ENVIRONMENT

FIELD OF THE INVENTION

The present invention relates to a battery energy storage system for installation in an urban environment.

BACKGROUND OF THE INVENTION

In particular in urban areas, supply equipment for supplying electricity to electrical vehicle or any other sort of loads are expected to heavily load the grid in future. Already today, it is a problem in some areas and not necessarily due to EV charging. It can also be a problem if the grid cannot handle the transmission of power because it is not dimensioned for the peak loads. In order to address this issue, it is suggested to store electrical energy in containerised battery energy storage systems (BESS). Containerized battery energy storage systems are generally connected to medium voltage distribution system.

However, such containerised battery energy storage systems in urban areas are not without problems. In the cities, there is not much space to deploy containerized battery energy storage systems (BESS). Smaller urban battery energy storage systems may be provided instead.

Urban battery energy storage systems may be designed to be connected to a low voltage distribution system closer to the load. The voltage level and capacity is relatively less in urban storage concept compared to a containerized BESS. The voltage level and the energy capacity are significant in defining the risk level and hence the permissions required to install such systems in a city or urban zone.

OBJECT OF THE INVENTION

It is an object of the present invention to provide an urban battery energy storage systems which is suitable for an urban storage concept, which enables storage units in a smaller pieces to be connected and distributed in the city/urban zone. It is a further object to provide a battery energy storage system, which addresses safety issues associated with voltage level and capacity of the battery storage systems and achieves the acceptable risk level required for being permitted to be installed in a city or urban zone.

SUMMARY OF THE INVENTION

In the present disclosure, there is described several embodiments of a battery energy storage system for installation in an urban environment, such as an urban furniture, where the system comprises a housing installed on a groundwork, said housing comprising a frame provided with an outer cover and at least a first compartment and a second compartment, and wherein the first compartment is accommodating a battery unit comprising at least one battery pack, and the second compartment is accommodating electrical components so that the at least one battery pack is electrically connected to a public electrical power grid, whereby electrical energy can be charged or discharged to the at least one battery pack.

By the invention there is provided a compact battery energy storage system, which is suitable for installation in an urban environment as the particular design allows for a safe storage of the batteries in the housing in such a manner that the batteries are easily accessible in case of fire. In relation to battery installations it is important to provide easy access to the batteries in case of fire so that the batteries can be removed. By the invention, the stationary urban installation with a battery energy storage system can be handled like an electrical vehicle in the urban environment, including how the system is to be handled in case of fire.

A plurality of such urban storage units may be distributed on the same network can be synchronized to act as a virtual storage unit with a bigger power and energy capacity. This may allow for entering more grid services, such as frequency regulation, voltage regulation, supply quality, etc. Such applications require to pass the capacity limit criteria of the distribution system operators (DSO); for example, the minimum capacity requirement to do a frequency containment reserve (FCR) service in Denmark is 500 kW and this might increase in future. A frequency containment reserve or FCR is a service to the DSO (i.e. the grid operator) where a grid connected equipment, such as power plants or energy storage systems will provide energy in the form of power to the grid based on a specific and agreed on frequency deviation. It can be both positive and negative power injection to the grid in FCR. Depending on the agreement with the DSO. The FCR is a given disposed amount of energy and/or power to be used to stabilize the grid.

From cost perspective the invention may be advantageous although it may generally be the case that the smaller the building block, the higher the cost per kWh. However, by the present invention it is realized that it may be advantageous to use 2 ^nd life EV batteries in the urban battery energy storage system concept to keep the cost competitive limits compared to conventional solutions.

Besides, there is a benefit of introducing 2 ^nd life batteries in the battery energy storage system according to the invention for social responsibility, as this invention hereby allows for a reuse of old batteries, such as old batteries from electric vehicles. Although batteries may have lost some of its capacity over time and while installed in e.g. an electrical vehicle, it is not critical in the battery energy storage system according to the present invention that the batteries are not up to full capacity and therefore take up comparatively much more space than if the batteries were new.

In a second aspect of the invention, there is provided a stationary urban furniture accommodating a battery energy storage system of the above mentioned kind. The battery energy storage system may be "hidden" in an urban installation such as an urban furniture and allows for a compact design and allows for designs that can will not compromise the aesthetics of the urban environment. It is furthermore advantageous from both a planning and a safety point that the battery energy storage system according to the invention can be regarded and handled as a parked electrical vehicle.

In the present disclosure the terms "battery pack" or "battery unit" are understood as meaning the same, i.e. a unit comprising one or more battery cells. In an embodiment of the system, the housing is cubical with a rectangular base, four sides and a roof. This form is relative simple and easy to build and may fit into a variety of urban furniture types.

In a preferred embodiment of the system, the roof is openable, for instance a hinged roof, whereby there may be established a direct access via the roof to at least the first compartment with the battery unit. This is furthermore advantageous as the roof may be opened from the outside by a crane or the like without direct human contact.

Preferably, the battery unit or each of the battery packs are provided with gripping means for lifting the battery pack or the battery unit as a whole out of the housing. The battery unit is removable from the system by lifting equipment, such that the battery unit as a whole or an individual battery pack is insertable and removable into the first compartment when the roof is opened. The lifting equipment is a crane, in particular a movable crane, such as a manual mobile floor crane or a truck with a crane installed thereon. These features allow for easy pick-up for hazard responders in case of fire, and the actions required involves no human contact with the battery unit, and the procedure mimics the procedures a fire fighting teams use when approaching an electrical vehicle after a hazard, such as fire.

In one design of the housing of the system, the second compartment is the lowermost compartment accommodating the electrical components and the first compartment is the uppermost and accommodates the battery unit. In another design, the first and second compartments are provided in the frame side by side. In both designs there can be established direct access through the roof to the batteries.

To facilitate easy removal, the battery is mounted in the first compartment on a rail system. Particularly, this rail system may be telescopic so it allows for the insertion and removal of the battery unit by supporting the battery unit during the removal or insertion. In alternative or as a supplement to the telescopic rail system, the rails may be pivotable from an inactive position to an active position. This allows for that the battery unit can be removed via a front opening in the housing frame instead of through the roof. Accordingly, the rails may be pivotable from a substantially vertical inactive position to a sloping active position, and where the housing is provided with an opening on the side of the first compartment so that battery unit is pivoted out of the frame for removal. In another embodiment, the rails may be both telescopic and pivotable from a substantially horizontal inactive position to a substantially vertical active position where the rails are telescopic and extended in the active position through a roof opening for guiding the battery unit in or out of the frame.

In a preferred embodiment, at least the first compartment of the housing is provided with a fire extinguishing system including at least one fire detection sensor and a one or more sprinklers in fluid connection with a water supply, such as a remote distance water supply. Through such fire extinguishing system, a fire agent may be supplied to the sprinklers either as an alternative or in addition to a water supply. Hereby, a detection of fire can be automatically responded to quickly and a cooling water spray may extinguish the fire or at least cool the battery section.

The groundwork in relation to the system according to this disclosure may comprises a foundation and means for electrical grid connection. Hereby, the battery unit is connected to the electrical grid and the batteries may be charged or discharged depending on the electrical power demand in the grid.

In the electrical components accommodated in the second compartment, there may be provided at least one of:

- at least one power conversion system (PCS), such as inverter modules,

- at least one transformer, such as an isolation transformer (ISO-trafo),

- an uninterruptible power supply (UPS).

In addition, the electrical components in the second compartment further comprises one or more control units for controlling one or more of the electrical components. In the first compartment, where the battery is, there is preferably also surveillance systems for observing the batteries.

Preferably, in the first compartment holding battery pack includes integrated battery specific electronics. The second compartment comprises components such as an inverter, a circuit breaker, a transformer, a PLC, an Auxiliary power supply (e.g., 24 V for PLC and 12 V for car battery), the auxiliary power supply has UPS/back up power functionality.

The advantage of providing a UPS at the electronics compartment is that if grid or battery power is lost, the UPS gives enough time to the PLC so the PLC can data-log the event and open the contactors/relays in a desired sequence. The UPS can be based on batteries or ultra-capacitors. The UPS with ultra-capacitors gives enough time, like 1 minute, for PLC to log the event, and shut down the system in a correct sequence.

DETAILED DESCRIPTION

The invention is described in the following with reference to the accompanying drawings, in which:

Figure 1 is a schematic illustration of a grid with urban battery energy storage systems according to the invention;

Fig. 2 is a schematic perspective view of a battery energy storage system with a housing according to a first embodiment of the invention;

Fig. 3 is a schematic perspective view of a battery energy storage system with a housing according to a second embodiment of the invention;

Fig. 4 is a schematic perspective view of a battery energy storage system with a housing according to a third embodiment of the invention;

Fig. 5 is a perspective view of an example of an urban furniture made up by one or more battery energy storage systems according to the invention;

Fig. 6 to 8 are schematic sequential perspective illustrations of the removal of a battery unit in a battery energy storage system with a housing according to the third embodiment of the invention; Fig. 9 is a schematic perspective illustration of the removal of a battery unit in a battery energy storage system with a housing according to the first embodiment of the invention;

Fig. 10 is a schematic perspective illustration of the removal of a battery unit in a battery energy storage system with a housing according to another embodiment of the invention;

Fig. 11 is a schematic diagram of an embodiment of a fire extinguishing system in a battery energy storage system according to the invention; and

Fig. 12 is schematic diagram of another embodiment of a fire extinguishing system in a battery energy storage system according to the invention.

With reference to fig. 1, the urban battery energy storage systems 1 may be designed to be connected to a low voltage distribution system VD closer to the load. The low voltage distribution system VD may be connected to an electrical grid 3. The voltage level and the energy capacity may be configured so that it is similar to an electric vehicle charging station 2. This equals the safety risk level of the stationary urban battery energy storage system 1 to the electric vehicle charging stations 2 and thus can be handled in accordance with the same procedures for such systems when installed in a city or urban zone.

The concept of mimicking the electric vehicle charging stations 2 is also advantageous as the same hardware may be used for managing the battery energy storage in the battery energy storage system (BESS) 1.

As shown in figures 2 and 3, the battery energy storage system 1 comprises a housing installed on a groundwork, said housing comprising a frame 10 provided with an outer cover 13 (see figs. 3 and 5) and at least a first compartment 11 and a second compartment 12. In the first compartment 11 there is provided a battery unit 20 comprising at least one battery pack. In the second compartment 12 there is accommodated electrical components 21 so that the at least one battery pack 20 is electrically connected to a public electrical power grid 3, whereby electrical energy can be charged or discharged to the battery pack 20 or battery packs 20 (as shown in fig. 3). In the embodiments shown in figures 2 and 3, the housing is cubical with a rectangular base, four sides and a roof 14. It is realised, however, that the housing may be provided in any other suitable shape. In an advantageous embodiment, the roof 14 is openable, for instance the roof is provided as a hinged roof, so that there is direct access via the roof 14 (when open) to at least the first compartment 11 with the battery unit 20. The second compartment 12 is the lowermost compartment accommodating the electrical components 21 and the first compartment 11 is the uppermost and accommodates the battery unit 20.

In the embodiment shown in fig. 4, the first and second compartments 11, 12 are provided in the frame side by side. Also in this configuration there is direct access via the roof 14 when opened to the battery unit 20. In the embodiment shown in fig. 4, the roof 14 may be provided with external fittings 15 for holding a shelter roof and the housing frame 10 may be provided with an external cover 13 for providing an urban furniture, which in the example shown in fig. 5 is a bicycle shelter. As shown in fig. 5, the urban furniture may be provided by positioning a plurality of battery energy storage systems 1, 1' and 1" side by side. The number of battery energy storage systems and the configuration of the battery energy storage systems used for forming the urban furniture can of course vary depending on the shape and type of urban furniture is desired.

In the figures 6 to 8, the steps of removing the battery unit 20 from the first compartment 11 are shown. In fig. 4, the battery energy storage system 1 is shown in a perspective view. This embodiment of the battery energy storage system 1 is similar to the system shown in figs. 4 and 5. The roof 14 is provided with the external fittings 15 in the form of supporting beams for a shelter roof (see fig. 5). The roof 14 is hinged such that by lifting the beams 15, the roof is opened, as shown in fig. 7. Hereby the first compartment 11 is open at the top so that the battery unit 20 is accessible. As shown in fig. 8, the battery unit 20 can then be lifted up through the open roof 14 and thereby removed. In this manner, the battery unit 20 removal can be achieved without human contact, which may be important for emergency responders and thus contributes to a safe urban battery energy storage system. Both the opening of the roof 14, i.e. the pivoting of the shelter roof, i.e. the beams 15 supporting the shelter roof, and the lifting of the battery unit 20 may be carried out by a suitable lifting device, such as a manual mobile floor crane for smaller installations or a truck with a crane for larger installations. The battery unit 20 may be provided on rails 21, for instance telescopic rails for better support during removal - and insertion. The battery unit 20 may also have an easy pick-up mechanism, such as a gripping mechanism so that a hook of the crane can be easily attached by hazard responders so that the battery unit 20 may be removed quickly and safely.

In fig. 9, there is shown an example where the battery unit 20 is provided with a cassette with rails 21 that fit into the portion of the frame 10 defining the first compartment 11. As partly shown in fig. 9, the second compartment 12 may be covered by a hinged door or the like in the outer cover 13 so that easy access to the electrical components in the second compartment 12 can be established.

In fig. 10, another embodiment for a battery removal solution is shown. According to this embodiment, the first compartment 11 of the frame 10 is provided with a front cover 13, which is bottom-hinged so that it swings open and also swings the battery unit 20 into an inclined position from which the battery unit 20 is easy to attach to a lifting device or the like in order to remove the battery.

In the stationary urban battery energy storage system, the battery units 20 may preferably be provided with automatic electrical plugs so that the battery automatically disconnects from the electrical supply when being removed. This further facilitates quick removal of the battery units in case of a fire or other hazards.

With reference to figure 11 and 12, there are shown two embodiments of an injection system injecting water/coolant to the battery unit or the entire battery energy storage system in case of a fire. In order to observe safety requirements, the interference in case of a fire requires no human contact, and this can be achieved by an automated direct injection system. Both the solutions can be addressing safety requirements without compromising aesthetic which requires a compact design.

In the first embodiment of this fire extinguishing system, at least the first compartment 11 of the housing is provided with a fire extinguishing system 30 including at least one fire detection sensor 31 and a one or more sprinklers 34 in fluid connection with a water supply 32, such as a remote distance water supply 32 as shown in fig. 12. As indicated in fig. 11, a fire agent is supplied to water supply 32 to the sprinklers 34, if deemed appropriate.

The sensor 31 will react to a fire in the battery 20 and send a signal to the controller 33, which operates a solenoid valve 36 in the embodiment shown in fig. 11. This valve opens for the water supply 32 to the sprinklers 34 that then sprinkles water and/or other coolant gents onto the battery unit 20 to extinguish or at least contain the fire and thereby limiting the spreading of the fire. As shown in fig. 12, there may also be provided a fire/hazard light 35 which will be turned on when the sensor 31 reacts to a fire indication in the battery 20 thereby visually alarming the surroundings of the fire. This may further be supplemented with an audio alarm.

Although the present invention has been described in connection with the specified embodiments, it should not be construed as being in any way limited to the presented examples. The scope of the present invention is set out by the accompanying claim set. In the context of the claims, the terms "comprising" or "comprises" do not exclude other possible elements or steps. Also, the mentioning of references such as "a" or "an" etc. should not be construed as excluding a plurality. The use of reference signs in the claims with respect to elements indicated in the figures shall also not be construed as limiting the scope of the invention. Furthermore, individual features mentioned in different claims, may possibly be advantageously combined, and the mentioning of these features in different claims does not exclude that a combination of features is not possible and advantageous.