GB2586172A

GB2586172A - Cabin with AC solar panel and power system comprising the same

Info

Publication number: GB2586172A
Application number: GB1914119.1A
Authority: GB
Inventors: Fletcher Simon
Original assignee: Easycabin Holdings Ltd
Current assignee: Easycabin Holdings Ltd
Priority date: 2019-08-07
Filing date: 2019-10-01
Publication date: 2021-02-10
Anticipated expiration: 2039-10-01
Also published as: GB2586172B; GB2586147A; GB201911309D0; GB201914119D0

Abstract

A cabin comprises a self-contained cabin, the cabin comprising a solar panel mounted on its outside, the solar panel comprising a plurality of photovoltaic cells and an inverter for providing AC power directly from the solar panel. The solar panel is connected to a power circuit of the cabin for providing on demand power to one or more connected electrical devices. A weather sealed junction box may be provided on the outside of the cabin, optionally on the roof with the solar panel. The junction box may provide a circuit breaker and connections to a power socket, the solar panel and a supplemental power source. The solar panel may be receiving spaced guide rails on the cabin, may be locked against sliding or may be mounted using clamps. A plurality of solar panels may be provided. An off grid power unit may also be provided comprising a battery and a power source which may be a generator, a fuel cell, a solar panel or a wind turbine, or some combination thereof. A system may comprise a plurality of cabins and a plurality of off grid power units.

Description

Cabin with AC solar panel and power system comprising the same The present disclosure relates to a cabin, which comprises a power circuit for providing power to one or more connected electrical devices and a solar panel providing AC power to the power circuit. It further relates to a system comprising the cabin and an off-grid unit for storing energy generated by the solar panel and for providing electrical power to the power circuit.

Cabins come in many forms and are used for temporary, semi-permanent and to permanent accommodation. They may be portable and/or modular. They may be single or multi-storey. They may be used as an office, a canteen, toilets, drying rooms, storage rooms or otherwise.

One form of cabin is a welfare unit. Welfare units are typically movable cabins, providing temporary accommodation and welfare facilities, such as basic sanitary and kitchen facilities, to site personnel at work locations, such as building sites or similar, where no other accommodation or welfare facilities may be provided. With recent changes to health and safety legislation, virtually all outside work sites will have to provide temporary accommodation and welfare facilities for site personnel.

Welfare units have typically been powered using generators that are powered by non-renewable energy sources, such as diesel generators. The generators are housed within the welfare units themselves. Such generators, whilst offering a reliable source of power, tend to be noisy and pollute the environment. To limit the runtime of generators it is common to provide one or more batteries for powering devices in the welfare unit, which batteries are housed within the welfare unit and may be charged by the generator. In addition, in an effort to limit environmental impact and further limit runtime of the generator, a secondary (renewable) energy source, such as one or more solar panels may be provided for charging the batteries.

In systems provided with solar panels, the solar panels provide a direct current (DC) output. The direct powering of devices within the cabin is not possible from the solar panels. In addition to the batteries, an inverter is required along with control circuitry to manage the charging of batteries.

An issue with prior art systems is the cost and complexity of their integration into cabins. In addition to the solar panels, the inverter, control circuitry and batteries are required. These components add cost and must be suitably housed. Also, it is not straightforward to provide solar equipment in a cabin retrospectively. The cabins io must generally be designed from the outset with the solar systems integrated therein.

The present invention arose in a bid to provide an improved power system, offering increased flexibility, reduced costs and the possibility for retrospective fitting.

According to the present invention in a first aspect, there is provided a cabin as recited by Claim 1.

Preferably, there is provided a junction box, which is connected to the power circuit and is provided on an outside of the cabin, wherein the solar panel is connected to the junction box. Most preferably, the junction box is detachably connected to a power socket mounted on the outside of the cabin.

With the solar panel providing AC power, it is possible to connect the solar panel directly to the power circuit for providing electrical power to the one or more connected electrical devices. Retrofitting of solar panels becomes uniquely possible. This is particularly so when the power is fed to an external power socket. No modification to a welfare unit is required. The junction box allows for additional power sources to be connected, such as but not limited to generators or otherwise.

A balanced power solution becomes possible in a manner not previously conceived.

According to the present invention in a further aspect, there is provided a system comprising a cabin according to the first aspect and an off-grid unit comprising a battery.

The off-grid unit is a separate unit to the cabin. It is preferably self-contained.

The system will preferably comprise a plurality of the cabins and one or more of the off-grid units, wherein each of the off-grid units is connected to a plurality of the cabins.

io Further, preferred, features are presented in the dependent claims.

The present invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows a simplified schematic illustration of a system comprising a cabin and an off-grid unit; Figure 2 shows a perspective view of the system of Figure 1; Figure 3 shows a perspective view of the cabin showing the features of the roof of the cabin; and Figure 4 shows a schematic illustration of the junction box of the cabin.

In broadest terms, there is provided a cabin 1 comprising a solar panel 2 mounted on its outside that provides AC power directly to a power circuit (not shown) of the cabin 1 for providing on demand power to one or more connected electrical devices. For the provision of AC power from the solar panel, the solar panel itself comprises an inverter (otherwise referred to as a micro inverter) (not shown).

Whilst there may be arrangements with a single solar panel only, there will typically be a plurality of the solar panels 2 provided, with each solar panel comprising its own inverter, as in the depicted arrangement.

Such an arrangement contrasts to prior art arrangements in which a plurality of solar panels are mounted on a cabin that provide DC power. In such arrangement the DC power from the solar panels is used to charge a battery bank with a single common inverter (separate from the solar panels) provided to convert the DC power to AC power for use in a power circuit for providing on demand power to one or more connected electrical devices.

The unique arrangement of the present invention renders it far easier to equip a cabin with solar panels for powering electrical devices within the cabin. There is no internal reconfiguration required to house the previously required inverter, battery bank and other associated components. Modularity (and retrofitting) become possible, whereby a common design of cabin may be provided that can be equipped with solar panels or with the capability for the subsequent addition of solar panel(s).

It is preferable that there is a junction box 3 provided, which is connected to the power circuit and is provided outside of the cabin.

Figures 1 to 3 show a first arrangement for the junction box and the connection of the solar panels to the power circuit of the cabin. The solar panels are connected to the junction box using suitable cabling. The junction box is mounted at a suitable location for connection to the solar panels. It will preferably be provided adjacent one of the solar panels. In the depicted arrangement, as is preferred, it is mounted on a roof of the cabin along with the solar panels. The junction box is preferably connected to a distribution board 4 located within the cabin 1 in a conventional manner.

In an alternative arrangement, particularly suited to the retrofitting of solar panels to a cabin but also applicable to cabins that are designed with solar power in mind, one or more solar panels may be added simply by plugging them in to an external power socket 9 connected to the power circuit. The connection of the solar panel to the plug socket could be direct but is most preferably through a junction box to allow for the connection of additional power sources. In such an arrangement there is provided an external junction box that detachably connects to the external plug socket 9 of the cabin. By such an arrangement, an entirely non-invasive system is provided.

The junction box 3 is preferably a three-way junction box, as shown schematically in Figure 4, which comprises a first connector 30 for connection to the power socket, a second connector 40 for connection to the solar panel and a third connector 50 for connection to a supplemental power source. The supplemental power source may take any conventional form. It may comprise a generator or otherwise. It may comprise an off-grid power unit 5, as discussed below. The connectors are preferably plug sockets.

In accordance with a preferred arrangement, the junction box comprises a circuit breaker as shown. The junction box preferably comprises a weather sealed box. The junction box may be attached to an outside of the cabin using any suitable fastenings. In a particularly preferred arrangement it is detachably fixed using magnets.

The solar panels 2 are preferably removably mounted to the cabin. In the depicted and preferred arrangement they are slidably mounted. The cabin comprises a pair of spaced and suitable profiled guide rails 11 arranged to slidably receive the solar panel therebetween. The rails are profiled to prevent uplift of the solar panels and to allow only translational sliding movement of the panels that are slidably received thereby. A suitable locking arrangement will be provided for locking the solar panels in place, i.e. locking them against sliding movement along a channel defined by the guide rails. Numerous alternative mounting arrangements will be possible, however. In one arrangement, for example, the solar panels may be fixed using clamps.

The cabin may be of any conventional structure and layout and the present invention is not to be limited in this regard. The cabin may, for example, comprise a welfare unit to be used on building sites, or the like, in particular where lavatory facilities are not otherwise available. The cabin is preferably free standing and transportable. It may be formed as a trailer and provided with its own wheels. It may otherwise be arranged to be transported using a flat-bed vehicle. It could, less preferably, be arranged to be permanently located (by the connection to services, such as plumbing). In some arrangements, as discussed below, the power circuit could be connected to the power grid. The cabin preferably comprises a typical rectangular box shape.

It may be equipped, as will be readily appreciated by those skilled in the art, in accordance with any conventional cabin. It may, for example, be provided with one or more toilets and/or showers. It may comprise kitchen facilities. It may be configured as an office or as living accommodation. The present invention is not to be limited to any specific configuration. Numerous conventional layouts and provided facilities will be possible and readily conceived by those skilled in the art. Irrespective of the layout/facilities, the cabin will feature at least one electrical device connected to the power circuit for receiving on demand power therefrom. There will most likely be a plurality of connected electrical devices and a plurality of plug sockets. Electrical devices may be hard wired to the power circuit or connected via plug sockets, and may include, for example, any combination of electric lighting, proximity sensors, a water boiler, an air conditioning unit, a heater, or otherwise. A sensor may be provided for detecting entry of a user into the cabin. The sensor may automatically activate an electric light within the cabin when a user enters the cabin and deactivate the light when the cabin is vacated. Such an arrangement will further enhance the energy efficiency of the cabin.

The cabin may additionally comprise a secondary power source for providing power to the power circuit. The secondary power source may comprise a fossil fuel powered generator, such as a diesel generator, or a fuel cell, such as a hydrogen fuel cell. Use of the secondary power source will be kept to a minimum. The secondary power source will only be used when the power generated by the solar panels is insufficient. The secondary power source will be present as a reliable energy source, always available irrespective of environmental conditions. In normal operation, therefore, the solar panels alone will provide power to the power circuit. The secondary power source will be switched on by a suitable controller only when the detected load on the power circuit rises above a detected live power output of the solar panels.

In a further particularly preferred arrangement, the cabin may form part of a system 10 that comprises the cabin 1 and an off-grid power unit 5, wherein the off-grid power unit comprises a battery, and the power circuit is connected to the off-grid unit such that the power circuit may receive power from the battery or provide power to the off grid power unit for charging the battery. In such a system, the cabin may or may not comprise the secondary power source as discussed above.

The off-grid power unit 5 preferably comprises a self-contained housing 6 that houses one or more batteries (not shown) for storing power from the solar panels 2 to of the cabin 1. The off-grid power unit preferably comprises a plurality of solar panels 7a, 7b with the batteries also storing power from the solar panels of the off-grid power unit. The off-grid power unit preferably further or alternatively comprises a backup power generation means (not shown), wherein a control means (not shown) is provided for controlling operation of the backup power generation means.

The backup power generation means of the off-grid power unit may comprise a generator that is powered by a fossil fuel, such as diesel, or a fuel cell, which may comprise a hydrogen fuel cell. In the present arrangement the backup electricity producing means comprises a generator, wherein references to the generator are applicable to the alternative of a fuel cell in arrangements where the generator is replaced by a fuel cell.

It is to be noted that systems may be provided in which the off-grid power unit omits the solar panels on the off-grid power unit, although it is preferable that they are provided to optimise the use of renewable energy. A wind turbine may be provided in addition to or as an alternative to the solar panels on the off-grid power unit.

Various configurations of the off-grid power unit will be possible, wherein the off-grid power unit comprises one or more or all of a generator, a fuel cell, a solar panel and a wind turbine as a power source for charging the batteries of the off-grid power unit, or which omits all of these.

The system will preferably comprise one or more of the off-grid power units and a plurality of the cabins connected to each of the off-grid power units. The system is scalable.

The solar panels 8a, 8b of the off-grid power unit may output DC power to charge the batteries and there may be provided one or more inverters/battery chargers in the off-grid power unit so that excess AC power from the solar panels of the one or more cabins can be used to charge the batteries of the off-grid power unit and the power circuits of the one or more cabins can each receive AC power from io the batteries of the off-grid power unit when load on the respective power circuit is too high for the solar panels of the welfare cabin to cope with.

Each of the one or more cabins 1 may be connected to the off-grid power unit for providing and receiving power therebetween via a cable 19. The cable will be connected to the plug socket 9, directly or via the junction box, in dependence on the configuration implemented. The off-grid power unit will be provided with a plurality of corresponding plug sockets.

By virtue of the system, batteries for the storage of solar energy and the associated components, including an inverter/battery charger, may be removed from the cabin and centralised for a plurality of the cabins. The rollout of solar systems to the cabins themselves is greatly simplified.

Further, preferable, features of the off-grid power unit for use in the system are discussed below.

The off-grid power unit preferably comprises a base and a plurality faces, wherein a first of the faces is arranged at an oblique angle to the base and is substantially entirely covered by solar panels. In the present arrangement, as is preferred, in addition to the first face being substantially entirely covered by solar panels, a second face of the housing, which is adjacent to the first face is also substantially entirely covered by solar panels. Although this need not be the case in alternative arrangements. The second face lies at an oblique angle to the first face.

The second face preferably lies parallel to the base. It is preferable that the second face is the uppermost face of the body in use. The first and second faces may abut one another.

The off-grid power unit 5 preferably comprises movable solar panels 8a, such that a large solar collection area and high power generation capacity is achieved with a more compact unit. A more compact unit may be more easily transported. For this purpose, the unit of the present arrangement may be provided with wheels and a tow hitch. The wheels and tow hitch could, however, be omitted in alternative arrangements. Moreover, whilst the present arrangement is provided with lifting points on its corners to allow for cane lifting, which may comprise tabs with holes for receiving a chain or hook, and forklift pockets, either or both could be included or omitted, irrespective of the provision of wheels.

Considering the solar panels, the unit comprises a plurality of fixed panels 8b and a plurality of moveable panels 8a, wherein the unit is configured to have a retracted state (for transport/storage) and an extended state (in use, as shown). In the retracted state, each of the moveable panels is arranged to overlap with one of the fixed panels. In the extended state, there is no overlap. There is preferably a total overlap of panels in the retracted state so as to minimise the size of the unit for transport or storage. In the extended state, there is preferably no overlap, as shown, so as to maximise the solar capacity. Most preferably, as is the case with the depicted arrangement, the movable panels further overlap with one another in the retracted state to further reduce the size of the off-grid power unit in its retracted state.

The panels are slidable in the present arrangement, as is preferred. Runners are provided, which support the movable panels. Numerous alternative slidable support means will be readily appreciated by those skilled in the art. Suitable locking means may be provided to lock the movable panels in the retracted and/or extended positions. In the depicted arrangement, the movable panels slide over the fixed panels. In alternative arrangements, they could slide under the fixed panels.

Any suitable movement mechanism may be implemented for moving the panels. The panels may be manually moved or there may be a powered arrangement using one or more electric motors or hydraulic actuators. The sliding of the panels may be guided using alternative mechanisms to the depicted runners, as will be appreciated by those skilled in the art. Moreover, instead of being slidable, the movable panels could be pivotally mounted. Although such an arrangement is less preferable.

When wheels are provided, the wheels are most preferably retractable. In a deployed state, the wheels can support the unit during transportation with the base raised from the ground. In a retracted state, the wheels will be raised above the level of the base so that the base may rest upon the ground. This is preferable to provide a solid, planted, structure in use. The wheels may retract into the unit through openings in the base. A retraction mechanism for retracting the wheels will be provided, which may be hydraulically or electrically powered. Of course, to save costs, the wheels may be otherwise arranged so that they do not retract, in which case, the unit will be supported by the wheels at all times.

In an alternative arrangement to the above described system, the power circuit of the cabin may be connected to the power grid, wherein excess power from the solar panels may be fed to the power grid. The power circuit may also receive power from the grid in the event the load on the power circuit is too great for the solar panels.

Numerous modifications and alterations will be readily appreciated by those skilled in the art, within the scope of the claims that follow.

Claims

Claims 1. A cabin comprising a solar panel mounted on its outside, the solar panel comprising a plurality of photovoltaic cells and an inverter for providing AC power directly from the solar panel, wherein the solar panel is connected to a power circuit of the cabin for providing on demand power to one or more connected electrical devices.
2. A cabin as claimed in Claim 1, wherein a junction box, which is connected to the power circuit, is provided outside of the cabin and the solar panel is connected to the junction box.
3. A cabin as claimed in Claim 2, wherein the solar panel and junction box are both mounted on the roof of the cabin.
4. A cabin as claimed in Claim 2, wherein the junction box is detachably connected to a power socket mounted on the outside of the cabin.
5. A cabin as claimed in Claim 4, wherein the junction box is a three-way 20 junction box comprising a first connector for connection to the power socket, a second connector for connection to the solar panel and a third connector for connection to a supplemental power source.
6. A cabin as claimed in any of Claims 2 to 5, wherein the junction box comprises a circuit breaker.
7. A cabin as claimed in any of Claims 2 to 6, wherein the junction box comprises a weather sealed box.
8. A cabin as claimed in any preceding claim, wherein the solar panel is removably mounted to the cabin.
9. A cabin as claimed in any preceding claim, wherein the cabin comprises a pair of spaced guide rails arranged to slidably receive the solar panel therebetween.
10. A cabin as claimed in Claim 5, wherein a lock is provided for locking the solar panel against sliding movement.
11. A cabin as claimed in any of Claims 1 to 8, wherein the solar panel is mounted to the cabin using one or more clamps.
12. A cabin as claimed in any preceding claim comprising a plurality of the solar panels.
13. A system comprising a cabin as claimed in any preceding claim and an off-grid power unit, wherein the off-grid power unit comprises a battery, and the power circuit is connected to the off-grid unit such that the power circuit may receive power from the battery or provide power to the off grid power unit for charging the battery.
14. A system as claimed in Claim 13, wherein the off-grid power unit further comprises at least one power source for charging the battery, which comprises one or more or all of a generator, a fuel cell, a solar panel and a wind turbine.
15. A system as claimed in Claim 13 or 14, wherein the off-grid power unit comprises a solar panel comprising a plurality of photovoltaic cells for providing DC power directly from the solar panel and the off-grid power unit further comprises an inverter.
16. A system as claimed in any of Claims 13 to 15 comprising one or more of the off-grid power units and a plurality of the cabins connected to each of the off-grid power units.