Subsea energy storage and usage

Abstract

The present invention provides a modular system and method of use for undersea energy storage. The modular system comprises an energy management system and a rechargeable energy storage system. The energy management system is configured to control the transfer of electrical energy between the rechargeable energy storage system and at least one energy source and / or at least one electrical load.

Description

[Technical field]

[0001] FIELD OF THEINVENTION The present invention relates to energy supply and storage, and in particular to subsea energy supply and storage.Aspects of the invention relate to systems and methods of use for offshore energy storage and management. [Background technology]

[0002] Recently, there has been a move towards electrification of the oil and gas industry as well as subsea processing for offshore wind power generation in order to reduce emissions.

[0003] Electrification of subsea installations and equipment offers many opportunities to improve operational efficiency, reduce life-of-field capital, operating costs, and reduce carbon footprint. However, the move towards electrification of subsea installations and equipment presents several obstacles, including more electrical loads, higher power requirements, limited accessibility due to deeper water depths, and longer distances to deliver power supplies, particularly in the oil and gas industry and subsea processing for offshore wind power generation.

[0004] Traditionally, offshore platforms generate power using large generators driven by diesel engines or gas turbines. This method of providing offshore electricity produces significant harmful emissions of greenhouse gases.

[0005] Due to the distances between the operating platform and the subsea equipment (often tens of thousands of feet), it can be difficult and costly to provide a safe and reliable supply of electricity to the subsea equipment. An additional problem is the requirement for long cable (umbilical) connections needed to connect the offshore platform to the subsea equipment. Often these cables can reach tens of kilometers in length, which can result in large voltage drops that can cause damage to the remote subsea equipment and reduce power transfer efficiency.

[0006] Vessels in the offshore industry are required to meet high standards for environmental protection, limit emissions, and improve overall sustainability. To help comply with such stringent regulations, vessels, including Offshore Support Vessels (OSVs), Service Operation Vessels (SOVs), and Crew Transfer Vessels (CTVs), are required to reduce their environmental footprint by using cleaner energy systems, such as fully electric or electric hybrid systems.

[0007] There is a need for increased capacity of sustainable energy for offshore and subsea equipment and vessels in the oil and gas industry. Summary of the Invention

[0008] It is an object of aspects of the present invention to eliminate or at least mitigate the above-mentioned limitations of existing offshore electric energy technology.

[0009] Another object of aspects of the present invention is to provide a modular subsea energy storage system to provide power for vessels, subsea equipment, vehicles and infrastructure.

[0010] It is a further object of aspects of the present invention to provide a modular system with interchangeable components that can be configurable to different power requirements for a particular application.

[0011] Another object of aspects of the present invention is to provide an energy storage system that includes an energy management system for maximizing battery life, controlling electrical loads, and providing data collection for surfaces.

[0012] It is among the goals and objectives of the present invention to provide a method and / or apparatus for subsea power storage and / or management that allows for easy deployment and maintenance, which may be powered by renewable or non-renewable energy.

[0013] In particular, one goal of embodiments of the present invention is to provide methods and / or apparatus that can be configured or optimized to provide energy storage in close proximity to the subsea location of use, thus minimizing capital and operating expenditures.

[0014] Further objectives of the invention will become apparent from the following description. [Means for solving the problem]

[0015] According to a first aspect of the present invention there is provided a modular system for undersea energy storage, the modular system comprising: An energy management system; Rechargeable Energy Storage Systems and Equipped with A modular system is provided in which an energy management system is configured to control the transfer of electrical energy between a rechargeable energy storage system and at least one energy source and / or at least one electrical load.

[0016] The rechargeable energy storage system may be a subsea rechargeable energy storage system. One or more components or modules of the rechargeable energy storage system may be located subsea. One or more components or modules of the rechargeable energy storage system may be located on, at, or above the water surface.

[0017] The rechargeable energy storage system may be a modular system. Preferably, the rechargeable energy storage system is a rechargeable battery system. The rechargeable battery system may comprise at least one battery. The at least one battery may be located subsea. The rechargeable battery system may comprise a plurality of batteries. The rechargeable battery system may comprise two or more batteries. The number of batteries in the rechargeable battery system may depend on the desired energy capacity of the rechargeable battery system. The rechargeable battery system may comprise up to 100 batteries. The rechargeable battery system may comprise more than 100 batteries. The rechargeable battery system may comprise up to 50 batteries. The rechargeable battery system may comprise between 10 and 40 batteries. The rechargeable battery system may comprise 30 batteries. The capacity of the battery system may be up to 1 GWh. The capacity of the battery system may be in the range of 0.1 MWh to 1 GWh. The capacity of the battery system may be in the range of 0.5 MWh to 500 MWh. The capacity of the battery system may be up to 100 MWh. The capacity of the battery system may be up to 15 MWh. The rechargeable energy storage system may be based on lithium ion technology. The at least one battery may be a lithium ion battery. The at least one battery may be selected from the group comprising nickel metal hydride, lithium ion, lead acid, and / or nickel cadmium batteries. The two or more batteries may be arranged in a parallel or series orientation.

[0018] Each battery may include at least one battery cell. Each battery may include two or more battery cells. Each battery may include a plurality of battery cells. Each battery may be a subsea removable unit. The two or more batteries may be arranged in a battery array. The battery array may be a subsea removable unit. Each battery may be provided in an individual battery enclosure. The two or more batteries may be provided in a battery enclosure. Each battery enclosure may be a subsea removable unit.

[0019] The modular system may include a plurality of components or modules. At least one of the components may be a subsea removable unit. The modular system may be a bi-directional power transfer system. The energy storage system may be a bi-directional power transfer system.

[0020] The energy management system may be configured to communicate with the energy storage system. The energy management system may be connected to the energy storage system. The energy management system may be connected to at least one component of the energy storage system. The energy storage system may comprise an energy management system. The energy storage system may comprise at least one component or module of the energy management system. The energy management system may be a component of the energy storage system. The energy management system may be a modular system. The energy management system may be configured to direct power from at least one energy source and / or at least one electrical load to charge or partially charge the rechargeable energy storage system. The energy management system may be configured to transfer power from the rechargeable energy storage system to the at least one energy source and / or at least one electrical load. The energy management system may be configured to control the state of charge of the rechargeable battery system and / or the at least one battery. The energy management system may be configured to control the transfer of power between the at least one energy source and the battery system and / or the at least one battery. The energy management system may be configured to control the transfer of power from the at least one energy source to the battery system and / or the at least one battery to charge the battery system and / or the at least one battery. The energy management system may be configured to control the transfer of power from the at least one electrical load to the battery system and / or the at least one battery.

[0021] The energy management system may be configured to control the transfer of power from the battery system and / or the at least one battery to the at least one energy source. The energy management system may be configured to control the transfer of power from the battery system and / or the at least one battery to the at least one electrical load.

[0022] The modular system may comprise at least one energy source. The modular system may be configured to be connected or connectable to the at least one energy source. The at least one energy source may be selected from the group comprising a renewable energy source, a non-renewable energy source, an electric grid, at least one turbine, at least one vessel, at least one onshore substation, at least one offshore substation (topside or subsea), at least one wave energy converter, at least one tidal energy converter, at least one ocean current energy converter, at least one ocean thermal energy converter and / or at least one solar panel system. The at least one energy source may be located on the surface (topside) or subsea. The at least one energy source may be a renewable energy source.

[0023] The modular system may include at least one electrical load. The modular system may be configured to be connected or connectable to at least one electrical load. The at least one electrical load may be selected from the group comprising an electrical grid, a wind farm grid, an underwater autonomous vehicle, a remotely operated vehicle, an electrolyser, a hydrogen electrolyzer, a Christmas tree, a well control package, a subsea hydraulic power unit, a subsea service module, a subsea pump, and / or a subsea test tree. The at least one vessel may be a crew transfer vessel, a service operations vessel and / or an offshore support vessel.

[0024] The modular system may comprise at least one module selected from the group comprising at least one energy management system, at least one DC distribution board, at least one DC-DC converter, at least one AC-DC converter, at least one DC load distribution panel, at least one AC load distribution panel, and / or at least one battery.

[0025] The modular system may comprise a support frame. The modular system or at least one component of the modular system may be removably mounted on the support frame. The modular system or at least one modular component of the modular system may be removably mounted on the support frame. The energy storage system or at least one component of the modular energy storage system may be removably mounted on the support frame. The energy management system or at least one component of the energy management system may be removably mounted on the support frame. The modular system mounted on the support frame may be configured to be installed and / or secured to the seabed. The modular system mounted on the support frame may be configured to be suspended underwater above the seabed. The support frame may comprise a plurality of receptacles for mounting functional modules on the support frame. The functional modules are selected from the group comprising at least one AC transformer, at least one AC power distribution board, at least one AC-DC converter, at least one DC power source, at least one energy management system, at least one DC distribution board, at least one DC-DC converter, at least one AC-DC converter, at least one DC load distribution panel, at least one AC load distribution panel, and / or at least one battery.

[0026] The modular system may comprise a surface mountable first modular system and a subsea mountable second modular system. The modular system may comprise a surface mountable first modular system connected to a subsea mountable second modular system. The energy storage system may comprise a surface mountable first modular system and a subsea mountable second modular system. The surface mountable first modular system may comprise a first support frame comprising a plurality of receptacles for mounting functional modules of the surface mountable first modular system. The surface mountable first modular system may comprise functional modules selected from the group comprising at least one AC transformer, at least one AC power distribution board, at least one AC-DC converter, at least one DC power source. The surface mountable first modular system may be configured to be connected to at least one energy source. The surface mountable first modular system may be configured to be connected to at least one energy source to convert alternating current provided by the at least one energy source to direct current.

[0027] The subsea mountable second modular system may comprise functional modules selected from the group comprising at least one energy management system, at least one DC distribution panel, at least one DC-DC converter, at least one AC-DC converter, at least one DC load distribution panel, at least one AC load distribution panel, and / or at least one battery. The subsea mountable second modular system may comprise a second support frame comprising a plurality of receptacles for mounting the functional modules of the subsea mountable second modular system. The subsea mountable second modular system may be connected to the surface mountable first modular system by at least one cable or umbilical. The subsea mountable second modular system may be configured to receive a DC power supply provided by the surface mountable first modular system.

[0028] The energy management system may be configured to monitor the power resources of the second subsea mountable modular system and / or control the distribution of power between at least one battery, the DC load distribution panel and / or the AC load distribution panel.

[0029] The support frame and system components may form an integral assembly configured to be towed to an installation and / or submerged to the bottom of a body of water. The support frame may be a sealed frame. The support frame may be a pressurized compartment that may be fluid-tight. The support frame may have ports and / or hatches associated with each of the receptacles. Each component of the system may be removed or installed through at least one port and / or hatch on the frame. Each component of the system may be attached to a receptacle by a quick connector.

[0030] The energy management system may be configured to collect data and send the data to the surface. The energy management system may be configured to analyze the data before it is sent to the surface. The energy management system may be configured to collect or monitor data selected from the group comprising energy usage, individual battery status, individual battery health, temperature, operational data, toxic impurities, humidity, water ingress, internal pressure, capacity decay, power decay status of circuit breakers, on / off / tripped status of components, electrical parameters of distribution boards or enclosures, weather conditions and / or environmental conditions. The energy management system may be an intelligent energy management system.

[0031] The energy management system may be configured to collect data relevant to the reliability of the energy storage system in extreme environments (e.g., subsea). The energy management system may be configured to collect data to understand the performance changes and health state of one or more of the batteries over an extended period of time. The energy management system may be configured to measure and / or implement an active state of health management system for a battery system installed in a difficult to access location, such as a subsea environment. The energy management system may be configured to accurately predict and / or actively manage battery cell performance over extended durations in extreme environments. The energy management system may be configured to determine target reliability parameters for the system design, including the performance of the specific battery cell chemistry and architecture used within the energy storage technology. The energy management system may be configured to manage electrical efficiency to ensure that internal power requirements do not unduly impact power availability to end users.

[0032] The energy management system may be configured to measure, monitor, track and / or quantify battery degradation. The energy management system may be configured to measure, monitor and / or quantify capacity fade, power fade and / or battery aging mechanisms to quantify battery degradation with respect to the nominal state of the battery. The energy management system may use the capacity fade, power fade and / or battery aging mechanism measurements to estimate the state of health of one or more of the batteries. The battery aging mechanisms may include conductivity loss, loss of lithium inventory and / or loss of active material. The energy management system may be configured to measure, monitor, track and / or quantify battery degradation in situ or ex situ. Tests performed to measure, monitor, track and / or quantify battery degradation may be non-invasive or invasive.

[0033] The energy management system may be configured to monitor and / or predict future environmental conditions. The energy management system may be configured to monitor and / or predict metocean, wind and / or solar conditions. The energy management system may be configured to provide demand response requirements to avoid and / or minimize curtailment. The energy management system may be configured to maximize the ability of the storage system to capture and later dispatch available resources.

[0034] The ability of an energy management system to track and / or predict the aging process of one or more batteries will significantly increase battery life by actively modifying charge / discharge tolerances.

[0035] The energy management system may be configured to identify or investigate trends and patterns regarding power requirements. The energy management system may process one or more vital indicators and send data to the surface and / or to the base. The sent data may enable a model or digital twin to be established using minimal parameters. The model or digital twin may enable both in situ and ex situ measurement, monitoring, tracking and / or quantification to be applied and processed topside. The energy management system may utilize data from the model or digital twin to increase or improve the performance or health of one or more of the batteries.

[0036] The system may be an autonomous system or a semi-autonomous system. The system may be an automatic system or a semi-automatic system. The system may be remotely controlled by a user. The energy management system may be an autonomous system or a semi-autonomous intelligent energy management system.

[0037] In this context, subsea means that the modular system, or at least one component or module of the modular system, is located underwater or below the surface of a body of water, such as the ocean. The modular system is designed for storage and / or distribution of energy underwater or below the surface of the ocean.

[0038] According to a second aspect of the present invention there is provided a modular system for undersea energy storage, the modular system comprising: An energy management system; a first modular device configured to be connected to at least one energy source; a second modular device configured for installation subsea; and Equipped with a second modular device comprising a rechargeable energy storage system; the first modular device is configured to transfer power from at least one energy source to the second modular device; A modular system is provided in which an energy management system is configured to control the transfer of electrical energy between a rechargeable energy storage system and at least one energy source and / or at least one electrical load.

[0039] The first modular apparatus may be mountable to at least one energy source at, above, or on the surface of the body of water or subsea. Preferably, the first modular apparatus is a surface mountable first modular system.

[0040] The first modular device may comprise a first support frame comprising a plurality of receptacles for mounting functional modules of a surface mountable first modular system. The surface mountable first modular system may comprise functional modules selected from the group comprising at least one AC transformer, at least one AC power distribution board, at least one AC-DC converter, at least one DC power source. The first modular device may be configured to be connected to at least one energy source to convert alternating current provided by the at least one energy source to direct current. The first modular device may be designed to be mounted to existing energy source structures or devices, such as wind turbines, to retrofit their installation.

[0041] The second modular apparatus may be configured to be mounted and / or anchored to the ocean floor. The second modular apparatus may be configured to be mounted and / or anchored on the bottom of a body of water. The second modular apparatus may be configured to be suspended underwater above the ocean floor.

[0042] The second modular apparatus may comprise a functional module selected from the group comprising at least one energy management system, at least one DC distribution panel, at least one DC-DC converter, at least one AC-DC converter, at least one DC load distribution panel, at least one AC load distribution panel, and / or at least one battery. The subsea mountable second modular system may comprise a second support frame comprising a plurality of receptacles for mounting the functional modules of the subsea mountable second modular system. The second modular apparatus may be a subsea mountable second modular system. The second modular apparatus may be connected to the first modular apparatus by at least one cable or umbilical. The second modular apparatus may be configured to receive a DC power supply provided by the first modular apparatus.

[0043] Embodiments of the second aspect of the invention may include one or more features of the first aspect of the invention or embodiments thereof, or vice versa.

[0044] According to a third aspect of the present invention there is provided a method of storing energy in the ocean, the method comprising: An energy management system; Rechargeable Energy Storage Systems and providing a modular subsea energy storage system comprising: transferring electrical energy from at least one energy source and / or at least one electrical load to a rechargeable energy storage system; A method is provided, comprising:

[0045] The modular subsea energy storage system may be configured to be mounted and / or anchored to the ocean floor. The modular subsea energy storage system may be configured to be mounted and / or anchored on the bottom of a body of water. The modular subsea energy storage system may be configured to be suspended underwater above the ocean floor.

[0046] The method may include transferring electrical energy from at least one energy source and / or at least one electrical load to the rechargeable energy storage system to charge or partially charge the rechargeable energy storage system.

[0047] The method may include managing a transfer of electrical energy from the rechargeable energy storage system to at least one energy source and / or at least one electrical load.

[0048] The method may include controlling transfer of electrical energy between the rechargeable energy storage system and at least one energy source and / or at least one electrical load based on an operating schedule, maintenance activities, installation activities, electrical load power requirements, energy source power requirements, weather conditions and / or forecasted weather conditions.

[0049] The method may include collecting data and / or sending the data to the surface. The method may include analyzing the data before the data is sent to the surface. The method may include collecting or monitoring data selected from the group consisting of energy usage, individual battery status, individual battery health, temperature, operational data, toxic impurities, humidity, water ingress, internal pressure, capacity decay, power decay status of circuit breakers, on / off / trip status of components, electrical parameters of a distribution board or enclosure, weather conditions and / or environmental conditions. The method may include collecting data related to the reliability of the energy storage system in an extreme environment (e.g., subsea). The method may include collecting data to understand performance changes and health status of one or more of the batteries over an extended period of time. The method may include measuring and / or implementing an active state of a health management system for a battery system installed in a difficult to access location, such as a subsea environment. The method may include predicting and / or actively managing battery cell performance over an extended duration in an extreme environment. The method may include obtaining or monitoring target reliability parameters for a system design, including performance of a particular battery cell chemistry and architecture used within the energy storage technology. The method may include managing electrical efficiency to ensure that internal power requirements do not unduly impact power availability to end users. The method may include measuring, monitoring, tracking, and / or quantifying battery degradation. The method may include measuring, monitoring, and / or quantifying capacity fade, power fade, and / or battery aging mechanisms to quantify battery degradation relative to the nominal state of the battery. The method may include estimating the state of health of one or more of the batteries. The method may include monitoring and / or predicting future environmental conditions. The method may include monitoring and / or predicting metocean, wind, and / or solar conditions.The method may include identifying or investigating trends and patterns related to power requirements. The method may include creating a model or digital twin based on the collected data.

[0050] Embodiments of the third aspect of the invention may include one or more features of the first or second aspects of the invention or embodiments thereof, or vice versa.

[0051] According to a fourth aspect of the present invention, there is provided a method of distributing power from a modular subsea energy storage system, the method comprising: An energy management system; Rechargeable Energy Storage Systems and providing a modular subsea energy storage system comprising: transferring electrical energy between the rechargeable energy storage system and at least one energy source and / or at least one electrical load; A method is provided, comprising:

[0052] The modular subsea energy storage system may be configured to be mounted and / or anchored to the ocean floor. The modular subsea energy storage system may be configured to be mounted and / or anchored on the bottom of a body of water. The modular subsea energy storage system may be configured to be suspended underwater above the ocean floor.

[0053] Embodiments of the fourth aspect of the invention may include one or more features of the first to third aspects of the invention or embodiments thereof, or vice versa.

[0054] According to a fifth aspect of the present invention there is provided a method of servicing a modular subsea energy storage system, the method comprising: An energy management system; Rechargeable Energy Storage Systems and providing a modular system comprising: Accessing modular components of a modular system; Releasing modular components from a modular system; A method is provided, comprising:

[0055] The modular system may be configured to be mounted and / or anchored to the ocean floor. The modular system may be configured to be mounted and / or anchored on the bottom of a body of water. The modular system may be configured to be suspended underwater above the ocean floor.

[0056] The method may include mounting a replacement modular component on or in a modular system. The modular system may comprise a support frame. The modular system or at least one component of the modular system may be removably mounted on the support frame. The modular system mounted on the support frame may be configured to be attached and / or secured to the seabed. The modular system mounted on the support frame may be configured to be suspended submerged above the seabed. The support frame may comprise a plurality of receptacles for mounting functional modules on the support frame. The functional modules are selected from the group comprising at least one AC transformer, at least one AC power distribution board, at least one AC-DC converter, at least one DC power source, at least one energy management system module, at least one DC distribution board, at least one DC-DC converter, at least one AC-DC converter, at least one DC load distribution panel, at least one AC load distribution panel, and / or at least one battery.

[0057] The support frame may be a sealed frame. The support frame may be a pressurized compartment that may be fluid-tight. The support frame may have ports and / or hatches associated with each of the receptacles. Each component of the system may be removed or installed through at least one port and / or hatch on the frame. Each functional module (component) of the system may be attached to a receptacle by a quick connector.

[0058] The method may include accessing a receptacle on the support frame. The method may include releasing a functional module from the receptacle. The method may include accessing the receptacle through a hatch or port positioned above or adjacent to the receptacle. The method may include releasing the functional module from the receptacle manually or via a control module. The method may include installing the functional module into the receptacle. The method may include installing the functional module into a previously empty receptacle.

[0059] Embodiments of the fifth aspect of the invention may include one or more features of the first to fourth aspects of the invention or embodiments thereof, or vice versa.

[0060] According to a sixth aspect of the present invention there is provided a modular system for undersea energy storage, the modular system comprising: a support frame having a plurality of receptacles for mounting functional modules on the support frame; A plurality of functional modules each having at least one energy management system and a plurality of rechargeable batteries; A modular system is provided, comprising:

[0061] Embodiments of the sixth aspect of the invention may include one or more features of the first to fifth aspects of the invention or embodiments thereof, or vice versa.

[0062] According to a seventh aspect of the present invention there is provided an apparatus for the storage of energy at the bottom of a body of water, the apparatus comprising: a support frame having a plurality of receptacles for mounting functional modules on the support frame; A plurality of functional modules each having at least one energy management system and a plurality of rechargeable batteries; Equipped with An apparatus is provided in which a support frame and a plurality of functional modules form an integrated assembly configured to be towed to a mounting location and / or submerged to the bottom of a body of water.

[0063] Embodiments of the seventh aspect of the invention may include one or more features of the first to sixth aspects of the invention or embodiments thereof, or vice versa. According to an eighth aspect of the present invention there is provided a method of storing and managing energy on the bottom of a body of water using apparatus according to the first, second, sixth or seventh aspect of the present invention.

[0064] Embodiments of the eighth aspect of the invention may include one or more features of the first to seventh aspects of the invention or embodiments thereof, or vice versa.

[0065] According to a ninth aspect of the present invention there is provided a method of installing an apparatus for energy storage and management on the bottom of a body of water, the method comprising: Providing an apparatus comprising an integrated assembly having a support frame and a plurality of functional modules mounted on the support frame Including, The plurality of functional modules comprises at least one energy management system and a plurality of rechargeable batteries; A method is provided in which the support frame and a plurality of functional modules form an integrated assembly configured to be towed to a mounting location and / or submerged to the bottom of a body of water.

[0066] The method may include connecting the device to at least one energy source. The at least one energy source may be located on the surface or subsea. The method may include connecting the device to the at least one energy source by at least one cable or umbilical. The method may include connecting the device to at least one electrical load.

[0067] Embodiments of the ninth aspect of the invention may include one or more features of the first to eighth aspects of the invention or embodiments thereof, or vice versa.

[0068] According to a tenth aspect of the present invention there is provided a method of storing and managing energy on the bottom of a body of water, the method comprising: Providing an apparatus comprising an integrated assembly having a support frame and a plurality of functional modules mounted on the support frame, Providing a plurality of functional modules, the functional modules comprising at least one energy management system and a plurality of rechargeable batteries; submerging the integrated assembly to the bottom of the body of water and positioning the device on the ocean floor; operating at least one energy management system to control a transfer of electrical energy between at least one of the rechargeable batteries and at least one energy source and / or at least one electrical load; A method is provided, comprising:

[0069] Embodiments of the tenth aspect of the invention may include one or more features of the first to ninth aspects of the invention or embodiments thereof, or vice versa.

[0070] According to an eleventh aspect of the present invention there is provided a modular system for subsea energy storage and / or distribution, the modular system comprising: at least one energy management system; at least one rechargeable energy storage system; Equipped with A modular system is provided in which at least one energy management system is configured to control the transfer of electrical energy between at least one rechargeable energy storage system and at least one energy source and / or at least one electrical load.

[0071] The modular system may include two or more rechargeable energy storage systems. The at least one energy management system may be configured to control the transfer of electrical energy between the two or more rechargeable energy storage systems. The at least one energy management system may be configured to control the transfer of electrical energy between the two or more rechargeable energy storage systems and at least one energy source and / or at least one electrical load.

[0072] Embodiments of the eleventh aspect of the invention may include one or more features of the first to tenth aspects of the invention or embodiments thereof, or vice versa.

[0073] Various embodiments of the present invention will now be described, by way of example only, with reference to the drawings, in which: [Brief description of the drawings]

[0074] [Figure 1] FIG. 1 is a diagram of a subsea energy storage and management system, according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram illustrating components of the subsea energy storage and management system of FIG. [Figure 3A] FIG. 3A is a schematic diagram illustrating a surface mountable modular system for a subsea energy storage and management system, in accordance with one embodiment of the present invention. [Figure 3B] FIG. 3B is a schematic diagram illustrating a subsea mountable modular system of a subsea energy storage and management system configured to be connected to the surface mountable modular system of FIG. 3A. [Figure 4] FIG. 4 is a schematic diagram showing the components of the subsea energy storage and management system of FIG. 1 with the batteries mounted in a separate frame. [Diagram 5] FIG. 5 is a schematic diagram illustrating an alternative subsea mountable modular system of a subsea energy storage and management system according to one embodiment of the present invention configured to be connected to the surface mountable modular system of FIG. 3A with batteries mounted in a separate frame. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0075] 1 is a system 10 for storing and providing electrical power underwater. The system 10 includes an energy storage system 11, in this example, located on the ocean floor 15. It will be appreciated that in other examples the system or components of the system may be located underwater but suspended above the ocean floor. It will also be appreciated that components of the system may be located on, at, or above the ocean surface 17 (as described below with respect to FIGS. 3A and 3B ).

[0076] The system 10 may comprise an energy source 12 that provides power to the energy storage system via an umbilical cable 14. The energy source 12 may be a form of renewable energy, such as wind, tides, ocean currents, wave energy, ocean thermal, or solar power. Additionally or alternatively, the energy may be provided by surface equipment, such as an offshore platform, an offshore substation (topside or subsea), a vessel, a turbine, or an electric grid. The system 10 may comprise two or more power sources located subsea, on the surface, or above the surface, or a combination of subsea and surface energy sources. Surface means equipment located at or above the water surface, which may include floating and / or fixed equipment. In the present example shown in FIG. 1, the energy source is a wind turbine 13. Subsea means below the water surface.

[0077] The energy storage system 11 comprises at least one battery 18 (best shown in FIG. 2). The at least one battery 18 is housed in a battery enclosure. The energy storage system 11 has at least one electrical load connector 16. The electrical load connectors may be configured to serve as inputs and / or outputs to the energy storage system. In this example, three electrical load connectors 16a, 16b and 16c are shown. A power buoy 20 is connected to the electrical load connector 16a via a cable umbilical 19 and is configured to serve as an outlet and either draw power from the energy storage system 11 or supply power to the energy storage system 11, depending on the mode of operation.

[0078] Although three electrical load connectors are shown in Figure 1, it will be appreciated that the energy storage system 11 may include more or less than three electrical load connectors. It will also be appreciated that multiple devices may be connected to the electrical load connectors (a second, unconnected power buoy 21 is shown in Figure 1).

[0079] In the battery charging mode, the energy storage system 11 is configured to charge or at least partially charge the at least one battery 18. In this example, power is provided by the turbine 13, via the umbilical cable 14, to the energy storage system 11 via the connector 23. Additionally or alternatively, in the battery charging mode, power generated by the power buoy 20 may be transferred to the energy storage system 11 via the electrical load connector 16a, which serves as an electrical inlet for charging the at least one battery 18. Additionally or alternatively, the power buoy 20 may be connected to a surface vessel (not shown), and power may be transferred from the vessel to the energy storage system 11 via the power buoy 20 for charging the at least one battery 18.

[0080] In the energy production mode (battery discharging), the energy storage system 11 is configured to provide power from at least one battery 18 to the electrical load connector 16 to power devices connected to the electrical load connector 16. Additionally or alternatively, in the energy production mode (battery discharging), the energy storage system 11 may be configured to supply power from the at least one battery 18 to the turbine to operate the wind turbine when a black start of the turbine system is required. Additionally or alternatively, in the energy production mode (battery discharging), the energy storage system 11 may be configured to supply power from the at least one battery 18 to provide power to the surface vessel via the umbilical 19 and the power buoy 20.

[0081] The system 10 includes at least one energy management system 70, best shown in Figure 2, configured to control the management of power in the energy storage system between a battery charging mode and a battery discharging mode. The at least one energy management system is configured to monitor the status of the at least one battery and to control the transfer of power to or from the at least one battery when needed.

[0082] 1 shows a wind turbine 13 and a power buoy 20 connected to the energy storage system 11, it will be appreciated that a wide range of different types of subsea and / or surface devices may be connected to the energy storage system to supply and / or receive power from the energy storage system. Examples of devices that may be connected include wave generators, solar panel systems, electrolyzers, AUVs, subsea pumps and / or Christmas trees.

[0083] FIG 2 is a schematic diagram illustrating components of the energy storage system 11 of FIG 1 for storing and providing electrical power subsea. FIG 2 also illustrates an energy management system 70 configured to monitor and / or control the energy storage system. A wind turbine 13 connected to the energy storage system 11 via an umbilical 14 generates AC electrical power. The energy storage system 11 comprises a module, in this example including an AC transformer 30 for modifying the voltage of the alternating current (AC) received from the wind turbine. An AC power distribution board 32 is connected to the AC transformer 30, which is connected to an AC-DC converter 34 for converting the alternating current (AC) to a direct current (DC). The output of the AC-DC converter 34 is connected to a DC distribution board 36.

[0084] The system is configured to supply and receive DC and / or AC loads. For DC loads, a DC-DC converter 38 is connected to the distribution board 36 to convert direct current from one voltage level to another. A DC load distribution panel 40 is connected to the DC-DC converter 38 and supplies DC power to a number of DC load connectors 42.

[0085] For AC loads, the energy storage system 11 includes an AC load connector 52 connected to an alternating current (AC) load distribution panel 50, which is connected to an AC-DC converter 54. The AC-DC converter 52 is connected to the distribution board 36 to convert the alternating current (AC) to direct current (DC).

[0086] The energy storage system 11 comprises a battery system 60 comprising a plurality of modular rechargeable batteries 18 (only two are shown for simplicity). In this example, the battery system has a combined capacity of up to 15 MWh. It will be appreciated that larger or smaller battery capacities may be used. It is preferred that the battery capacity should be equivalent to the energy capacity generated by the connected wind turbine. The modular batteries 18 are connected to a DC distribution board 36. The number of modular batteries depends on the load requirements. Optionally, additional batteries may be added at a later point in time if the load requirements or electrical storage capacity requirements of the system change. Each individual battery stored in a battery enclosure may be returned to the surface for maintenance or replacement. Each battery may be positioned and operated independently of the others. Each battery may be charged and / or discharged independently of the others.

[0087] The modular system 10 includes an energy management system 70 configured to monitor the condition of the batteries 18. The energy management system 70 may measure battery parameters and conditions, such as state of charge, health, and temperature. Each battery 18 may individually communicate with the energy management system to provide real-time data regarding the status of the batteries. The energy management system may monitor and control energy flow within the system, including through the DC distribution board 36 and the battery system 60. The energy management system may be configured to collect and analyze energy data to enable efficient power resource management of the system.

[0088] The energy management system may control the charging and / or discharging of each of the batteries independently, selected groups of batteries, or all of the batteries in the battery system to provide optimal charging or energy output. The energy management system may switch between battery charging and / or discharging depending on the power requirements of devices connected to the system.

[0089] All DC-DC converters are bidirectional. This may facilitate the modular batteries being charged from the load. All AC-DC converters are bidirectional. This may facilitate the batteries providing power to an energy source, such as the turbine 13 and / or the turbine grid.

[0090] In use, in battery charging mode, AC power is provided from the wind turbine 13 via the umbilical 14. The AC power generated by the wind turbine 13 is converted to DC in the sea via the AC-DC converter 34 as described above. The DC power is provided to the distribution board 36. The energy management system 70 monitors the power resources of the system and controls the distribution of power between the modular batteries 18, the DC load connector 42 and / or the AC load connector 52. Optionally, in this example, the power buoy 20 is connected to the DC load connector 42, and the energy management system distributes power between the power buoy 20 and the modular batteries 18 to charge the modular batteries 18 depending on the power status of the modular batteries 18 and the power status of the power buoy 20. Additionally or alternatively, a vessel may be connected to the power buoy 20 to provide power via the power buoy 20 to charge the modular batteries 18. This is controlled by the energy management system 70.

[0091] In a battery discharge mode (energy release mode), the energy management system 70 controls the discharge or release of power from the battery system 60 to the distribution board 36. The energy management system 70 may control the discharge or release of individual modular batteries, selected groups of modular batteries, or all of the modular batteries. The energy management system 70 controls the distribution of power between the DC load connectors 42, the AC load connectors, and / or energy sources, such as wind turbines in this example. In this example, a wind turbine 13 and a power buoy 20 are connected to the system. The energy management system controls the distribution of power between the modular batteries and the wind turbines and / or power buoys 20 depending on the power needs of each of the wind turbines (black start) power buoys 20 and / or the status of the batteries 18.

[0092] The energy management system 70 may monitor an electrical grid connected to an energy source, in this example a wind farm grid connected to a wind turbine, and may control the transfer of power from the battery system 60 to the wind farm grid when wind power levels drop or the turbine is unable to operate.

[0093] Additionally or alternatively, the power buoy 20 may act as a connection hub for surface equipment or a battery-powered vessel (or an electric hybrid vessel). The energy management system 70 is in communication with the surface equipment or vessel via the power buoy 20 and may control infield charging of batteries on the vessel. The distribution of power may depend on the power level of the battery system 60.

[0094] Other devices or systems may be connected to the system 10, including, but not limited to, AUVs, hydrogen electrolyzers, electric Christmas trees, well control packages, subsea power units, subsea hydraulic power units, subsea service modules, subsea pumps, and subsea test trees.

[0095] The energy storage system 11 is mounted in a frame 80. The frame 80 is fixed to the seabed. The frame includes a number of receptacles, with each component of the modular system being placed in a separate receptacle. Each component of the system may be stored in an individual enclosure that is reversibly or removably mounted to the frame. The frame may have receptacles for placing duplicates or multiples of each of the components of the system as redundancies or to improve the functionality of the system. As an example, FIG. 2 shows the duplication of AC-DC converters 34, 34a, DC-DC converters 38, 38a and AC-DC converters 54, 54a. For simplicity, not all duplication of components is shown in FIG. 2. It will be appreciated that the system may be mounted in two or more frames depending on the size of the components. Some of the components of the system may be mounted in separate frames.

[0096] Each component unit is attached to a receptacle on the frame by a suitable quick connector that allows for fast and reliable attachment / detachment of the component to / from the frame receptacle. The quick connector may be a mechanical connector or, in an alternative embodiment, the quick connector is preferably operable by fluid pressure. The quick connector may comprise an upper connector assembly and a lower connector assembly secured to the component (or component enclosure) and the receptacle, respectively.

[0097] The battery system 60 has multiple receptacles or enclosures with each battery 18 mounted in a separate receptacle on the frame. Each of the batteries has individual connections for monitoring, charging and discharging. In this example, FIG. 2 shows a battery system with two batteries 18 for simplicity. Each of the batteries 18 is placed in an individual receptacle or enclosure. However, if additional battery power capacity is required, additional receptacles or enclosures for batteries are provided. It will be appreciated that more than two batteries can be placed on the frame. It will be appreciated that one battery can be placed on the frame. Optionally, the system can have a battery enclosure 61 fitted to the frame for a smaller energy storage system.

[0098] The components of the energy storage system 11, including the batteries 18, are mounted in receptacles and electrically connected by a system of electrical conductors configured for transfer of electrical energy from each component unit to a common wet-mate connector. The wet-mate connector allows the equipment to be connected to a single umbilical that can be connected to turbines, turbine grids, substations and / or subsea or surface devices.

[0099] The individual modular components of modular energy storage system 11 are designed to be conveniently installable, easily replaceable, and / or replaceable modules in the system.

[0100] After assembly of the system on the frame apparatus at the surface in the desired configuration, the frame is submerged to the seabed location where it will be attached. In the case of a seabed fixed apparatus, the wetmate connections of the subsea umbilical are configured to connect the modular system 10 to the surface wind turbine infrastructure in this example.

[0101] After a period of use, it may be necessary to remove, replace, or service one or more components from the system. The modular system configuration facilitates access to individual components of the system via ports or hatches positioned above each receptacle. A remotely operated vehicle (ROV) identifies the associated port or hatch positioned above the component to be removed. The port or hatch is removed and the component is released from the receptacle either manually using the ROV or via a control signal (which may be activated by a remote signal received by the energy management system or control module). The component to be removed may be easily removed from the system via the hatch or port, for example, by lifting the component from the surface using the ROV or a cable, or by attaching the component to a controllable buoyancy device to allow the component to be returned to the surface. A replacement (or additional) component may be easily installed in the device by submerging the component from the surface and placing it in the associated receptacle using the ROV. As described, the system may have duplicate or multiple components as redundancy to ease component replacement.

[0102] Advantageously, individual components or modules of a modular system may be removed and / or installed in the apparatus without disturbing the installation or operation or other components which form part of the apparatus.

[0103] In an alternative configuration, several energy storage systems 11 may be connected together to "daisy chain" the systems 11 into a larger energy storage and management system. One or more energy management systems may control the transfer of power between the various connected energy storage systems 11a, 11b, etc., depending on the power requirements of each of the systems 11 and the connected loads.

[0104] 4 illustrates a modular system 210 comprising an energy storage system 211 and an energy management system 270. The energy storage system 211 is an alternative configuration to the modular system 11. The energy storage system 211 is similar to the system 11 of FIG. 2 and will be understood from the description of FIG. 2. However, the modular system 211 has a battery 218 disposed in an enclosure mounted in separate frame units 280b and 280c that are separate from the frame 280a that houses the other components of the energy storage system 211 and, optionally, the energy management components 270.

[0105] Figures 3A and 3B show a modular system 110 for subsea energy storage, similar to the modular system 10 of Figure 2 and understood from the description of Figure 2. However, the modular system 110 comprises a surface modular system 111a, shown in Figure 3A, and a subsea modular system 111b, shown in Figure 3B. The initial step of converting AC generated by the wind turbine to DC is performed at the surface using the surface modular system 111a, shown in Figure 3A. The resulting DC output is transferred to the subsea modular system 111b via an umbilical 114, shown in Figure 3B.

[0106] FIG. 3A shows a first modular system, a surface modular system 111a, which includes surface components of the energy storage system 111. In this example, the first modular system includes components of the energy management system 170a. The system 111a includes an AC transformer 130 connected to a wind turbine (not shown). The AC transformer 130 changes the voltage of the alternating current (AC) received from the wind turbine. An AC power distribution panel 132 is connected to the AC transformer 130, which is connected to an AC-DC converter 134 for converting the alternating current (AC) to direct current (DC) and a DC power distribution panel 135. The surface modular system 111a is preferably located on the surface as part of or in close proximity to the wind turbine equipment. As wind turbine technology improves and there is insufficient space at the surface for the AC-DC conversion equipment, the subsea system described in FIG. 2 may be used.

[0107] 3B illustrates a second modular system, a subsea modular system 111b, that includes subsea components of the energy storage system 111. The system 111b includes a DC distribution board 136 for receiving direct current from the surface modular system 111a via the umbilical 114.

[0108] The system is configured to supply and receive DC and / or AC loads. For DC loads, a DC-DC converter 138 is connected to the distribution panel 136 to convert direct current from one voltage level to another. A DC load distribution panel 140 is connected to the DC-DC converter 138 and supplies DC power to a number of DC load connectors 142.

[0109] For AC loads, the modular system 111b includes an alternating current (AC) load connector 152 connected to an AC load distribution panel 150, which is connected to an AC-DC converter 154. The AC-DC converter 152 is connected to the distribution panel 136 to convert the alternating current (AC) to direct current (DC).

[0110] The subsea modular system 111b comprises a number of modular rechargeable batteries 118 (only two are shown for simplicity). The modular batteries 118 are connected to a DC distribution board 136. The number of modular batteries depends on the load requirements. Optionally, additional batteries may be added at a later time if the load requirements or electrical storage capacity requirements of the system change. Individual batteries may be returned to the surface for maintenance or replacement. Each battery may individually communicate with an energy management system to provide real-time data regarding the battery's status.

[0111] The subsea modular system 111b is mounted in a frame 180. In this example, the components of the energy management system 170b are also optionally mounted in the frame. The frame 180 is fixed to the seabed. The frame includes a number of receptacles, with each component of the modular system being placed in a separate receptacle. Each component may be stored in an individual enclosure that is reversibly or removably mounted to the frame. The frame may have receptacles for placing duplicates or multiples of each of the components of the system as redundancies or to improve the functionality of the system. As an example, Figures 3A and 3B show duplications of the AC-DC converters 134, 134a, the DC-DC converters 138, 138a, and the AC-DC converters 154, 154a. For simplicity, not all duplications of components are shown in Figure 3B.

[0112] Each component unit is attached to a receptacle on the frame by a suitable quick connector that allows for fast and reliable attachment / detachment of the component to / from the frame receptacle. The quick connector can be a mechanical connector or, in an alternative embodiment, the quick connector is preferably operable by fluid pressure. The quick connector may comprise an upper connector assembly and a lower connector assembly fixed to the component (or enclosure) and the receptacle, respectively. Optionally, the system may have a battery enclosure 161 fitted to the frame for a smaller energy storage system.

[0113] The operation and benefits of the modular systems 111 (surface modular system and subsea modular system 111b) are the same as the modular system 11 described in FIG. 2 and will be understood from the description of FIG.

[0114] Figure 5 shows a modular system that is a subsea modular system 311b that is similar to modular system 111b of Figure 3B and includes subsea components of an energy storage system 311 for storage of energy underwater, as understood from the description of Figure 3B. However, modular system 311b has a battery 318 disposed in an enclosure that is reversibly or removably mounted on separate frame units 380b and 380c that are separate from the frame 380a that houses the other components of subsea modular system 311b. In this example, components of an energy management system 370b are also optionally mounted in the frames.

[0115] By providing a modular subsea energy storage system with an energy management system, the modular batteries can be closely monitored to assess their health and maximize battery life. The energy management system can also control the distribution of energy throughout the system across multiple devices to control loads, facilitate efficient charging, and / or supply stored energy for a wide range of subsea equipment and applications.

[0116] The energy management system described in the above examples may control the extraction or taking of energy from energy sources, such as wind farm turbines, wind farm inter-array cables or junction boxes, offshore substations (topside and subsea), wave energy converters, tidal energy converters, ocean current energy converters, ocean thermal energy converters, electric grids, vessels, and / or connected surface and / or subsea equipment, to recharge or partially recharge the battery system. This power is stored offshore in an energy storage system for use when needed. The stored energy may be used to supply various offshore loads, vessels, and / or return power to the energy source(s) when needed.

[0117] The energy management system may collect and optionally analyze data. The energy management system may provide data to the surface for optional further analysis. The energy management system may collect or have access to data regarding the operation of the energy sources. As an example, if at least one energy source is a wind turbine, the energy management system may use actual or predicted weather conditions to predict power demand. The energy management system may be configured to switch to a battery charging mode if a weather forecast predicts bad surface weather that will affect the ability of the wind turbine to function. This may facilitate the batteries in the energy storage system to fully charge. If the wind turbine is shut down to prevent unnecessary strain and damage to the turbine due to bad weather, the energy management system may direct power from the batteries in the energy storage system to the grid to maintain power levels in the turbine grid.

[0118] Another example where power from the energy storage system may be needed is during scheduled supply, maintenance, installation and / or repair work on the surface with the electrically powered vessel. Prior to the scheduled supply, maintenance, installation and / or repair work, the energy management system of the energy storage system may control the system to switch to a battery charging mode to ensure that the batteries in the energy storage system are fully charged and power is available for the vessel.

[0119] The energy management system may control switching of the energy storage system to a battery charging mode when the vessel has a power surplus to facilitate recharging or partial recharging of the batteries in the energy storage system.

[0120] The present invention provides a modular system and method of use for undersea energy storage. The modular system may include an energy management system and a rechargeable energy storage system. The energy management system may be configured to control the transfer of electrical energy between the rechargeable energy storage system and at least one energy source and / or at least one electrical load.

[0121] Providing a subsea modular system that is mounted on the seabed provides operational flexibility and allows the system to be located in a wide range of locations close to where the energy demand is greatest without space limitations. Furthermore, by locating the system in an offshore location close to the energy demand, the need for costly and redundant power umbilicals may also be reduced and power losses through redundant power umbilicals may be mitigated.

[0122] Embodiments of the invention may allow a system to be designed and constructed according to the power requirements of the particular location where it is to be deployed. The system may be designed and constructed according to the application of the technology. The system may also be designed and constructed according to the requirements of the system (surface and / or subsea) that is providing the power to charge the energy storage system and / or the system (surface and / or subsea) to which the energy storage system is delivering stored energy.

[0123] The designed and assembled modular system and equipment can be adjusted or reconfigured in situ while it is subsea and anchored to the seabed. The components of the modular system are replaceable. The equipment forms an integral modular assembly with the frame structure and the system components. The modular nature of the system can allow for varying loads and cost-effective maintenance.

[0124] Aspects of the present invention may complement existing methods of delivering power offshore by providing an easy-to-install means of storing energy underwater and overcoming the intermittency of renewable resources. As an example, the present invention may be used with wave / tidal / current / ocean thermal energy generation for remote subsea tie-backs, or floating / fixed offshore wind turbines to power subsea equipment such as pumps. Aspects of the present invention may also complement and / or replace diesel / gas turbines on offshore platform electrification.

[0125] Aspects of the present invention can provide high energy storage undersea. By providing the system undersea, it relieves space requirements for existing surface equipment, such as wind farm assets, for retrofitting.

[0126] Embodiments of the present invention may facilitate monitoring of battery performance of a subsea energy storage system, including monitoring the health and function of batteries in the energy storage system. By providing an autonomous intelligent energy management system, battery life may be maximized. Data collection regarding the system, including operational data, may be provided to the surface.

[0127] Throughout this specification, unless the context requires otherwise, variations such as "comprise" or "include", or "comprises" or "comprising", "includes" or "including" are understood to imply the inclusion of a stated whole or group of wholes, but not the exclusion of any other whole or group of wholes. Furthermore, relative terms such as "top", "bottom", "upper", "lower", "upper", "lower", "upper side", "lower", "upward", "downward", "horizontal", "vertical", and the like are used herein to indicate directions and locations as they apply to the accompanying drawings and are not to be construed as limiting the invention and its features to a particular arrangement or orientation. Similarly, the term "outlet" or "output" shall be construed as being a location or connection type that may also serve as an "inlet" or "input" depending on the direction of power, signal or charge, and vice versa.

[0128] Various modifications to the embodiments described above may be made within the scope of the invention, which extends to combinations of features other than those expressly claimed herein.

Claims

1. 1. A modular system for undersea energy storage, said modular system comprising: an energy management system; Rechargeable undersea energy storage system and Equipped with A modular system, wherein the energy management system is configured to control the transfer of electrical energy between the rechargeable energy storage system and at least one energy source and / or at least one electrical load.

2. The modular system of claim 1 , wherein the rechargeable energy storage system is a rechargeable battery system comprising at least one battery.

3. 3. The modular system of claim 1 or 2, wherein at least one component of the rechargeable energy storage system is a subsea retrievable unit.

4. The modular system of claim 1 , wherein the modular system is a two-way power transfer system.

5. 2. The modular system of claim 1, wherein the energy management system is configured to control power transfer between the at least one energy source and / or the at least one electrical load to the rechargeable energy storage system to charge or partially charge the rechargeable energy storage system.

6. The modular system of claim 1 , wherein the energy management system is configured to control power transfer between the rechargeable energy storage system and the at least one energy source and / or the at least one electrical load.

7. The modular system of claim 1 , wherein the energy management system is configured to control a state of charge of the rechargeable energy storage system.

8. 2. The modular system of claim 1, wherein the at least one energy source is selected from the group comprising a renewable energy source, a non-renewable energy source, an electric grid, at least one turbine, at least one vessel, at least one onshore substation, at least one offshore substation, at least one wave energy converter, at least one tidal energy converter, at least one ocean current energy converter, at least one ocean thermal energy converter and / or at least one solar panel system.

9. The modular system of claim 1 , wherein the at least one energy source is located at, above and / or below the surface of the ocean.

10. 10. The modular system of claim 1, wherein the at least one electrical load is selected from the group comprising an electrical grid, a wind farm grid, an underwater autonomous vehicle, a vessel, a remotely operated vehicle, an electrolyzer, a hydrogen electrolyzer, a Christmas tree, a well control package, a subsea hydraulic power unit, a subsea service module, a subsea pump, and / or a subsea test tree.

11. 10. The modular system of claim 1, wherein the system comprises at least one functional module selected from the group comprising at least one AC transformer, at least one AC power distribution panel, at least one AC-DC converter, at least one DC power source, at least one energy management system, at least one DC distribution panel, at least one DC-DC converter, at least one AC-DC converter, at least one DC load distribution panel, at least one AC load distribution panel, and / or at least one battery.

12. The modular system of claim 1 , wherein the system comprises a first surface-mountable modular system and a second subsea-mountable modular system.

13. 13. The modular system of claim 12, wherein the surface-mountable first modular system is configured to be connected to the at least one energy source to convert alternating current provided by the at least one energy source to direct current.

14. 14. The modular system of claim 12 or 13, wherein the subsea-mountable second modular system is configured to receive a DC power supply provided by the surface-mountable first modular system.

15. The modular system of claim 1 , wherein the modular system comprises a support frame, and the modular system or at least one component of the modular system is removably mounted on or to the support frame.

16. The modular system of claim 15 , wherein the modular system mounted on the support frame is configured to be attached and / or anchored to the seabed.

17. The modular system of claim 1 , wherein the energy management system is configured to collect data and / or transmit data to a surface.

18. 10. The modular system of claim 1, wherein the energy management system is configured to collect and / or monitor data selected from the group consisting of energy usage, individual battery status, individual battery health, temperature, operational data, toxic impurities, humidity, water ingress, internal pressure, capacity decay, circuit breaker power decay status, component on / off / trip status, distribution panel or enclosure electrical parameters, weather conditions, and / or environmental conditions.

19. The modular system of claim 1 , wherein the system is an autonomous system or a semi-autonomous system.

20. 1. A method for storing energy in the ocean, said method comprising: an energy management system; Rechargeable undersea energy storage system and providing a modular subsea energy storage system comprising: transferring electrical energy between the rechargeable energy storage system and at least one energy source and / or at least one electrical load; A method comprising:

21. 21. The method of claim 20, comprising transferring electrical energy from the at least one energy source and / or the at least one electrical load to the rechargeable energy storage system to charge or partially charge the rechargeable energy storage system.

22. 22. The method of claim 20 or 21, comprising managing the transfer of electrical energy from the rechargeable energy storage system to at least one energy source and / or at least one electrical load.

23. 21. The method of claim 20, comprising controlling the transfer of electrical energy between the rechargeable energy storage system and at least one energy source and / or at least one electrical load based on an operating schedule, maintenance work, installation work, electrical load power requirements, energy source power requirements, environmental conditions, weather conditions, and / or forecasted weather conditions.

24. 1. A method of servicing a modular subsea energy storage system, comprising: an energy management system; Rechargeable undersea energy storage system and To provide a modular system comprising: providing an energy management system configured to control the transfer of electrical energy between the rechargeable energy storage system and at least one energy source and / or at least one electrical load; accessing a modular component of the modular system; releasing the modular component from the modular system; A method comprising:

25. 25. The method of claim 24, comprising installing a replacement modular component on or in the modular system.

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