Integrated energy buffer system for urban storage

Abstract

The invention is in the field of an integrated energy buffer system for urban storage, such as in a building, in particular in a parking lot thereof, for mitigating electrical grid con- gestion of transport of electrical power in particular in urban areas, and for balancing demand and supply of electrical energy.

Description

[0001] INTEGRATED ENERGY BUFFER SYSTEM FOR URBAN STORAGE

[0002] FIELD OF THE INVENTION

[0003] The invention is in the field of an integrated energy buffer system for urban storage, in particular of green energy, such as in a building, in particular in a parking lot thereof, for miti- gating electrical grid congestion of transport of electrical power in particular in urban areas, and for balancing demand and supply of electrical energy.

[0004] RELATED APPLICATIONS

[0005] The present application claims the benefit of priority from Dutch Patent Application NL2038419, filed on August 8, 2024, in the name of J. J. Koning Investeringen B.V., The Netherlands.

[0006] The entire contents of the above-referenced applications and of all priority documents referenced in the Application Data Sheet filed herewith are hereby incorporated by reference for all purposes.

[0007] BACKGROUND OF THE INVENTION

[0008] The congestion of electrical energy in cities can be a large problem. It may result in a need for more electrical power transportation capacity over the grid to the city, and in the city, and can be regarded as a local surplus or shortage of electrical power. Soil is typically expen- sive in cities. Having a buffer for hundreds or thousands households and / or for companies to- gether, typically consuming more than 10MW (e.g., 20MW or 100MW or more) would need a buffer of tens of battery units, each having a size of a small building, and with a capacity of something like 2 or 3 MWh each. The area of the size of a soccer field may be envisaged, which would be filled with battery systems with a storage capacity of many MWh (for in- stance something like 50MWh, up to 350MWh, or more). With these batteries the energy peaks in supply or demand at the substation could be matched by buffering the electrical power. By buffering over a cycle of a full day, the daily peaks can be averaged out.

[0009] Electrical energy is typically transported over large distances through a high voltage en- ergy systems, such as power cables which are typically provided above ground, and may be in the ground. The power is brought from and to the high voltage network to a medium voltage station, which has transformers to step down the voltage from the high voltage to the medium voltage. In Europe such electrical power transfer is typically at a frequency of 50 Hz.

[0010] It is noted that in the Netherlands the medium voltage (MV) grid is owned by Distribu- tion System Operator (DSO) companies (e.g. Liander, Stedin, Enexis). The Low Voltage grid LV is defined as 220-240VAC Root Mean Square (RMS) or 400V between phases, and is in connection with the medium voltage power station, at a voltage of lOkV, whereas the high voltage network is at >100 kV, like 150kV or 380kV. This is presently an AC, but DC cannot be excluded. The grid companies that own these local substations are the DSO’s. Also TSO’s have voltage lines and stations of 150kV or 380kV or similarly high voltages. A battery solu- tion can match supply and demand by providing the electricity at the right time to the grid (LV or MV or HV grid).

[0011] Incidentally reference can be made to CN 111 463 787 A, and Thomas, http:. / / puplica- tions.rwth-aachen de / record / 660267 / fiies / Volume4Jssue8.pdf CN 111 463 787 A recites a flexible networking system for power grids with different voltage levels in an enterprise. The flexible networking system comprises a first bidirectional converter and a second bidirectional converter, wherein an alternating current side port of the first bidirectional converter is con- nected with a first power supply bus with a first power supply voltage, an alternating current side port of the second bidirectional converter is connected with a second power supply bus with a second power supply voltage, the first power supply bus and the second power supply bus are electrically connected through a distribution transformer, direct-current side ports of the first bidirectional converter and the second bidirectional converter are interconnected through direct-current buses, a mesh connection network capable of allowing electric energy to migrate is formed through the first bidirectional converter, the second bidirectional con- verter and the direct-current bus, and interconnection networking of power grids of different voltage levels is achieved. Thomas et al. investigate new requirements on design, planning and operation of power systems in view of increasing power generation based on volatile en- ergy sources, such as wind and solar energy.

[0012] In addition to the issues above, green energy is often created when the sun shines or the wind blows , while at that moment in time the demand is not necessarily high. Grid congestion for transport of electricity in city areas is therefore a very large problem. And it is growing due to the increasing consumption of electricity. As a consequence, demand and supply are typically not matched in time. And unfortunately, the green energy is not consumed for a large part due to this mismatch.

[0013] The present invention therefore relates to an improved energy buffer system for urban locations, which overcome one or more of the above disadvantages, without jeopardizing functionality and advantages.

[0014] SUMMARY OF THE INVENTION

[0015] The present invention relates in a first aspect to an energy storage system 10, such as schematically depicted in figures 3 and 5, comprising a DC electrical storage configured to operate at a DC voltage, wherein the DC electrical storage comprises an electrical storage transformer, which may also be considered to be an electrical storage converter, configured for electrical connection with the DC electrical storage and for transforming the DC voltage thereof to an AC medium voltage of a said medium voltage station or to an AC high voltage of a said high voltage station, or vice versa, that is, primarily converting an AC to a DC volt- age, such as by a rectifier, and optionally, secondary, converting typically the AC voltage to a lower voltage, typically a voltage of the DC electrical storage, which may still be up to 100 kV or the like, and, the DC electrical storage comprising at least one container, wherein the at least one container is configured to be electrically connected in series and / or in parallel, wherein the at least one container comprises a multitude of batteries, wherein each individual container has a storage capacity of 0.1-100 MWh, in particular 1-50 MWh, more in particular 2-20 MWh, such as 3-15 MWh, e.g. 8-10 MWh, and wherein the DC electrical storage, of which the DC voltage may be converted to an AC voltage in the converter 28, which may comprise a transformer, placed within or underneath or on top of a building 40, connected electrically via a line within the building 42, and outside the building a line 15 to a substation 20 which contains at least one transformer 13 connected to a MV line 31 and a HV line 30, while the line 15 is connected possibly in a switchable way, such that the DC electrical stor- age, connects to and comprises at least one switch selected from a first switch (27 A) for con- necting and disconnecting to a high voltage network, and from a second switch (27B) for con- necting and disconnecting to a medium voltage network, wherein the first and second switch (27A,27B) are configured to be in electrical contact with the medium voltage network, or with the high voltage network, or to be in idle mode, and optionally one or more fuses, at least one transformer, each individually in connection with the DC voltage storage at one end and with one or both of a middle voltage and high voltage at another end, in particular a connection to a middle voltage of the high voltage network, e.g. 33 kV, in particular wherein a said trans- former, such as a spare transformer, of the said medium voltage station, or the said medium voltage network, or the high voltage network, respectively, and the DC electrical storage are configured to be in connection with either ends of at least one power cable 15, and typically wherein the present energy storage system is connected to a higher (voltage) end of the availa- ble medium or high voltage network, wherein the at least one cable is configured for an en- ergy flux of 1-500 * 106W, in particular 10-100 * [ 106W], more in particular 10-70 * [ 106W], and wherein the energy storage system is configured for mitigating energy congestion on at least one of a high voltage network and a medium voltage network, configured for provid- ing electrical energy and receiving electrical energy to and from at least one medium voltage station, in particular to and from a [spare] transformer of said medium voltage station, wherein the medium voltage station (IEC 62271-200) is configured to operate at a medium voltage in a range of 10 kV-120 kV AC, and wherein the [spare] transformer is configured for transforming the medium AC to a high voltage network, wherein the high voltage network is configured to operate in a range of 130-600 kV. The present energy storage system is config- ured to store huge amounts of electrical energy, typically in an urban area, such as in a build- ing. This diminishes the need for transport to and from the high voltage lines to the city. The present energy storage system may be considered to comprise a filter, wherein the DC voltage storage, e.g. the batteries therein, may be considered to form a capacitive part of the filter; op- tionally a transformer, such as transformer 13B, may be considered to form an indicative part of the (LC) filter. The filter provides inherently control of an amplitude and frequency (typi- cally 50 Hz or 60 Hz) of the medium or high voltage. With the presence of the filter and the control provided therewith, a much better transfer of power can be achieved. When reference is made to “power”, typically “electric power” is envisaged. Electrical power is typically transferred to and from an AC medium voltage system. The medium voltage station (IEC 62271-200) is configured to operate at a medium voltage in a range of 10 kV-120 kV AC. Said medium voltage station is typically in electrical contact with a high voltage network, which is configured to operate in a range of 130-600 kV, typically 150-300 kV. The present system may make use of the available spare transformer in the medium voltage station (e.g. 13 in fig. 4), or a switchable network of two transformers in fig 5 with transformers connect- ing de AC power line 15 from the energy storage system to both the HV and MV powerline switching after choice via switches 27 A and 27B, or a transformer 13C with a intermediate voltage output such as 30A in fig 2, which transformer is configured to be in electrical contact with the high voltage network (see e.g. fig. 1)). Keeping power connection line (15) of a bat- tery storage system to a medium or high voltage station line as short as possible is beneficial to control the phase of AC current relative to voltage, for preventing loss of efficiency, also known as blind current or reactive power, as otherwise large currents will be transported with- out transferring power. It is therefore an advantage if the battery system is connected closely to the local substation in the city itself, e.g. within 100 meters. Also the present energy storage system can, depending on a situation, mitigate a peak load at either of the high or medium voltage network, such as by its filtering action. The presence of the present battery system at close distance performs as a capacitance, which enables filtering and control for stability of the AC current that is e.g. provided by the medium voltage station towards the higher or lower voltage side of the system. By providing a large battery storage in the city, in this case a building, the city becomes less vulnerable for disturbances on the high voltage grid like a brown out on the high voltage line, which can be compensated for by the stored power in the battery system, which then acts effectively as a filter for disturbances. Also a quick restart in the city after a black out is facilitated. This increases regional independency from the high voltage grid. Four main configurations to connect the battery energy storage system (line 15) to the transformers in substation 20 may be considered: 1. la Line 15 (e.g. 33kV) connects via a dedicated transformer (fig 5, 13B while 13 A is not present) directly to the MV line 31 (10 or 20kV). Advantage: one may capture power from solar panels or home batteries in a buffer via line 15, and thus relieve the already present MV-HV transformer(s) 13 and also the HV net- work which is overcrowded. Trading is possible via the already present MV-HV trans- formers) 13. There are two more options if one has a 20kV MV grid, one can make a 20kV line 15 that runs between the substation and the battery storage system / parking garage (prefer- ably not a lOkV line because that can only transport 10MW): lb then one could place the ded- icated transformer 13 A next to the parking garage, instead of in the substation where there is not always enough space. 1c Or one can ask the battery supplier to make their own trans- former that is supplied with the converters (not shown, in the present case it is in the converter unit 28) not 33kV but 20kV. That saves us the extra transformer 13B, space and delivery time 2. 2a Line 15 connects via dedicated transformer (fig 5, 13 A, now 13B is missing) directly to HV grid line 30. One can still upload surplus power from households via an existing MV-HV transformer 13 or supply it in case of shortage. And one can obtain unlimited trading to the HV-net 30. 2b if the batteries with converter are supplied with matching transformer in unit 28, or one transformer per electrical storage system or per container, then this is already pre- sent in the parking garage and a dedicated transformer 13 A is not needed. 2c Or one can place transformer 13 A next to the parking garage with a fence around it. So this does not always have to be in the substation, where there is not always enough space. 3. Complete system in fig. 5, with the combination of transformers and switches where one can switch between the HV and MV network connection as in fig. 5. That requires more space and investment but one can act freely towards the HV network, while one does not burden the existing transformer 13. One solves the congestion at transformer 13, and also in the high-voltage network because one buffers the demand on the LV and MV network and prevent this from burdening the HV network. And one buffers the national HV network by means of the trading mechanism. That can differ per substation. 4. Line 15 connects to a dedicated transformer with extra intermedi- ate voltage connection 30A, see fig. 2. That may require an extra investment and space in the substation. When reference is made to “a said medium voltage station” or likewise “a said spare transformer” or likewise “a said building” it implies that the voltage station, trans- former, and building are not directly part of the claimed invention, but functionally relate to the invention.

[0016] The present invention provides a solution to store the electricity in battery buffers in the city. The batteries can be connected to the local MV power station (substation) for instance, or directly to a high voltage station. The present solution is a new concept, for instance in the form of a parking garage integrated battery storage system. In, below, or on top of a building, e.g. a parking lot, a number of battery units like described above is included, together making it a system where cars can be parked and at the same time buffering of the supply and demand peaks of electricity of a (sub)station of a DSO or TSO takes place. These batteries are not al- lowed to connect to solar panels or chargers for cars, as this would bypass the grid structure from the high or medium voltage to the low voltage, with dangers of high voltage cross con- nections to consumers. The present solution does not consume extra space within the city, for the large scale buffering using a double usage area, while solving the congestion problem at the substation or HV-station. Technically, the combination involves the integration of high or medium voltage cables with connectors and possibly terminations within the parking garage building. It is considered unique in the sense that the functionality of a building, e.g. parking lot, has never been constructed before with the combination of a large scale electricity storage system. A benefit is that green energy can be stored during the daytime and it can be used dur- ing the peak demand at the substation in the city quarter in the evening or morning hours, thus averaging out the peaks in demand and supply. This diminishes the problem of congestion on the local MV-HV (sub-)station transformer in the city, and the HV grid leading towards the city, thus lowering the need for investment and extra cables in the grid. By trading the stored electricity on the electricity market, typically to the high power grid, a margin can be obtained earning back the investment for the batteries. This way green electricity from sun and wind can become useful in the city at hours that no sunshine or wind is present. Advantages are fur- ther that by constructing e.g. a parking garage including large scale battery storage, inventors prevent the expenditure for an extra area (comparable to a size of a soccer field) with just bat- teries in the middle of a city. By this combination, like placing batteries on top of or under- neath the garage, double usage of the area prevents wasted space, and also, for city planning of a living area it is not very desirable to spend a lot of area on just container-sized battery systems without other functionality. On the other hand, for a parking garage it will be rather natural to have an electrical storage system with some type of batteries, as those batteries will be useful for charging cars for instance when people have returned home from the job, having majority of cars to be electric in the future. These batteries are not the ones connected to the high / medium voltage grid, but the combination will look natural. As such, batteries in parking lots are not new as this is combined with solar panels and / or charging of cars, but we consider batteries for a high voltage system exclusively connected to high power voltage lines of a sub- station. Battery systems for charging of cars will be connected to charging poles of cars which is not considered as a high voltage system in the range we indicated above, as the charging and discharging requirements of DSO substations are much larger concerning the power ca- bles that are to be connected. For example, for charging 1000 cars in a parking lot with each some 30kWh, a battery capacity of 30MWh is needed over a night of some 10 hours. This dis- charging the batteries asks for 3MW power connection for charging the cars in 10 hours. For charging these 30MWh batteries during low-priced hours, between 10am and 2pm, a charging cable of 8MW cable could be sufficient. This can be provided by a lOkV power cable. While for a 150MWh buffer system that stabilizes the substation a power connection in the range of 35MW to 50MW is required, for which a 50kV power cable would be sufficient.

[0017] In a second aspect the present invention relates to a building comprising at least one en- ergy storage system according to the invention, typically integrated into the building.

[0018] In a third aspect the present invention relates to a household energy supply and conges- tion mitigation system, comprising the building according to the invention or the energy stor- age system according to the invention, and at least one medium voltage station, in particular to and from a spare transformer of said medium voltage station, wherein the medium voltage station (IEC 62271-200) is configured to operate at a medium voltage in a range of 10 kV- 120 kV AC, and wherein the spare transformer is configured for transforming the medium AC to a high voltage network, in particular wherein the household energy supply and congestion miti- gation system is configured to be connected to 103-5*104households.

[0019] Thereby the present invention provides a solution to one or more of the above-men- tioned problems.

[0020] Advantages of the present invention are detailed throughout the description.

[0021] DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention relates in a first aspect to an energy storage system. Details on the power connection are for instance that high voltage lines have a capability to provide current for large power. For instance, for a lOkV line only some 10MW of power can be transported. For a 50kV line or higher, large power quantities like 45MW or 50MW can be transported. And with power lines up to 150kV or even 380kV in case of a connection to a HV power station of a TSO a transport power quantity of more than 100MW is possible. Such high voltage lines offer the additional advantage that a battery system can be charged and discharged in a short time. For example, to discharge a battery system of 160MWh in just one hour (C=l) it needs a 160MW powerline, but for the same battery system to discharge in 4 hours (C=0.25), it needs 40MW. In case of a 10MW powerline, discharging the battery system takes a much longer time. For ex- ample, trading on the day-ahead market offers the possibility to offer electricity for timeslots of 4 hours. The battery can be used for trading only by the full capacity on this market if it can be discharged and charged in 4 hours. So, for a 160MWh capacity it means that a powerline of 40MW is required. Also, for the frequency stability mar- ket, some extra power on the line might be required. In the design of the electrical sys- tem, these requirements are to be taken into account. This makes it a necessity for such a battery buffer system to have a high voltage connection to the MV DSO substation or HV TSO station. This is a unique feature of the present solution: having a high power connection of the parking garage integrated battery system with a high voltage, with a capability of >10MW, like 30MW or 50MW or much more for charging and discharg- ing the battery system.

[0023] Design features for implementation

[0024] The parking integrated buffer system may contain the electrical storage on top of the building, e.g. garage, or inside, with or below the parked cars. This prevents that the batteries use extra area in the city. The power connections of the batteries may be ex- clusively to the high power cable to the (sub)station of the DSO or TSO. The cables can approach the parking integrated buffer system from underground or from above from pylons. From the entry point of the high voltage cables arriving at the parking building, a high voltage insulated fixation is in place to fixate the cables in a duct or cable tube, which should prevent physical contact with the cables, leakage current, and high elec- trie fields to radiate to the open spaces around the cables by shielding. These encapsu- lations can be filled with oil, or more commonly with solid materials such as XLPE (cross-linked polyethylene) or EPR with the purpose of providing electrical insulation. The cable should have a joint or be connected to the battery system main switches di- rectly or have a switch or a transformer in between the arriving cable and the battery system. The connected medium or high voltage cables typically consist of a conductor, a stranding, and or solid wire, a strand shielding and insulation layer. The cables could be connected to a relay protection system to clear ground faults, or a higher level of in- sulation for the case system could not be de-energized within a short time. The shield is usually grounded to limit dielectric field induced voltages outside the cable, prevent electric shock, perform EMC, and conduct leakage currents to ground. Around, a jacked is present to provide mechanical robustness. Also, splicing of cables may be present, as well as cable terminations that follow the existing standards for a MV / HV seal to the external environment with cable grounding. The cables could be inside a surrounding cover, arriving at the parking lot coming from (under)ground or air to the floor where the connections to the electrical storage system are made. The cover can be removed by an engineer skilled in the art for maintenance, or inspection, or repair of the cables.

[0025] Supporting structure

[0026] The weight of the batteries might be some 40 to 50 tonnes and for the electronic power control unit another 10 to 20 tonnes, totaling to some 60 tonnes of weight for a unit with a capacity of some 3 to 4 MWh. For a size of a unit of some 18 x 3 meter with about 2 m space around the estimate would be that each unit takes some 22 x 7m = 150m2 area. Compare this area to about 7 electric cars of each 2 tonnes which will amount to some 15 tonnes. Therefore, the weight of the battery plus electronics of some 60 tonnes compares to 4 times the weight of the cars on that same parking area. For a parking garage the weight is to be supported by a floor that is equipped well enough to carry the weight of the batteries and power unit. This type of construction of the build- ing might be well recognizable. For placement of the battery systems damage to the floor of the building should be prevented. Systems with active damping supports or passive damping layers on which the containers land during placement and which could be deflated or removed at the final stage of placement.

[0027] Absorption of Noise

[0028] The containers with batteries and power electronics can have built-in fans which produce sound. The parking building can be equipped with absorption edges around the floor with batteries, shaped as walls with sound absorbing materials. Also, the floor be- tween the battery containers can be provided with a layer of sound absorbing materials.

[0029] Safety The batteries that are connected to the high / medium voltage grid may not be con- nected to cars chargers or solar panels, as this can cause hazards in case of shorts or cross connections. This makes the energy storage system unique from existing battery systems in parking lots that are meant to charge cars or collect energy from sources on the building itself like solar panels. The batteries under consideration are separated from other applications and uniquely used to buffer the energy from the grid. Regarding safety for service engineers, spaces around the battery containers and even- tually present high voltage transformers are maintained for people to back out in case of fire. The control system to manage the batteries will have a separate electrical sup- ply, for cases of power down of the grid. This may have its independent backing of a safety system with a battery. The power cables need to be encapsulated to keep humans at a distance and to prevent the high electrical fields to extend to the area where hu- mans can come. These cables may run through vertical pillars at the outer edges of the building and / or through a tube inside the building. For access by maintenance engineers the encapsulation could be opened or unlocked by bolts or other systems. The encapsu- lations can be of metallic electrically conductive materials and grounded electrically, and can have a rectangular or cylindrical shape as a tube.

[0030] In an exemplary embodiment the present energy storage system comprises at least one storage controller, wherein the storage controller is configured to switch between modes of operation, wherein modes are selected from (i) idle, from (ii) receiving energy from the at least one medium voltage station and storing said energy in the DC electrical storage, and from (iii) transferring energy from the DC electrical storage to the at least one medium volt- age station, in particular wherein the storage controller is configured to switch within 5 sec- onds between modes, and / or a power regulator, wherein the power regulator is configured to be in power contact with the said spare transformer and with the DC electrical storage. Fig. 1 provides an example thereof.

[0031] In an exemplary embodiment the present energy storage system, with reference to amongst others figure 1, comprises at least one storage controller, wherein the storage control- ler is configured to switch between modes of operation, wherein modes are selected from (i) idle, from (ii) receiving energy from the at least one medium voltage station and storing said energy in the DC electrical storage, and from (iii) transferring energy from the DC electrical storage to the at least one medium voltage station, in particular wherein the storage controller is configured to switch within 5 seconds between modes, typically within 1 second, such as within 300 msec, such as within 100 msec; typically not faster than 50 or 60 Hz, that is within 20 msec or 16.6 msec. Therewith power can be mitigated, energy supplied to e.g. households, a maintenance mode is easily obtained, etc.

[0032] In an exemplary embodiment the present energy storage system, with reference to amongst others figure 1, comprises at least one storage controller, wherein the storage control- ler is configured to switch between modes of operation, in particular wherein said modes of operation are selected from (i) idle, from (ii) receiving energy through power cable (15) from the high voltage network and storing said energy in the DC electrical storage, and from (iii) transferring energy through power cable (15) from the DC electrical storage to the high volt- age network, in particular wherein the storage controller is configured to switch within 5 sec- onds between modes.

[0033] In an exemplary embodiment the present energy storage system comprises two or more power cables 15, such as at least one first power cable for connecting to the medium voltage network / station, and at least one second power cable for connecting to the high voltage net- work.

[0034] In an exemplary embodiment the present energy storage system comprises a power reg- ulator, wherein the power regulator is configured to be in power contact with the said spare transformer and with the DC electrical storage.

[0035] In an exemplary embodiment the present energy storage system is configured to form a part of a building, wherein the part is selected from a roof structure, a storey (or floor) struc- ture, a cellar structure, and combinations thereof, in particular an integral part of said build- ing.

[0036] In an exemplary embodiment the present energy storage system batteries are selected from ion batteries, such as Li-batteries, in particular LiFe comprising batteries, such as LiFePC batteries, Na-batteries, alkaline batteries, zinc-carbon batteries, NiCd batteries, and NiMH batteries, and from redox flow batteries, and solid state batteries.

[0037] In an exemplary embodiment the present energy storage system is configured to receive energy from the at least one medium voltage station and to buffer 0.1-100 MWh of electrical energy, in particular 1-20 MWh, more in particular 5-10 MWh, in particular to buffer said en- ergy within 8 hours, more in particular within 4 hours.

[0038] In an exemplary embodiment the present energy storage system is configured to transfer 0.1-100 MWh of electrical energy to the at least one medium voltage station, in particular 1- 20 MWh, more in particular 5-10 MWh, in particular to transfer said energy within 8 hours, more in particular within 4 hours.

[0039] In an exemplary embodiment of the present energy storage system the at least one cable comprises at least one medium voltage termination at the DC cable end, and / or wherein the at least one cable comprises a splice at the DC cable end, and / or the at least one cable comprises at least one medium voltage termination at the AC cable end, and / or wherein the at least one cable comprises a splice at the AC cable end.

[0040] In an exemplary embodiment the present energy storage system comprises sound insula- tion, wherein the sound insulation is configured to reduce noise by 10-30 dB.

[0041] In an exemplary embodiment of the present energy storage system the at least one cable is incorporated into at least one encapsulation, wherein the at least one encapsulation is con- figured to reduce electro-magnetic fields extending from the at least one cable, such as verti- cal and / or horizontal encapsulation.

[0042] In an exemplary embodiment of the present energy storage system the at least one en- capsulation is made of an electrically conductive material, in particular wherein the at least one encapsulation is electrically grounded, and / or configured to be opened for repair or maintenance or replacement of the cables.

[0043] In an exemplary embodiment the present energy storage system the energy storage sys- tem comprises vibrational insulation, wherein the vibrational insulation is configured to re- duce vibration by 10-30 dB.

[0044] In an exemplary embodiment the present energy storage system comprises 2-100 con- tainers, in particular 5-50 containers, more in particular 20-40 containers, and / or wherein each container is removably attached to the energy storage system, and / or wherein each container is individually accessible, such as for maintenance.

[0045] In an exemplary embodiment of the present energy storage system each container is provided with wheels and wherein each container is provided on rails configured for receiv- ing the wheels, wherein the rails are configured to move each container into the DC electrical storage and out of the DC electrical storage. Therewith the containers can be easily moved in- side and outside the storage system. Also the containers can be provided in any location of the storage system, such as in a basement thereof. In addition a height of a space comprising the containers can be much lower, e.g. slightly higher than the sum of the heights of the contain- ers and the rails. Further, e.g. in case of emergency, or in case of replacement, the containers can be swiftly removed from the storage.

[0046] In an exemplary embodiment the present energy storage system the electrical storage transformer is configured to operate at 10 kV-120 kV AC at one primary end thereof, in par- ticular 33-50 kV AC, and 10 kV-120 kV DC at one secondary end thereof, and / or configured to operate at 50-60 Hz or a multitude thereof.

[0047] In an exemplary embodiment the present energy storage system comprises at least one further controller, wherein the further controller is selected from a heat controller, an energy storage controller, a communication controller, a flow controller, and an operational control- ler.

[0048] In an exemplary embodiment of the present energy storage system the energy storage controller is configured to control at least one of input conditions of the energy storage sys- tem, output conditions of the energy storage system, such as time of storage, amount of en- ergy storage, distribution of power from and to the energy storage system, and conversion of energy, such as to another source of energy, e.g. methane, hydrogen, etc.

[0049] In an exemplary embodiment of the present energy storage system the storage controller is configured to control at least one of health, such as radiation, to switch between outputs (in view of customer priority), a charging process of the electrical storage system or part thereof, a discharging process of the electrical storage system or part thereof, to handle failures, that is to switch modes, to distribute or transfer power in an alternative manner being available, and to distribute power, in order to mitigate congestion, or to provide required power, such as to a household, or to balance a middle or high voltage network, etc.;

[0050] In an exemplary embodiment of the present energy storage system the heat controller is configured to control at least one of distribution of coolant, a storage temperature of the elec- trical storage system or part thereof, a coolant temperature of the electrical storage system or part thereof, and removal of coolant heat.

[0051] In an exemplary embodiment the present energy storage system the communication controller is configured to control at least one of communication with a supplier of power, communication with a distributor of power, communication with a buyer of power, communi- cation with emergency services, and communication of priorities. The distributor of power is typically the owner of the power network or part thereof.

[0052] In an exemplary embodiment of the present building cables run through vertical pillars of the building at the outer edges of the building and / or through a tube inside the building, in particular wherein the encapsulation is configured to be opened or unlocked by bolts or other systems, and / or wherein said building is configured to structurally support a weight of the energy storage sys- tem.

[0053] The invention is further detailed by the accompanying figures and examples, which are exemplary and explanatory of nature and are not limiting the scope of the in- vention. To the person skilled in the art, it may be clear that many variants, being obvi- ous or not, may be conceivable falling within the scope of protection, defined by the present claims.

[0054] SUMMARY OF THE FIGURES

[0055] Figures 1-14 show an exemplary embodiments of the present invention.

[0056] DETAILED DESCRIPTION OF THE FIGURES

[0057] In the figures:

[0058] 1 Buffer energy

[0059] 2 control heat

[0060] 3 control storage / operations

[0061] 4 store energy

[0062] 5 communicate with outside

[0063] 8 fuse

[0064] 9 spline

[0065] 6 Condition power in

[0066] 7 Battery connection 8 Fuse

[0067] 9 Spline

[0068] 10 Battery energy storage system BESS

[0069] 11 container

[0070] 12 battery

[0071] 13 (A,B) transformer

[0072] 14 splice

[0073] 15 power cable

[0074] 15a open air insulated connector

[0075] 15b in-housing connector

[0076] 15c cable encapsulation with insulation

[0077] 16 controller

[0078] 17 condition power out

[0079] 18 distribute energy

[0080] 19 convert energy type

[0081] 20 medium voltage station; sub-station

[0082] 21 spare transformer

[0083] 22 control charge discharge

[0084] 23 condition power

[0085] 24 Handle energy

[0086] 25 Step-down transformer

[0087] 26 Step-up transformer

[0088] 27 Switch

[0089] 28 Power converter with optional transformer

[0090] 29 Emergency services

[0091] 30 high voltage network

[0092] 31 Low voltage network

[0093] 32 Control room

[0094] 33 C&DH

[0095] 34 System controller

[0096] 35 C / D controller

[0097] 36 Cooling system

[0098] 37 Monitoring

[0099] 38 PDS

[0100] 39 Evaluate states

[0101] 40 BESS and parking building

[0102] 41 electrical insulation

[0103] 42 noise / vibrational insulation 43 Determine C / D parameters

[0104] 44 Determine cooling parameters

[0105] 45 Storage in battery

[0106] 52 Communicate externally

[0107] 53 Communicate with trader

[0108] 54 report status

[0109] 55 Alert emergency services

[0110] 56 prioritise

[0111] 57 Evaluate health

[0112] 58 Talk to trader

[0113] 59 Communicate emergencies

[0114] 60 GROUND

[0115] S signal

[0116] S-2 External control

[0117] S-4 Health signal

[0118] S-5 Control cooling

[0119] S-6 Control storage

[0120] S-7 Talk to trader

[0121] S-8 System status

[0122] S-9 Emergency alert

[0123] S-10 Set C / D state

[0124] S-l l Storage system status

[0125] S-12 Cooling system status

[0126] S-13 Stay alive ping

[0127] S-14 Distress signal

[0128] S-15 Available trade actions

[0129] S-16 Trader signal

[0130] S-17 Set C / D

[0131] S-18 Available C / D space

[0132] P power signal

[0133] P-1 Power in

[0134] P-2 Power out

[0135] P-3 Internal power

[0136] 0-1 System heat / Storage heat

[0137] 0-2 System heat / Storage heat

[0138] C-l Service coolant

[0139] C-2 Coolant disposal

[0140] C-3 Coolant C-4 Hot coolant

[0141] Figure 1 shows an exemplary embodiment of the present energy storage system with emphasis on an optional transformer 13 typically has a connection to a lower voltage line 31 and a higher voltage line 30. It can be protected by a fuse 8 on both sides, and a switch 27 in order to disconnect the system for maintenance or replacement. The lines typically consist of three wires, one for each phase of the AC current and possibly a common ground connection.

[0142] Figure 2 shows an exemplary embodiment of the present energy storage system with emphasis on an optional transformer 13 A, which can be of a type where on one side an inter- mediate connection 30A gives an intermediate voltage. For example, if the HV line 30 con- nects to 50kV (or 150kV or 380kV or other) the intermediate voltage maybe 33kV and lead to a battery electrical storage system (BESS), while the lower voltage side of the transformer is connected to a MV voltage line 31 of lOkV or 20kV or similar. The connections involve a connection to ground 60.

[0143] Figure 3 shows a further exemplary embodiment of the present energy storage system. Ensemble of substation 20 with building 40 for parking of cars including a battery energy storage system (BESS). Substation contains one or more transformers 13 with fuses and switches as detailed in diagrams 2 or 3, with a controller 16 for the switches to manage the connections of the BESS with the medium voltage lines 31 or high voltage lines 30. Building 40 is connected to substation 20 by a line 15 to conduct currents from the battery energy stor- age system BESS 10. The line consists of 3 wires, one for each phase, and a ground connec- tion. The power cable might consist of more cables in series that are connected with each other with a spline 9. The cables include safety encapsulation 15c and can be under the ground or through the air like suspended pylons. Before the line cables enter the building 40 these could surrounded by a shielding structure probably filled with insulating material 41 to protect outsiders from high electric fields and to prevent individuals from touching or damag- ing the cables. The cables arrive at the BESS 10 in open air at a connector with shield from rain or moisture or other external influences 15a, or arrive inside a housing connected with an in-house connector 15b. The BESS consists in large of a number of containers 11 with batter- ies 12, and with electronics units 28 including converters and possibly transformers. The building 40 can be open to ventilate air, as charging and discharging the batteries requires cooling of a few % up to 10% or even 20% of the power stored in the batteries depending on the rate of (dis)charging, although for liquid cooled systems the building 40 can be closed, like for in-house or underground battery storage systems.

[0144] Figure 4 shows a further exemplary embodiment of the present energy storage system. The substation 20 should contain at least one transformer 13, connecting the medium voltage lines 31 that go down into the city quarter, which can be many lines, and which might be con- nected in a circular way to prevent disconnects of one or more lines due to failures of compo- nents, with the high voltage lines 30 of the high voltage grid going to a regional or national level. Three alternative possible connecting power lines 15 to the BESS are given to either the high voltage side of a transformer (top), to either the lower voltage side of the transformer leading to the medium voltage grid (bottom), or to the transformer itself (middle) for an inter- mediate voltage connection as given in figure 2.

[0145] Figure 5 shows a further exemplary embodiment of the present energy storage system. It shows a Battery Energy Storage System BESS 10 connected via line 15 and via fuses 8 to switches 27 A and 27B. Switch 27 A could connect the battery system to the high voltage power line 30 via optional transformer 13A coping with an eventual voltage difference (if pre- sent) between 30 and 15. And 27B could connect the battery system to the medium voltage line 31 via optional transformer 13B coping with a possible voltage difference with line 15 if necessary. This switchable system is to be within a substation 20 which contains a trans- former 13. By closing switch 27 A congestion on the line 30 can be diminished as the battery system can act as a buffer, while switch 27B can be used to protect transformer(s) 13 from overload with current by providing or taking away current via line 15.

[0146] Figure 6 shows a further exemplary embodiment of the present energy storage system, showing functionalities. The medium and high voltage part are typically provided by a further company.

[0147] Figure 7 shows a block diagram of interconnected functionalities. Buffering of energy 1 is main functionality. This decomposes into four possible functionalities, control of heat from charging and discharging 2, control of the storage system for operations 3, storage of energy 4, and communication 5.

[0148] Figure 8 shows a further block diagram of interconnected functionalities. Function 4 could be decomposed into conditions for power in 6 and condition power out 17, which con- tains the transformation of the different input voltages to the system voltage and back, distri- bution of energy 18 and a possible function to convert types of energy 19 like for the case if storage of heat and electrical storage or other forms of energy storage are to be combined into one system.

[0149] Figure 9 shows a further block diagram of interconnected functionalities. The manage- ment of the storage function depends on the state of charge of the batteries and other parame- ters such as temperature, current flow and voltages. This flow diagram shows that the signal S-10 activates functions 22 and 24. It puts the control function 22 in charge or discharge state which adapts it to the system conditions as mentioned before and which it gives out as the sig- nal S-l 1, while it triggers the store energy function 22 by signal S-17 for release or storage of electrical energy in the batteries, while this power is then conditioned to the required output conditions by the Condition Power function 23. Storage in the battery happens in function 45. The legends of the signals are given in de table.

[0150] Figure 10 shows a further block diagram of interconnected functionalities. The energy storage function is given in the flow diagram as Handle energy, with incoming power signal P-1 and outgoing power signal P-2. This essentially the same at functionality 4.

[0151] Figure 11 shows a further block diagram of interconnected functionalities. Overview of the functionalities of different parts in the substation (25-26-27) and the BESS system which is in the building with the parking garage, (no 28 and higher and the batteries 12) Figure 12 shows a further block diagram of interconnected functionalities. Before the signal charge / discharge S-10 is created, the states of the system are to be evaluated 39, and the health signal is communicated S-4, and also the thermal state is evaluated 44. S-18 com- municates what actions S-10 are allowed for instance due to temperature of the system.

[0152] Figures 13-14 shows a further block diagram of interconnected functionalities. in two diagrams the possible communication system is displayed. First (figure 13) a possible func- tionality diagram is shown. Then a possible flow diagram fig. 14 is shown which is open to external signals. Signal S-8 contains the system status.

Claims

AMENDED CLAIMS received by the International Bureau on 26 December 2025 (26.12.2025)1. An energy storage system comprising a DC electrical storage (10) configured to operate at a DC voltage, wherein the DC elec- trical storage comprises an electrical storage converter configured for electrical connection with the DC electrical storage and for transforming the DC voltage thereof to an AC medium voltage of a said medium voltage station or to an AC high voltage of a said high voltage sta- tion, the DC electrical storage comprising at least one container (11), wherein the at least one container is configured to be electrically connected to at least one further container in series and / or in parallel, wherein the at least one container comprises a multitude of batter- ies (12), wherein each individual container has a storage capacity of 0.1-100 MWh, in particu- lar 1-50 MWh, more in particular 2-20 MWh, and wherein the DC electrical storage comprises a first switch (27 A) configured for connect- ing and disconnecting the DC electrical storage to a voltage of a high voltage network, and from a second switch (27B) configured for connecting and disconnecting the DC electrical storage to a voltage of a medium voltage network, wherein the first and second switch (27A,27B) are configured to be in electrical contact with the medium voltage network, or with the high voltage network, or to provide an idle mode, wherein a said transformer of the said medium voltage station, or the said medium volt- age network, or the high voltage network, respectively, and the DC electrical storage are con- figured to be in connection with either ends of at least one power cable (15), wherein the at least one power cable is configured for an energy flux of 1-500 * [106W], in particular 10- 100 * [106W], more in particular 10-70 * [106W], and wherein the energy storage system is configured for mitigating energy congestion on at least one of said high voltage network and said medium voltage network, configured for providing electrical energy and receiving electrical energy to and from said at least one medium voltage network or to and from the high voltage network, in particular to and from the transformer of said medium voltage station, wherein the medium voltage station is configured to operate at a medium voltage in a range of 10 kV-120 kV AC, and wherein the transformer is configured for transforming the medium AC to the high voltage network, wherein the high voltage net- work is configured to operate in a range of 130-600 kV.

2. The energy storage system according to claim 1, comprising at least one storage controller (16), wherein the storage controller is configured to switch between modes of operation, in particular wherein said modes of operation are selected from (i) idle, from (ii) receiving en- ergy through power cable (15) from the at least one medium voltage station and storing said energy in the DC electrical storage, and from (iii) transferring energy through said at least one power cable (15) from the DC electrical storage to the at least one medium voltage station, inparticular wherein the storage controller is configured to switch within 5 seconds between said modes, and / or wherein the storage controller is configured to switch between modes of operation, in particu- lar wherein said modes of operation are selected from (i) idle, from (ii) receiving energy through power cable (15) from the high voltage network and storing said energy in the DC electrical storage, and from (iii) transferring energy through power cable (15) from the DC electrical storage to the high voltage network, in particular wherein the storage controller is configured to switch within 5 seconds between modes, and / or comprising a power regulator, wherein the power regulator is configured to be in power con- tact with the said spare transformer and with the DC electrical storage.

3. The energy storage system according to any of claims 1-2, wherein the energy storage sys- tem is configured to form a part of a building, wherein the part is selected from a roof struc- ture, a storey structure, a cellar structure, and combinations thereof, in particular an integral part of said building.

4. The energy storage system according to any of claims 1-3, wherein said batteries (12) are selected from ion batteries, such as Li-batteries, in particular LiFe comprising batteries, such as LiFePO4batteries, Na-batteries, alkaline batteries, zinc-carbon batteries, NiCd batteries, and NiMH batteries, and from redox flow batteries, and from solid state batteries, and / or wherein the energy storage system is configured to receive energy from the at least one me- dium voltage station and to buffer 0.1-100 MWh of electrical energy, in particular to buffer said energy within 8 hours, more in particular within 4 hours, and / or wherein the energy storage system is configured to transfer 0.1-100 MWh of electrical energy to the at least one medium voltage station, in particular to transfer said energy within 8 hours, more in particular within 4 hours.

5. The energy storage system according to any of claims 1-4, wherein the at least one power cable (15) comprises at least one medium voltage termination at a DC power cable end, and / or wherein the at least one power cable comprises a splice at a DC power cable end.

6. The energy storage system according to any of claims 1-5, wherein the energy storage sys- tem comprises sound insulation, wherein the sound insulation is configured to reduce noise by 10-30 dB.

7. The energy storage system according to any of claims 1-6, wherein the at least one power cable is incorporated into at least one encapsulation, wherein the at least one encapsulation is configured to reduce electro-magnetic fields extending from the at least one power cable, such as vertical power cable encapsulation and / or horizontal power cable encapsulation.

8. The energy storage system according to claim 7, wherein the at least one encapsulation is made of an electrically conductive material, in particular wherein the at least one encapsula- tion is configured to be electrically grounded, and / or is configured to be opened for repair or maintenance or replacement of the at least one cable.

9. The energy storage system according to any of claims 1-8, wherein the energy storage sys- tem comprises vibrational insulation, wherein the vibrational insulation is configured to re- duce vibration by 10-30 dB.

10. The energy storage system according to any of claims 1-9, comprising 2-100 containers (11), in particular 5-50 containers, more in particular 20-40 containers, and / or wherein each container is removably attached to the energy storage system, and / or wherein each container is provided with wheels and wherein each container is provided on rails configured for receiving the wheels, wherein the rails are configured to move each con- tainer into the DC electrical storage and out of the DC electrical storage, and / or wherein each container is individually accessible, such as for maintenance.

11. The energy storage system according to any of claims 1-10, wherein the electrical storage converter is configured to operate at 10 kV-120 kV AC at one primary end thereof, and 10 kV-120 kV DC at one secondary end thereof, and / or configured to operate at 50-60 Hz or a multitude thereof.

12. The energy storage system according to any of claims 1-11, further comprising at least one further controller, wherein the further controller is selected from a heat controller, an en- ergy storage controller, a communication controller, a flow controller, and an operational con- troller.

13. The energy storage system according to claim 12, wherein the energy storage controller is configured to control at least one of input conditions of the energy storage system, output con- ditions of the energy storage system, time of storage, amount of energy storage, distribution of power from and to the energy storage system, and conversion of energy.

14. The energy storage system according to any of claims 2-13, wherein the storage controller is configured to control at least one of health, to switch between outputs, a charging process of the electrical storage system or part thereof, a discharging process of the electrical storage system or part thereof, to handle failures, and to distribute power.

15. The energy storage system according to any of claims 12-14, wherein the heat controller is configured to control at least one of distribution of coolant, a storage temperature of the elec- trical storage system or part thereof, a coolant temperature of the electrical storage system or part thereof, and removal of coolant heat.

16. The energy storage system according to any of claims 12-15, wherein the communication controller is configured to control at least one of communication with a supplier of power, communication with a distributor of power, communication with a buyer of power, communi- cation with emergency services, and communication of priorities.

17. A building comprising at least one energy storage system according to any of claims 1-16.

18. The building according to claim 17, wherein power cables are configured to run through vertical pillars of the building at the outer edges of the building and / or through a tube inside the building, in particular wherein the encapsulation is configured to be opened or unlockedby bolts or other systems, and / or wherein said building is configured to structurally support a weight of the energy storage sys- tem.

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