 within the electrolyser sub-system, in communication with controller 110, will switch on / off banks of electrolysers using a combination of power switching and software throttling control based on total power available to the system and total power consumed by each cluster of electrolysers.

[0095] Currently, most electrolyser systems work on the assumption that grid power is always available. If power is suddenly removed during operation, this will have a negative impact on overall system longevity and worst case could damage the electrolyser stack and its peripherals.

[0096] Various embodiments of the present invention utilise renewable energy to power electrolysers, and in some embodiments the renewable energy source used is mainly solar / PV. As a result, power systems according to embodiments of the present invention will be exposed to daily power dropouts. This could also be true if the systems were grid coupled, for example due to the partial availability within certain geographic regions like Southern Africa.

[0097] Examples of electrolysers used in embodiments of the present invention include electrolyser systems 500 that are internally made up of small clusters 520. Each cluster is powered independently and within each cluster each electrolyser is able to be power throttled. A power system as described herein (e.g., system 300) will be MPPT tracking its connected solar array. As the sun rises, the system 300 will see a predictable increase in power transfer. System controller 110, leveraging this information of increased available power from the solar array, passes this information to controller 510 that is then able to start to warm up the clusters 520 in preparation to generate hydrogen through commands, based on the power available. This way, rather than wait until the full electrolyser can come online, it is possible to sequence the startup and initiate hydrogen generation earlier on a reduced number of clusters.

[0098] Similarly, as sunset approaches, the power system 300 will see a reduction in power available. The ramp rate will be predictable and the system controller 110, in communication with controller 510, can slowly reduce power across clusters 520, balancing power consumption against hydrogen production until no longer viable. The power system 300 can then allow controlled shutdown of electrolyser system 500 and maintenance of a standby mode awaiting the dawn. The same basic approach would apply, for example, if a storm system were to pass. The power system 300 would see a reduction of power during the middle of the day, but would still be able to ramp down power delivered to some or all of the electrolyser clusters 520 to maximise hydrogen output in the given conditions rather than simply shut down the whole electrolyser system 500 awaiting full power to return.

[0099] Increased Efficiency of PV and Electrolysis

[0100] FIG. 4 is a diagram showing an embodiment of a system having a thermal management configuration 400, which can provide combined heat and water recovery for a wider ecosystem and electrolyser system. One or more power systems as described herein can be configured to collect the heat and water released during their operation for input into an electrolyser. In addition, cool source water for the electrolyser can be used to cool power system photovoltaic panels before it is input into the electrolyser.

[0101] Systems according to embodiments of the present invention release heat 205 and waste exhaust hot water 122 when operating. In various embodiments of the present invention, the waste exhaust hot water 122 from a power system is collected and fed into a thermal store 206 (which is an external hot water system 206 analogous to the examples shown in FIGS. 2A and 2B). This waste exhaust hot water 122 can either be collected on the trailers 112, 113 for a system 100 as shown in FIG. 3 (clustered form) or direct input to the thermal store 206 if the electrolyser 500 is coupled to a system 300 as shown in FIG. 4. The electrolysis process requires water temperature above ambient and heating up the water prior to entering the electrolyser system 500 saves valuable electrical energy, increasing the efficiency of the electrolysis. In addition, using the waste hot water from one or more power systems (100 and / or 300) reduces the volume of source water 403 needed for the electrolysis.

[0102] Photovoltaic (PV) panels lose efficiency when heated above STC (standard test conditions) of 25 degrees Celsius ambient temperature, which occurs when subjected to ambient air in the sun. Cooling down the PV panels 101 with a heat exchanger 405 (e.g., back plate or film cooling) using the cool source water 403 going into the electrolyser system 500 (via pump

[0103] 404) not only benefits the electrolysis, but also can increase the PV panels’ efficiency and allow a smaller PV system to provide the same power / energy as a standalone system.

[0104] Hydrogen Trailer Fleet Management

[0105] A power system-electrolyser ecosystem with multiple power system installations and a centralised electrolyser can be configured to manage the hydrogen fuel distribution as follows.

[0106] In various embodiments of the present invention, a trailer system is provided that is able to store 72 kg of hydrogen. The trailer system is based on European ADR regulations (Accord europeen relatif au transport international des marchandises dangereuses par route / European Agreement concerning the International Carriage of Dangerous Goods by Road).

[0107] The trailer(s) (e.g., trailer 112 and / or 113) can be towed by a standard Toyota Hilux vehicle, allowing ready access and distribution in an off-road environment. This size of storage is estimated to support operation of a single power system 100 for one week. Each power system 100 may have connectivity for up to two trailers to be attached. In some embodiments, the trailer(s) may comprise a commercial trailer configured to include a local controller 121 that can be interrogated by both the electrolyser system 500 during filling and the power system 100 during consumption. This provides a defined and logged audit trail. In some embodiments, this audit trail may be used to verify the hydrogen source, and hydrogen provided without this audit trail / source verification may not be accepted.

[0108] In some embodiments, in order to enhance trailer fleet mobility, the power system 100 will use the lowest (least filled / emptiest) connected trailer preferentially before automatically swapping to the next one through an automatic valve controlled by the controller 110 based on pressure sensor feedback. This way, the empty trailer can be removed by the operator at the earliest opportunity for refilling. Conversely, at the electrolyser, the fullest trailer will be filled first, allowing it to be re-deployed, before moving to the next fullest in the sequence. This differs from the classical refilling approach taken with large bulk systems, where it is common to refill the bulk at the lowest common pressure building up the whole bank over time.

[0109] In some embodiments, high pressure in the trailers, which can be dangerous, can be regulated down. For example, as shown in FIG. 3, the trailers can be filled at one pressure, which may be a relatively high pressure (e.g., 381 bar) and used at a lower pressure (e.g., 10-17 bar). This trailer side pressure regulation can be achieved by a regulator (e.g., an EC79 approved pressure regulator) and will provide a safer, low pressure hydrogen feed for the end user. It also has the benefit that the hydrogen storage and / or transportation medium can change over time, and as long as gaseous hydrogen in the 10-17 bar range is available as an output the end power system 100 can use it.

[0110] While there have been shown and described fundamental novel features of the invention as applied to the preferred and illustrative embodiments thereof, it will be understood that omissions and substitutions and changes in the form and details of the disclosed invention may be made by those skilled in the art without departing from the spirit of the invention. Moreover, as is readily apparent, numerous modifications and changes may readily occur to those skilled in the art. For example, various features and structures of the different embodiments discussed herein may be combined and interchanged. Hence, it is not desired to limit the invention to the exact construction and operation shown and described and, accordingly, all suitable modification equivalents may be resorted to falling within the scope of the invention as claimed. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.

Claims

CLAIMS1. An integrated power system providing uninterrupted power, comprising: a DC bus configured to accept DC and AC power inputs from a plurality of power input sub-systems, including grid, one or more renewable energy sources, and a hydrogen fuel cell, the DC bus including one or more voltage or current sensors; a battery sub-system directly coupled to the DC bus; a micro-grid inverter configured to provide power from the DC bus in a single uninterruptible system output; and a system controller configured in accordance with computer readable instructions to perform functions, including to: (i) monitor energy flow onto and from the DC bus via the one or more voltage or current sensors, (ii) direct energy to the battery sub-system, thereby charging the battery sub-system, when energy flow onto the DC bus is greater than energy flow from the DC bus, and (iii) select as an active power input the input from at least one of the plurality of power input sub-systems and the battery sub-system based on one or more programmable prioritisation criteria, where the active power input changes based on the one or more programmable prioritisation criteria.

2. The system of claim 1, wherein the programmable prioritisation criteria include at least one of end user preference, availability, time of day, and cost.

3. The system of claim 1, wherein each power input sub-system is configured to track variations in voltage of the DC bus.

4. The system of claim 1, wherein the system output is 3-phase+N+PE.

5. The system of claim 1, wherein the system is operated stand-alone.

6. The system of claim 1, wherein the system is operated in a co-operative mode, connected in parallel to at least one additional system according to claim 1.

7. The system of claim 1, further including the hydrogen fuel cell, wherein the hydrogen fuel cell includes low temperature and high temperature cooling loops combined and utilised with a temperature-controlled cooling fan to safeguard against system overheating.

8. The system of claim 7, wherein heat from the combined cooling loops is aggregated and input into a customer's hot water system or an absorption HVAC system.

9. The system of claim 1, wherein heat and water produced by the system are collected and input into an electrolyser.

10. The system of claim 1, further including the hydrogen fuel cell, wherein the system includes one or more trailers supplying hydrogen for the fuel cell, each trailer including a local controller configured to be interrogated both by the system and by an electrolyser filling the trailer, providing a logged audit trail.

11. The system of claim 10, wherein the system includes at least two trailers, and is configured to use the emptiest trailer preferentially, and to switch to the next trailer automatically via an automatic valve controlled by the system controller based on pressure sensor feedback.

12. The system of claim 1, wherein the system controller is configured to select the battery subsystem and the hydrogen fuel cell as the active power input, in a predetermined battery to fuel cell ratio.

13. The system of claim 12, wherein the system controller is configured to adjust the battery to fuel cell ratio based on availability of the one or more renewable energy sources.

14. The system of claim 1, wherein the system controller is configured to select the hydrogen fuel cell as the active power input when the battery sub-system charge is below a predetermined threshold and no renewable energy sources are detected.

15. The system of claim 1, wherein the system is configured to provide power to an electrolyser comprising a plurality of clusters.

16. The system of claim 15, wherein the electrolyser includes a field controller, the field controller configured and adapted to communicate with the system controller, receive an indication of available power, and limit hydrogen production to match the available power.

17. The system of claim 16, wherein the field controller in communication with the system controller is configured to power a portion of the clusters proportional to the power available from the one or more power input sub-systems.

18. The system of claim 15, wherein the one or more power input sub-systems include solar and the system is configured to use source water for the electrolyser to cool one or more photovoltaic panels connected to the DC bus.

19. The system of claim 15, wherein the system and the electrolyser each include a wireless communication channel.

20. The system of claim 1, wherein the system includes a wireless communication channel.

21. The system of claim 10, wherein each trailer includes a pressure regulator and is configured to be filled at a high pressure and to provide a lower pressure hydrogen feed to the system.

22. The system of claim 15, wherein the electrolyser includes a field controller in communication with the system controller and wherein the field controller and the system controller are configured to implement power matching, whereby the amount of power drawn by the electrolyser does not exceed the amount of power available from the system.

23. A method of providing uninterrupted power, comprising: providing a DC bus directly coupled to a battery sub-system, the DC bus configured to accept DC and AC power inputs from a plurality of power input sub-systems, including grid, one or more renewable energy sources, and a hydrogen fuel cell, the DC bus including one or more voltage or current sensors; monitoring energy flow onto and from the DC bus via the one or more voltage or current sensors; directing energy to the battery sub-system, thereby charging the battery sub-system, when energy flow onto the DC bus is greater than energy flow from the DC bus; selecting as an active power input the input from at least one of the plurality of power input sub-systems and the battery sub-system based on one or more programmable prioritisation criteria, where the active power input changes based on the one or more programmable prioritisation criteria; and providing power from the DC bus in a single uninterruptible system output.

24. The method of claim 23, wherein the programmable prioritisation criteria include at least one of end user preference, availability, time of day, and cost.

25. The method of claim 23, wherein the system output is 3-phase+N+PE.

26. The method of claim 23, wherein the system output is DC.

27. The method of claim 23, further comprising aggregating heat produced by the system and providing the aggregated heat as input into a customer's hot water system or an absorption HVAC system.

28. The method of claim 23, further comprising collecting heat and water produced by the system and providing the collected heat and water as input into an electrolyser.

29. The method of claim 23, further comprising using the system output to power an electrolyser comprising a plurality of clusters.

30. The method of claim 29, further comprising using the system output to power a portion of the clusters proportional to the power available from the one or more power input sub-systems.

31. The method of claim 29, wherein the one or more power input sub-systems include solar and the method further comprises using source water for the electrolyser to cool one or more photovoltaic panels connected to the DC bus.

32. The method of claim 29, further comprising matching the power used by the electrolyser to the power available from the DC bus.

33. The method of claim 23, wherein the selecting comprises selecting the battery sub-system and the hydrogen fuel cell as the active power input, in a predetermined battery to fuel cell ratio.

34. The method of claim 33, further comprising adjusting the battery to fuel cell ratio based on availability of the one or more renewable energy sources.

35. The method of claim 23, wherein the selecting comprises selecting the hydrogen fuel cell as the active power input when the battery sub-system charge is below a predetermined threshold and no renewable energy sources are detected.

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