Patent Description:
When it comes to energy resources, the question of sustainability is becoming increasingly topical. It is also important to consider how resources can be used in the long term. Some resources will practically never run out: these are the so-called renewable resources. Renewable resources produce clean energy, which means less pollution and greenhouse gas emissions that contribute to climate change.

Dynamic Wireless Power Transfer (DWPT) charging of electric cars has recently been proposed. This technology, based on dynamic induction, allows electric vehicles to recharge their batteries simply by driving along a stretch of motorway. With DWPT, electric vehicles can be recharged in wireless mode by travelling on wired lanes thanks to a system of loops placed under the asphalt. This technology is adaptable to vehicles equipped with a special receiver module that transfers incoming energy from the road infrastructure to the battery. One of the benefits of this technology is the reduction of the capacity (and thus the mass) of the batteries and the time to recharge them. One of the goals of DWPT technology is to avoid vehicles having to carry large and heavy batteries, the production and disposal of which is problematic.

Patent <CIT> discloses a road pavement comprising a layer of intermediate material (interlayer) and a plurality of piezoelectric elements arranged therein, on or against the layer of intermediate material. Changes in pressure on the pavement, for example by a vehicle, generate electricity through the plurality of piezoelectric elements. A transmission line transmits the electric energy generated by the plurality of piezoelectric elements to an output.

US <NUM>/<NUM> A1 discloses methods and systems for harvesting vibrational energy from vehicles, as well as methods for locating vibrational energy on a vehicle. A vibrational energy harvester is coupled to a maximum vibrational displacement node of a structural element of a vehicle. Vibrational energy harvesters may be piezoelectric devices. The publication proposes methods for identifying appropriate structural elements for vibrational energy harvesting. Circuitry that converts electrical signals generated by vibrational energy harvesting devices from high voltage input alternating current to low voltage output direct current is provided, as well as circuitry for storing or utilizing the harvested electrical energy.

JP <NUM><NUM> A discloses power generation panels designed to convert an external force by walking of a pedestrian into electricity by way of a piezoelectric device, enabling the pedestrian to walk. The system comprises a housing which displaces by receiving the external force by the walking. A piezoelectric device disposed in the housing deforms according to a displacement of the housing to generate power. A display outputs prescribed information to the pedestrian using the electric power generated by the piezoelectric device.

KR <NUM><NUM> A discloses a wireless power transmission device comprising: an energy harvesting unit for converting idle energy generated in an automotive wheel into electric energy; a transmission source coil which is wound outside a rim of the automotive wheel, and transmits the electric energy received by the energy harvesting unit through magnetic induction; and a transmission resonance coil which is wound outside the rim of the automotive wheel, and wirelessly transmits the electric energy induced in the transmission source coil by resonating the electric energy through the magnetic resonance. A part of the idle energy generated by the wheel is transmitted to a device that may use it.

US <NUM>/ <NUM> A1 discloses a process for generating electricity from vehicular traffic. The process includes distributing a plurality of piezoelectric elements no higher than an adjacent surface of a roadway. Electric current is generated as traffic passes over the roadway, and the electric current conducted away from the piezoelectric elements to provide the electrical current for consumption.

US <NUM>/<NUM> A1 discloses the use of piezoelectric generators for recapturing expelled kinetic energy that would otherwise be wasted. Piezoelectric generators may be placed in shoes, clothing, tires, roads, and sidewalks in order to recapture the energy expelled in everyday human activities (e.g., walking, moving, and driving).

It is an object of the present invention to exploit hitherto unused mechanical energy from moving masses, and to transform at least part of this mechanical energy into electric power. A particular object of the invention is to generate clean energy with zero environmental and aesthetic impact.

The aforementioned and other objects and advantages are achieved, according to a first aspect of the present invention, by a system for generating electric current having the features set forth in claim <NUM>. Preferred embodiments of the invention are set forth in the dependent claims.

In summary, the invention provides a system for generating electric current comprising a carriageway having:.

In order that the present invention may be well understood, a few preferred forms thereof will now be described, by way of example, with reference to the accompanying drawings, in which:.

A system <NUM> for generating electric current comprises at least one electric current generating panel <NUM> and at least one electricity-using or electricity-storing device <NUM>, electrically connected to said electric current generating panel <NUM>. Such a system <NUM> may be implemented in different embodiments.

Referring initially to <FIG>, a carriageway according to a first exemplary embodiment of the present invention is designated in its entirety at <NUM>. The carriageway <NUM> comprises a dynamic induction charging lane <NUM> and a power-generating lane <NUM>, alongside the dynamic induction charging lane <NUM>.

The lane <NUM>, for dynamic induction charging, is to be considered known per se. Accordingly, only those elements of specific relevance and interest for implementing the present invention will be described in detail in the following description. For the implementation of parts and elements not illustrated in detail, reference may therefore be made to any known dynamic induction charging lane solution. Suffice it to recall herein that a dynamic induction charging lane <NUM> usually comprises a system of power transmission coils incorporated in the road pavement, typically under the road surface, and operatively induction-coupled with an electric power receiving module mounted on board an electric vehicle. The electric power receiving module comprises at least one electric power receiving coil and an associated receiving circuit mounted on board the same vehicle and arranged to transfer the incoming electric power into an on-board electrical storage unit. Thanks to the DWPT charging lane, electric vehicles are recharged electrically.

According to one aspect of the present invention, power transmission coils incorporated in the lane <NUM> are connected to and electrically powered by panels <NUM> of piezoelectric power generation elements <NUM> incorporated in the pavement of the lane <NUM>.

Each generator panel <NUM> comprises a plurality of piezoelectric current-generating elements <NUM>, which are oriented in a given direction, and arranged to be compressed in said given direction by the passage of a vehicle whose wheels rolling on the panel or on an element integral therewith, by the effect of gravity cause compression of the piezoelectric elements and generate a current which is conveyed to a user device <NUM>. The user device <NUM> may alternatively be represented either by the transmission coils incorporated in the road pavement of the charging lane, or by one or more current accumulators electrically connected to one or more of said transmission coils.

As known, the deformation to which piezoelectric generating elements <NUM> are subjected generates a potential difference that generates an electric current between opposite ends of each piezoelectric element.

According to the embodiment shown in <FIG>, for road applications, the piezoelectric elements <NUM> are oriented and arranged to be compressed in a direction perpendicular or substantially perpendicular to a flat surface in which the panel <NUM> extends, intended to be arranged in a parallel plane below the road surface <NUM>.

Preferably, the piezoelectric elements <NUM> are arranged towards or adjacent to side ends 20a and 20b of the power-generating lane <NUM> in such a way that they are located where the wheels of a vehicle travelling on the lane <NUM> pass.

Advantageously, the piezoelectric elements <NUM> may have an elongated shape along a transverse direction with respect to the direction of travel of the vehicles, i.e. they can extend from the side ends 20a and 20b of the lane <NUM> towards a mid-line of the same lane <NUM>. Such an arrangement of the piezoelectric elements <NUM> ensures the passage of the wheels of the vehicles over the piezoelectric elements <NUM> in the case of the passage of vehicles with different dimensions, i.e. vehicles having different widths, and/or in the case of small lateral displacements of the vehicles travelling on the power generating lane.

Therefore, it is the electric vehicles themselves which, simply by travelling along a length of the power-generating lane <NUM>, generate electric power due to their own gravitational force which, through the wheels of the vehicle, compresses and activates the piezoelectric elements <NUM>, resulting in the generation of electric current which is used to recharge, at least partially, the electric accumulators on board the same vehicle or other electric vehicles travelling on the dynamic induction charging lane <NUM>. Alternatively, the electric current generated by the piezoelectric elements <NUM> may recharge the stationary electric accumulators <NUM> arranged along the carriageway.

According to some embodiments, the dynamic induction charging lane <NUM> and the power-generating lane <NUM> are laterally or transversely arranged side-by-side for some carriageway sections <NUM> (<FIG>), so that vehicles travelling on the dynamic induction charging lane <NUM> can move sideways and change lanes, moving onto the power-generating lane <NUM> and then return to the dynamic induction charging lane <NUM> to recharge.

According to an alternative embodiment, sections of dynamic induction charging lane <NUM> may be interrupted by and alternated with sections of power-generating lane <NUM>, interspersed and aligned with stretches of dynamic induction charging lane <NUM>. In this way, vehicles do not need to change lanes to generate electricity on a power-generating lane <NUM> and then return to the dynamic induction charging lane <NUM> to recharge.

Advantageously, the provision of an electricity-generating lane allows electric vehicles travelling on this lane to be recharged, taking advantage of DWPT technology even in the absence of an electrical network connection for energizing the road pavement.

The compression of piezoelectric elements <NUM> not located in the immediate vicinity of the vehicle wheels can also be performed by means of vertically movable horizontal connecting beams, e.g. extended in a direction transverse to the direction of vehicle travel, which are configured to lower when a vehicle wheel passes over a part of them, and thus also cause the compression of piezoelectric elements not immediately below the area of a vehicle wheel passage.

In the following, other examples will now be described that are based, similarly to the gravity-driven operation that governs the above-described embodiments, on the principle of exploiting, for the generation of electric power, various forces that are produced by the movement of a mass, in particular, but not exclusively, by the movement of the mass of a vehicle.

According to some examples, exploited are systems of forces that are produced by the movement of a vehicle that moves forward and involves the displacement of a considerable mass, and/or moves at a very high speed, and in both cases impacts and exchanges considerable reaction forces with the fluid medium it passes through.

In accordance with the example that is not part of the invention shown in <FIG>, the forces developed on the hull of a vessel at the interface between a front, submerged surface <NUM> of the hull <NUM> when the vessel is in motion are exploited. One or more generator panels <NUM>, each comprising a plurality of piezoelectric current-generating elements <NUM> (<FIG>), may be fitted on an outer, submerged front surface <NUM> of the hull <NUM>, and thus below the waterline. The generator panels <NUM> are oriented facing the direction of advancement of the vessel. In this way, the piezoelectric elements <NUM> are repeatedly compressed in said direction by forces of continuously varying intensity due to the continuous changes and oscillations in the trim of the boat, with consequent and corresponding changes in the pressure determined by the resistance that the water opposes to the advancement of the vessel.

The electric current generated by the compression of piezoelectric elements <NUM> is used to recharge electrical devices <NUM> or accumulators placed on board the vessel.

The piezoelectric element panels <NUM> may be shaped to fit the profile or shape of the outer <NUM> submerged surface of the hull on which they are installed, typically a surface in the bow area. For example, one or more panels <NUM> of piezoelectric elements may be applied to the bulb of a ship's hull (<FIG>). In order to optimise the exploitation of dynamic forces, piezoelectric panels may be located, for example, in concave areas (<FIG>) of the bulb, facing forward, suitable to impact against the flow of water entering a hydrodynamic channel into which water is conveyed.

Due to the surface extension of the panels <NUM> of piezoelectric elements <NUM>, and the tonnage of a cruise ship, aircraft carrier, container ship, and LNG carrier, which can be hundreds of thousands of tonnes, the movement of the advancing vessel causes high forces of continuously varying intensity. These forces, acting on a multitude of piezoelectric elements <NUM> arranged on one or more impacting external surfaces <NUM>, generate an electric current that is transmitted to an electric accumulator mounted on board the vessel.

In the case of less heavy vessels, but with high sea speeds, such as motor yachts and speedboats, panels <NUM> of piezoelectric elements <NUM> arranged on external surfaces <NUM> impacting a mass of water may form power generating hulls.

The choice of placing panels <NUM> of piezoelectric elements <NUM> on external surfaces <NUM> facing perpendicular to the forward direction of the vessel is a preferred, but not essential choice from a performance and force intensity variation point of view. Panels <NUM> of piezoelectric elements <NUM> may also be arranged on submerged surfaces inclined with respect to the direction of advancement of the vessel.

According to the example illustrated in <FIG>, the forces developed on an external surface <NUM> of an aircraft are utilised, in particular (but not exclusively) on the front surface of the nacelle, and/or on the leading edges of wings and stabilisers. In this example, with lower masses than on a ship, but with much higher speeds than on a vessel, the movement of an aircraft creates high and continuously varying fluctuating forces during the flight.

One or more generator panels <NUM> each comprising a plurality of current-generating piezoelectric elements <NUM> may be applied to front facing surfaces <NUM> of the aircraft, oriented facing the forward direction of the aircraft and impacting the air during a flight. As with the examples described above, the piezoelectric elements <NUM> are repeatedly compressed in said direction due to forces of continuously varying intensity as a result of the continuous changes and oscillations in the attitude of the aircraft and the density of the air, with consequent and corresponding changes in the pressure determined by the resistance that the air opposes to the advancement. The electric current generated by the compression of the piezoelectric elements <NUM> is used to recharge electrical devices <NUM> or accumulators on board the aircraft.

The panels <NUM> of piezoelectric elements <NUM> may be shaped to fit the profile or shape of the front surface of the nacelle or the leading edges of wings or empennages where the panels are installed.

According to a further example, which is not part of the present invention, shown in <FIG>, variable forces developed in areas where a waterfall of a watercourse impacts against a supporting surface <NUM> are exploited. One or more panels <NUM> generators each comprising a plurality of piezoelectric current generating elements <NUM> may be applied to said supporting surface <NUM> (which may be, for example, a rock). Preferably, the panels <NUM> are oriented facing upwards, opposite the direction in which the waterfall flows. As with the preceding examples, the piezoelectric elements <NUM> are repeatedly compressed in said direction due to the continuously varying intensity forces of the falling and impacting water.

Claim 1:
A system (<NUM>) for generating electric current, comprising a carriageway (<NUM>) with:
at least one power-generating lane section (<NUM>) having a road pavement which incorporates a plurality of electric current generator panels (<NUM>) comprising a plurality of piezoelectric elements (<NUM>) compressible and oriented facing a given direction, configured to be compressed and consequently generating an electric current due to the movement of a vehicle, characterized by
at least one lane section (<NUM>) for dynamic wireless power transfer with power transmission coils (<NUM>) electrically connected to said panels (<NUM>) of power-generating piezoelectric elements (<NUM>) and being configured to electrically recharge an electric vehicle transiting on the lane section (<NUM>) for dynamic wireless power transfer.