Power beaming systems and methods with wavelength control

Abstract

Power beaming systems and methods are disclosed. Method embodiments can include transmitting a beam from a transmitter during a beaming period; receiving the beam at a photovoltaic receiver configured to convert the beam into electrical power in based on a conversion efficiency response having a peak conversion efficiency wavelength; and controlling an emission wavelength of the transmitted beam based on changes in the peak conversion efficiency wavelength due to changes in the temperature of the receiver during the beaming period caused by beam or ambient heating. In some embodiments, controlling the beam emission wavelength includes varying the beam emission wavelength during the beaming period to reduce a mismatch between the beam emission wavelength and the peak conversion efficiency wavelength as the peak conversion efficiency wavelength changes due to temperatures changes of the receiver.

Description

POWER BEAMING SYSTEMS AND METHODS WITH WAVELENGTH CONTROLRELATED PATENT APPLICATION

[0001] The present application claims priority to U.S. Provisional Patent Application No. 63 / 580,565 filed on September 5, 2023, the disclosure of which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] The technical field pertains to power beaming, and specifically to power beaming systems and methods with wavelength control capabilities.BACKGROUND

[0003] Power beaming, a form of point-to-point wireless power transfer, employs directed beams of electromagnetic radiation, such as laser and microwave beams, to transmit electrical energy from a transmitter to a receiver, often over considerable distances (e.g., hundreds or even thousands of kilometers). Laser power beaming, in particular, offers the potential for high-intensity, low-divergence, long-range transmission, with applications spanning various fields and industries, both on Earth and in space. In these systems, a laser transmitter emits laser radiation toward a photovoltaic (PV) receiver, which is configured to capture the laser radiation and convert it into electricity. Despite ongoing advancements, numerous challenges persist in the field of power beaming.SUMMARY

[0004] The present description relates to power beaming systems and methods that enable control over the wavelength of the beam emitted by the transmitter, aligning with variations in the receiver’s peak conversion efficiency wavelength as the receiver’s temperature fluctuates due to beam heating and / or changes in ambient temperature. In some implementations, the beam wavelength is adjusted during the beaming period to either match or reduce the mismatch with the peak conversion efficiency wavelength, as it varies over time due to the receiver’s temperature fluctuations.

[0005] In accordance with another aspect, there is provided a power beaming method, including: transmitting, during a beaming period, a transmission beam from a beam transmitter; receiving, during the beaming period, the transmission beam at a photovoltaic (PV) receiver, wherein the PV receiver is configured to convert the transmission beam into electrical power in accordance with a conversion efficiency response of the PV receiver, the conversion efficiency response having a peak conversion efficiency wavelength; and determining a beam emission wavelength of the transmission beam transmitted by the beam transmitter in accordance with changes in the peak conversion efficiency wavelength occurring during the beaming period and resulting from changes in the temperature of the PV receiver.

[0006] In some embodiments, the transmission beam is a laser beam.

[0007] In some embodiments, at least one of the beam transmitter or the PV receiver is spacebome. In some embodiments, at least one of the beam transmitter or the PV receiver is landbome, waterborne, or airborne.

[0008] In some embodiments, the PV receiver includes an array of PV cells. In some embodiments, the PV cells include single-junction PV cells. In some embodiments, the PV cells include multi-junction PV cells.

[0009] In some embodiments, the PV receiver includes a semiconductor material having a bandgap energy, and the changes in the peak conversion efficiency wavelength are due to temperature-induced changes in the bandgap energy.

[0010] In some embodiments, the beam transmitter and the PV receiver are separated from each other by a beam transmission distance ranging from about 40 km to about 200 km.

[0011] In some embodiments, the beam emission wavelength lies within a waveband ranging from about 400 nm to about 2500 nm.

[0012] In some embodiments, the beaming period has a duration ranging from about one minute to about ten minutes.

[0013] In some embodiments, the changes in the temperature of the PV receiver are due at least in part to beam heating. In some embodiments, the changes in the temperature of the PV receiver are due at least in part to ambient heating or cooling.

[0014] In some embodiments, the transmission beam has a non-uniform irradiance profile with stronger intensity at a center of the transmission beam and radially decreasing intensity away from the center; and the beam emission wavelength is controlled based on changes in the peak conversion efficiency wavelength in a region of the PV receiver illuminated by the center of the transmission beam.

[0015] In some embodiments, controlling the beam emission wavelength of the transmission beam includes managing heat generation within the PV receiver in order to regulate heat transfer between the PV receiver and an asset coupled to the PV receiver. In some embodiments, the asset includes fixed equipment. In some embodiments, the asset includes mobile equipment.

[0016] In some embodiments, controlling the beam emission wavelength includes: varying the beam emission wavelength during the beaming period to reduce a mismatch between the beam emission wavelength and the peak conversion efficiency wavelength as the peak conversion efficiency wavelength changes over time due to the changes in the temperature of the PV receiver.

[0017] In some embodiments, varying the beam emission wavelength includes shifting the beam emission wavelength by about 10 nm to about 100 nm over the beaming period. In some embodiments, varying the beam emission wavelength includes adjusting the beam emission wavelength in increments ranging from about 0. 1 nm to about 10 nm.

[0018] In some embodiments, the power beaming method further includes: providing wavelength variation information about an expected variation in the peak conversion efficiency wavelength over time during the beaming period; and varying the beam emission wavelength according to the wavelength variation information. In some embodiments, providing the wavelength variation information includes performing a calibration operation to determine the expected variation in the peak conversion efficiency wavelength over time. In some embodiments, providing the wavelength variation information includes providing a model predicting the expected variation in the peak conversion efficiency wavelength.

[0019] In some embodiments, varying the beam emission wavelength includes adjusting the beam emission wavelength at a rate proportional to an intensity of the transmission beam.

[0020] In some embodiments, the power beaming method further includes: monitoring the temperature of the PV receiver over time during at least part of the beaming period; and varying the beam emission wavelength based on the monitored temperature.

[0021] In some embodiments, the power beaming method further includes: monitoring a parameter of the conversion efficiency response of the PV receiver over time during at least part of the beaming period; and varying the beam emission wavelength based on the monitored parameter. In some embodiments, the monitored parameter includes the peak conversion efficiency wavelength.

[0022] In some embodiments, varying the beam emission wavelength includes continuously adjusting the beam emission wavelength during all or part of the beaming period. In some embodiments, varying the beam emission wavelength includes intermittently adjusting the beam emission wavelength during all or part of the beaming period. In some embodiments, intermittently adjusting the beam emission wavelength includes changing the beam emission wavelength at a single point or interval during the beaming period. In some embodiments, intermittently adjusting the beam emission wavelength includes changing the beam emission wavelength at multiple distinct points or intervals during the beaming period.

[0023] In some embodiments, varying the beam emission wavelength includes increasing the beam emission wavelength as the peak conversion efficiency wavelength increases due to an increase in the temperature of the PV receiver.

[0024] In some embodiments, varying the beam emission wavelength includes decreasing the beam emission wavelength as the peak conversion efficiency wavelength decreases due to a decrease in the temperature of the PV receiver.

[0025] In some embodiments, varying the beam emission wavelength includes varying the beam emission wavelength linearly as a function of time.

[0026] In some embodiments, varying the beam emission wavelength includes reducing the mismatch between the beam emission wavelength and the peak conversion efficiency wavelength during the entire beaming period. In some embodiments, varying the beam emission wavelength includes reducing the mismatch between the beam emission wavelength and the peak conversion efficiency wavelength during a portion of the beaming period. In some embodiments, the portion of the beaming period begins after the start time of the beaming period and ends at the end time of the beaming period.

[0027] In some embodiments, varying the beam emission wavelength includes minimizing the mismatch between the beam emission wavelength and the peak conversion efficiency wavelength.

[0028] In some embodiments, controlling the beam emission wavelength includes, at or prior to the start time of the beaming period: setting the beam emission wavelength to match the peak conversion efficiency wavelength expected at a later time of the beaming period. In some embodiments, the later time is the end time of the beaming period.

[0029] In accordance with another aspect, there is provided a power beaming system, including: a beam transmitter configured to transmit a transmission beam during a beaming period; a photovoltaic (PV) receiver configured to receive the transmission beam from the beam transmitter during the beaming period and convert the transmission beam into electrical power in accordance with a conversion efficiency response of the PV receiver, the conversion efficiency response having a peak conversion efficiency wavelength; and a transmitter controller operatively coupled to the beam transmitter, the transmitter controller including a processor and a non-transitory computer readable storage medium having stored thereon computer readable instructions that, when executed by the processor, cause the processor to perform operations, the operations including determining a beam emission wavelength of the transmission beam transmitted by the beam transmitter in accordance with changes in the peak conversion efficiency wavelength occurring during the beaming period and resulting from changes in the temperature of the PV receiver.

[0030] In some embodiments, the beam transmitter includes a laser source configured to emit the transmission beam as a laser beam.

[0031] In some embodiments, at least one of the beam transmitter or the PV receiver is configured for spacebome operation. In some embodiments, at least one of the beam transmitter or the PV receiver is configured for landbome, waterborne, or airborne operation.

[0032] In some embodiments, the PV receiver includes an array of PV cells. In some embodiments, the PV cells include single-junction PV cells. In some embodiments, the PV cells include multi-junction PV cells.

[0033] In some embodiments, the PV receiver includes a semiconductor material having a bandgap energy, and the changes in the peak conversion efficiency wavelength are due to temperature-induced changes in the bandgap energy.

[0034] In some embodiments, the beam transmitter and the PV receiver are separated from each other by a beam transmission distance ranging from about 40 km to about 200 km.

[0035] In some embodiments, the beam emission wavelength lies within a waveband ranging from about 400 nm to about 2500 nm.

[0036] In some embodiments, the beaming period has a duration ranging from about one minute to about ten minutes.

[0037] In some embodiments, the changes in the temperature of the PV receiver are due at least in part to beam heating. In some embodiments, the changes in the temperature of the PV receiver are due at least in part to ambient heating or cooling.

[0038] In some embodiments, the beam transmitter is configured to emit the transmission beam with a non- uniform irradiance profile with stronger intensity at a center of the transmission beam and radially decreasing intensity away from the center; and the beam emission wavelength is controlled based on changes in the peak conversion efficiency wavelength in a region of the PV receiver illuminated by the center of the transmission beam.

[0039] In some embodiments, the operation of controlling the beam emission wavelength of the transmission beam includes managing heat generation within the PV receiver in order to regulate heat transfer between the PV receiver and an asset coupled to the PV receiver. In some embodiments, the asset includes fixed equipment. In some embodiments, the asset includes mobile equipment.

[0040] In some embodiments, the operation of controlling the beam emission wavelength includes: varying the beam emission wavelength during the beaming period to reduce a mismatch between the beam emission wavelength and the peak conversion efficiency wavelength as the peak conversion efficiency wavelength changes over time due to the changes in the temperature of the PV receiver.

[0041] In some embodiments, transmitter controller is configured to shift the beam emission wavelength by about 10 nm to about 100 nm over the beaming period. In some embodiments, the transmitter controller is configured to adjust the beam emission wavelength in increments ranging from about 0. 1 nm to about 10 nm.

[0042] In some embodiments, the operations performed by the processor further includes: providing wavelength variation information about an expected variation in the peak conversion efficiency wavelength over time during the beaming period; and varying the beam emission wavelength according to the wavelength variation information. In some embodiments, the operation of providing the wavelength variation information includes performing a calibration operation to determine the expected variation in the peak conversion efficiency wavelength over time. In some embodiments, the operation of providing the wavelength variation information includes providing a model predicting the expected variation in the peak conversion efficiency wavelength over time.

[0043] In some embodiments, the transmitter controller is configured to adjust the beam emission wavelength at a rate proportional to an intensity of the transmission beam.

[0044] In some embodiments, the power beaming system further includes a monitoring device operatively coupled to the transmitter controller and configured to monitor the temperature of the PV receiver over time during at least part of the beaming period, and the transmitter controller is configured to vary the beam emission wavelength based on the monitored temperature.

[0045] In some embodiments, the power beaming system further includes a monitoring device operatively coupled to the transmitter controller and configured to monitor a parameter of the conversion efficiency response of the PV receiver over time during at least part of the beaming period, and the transmitter controller is configured to vary the beam emission wavelength based on the monitored parameter. In some embodiments, the monitored parameter includes the peak conversion efficiency wavelength.

[0046] In some embodiments, the transmitter controller is configured to vary the beam emission wavelength continuously during all or part of the beaming period. In some embodiments, the transmitter controller is configured to vary the beam emission wavelength intermittently during all or part of the beaming period. In some embodiments, the transmitter controller is configured to vary the beam emission wavelength intermittently at a single point or interval during the beaming period. In some embodiments, the transmitter controller is configured to vary the beam emission wavelength intermittently at multiple distinct points or intervals during the beaming period.

[0047] In some embodiments, the transmitter controller is configured to vary the beam emission wavelength by increasing the beam emission wavelength as the peak conversion efficiency wavelength increases due to an increase in the temperature of the PV receiver. In some embodiments, the transmitter controller is configuredto vary the beam emission wavelength by decreasing the beam emission wavelength as the peak conversion efficiency wavelength decreases due to a decrease in the temperature of the PV receiver.

[0048] In some embodiments, the transmitter controller is configured to vary the beam emission wavelength linearly as a function of time.

[0049] In some embodiments, the transmitter controller is configured to vary the beam emission wavelength to reduce the mismatch during the entire beaming period. In some embodiments, the transmitter controller is configured to vary the beam emission wavelength to reduce the mismatch during a portion of the beaming period. In some embodiments, the portion of the beaming period begins after the start time of the beaming period and ends at the end time of the beaming period.

[0050] In some embodiments, the transmitter controller is configured to vary the beam emission wavelength to minimize the mismatch between the beam emission wavelength and the peak conversion efficiency wavelength.

[0051] In some embodiments, the operation of controlling the beam emission wavelength includes, at or prior to the start time of the beaming period: setting the beam emission wavelength to match the peak conversion efficiency wavelength expected at a later time of the beaming period. In some embodiments, the later time is the end time of the beaming period.

[0052] In accordance with another aspect, there is provided a power beaming method, including: transmitting, during a beaming period, a transmission beam from a beam transmitter, the transmission beam having a beam emission wavelength; receiving the transmission beam at a photovoltaic (PV) receiver, wherein the PV receiver is configured to convert the transmission beam into electrical power in accordance with a conversion efficiency response of the PV receiver, the conversion efficiency response having a peak conversion efficiency wavelength; and varying, during the beaming period, the beam emission wavelength to reduce a mismatch between the beam emission wavelength and the peak conversion efficiency wavelength as the peak conversion efficiency wavelength changes over time in response to changes in a temperature of the PV receiver.

[0053] In accordance with another aspect, there is provided a power beaming system, including: a beam transmitter configured to transmit a transmission beam during a beaming period, the transmission beam having a beam emission wavelength; a photovoltaic (PV) receiver configured to receive the transmission beam from the beam transmitter and convert the transmission beam into electrical power in accordance with a conversion efficiencyresponse of the PV receiver, the conversion efficiency response having a peak conversion efficiency wavelength; and a transmitter controller operatively coupled to the beam transmitter, the transmitter controller including a processor and a non-transitory computer readable storage medium having stored thereon computer readable instructions that, when executed by the processor, cause the processor to perform operations, the operations including controlling the beam transmitter to vary, during the beaming period, the beam emission wavelength to reduce a mismatch between the beam emission wavelength and the peak conversion efficiency wavelength as the peak conversion efficiency wavelength changes over time in response to changes in a temperature of the PV receiver.

[0054] In accordance with another aspect, there is provided a power beaming method, including: transmitting, during a beaming period, a transmission beam from a beam transmitter; receiving, during the beaming period, the transmission beam at a photovoltaic (PV) receiver, wherein the PV receiver is configured to convert the transmission beam into electrical power in accordance with a conversion efficiency response of the PV receiver, the conversion efficiency response having a peak conversion efficiency wavelength; and determining a beam emission wavelength of the transmission beam transmitted by the beam transmitter in accordance with changes in the peak conversion efficiency wavelength occurring during the beaming period and resulting from changes in the temperature of the PV receiver.

[0055] In some embodiments, the transmission beam is a laser beam.

[0056] In some embodiments, at least one of the beam transmitter or the PV receiver is spacebome. In other embodiments, at least one of the beam transmitter or the PV receiver is landbome, waterborne, or airborne.

[0057] In some embodiments, the PV receiver includes an array of PV cells, for example, single -junction PV cells or multi-junction PV cells.

[0058] In some embodiments, the PV receiver includes a semiconductor material, and the changes in the peak conversion efficiency wavelength are related to temperature-induced changes in a bandgap energy of the semiconductor material.

[0059] In some embodiments, determining the beam emission wavelength includes varying, during the beaming period, the beam emission wavelength to reduce a mismatch between the beam emission wavelength and the peak conversion efficiency wavelength as the peak conversion efficiency wavelength changes over time in response to changes in the temperature of the PV receiver. In some embodiments, varying the beam emission wavelength including varying the beam emission wavelength at a rate that is proportional to a beam intensity of the transmission beam. In some embodiments, varying the beam emission wavelength includesincreasing the beam emission wavelength as the peak conversion efficiency wavelength increases over time in response to an increase in the temperature of the PV receiver. In some embodiments, varying the beam emission wavelength includes decreasing the beam emission wavelength as the peak conversion efficiency wavelength decreases over time in response to a decrease in the temperature of the PV receiver.

[0060] In some embodiments, determining the beam emission wavelength includes setting, at or prior to a start time of the beaming period, the beam emission wavelength to match the peak conversion efficiency wavelength at a later time of the beaming period, for example, at an end time of the beaming period.

[0061] In accordance with another aspect, there is provided a power beaming system, including: a beam transmitter configured to transmit a transmission beam during a beaming period; a photovoltaic (PV) receiver configured to receive the transmission beam from the beam transmitter during the beaming period and convert the transmission beam into electrical power in accordance with a conversion efficiency response of the PV receiver, the conversion efficiency response having a peak conversion efficiency wavelength; and a transmitter controller operatively coupled to the beam transmitter, the transmitter controller including a processor and a non-transitory computer readable storage medium having stored thereon computer readable instructions that, when executed by the processor, cause the processor to perform operations, the operations including determining a beam emission wavelength of the transmission beam transmitted by the beam transmitter in accordance with changes in the peak conversion efficiency wavelength occurring during the beaming period and resulting from changes in the temperature of the PV receiver.

[0062] In some embodiments, the transmitter includes a laser source configured to emit the transmission beam as a laser beam.

[0063] In some embodiments, at least one of the beam transmitter or the PV receiver is configured for spacebome operation. In some embodiments, at least one of the beam transmitter or the PV receiver is configured for landbome, waterborne, or airborne operation.

[0064] In some embodiments, the PV receiver includes an array of PV cells, for example, single -junction PV cells or multi-junction PV cells.

[0065] In some embodiments, the PV receiver includes a semiconductor material, and the changes in the peak conversion efficiency wavelength are related to temperature-induced changes in a bandgap energy of the semiconductor material.

[0066] In some embodiments, the operation of determining the beam emission wavelength includes varying, during the beaming period, the beam emission wavelength to reduce a mismatch between the beam emissionwavelength and the peak conversion efficiency wavelength as the peak conversion efficiency wavelength changes over time in response to changes in the temperature of the PV receiver. In some embodiments, the transmitter controller is configured to vary the beam emission wavelength at a rate that is proportional to a beam intensity of the transmission beam. In some embodiments, the transmitter controller is configured to vary the beam emission wavelength by increasing the beam emission wavelength as the peak conversion efficiency wavelength increases over time in response to an increase in the temperature of the PV receiver. In some embodiments, the transmitter controller is configured to vary the beam emission wavelength by decreasing the beam emission wavelength as the peak conversion efficiency wavelength decreases over time in response to a decrease in the temperature of the PV receiver.

[0067] In some embodiments, the operation of determining the beam emission wavelength includes setting, at or prior to a start time of the beaming period, the beam emission wavelength to match the peak conversion efficiency wavelength at a later time of the beaming period, for example, at an end time of the beaming period.

[0068] In accordance with another aspect, there is provided a power beaming method, including: transmitting, during a beaming period, a transmission beam from a beam transmitter, the transmission beam having a beam emission wavelength; receiving the transmission beam at a photovoltaic (PV) receiver, wherein the PV receiver is configured to convert the transmission beam into electrical power in accordance with a conversion efficiency response of the PV receiver, the conversion efficiency response having a peak conversion efficiency wavelength; and varying, during the beaming period, the beam emission wavelength to reduce a mismatch between the beam emission wavelength and the peak conversion efficiency wavelength as the peak conversion efficiency wavelength changes over time in response to changes in a temperature of the PV receiver.

[0069] In accordance with another aspect, there is provided a power beaming system, including: a beam transmitter configured to transmit a transmission beam during a beaming period, the transmission beam having a beam emission wavelength; a photovoltaic (PV) receiver configured to receive the transmission beam from the beam transmitter and convert the transmission beam into electrical power in accordance with a conversion efficiency response of the PV receiver, the conversion efficiency response having a peak conversion efficiency wavelength; and a transmitter controller operatively coupled to the beam transmitter, the transmitter controller including a processor and a non-transitory computer readable storage medium having stored thereon computer readable instructions that, when executed by the processor, cause the processor to perform operations, the operations including controlling the beam transmitter to vary, during the beaming period, the beam emission wavelength to reduce a mismatch between the beam emission wavelength and the peakconversion efficiency wavelength as the peak conversion efficiency wavelength changes over time in response to changes in a temperature of the PV receiver.

[0070] Other method and process steps may be performed prior, during or after the steps described herein. The order of one or more steps may also differ, and some of the steps may be omitted, repeated, and / or combined, as the case may be. It is also to be noted that some steps may be performed using various analysis and processing techniques, which may be implemented in hardware, software, firmware, or any combination thereof.

[0071] Other objects, features, and advantages of the present description will become more apparent upon reading of the following non-restrictive description of specific embodiments thereof, given by way of example only with reference to the appended drawings. Although specific features described in the above summary and in the detailed description below may be described with respect to specific embodiments or aspects, it should be noted that these specific features may be combined with one another unless stated otherwise.BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Fig. 1 is a flow diagram of a power beaming method, in accordance with an embodiment.

[0073] Fig. 2 is a schematic representation of a power beaming system, in accordance with another embodiment.

[0074] Fig. 3 illustrates an example power beaming scenario where the beam emission wavelength Abeam is varied during the beaming period to reduce the mismatch with the peak conversion efficiency wavelength Apeak.

[0075] Fig. 4 illustrates an example power beaming scenario where the beam emission wavelength Abeam is initially set longer than the peak conversion efficiency wavelength Apeak to help warm the PV receiver, followed by subsequent tuning to align and adjust Abeam with the temperature-induced shift in Apeak.

[0076] Fig. 5 is a schematic representation of a power beaming system, in accordance with another embodiment.

[0077] Fig. 6 illustrates an example power beaming scenario where the beam emission wavelength Abeam is set before the start of the beaming period to correspond with the peak conversion efficiency wavelength Apeak at the end of the beaming period.

[0078] Fig. 7 is a schematic representation of a power beaming system, in accordance with another embodiment.DETAILED DESCRIPTION

[0079] The present description pertains to power beaming techniques that enable control and adjustment of a beam transmitter’s emission wavelength in response to temperature-induced variations in a photovoltaic (PV)receiver’s peak conversion efficiency wavelength. These variations occur due to beam heating and / or ambient temperature fluctuations. In some embodiments, as the PV receiver is irradiated during a beaming period, its temperature gradually increases, leading to a corresponding rise in the energy bandgap of the receiver’s PV material, thus altering the optimal emission wavelength of the beam transmitter. To compensate for these temperature-induced changes in the optimal emission wavelength, certain embodiments incorporate timedependent adjustments to the emission wavelength to maintain it near its optimum value as the optimum value varies over the duration of the beaming period. Such wavelength adjustments can be well suited for satellitebased, fly-by-type power beaming applications, which often involve short-duration, high-intensity power beaming operations.

[0080] The disclosed techniques are applicable across a wide range of fields and industries where enhanced power transfer via beaming is desired or necessary. Non-limiting examples include space-based solar power; space and astronomical body exploration and mining; Earth-orbit applications; telecommunications; land and aerial transportation; climate and environmental monitoring; remote area power supply; post-disaster aid and recovery; and energy decarbonization. The present techniques can be implemented in various environments and settings, including on Earth or within Earth’s atmosphere (encompassing ground, marine, and aerial applications), in space, or on other astronomical bodies such as the Moon or other planets.

[0081] Various aspects and implementations of the present techniques are described below with reference to the accompanying figures.

[0082] Referring to Fig. 1, a flow diagram of a power beaming method 100 is depicted, in accordance with an embodiment. The method 100 shown in Fig. 1 may be implemented within a power beaming system 200, such as the one depicted in the embodiment of Fig. 2, or within another suitable power beaming system. The power beaming system 200 generally includes a beam transmitter 202, a PV receiver 204 optically coupled to the beam transmitter, and a transmitter controller 206 operatively coupled to the beam transmitter 202. The beam transmitter 202 is configured to transmit a transmission beam 208, such as a laser beam, during a beaming period. The PV receiver 204 is configured to receive the transmission beam 208 during the beaming period and convert it into electrical power. The transmitter controller 206 includes a processor 210 and a non-transitory computer readable storage medium or memory 212. The memory 212 stores computer readable instructions that, when executed by the processor 210, cause the processor 210 to perform operations that control the beam transmitter 202.

[0083] The power beaming system 200 can be employed in various power beaming configurations, both on Earth and beyond. Non-limiting examples of such configurations include Earth-to-Earth, space-to-Earth, Earth- to-space, space-to-space, Moon-to-Moon, space-to-Moon, and Moon-to-space power beaming. In some embodiments, the beam transmitter 202 and the PV receiver 204 may be separated from each other by a beamtransmission distance ranging from about one or a few hundred meters to about one or a few hundred kilometers, for example, from about 40 km to about 200 km, although distances these ranges may be used in other embodiments. Additionally, either or both of the beam transmitter 202 and the PV receiver 204 may be configured for spacebome operations or, alternatively, for landbome, waterborne, or airborne operations on the Earth, the Moon, another planet, or another astronomical body. For example, in solar-based solar power applications, the beam transmitter 202 may be positioned in space (e.g., on a satellite), while the PV receiver 204 may be located on Earth (at a ground-based site).

[0084] In some embodiments, the beam transmitter 202 and the PV receiver 204 may each be mounted, integrated, or otherwise provided on respective transmitter and receiver platforms (not shown in Fig. 2). The term “platform” broadly encompasses any suitable type of landbome, waterborne, airborne, or spacebome devices, vehicles, infrastructures, or equipment — whether manned or unmanned, mobile or fixed — on which the beam transmitter 202 and the PV receiver 204 may be installed during a power beaming operation. Nonlimiting examples of platforms that can be used in space-based power beaming applications include launchers, landers, rovers, satellites, space probes, spaceplanes, space capsules, and space stations.

[0085] The structure, configuration, and operation of these and other possible components of the power beaming system 200 are detailed below. It is appreciated that Fig. 2 is a schematic representation that aims to illustrate various components and features of the power beaming system 200, such that additional components and features that may be useful or beneficial for its practical operation might not be depicted. Non-limiting examples of such additional features and components include optical components such as lenses, mirrors, and optical filters.

[0086] Referring to both Figs. 1 and 2, the method 100 can include a step 102 of transmitting the transmission beam 208 from the beam transmitter 202 during the beaming period. The beam transmitter 202 can include a light source 214 configured to generate the transmission beam 208, and transmitter conditioning optics 216 configured to condition the transmission beam 208 before it exits the beam transmitter 202. In some embodiments, the beaming period may range from about one minute to about a few tens of minutes, although other durations can be used in other embodiments.

[0087] The terms “light” and “optical”, along with their variants and derivatives, encompass radiation across any appropriate region of the electromagnetic spectrum. This includes not only visible light but also extends to invisible regions such as the microwave (MW), terahertz (THz), infrared (IR), and ultraviolet (UV) spectral bands.

[0088] The light source 214 can be any device or combination of devices capable of generating the transmission beam 208 with characteristics suitable for power beaming in accordance with the presenttechniques. In some embodiments, the light source 214 is a laser source configured to emit the transmission beam 208 as a laser beam. For example, the light source 214 may be a high-power, wavelength-tunable, singlemode laser source configured to emit the transmission beam 208 as a collimated (e.g., nearly diffraction limited) and narrowband (e.g., quasi-monochromatic) laser beam that can travel over long distances due to its low beam divergence. Non-limiting examples of laser sources used for power beaming applications include solid-state lasers, including bulk crystal lasers and fiber lasers; semiconductor lasers, including laser diodes; gas lasers, including carbon dioxide lasers and chemical oxygen-iodine lasers dye lasers. However, non-laser light sources such as light-emitting diodes (LEDs) may be also used in other embodiments. Depending on the specific application, the light source 214 may be operated in a continuous-wave or pulsed regime, and may or may not be modulated. The selection of the light source 214 may be based on various factors, including the operation wavelength; the beam irradiance; the spatial, temporal, and spectral beam profiles; the beam quality and divergence; the degree of coherence; the compactness, reliably, and ruggedness; and for pulsed light sources, pulse characteristics such as peak power, repetition rate, duration, and temporal shape. The theory, instrumentation, and operation of beam transmitters used in conventional power beaming applications are generally known in the art and need not be described in detail herein, except as necessary to understand the present techniques.

[0089] In some embodiments, the light source 214 is configured to emit the transmission beam 208 with a beam emission wavelength(e.g., center wavelength) lying within a waveband ranging from about 400 nm to about 2500 nm, encompassing the visible or near-IR portions of the electromagnetic spectrum. For example, in some cases, the beam emission wavelengthmay range from about 500 nm to about 1500 nm (e.g., from about 1000 nm to about 1110 nm), or from about 1900 nm to about 2100 nm. However, the present techniques can operate outside these ranges, including at shorter wavelengths (e.g., UV power beaming) or longer wavelengths (e.g., mid-IR, far-IR, THz, and MW power beaming). Furthermore, all descriptions provided herein as a function of wavelength could also be formulated as a function of frequency, wave number, energy, or other pertinent spectral parameters.

[0090] In some embodiments, the light source 214 is configured to emit the transmission beam 208 with a non-uniform irradiance profile, for example, with stronger intensity at the beam center and radially decreasing intensity away from the beam center, such as a Gaussian or quasi-Gaussian profile. However, other irradiance profiles may also be used in other embodiments, including nearly uniform irradiance profiles and non-Gaussian irradiance profiles (e.g. flat-top profiles).

[0091] The transmitter conditioning optics 216 may include any optical component or combination of optical components capable of shaping, focusing, concentrating, filtering, steering, collimating, expanding, or otherwise acting on the transmission beam 208 to achieve accurate, efficient, and safe beamed power transfer. Non-limiting examples of optical components for the transmitter conditioning optics 216 include lens, prisms,mirrors, diffraction gratings, and optical filters. Some of these components may function integrally, such as beam expanders (e.g., telescopes) or beam steering or pointing devices. The theory, instrumentation, and operation of transmitter conditioning optics used in conventional power beaming applications are generally known in the art and need not be described in detail herein, except as necessary to understand the present techniques.

[0092] The method 100 shown in Fig. 1 also includes a step 104 that involves receiving the transmission beam 208 at the PV receiver 204 during the beaming period, and converting the transmission beam 208 into electrical power based on a conversion efficiency response of the PV receiver 204.

[0093] The PV receiver 204 illustrated in Fig. 2 may include an array of PV cells 218. The PV cells 218 can be based on any suitable PV cell technology and can have various sizes, shapes, compositions, structures, and configurations (e.g., fill factor, cell packing density, array geometry), as well as electrical and thermal characteristics and circuitry arrangements. In some embodiments, the PV cells 218 may be designed for terrestrial use, while in other embodiments, the PV cells 218 may be configured for use in space or other extraterrestrial environments. The PV cells 218 may include single-junction PV cells in certain embodiments, or multi-junction cells in others, such as vertical multi-junction (VMJ) cells. Multi-junction PV cells include stacked layers of PV materials, with each layer generally having a different bandgap energy tailored for optoelectronic conversion of photons in different energy ranges.

[0094] The PV cells 218 may be composed of various PV materials, including both direct-bandgap and indirect-bandgap semiconductor materials capable of absorbing light and convert it into electrical power. Nonlimiting examples of possible PV materials include silicon (e.g., monocrystalline, polycrystalline, or amorphous silicon), germanium, III-V semiconductors and related alloys (e.g., GaAs, InP, InGaAs, InGaP, GalnP, InAlGaAs, InGaAsP, GaAlInAsSb), thin-film PV materials (e.g., CdTe, CIGS), and organic PV materials. The theory, instrumentation, and operation of PV cells are generally known in the art and need not be described in detail herein, except as necessary to understand the present techniques.

[0095] The PV receiver 204 may also include receiver conditioning optics 220 configured to collect, shape, concentrate, focus, direct, homogenize, or otherwise act on the transmission beam 208 before it reaches the PV cells 218. Non-limiting examples of optical components for the receiver conditioning optics 220 include lens, prisms, mirrors, diffraction gratings, and optical filters. The theory, instrumentation, and operation of receiver conditioning optics used in conventional power beaming applications are generally known in the art and need not be described in detail herein, except as necessary to understand the present techniques.

[0096] Referring still to Figs. 1 and 2, the photoelectric conversion efficiency of the PV receiver 204 depends on the alignment of the beam emission wavelength Abeam with the peak conversion efficiency wavelength Apeakof the conversion efficiency response of the PV receiver 204. When the transmission beam 208 irradiates the PV cells 218, electrical energy is generated if the photon energy of the transmission beam 208 is equal to or greater than the bandgap energy of the semiconductor material in the PV cells 218. The highest photoelectric conversion efficiency is expected when the photon energy matches or slightly exceeds the bandgap energy. High photoelectric conversion efficiencies are achievable when the transmission beam 208 is monochromatic or sufficiently narrowband, as in laser power beaming, as it allows the beam emission wavelength to closely match the bandgap energy of the PV material, or vice versa. This makes laser power beaming an attractive method for point-to-point wireless power transfer. In some embodiments, the PV material may have a bandgap energy ranging from about 0.5 eV (corresponding to a wavelength of about 2500 nm) to about 2.5 eV (corresponding to a wavelength of about 500 nm), although bandgap energy values outside this specific energy range are possible in other embodiments. The use bandgap-tunable PV materials is also contemplated in certain embodiments, as they can facilitate matching the bandgap energy with the energy of the incident photons.

[0097] The peak conversion efficiency wavelength Apeak depends not only on the beam emission wavelength but also on temperature, especially at the high irradiance levels typical of laser power beaming. This is because the bandgap energy of semiconductor materials varies with temperature, generally decreasing as temperature increases. As a result of these temperature -induced changes in bandgap energy, the peak conversion efficiency wavelength Apeak is generally expected to increase as the temperature of the PV receiver 204 rises due to beam heating. In other words, irradiation by the transmission beam 208 raises the temperature of the PV receiver 204 over the beaming period, gradually decreasing the PV material’s bandgap energy and increasing the peak conversion efficiency wavelength Apeak. Consequently, if the beam emission wavelength Abeamand the peak conversion efficiency wavelength Apeak are aligned at the beginning of the beaming period, they may become progressively mismatched over the duration of the beaming period, leading to suboptimal power beaming performance for all or part of that period.

[0098] In this context, the method 100 of Fig. 1 includes a step 106 that involves controlling the beam emission wavelength Abeamof the transmission beam 208 transmitted by the beam transmitter 202 based on changes in the peak conversion efficiency wavelength Apeak due to changes in the temperature of the PV receiver 204 occurring or expected to occur during the beaming period. These temperature changes can be caused by the beam heating effect mentioned above, but also, or alternatively, by the changes (i.e., either heating or cooling) in ambient temperature surrounding the PV receiver 204 during the beaming period. It is understood that PV receivers used in power beaming applications can be exposed to a wide range of temperatures, including extreme conditions, especially in high-altitude and extraterrestrial applications (e.g., in space or on the Moon).

[0099] In some embodiments, the step 106 of controlling the beam emission wavelength Abeamin accordance with temperature-induced changes in the peak conversion efficiency wavelength Apeak can include varying the beam emission wavelength Abeamduring the beam period to reduce a mismatch between the beam emissionwavelength and the peak conversion efficiency wavelengthas the peak conversion efficiency wavelength changes over time in response to temperature variations of the PV receiver 204. This is illustrated in Fig. 3, where it is shown that the beam emission wavelengthis adjusted over the duration of the beaming period to provide a match, or at least reduce a mismatch, with the peak conversion efficiency wavelength as the peak conversion efficiency wavelengthchanges due to temperature variations in the PV receiver 204 caused by beam heating and / or ambient temperature fluctuations. Specifically, the beam emission wavelengthis varied over time to match the peak conversion efficiency wavelengthwitha time ti, respectively. Depending on the specific application, varying the beam emission wavelengthmay involve increasing the beam emission wavelength as the peak conversion efficiency wavelengthincreases over time in response to rising temperatures in the PV receiver 204, or decreasing the beam emission wavelengthas the peak conversion efficiency wavelength Apeak decreases over time in response falling temperatures in the PV receiver 204.

[0100] The expression “reduce a mismatch” as used in herein is intended to mean that temperature-related differences between the beam emission wavelengthof the transmission beam 208 and the peak conversion efficiency wavelength Apeak of the PV receiver 204 are at least partially reduced during at least a portion of the beaming period. That is, the expression “reduce a mismatch” does not necessarily imply an identical match during the entire beaming period, an identical match during a portion of the beaming period, or a partial match during the entire beaming period, but is meant to encompasses various scenarios in which the mismatch between the beam emission wavelengthand the peak conversion efficiency wavelengthis reduced, altered, mitigated, suppressed, minimized, or lessened to an appropriate or sufficient degree over an appropriate or sufficient portion of the beaming period. It is understood that the appropriate or sufficient degree and portion depend on the circumstances or requirements of a given application. For example, in some embodiments, the mismatch between the beam emission wavelengthand the peak conversion efficiency wavelength can be considered to have been “reduced” if it does not have a noticeable or undesirable impact on the operation of the power beaming system 200.

[0101] It is understood that the light source 214 of the beam transmitter 202 may utilize various types of wavelength-tunable sources to provide precise control over the beam emission wavelengthto implement the present techniques. Non-limiting examples of wavelength-tunable sources include various laser source and LED sources. Control over the beam emission wavelengthcan be achieved through control signals received from the transmitter controller 206. The theory, instrumentation, and operation of wavelength-tunable light sources and associated controllers are generally known in the art and need not be described in detail herein, except as necessary to understand the present techniques.

[0102] Various wavelength-tuning implementations and scenarios are contemplated within the scope of the present disclosure. Non -limiting examples of such implementations and scenarios are presented below.

[0103] In some embodiments, the transmitter controller 206 is configured to vary the beam emission wavelength Abeam by a wavelength shift ranging from about 10 nm to about 100 nm over the beaming period. Other wavelength shift values may be used in other embodiments. Additionally, the transmitter controller 206 may be configured to vary the beam emission wavelength Abeam in wavelength increments ranging from about 0. 1 nm to about 10 nm, although other wavelength increment values are possible.

[0104] The transmitter controller 206 may be configured to vary the beam emission wavelength Abeam linearly with time, although non-linear wavelength variations are also possible.

[0105] In some embodiments, the transmitter controller 206 is configured to vary the beam emission wavelength Abeam to reduce the mismatch during all or part of the beaming period, as depicted in Fig. 3.

[0106] In other embodiments, the transmitter controller 206 may vary the beam emission wavelength Abeam to reduce the mismatch during a portion of the beaming period. For example, as shown in Fig. 4, this portion may start after the beaming period begins and end at a later time, such as the end of the beaming period. This wavelength-tuning scheme may be used when it is desirable for the beam emission wavelength Abeam to initially exceed the peak conversion efficiency wavelength Apeak (i.e., Abeam > Apeak at start time fi) to assist in warming the PV receiver. The peak conversion efficiency wavelength Apeak would then gradually drift until it aligns with the beam emission wavelength Abeam at a later time h. Subsequently, the beam emission wavelength Abeam may be adjusted during the remainder of the beaming period to match the temperature -induced increase in the peak conversion efficiency wavelength Apeak (i.e., Abeam ~ Apeak at t > h).

[0107] In some embodiments, the transmitter controller 206 is configured to vary the beam emission wavelength Abeam continuously (i.e., without interruption) during all or part of the beaming period. In other embodiments, the transmitter controller 206 is configured to vary the beam emission wavelength Abeam intermittently (i.e., in an on-and-off manner) during all or part of the beaming period. This may involve varying the beam emission wavelength Abeam at a single or multiple points in time, or during a single or multiple distinct time intervals throughout the beaming period. In some embodiments, the transmitter controller 206 may be configured to vary the beam emission wavelength Abeam continuously during one portion of the beaming period and intermittently during another portion.

[0108] In some embodiments, the operations performed by the processor 210 include providing wavelength variation information about the expected change in the peak conversion efficiency wavelength Apeak over time during the beaming period, and varying, through the transmitter controller 206, the beam emission wavelength Abeam based on this wavelength variation information. The method of providing the wavelength variation information can vary depending on the specific application.

[0109] In some embodiments, wavelength variation information is obtained through a calibration operation designed to measure or otherwise determine the expected variation in the peak conversion efficiency wavelength Apeak over time, for example, under conditions representative of power beaming operations. Various techniques can be used to measure the peak conversion efficiency wavelength Apeak of PV receivers in relation to parameters such as time, temperature, and irradiance levels.

[0110] In some embodiments, the wavelength variation information may be derived from a model that predicts the expected variation in the peak conversion efficiency wavelength Apeak over time. This model may be analytical, numerical, empirical, or any combination thereof.

[0111] In some embodiments, the wavelength variation information is provided in real-time or near real-time during the beaming period. For example, as shown Fig. 5, the power beaming system 200 may include a monitoring device 222 operatively coupled to the transmitter controller 206. The monitoring device 222 is configured to track one or more parameters affecting the conversion efficiency response of the PV receiver 204 during at least part of the beaming period. The transmitter controller 206 is configured to adjust the beam emission wavelength Abeam based on these monitored parameters, which may include the temperature of the PV receiver 204 or the peak conversion efficiency wavelength Apeak. Communication between the monitoring device 222 and the transmitter controller 206 can occur via wired and / or wireless links, enabling the exchange of timing, control, measurement, and data signals.

[0112] In some embodiments, the transmitter controller 206 is configured to vary the beam emission wavelength Abeam at a rate proportional to the beam intensity of the transmission beam 208. This approach assumes that temperature rise in the PV receiver 204 and the corresponding increase in the peak conversion efficiency wavelength Apeak are proportional to the beam intensity over a given time interval.

[0113] If the transmission beam 208 features a non-uniform irradiance profile, such as higher intensity at the center and decreasing intensity outward, the beam emission wavelength Abeam may be adjusted, set, or otherwise controlled based on changes in the peak conversion efficiency wavelength Apeak in the region of the PV receiver 204 illuminated by the center of the transmission beam 208 or another relevant area. Alternatively, the beam emission wavelength Abeam may be adjusted, set, or otherwise controlled based on changes in the peak conversion efficiency wavelength Apeak averaged over all or part of the illuminated region of the PV receiver 204.

[0114] Multi-wavelength power beaming are also contemplated. In such cases, the beam transmitter 202 is configured to emit a plurality of transmission beams at different beam emission wavelengths, with the PV receiver 204 converting these beams into electrical power. For example, the PV receiver 204 may include multi -junction PV cells 218 configured for multiwavelength operation. The overall conversion efficiencyresponse of the PV receiver 204 may exhibit multiple peak conversion efficiency wavelengths, each corresponding to a specific beam emission wavelength. Each beam emission wavelength can be set or adjusted according to changes in its corresponding peak conversion efficiency wavelength.

[0115] In some embodiments, the step 106 of controlling the beam emission wavelength Abeam in accordance with changes in the peak conversion efficiency wavelength Apeak does not require varying the beam emission wavelength Abeam during the beaming period. For example, as depicted in Fig. 6, the beam emission wavelength Abeam may be set at or prior to the start time / start of the beaming period to match the peak conversion efficiency wavelength Apeak at a later time, such as the end time tend of the beaming period. In such cases, the beam emission wavelength Abeam may remain unchanged throughout the beaming period (e.g., between tstart and tend in Fig. 5), although this is not mandatory.

[0116] In some implementations, the beam emission wavelength Abeam may not be controlled (or may not be controlled solely) to reduce a mismatch with the peak conversion efficiency wavelength Apeak of the PV receiver 204, but rather to manage (e.g., enhance or reduce) heat generation within the PV receiver 204 for the purpose of regulating (increase or decrease) heat transfer between the PV receiver 204 and an asset 224 coupled to it (e.g., mobile equipment, such as a rover, or fixed equipment, such as a base station), as illustrated in Fig. 7.

[0117] Returning to Fig. 2, the transmitter controller 206 can be implemented in hardware, software, firmware, or any combination thereof. The transmitter controller 206 may be connected to the beam transmitter 202 and other system components via wired and / or wireless communication links, enabling the exchange of various signals, including timing, control, measurement, and data signals. The transmitter controller 206 may be managed by direct user input and / or programmed instructions and may include an operating system for overseeing various functions of the beam transmitter 202. The transmitter controller 206 may be fully or partly integrated with the beam transmitter 202, or physically separate from it, and may incorporate a distributed and / or cloud computing network. As mentioned above, the transmitter controller 206 depicted in Fig. 2 generally includes a processor 210 and a memory 212.

[0118] The term “processor” refers herein to any electronic device, circuitry, or component capable of processing, receiving, or transmitting data or instructions, such as computer programs, commands, functions, processes, software codes, executables, applications, and similar entities. The term “processor” is meant to encompass a single processor or processing unit, multiple processors or processing units, or other suitably configured processing elements. When the processor 210 includes multiple processing elements, these elements may be located at a single site or distributed across multiple sites interconnected by a communication network. Examples of communication networks include local area networks (LANs) and wide area networks (WANs) such as the Internet. Non-limiting examples of processors include general-purpose single- or multi-core processors; central processing units (CPUs); microprocessors; controllers; microcontrollers; digital signalprocessors (DSPs); programmable logic devices; a field-programmable gate arrays (FPGAs); applicationspecific integrated circuits (ASICs); digital processors or circuits; analog processors or circuits; state machines; and / or any other device capable of processing information.

[0119] The term “memory” as used herein broadly refers to any electronic device, circuitry, or component capable of storing electronic data or information. In some instances, the term “memory” may be used interchangeably with the term “computer readable storage medium”. The term “memory” is meant to encompass a single memory or memory unit, multiple memories or memory units, or other suitably configured memory elements. When the memory 212 includes multiple memory elements, these elements may be located at a single site or distributed across multiple sites interconnected by a communication network. Non-limiting examples of memories include random-access memories (RAM) of any type; read-only memories (ROM) of any type; magnetic storage devices; optical storage devices; solid-state drive (SSD) devices, such as flash drive memories; and any other tangible and / or non-transitory computer readable medium capable of storing electronic data or information.

[0120] Throughout the present description, similar features in drawings have been given similar reference numerals. To avoid cluttering certain figures, some elements may not be indicated if previously identified in preceding figures. Elements in drawings are not necessarily depicted to scale, emphasis being on clearly illustrating elements and structures of disclosed embodiments. Positional descriptors indicating the location or orientation of one element relative to another are used for ease and clarity of description. Unless indicated otherwise, these descriptors should be understood in the context of the figures and should not be considered limiting. Such spatially relative terms are intended to encompass different orientations in use or operation of disclosed embodiments, in addition to orientations exemplified in the figures. Furthermore, when a first element is referred to as being “on”, “above”, “below”, “over”, or “under” a second element, the first element can be directly or indirectly on, above, below, over, or under the second element, respectively, such that one or multiple intervening elements may be disposed between the first element and the second element.

[0121] The terms “a”, “an”, and “one” are defined herein to mean “at least one”, and do not exclude a plural number of elements, unless stated otherwise.

[0122] The term “or” is defined herein to mean “and / or”, unless stated otherwise.

[0123] Terms such as “substantially”, “generally”, and “about”, which modify a value, condition, or characteristic of a feature of an exemplary embodiment, should be understood to mean that the value, condition, or characteristic is defined within tolerances that are acceptable for the proper operation of this exemplary embodiment for its intended application, or that fall within an acceptable range of experimental error. In particular, the term “about” generally refers to a range of numbers that one skilled in the art would considerequivalent to the stated value (e.g., having the same or nearly the same function or result). In some instances, the term “about” means a variation of ±10% of the stated value. It is noted that all numerical values used herein are assumed to be modified by the term “about”, unless stated otherwise.

[0124] The term “based on” as used herein is intended to mean “based at least in part on”, whether directly or indirectly, and to encompass both “based solely on” and “based partly on”. In particular, the term “based on” may also be understood as meaning “depending on”, “representative of’, “indicative of’, “associated with”, “relating to”, and the like.

[0125] The terms “match”, “matching”, and “matched” refer herein to a condition in which two or more elements are either the same or within some predetermined tolerance of one another. These terms are meant to encompass not only “exactly” or “identically” matching the two or more elements, but also “substantially”, “approximately”, or “subjectively” matching the elements, as well as providing a higher or best match among a plurality of matching possibilities.

[0126] The terms “connected” and “coupled”, and derivatives and variants thereof, refer herein to any connection or coupling, either direct or indirect, between two or more elements, unless stated otherwise. For example, the connection or coupling between the elements may be mechanical, optical, electrical, magnetic, thermal, chemical, logical, fluidic, operational, or any combination thereof.

[0127] The term “concurrently” refers herein to the simultaneous or overlapping occurrence of two or more processes. The term “concurrently” does not necessarily imply complete synchronicity but encompasses various scenarios. These scenarios include the simultaneous occurrence of two processes; a first process that both begins and ends during the duration of a second process; and a first process that starts during the duration of a second process but ends after the second process is completed.

[0128] The term “measured” when referring to a quantity or parameter is intended to mean that the quantity or parameter can be measured either directly or indirectly. In the case of indirect measurement, the quantity or parameter can be derived, retrieved, inferred or otherwise determined from directly measured data.

[0129] Numerous modifications could be made to the embodiments described above without departing from the scope of the appended claims.

Claims

CLAIMS1. A power beaming method, comprising: transmitting a transmission beam from a beam transmitter during a beaming period; receiving the transmission beam at a photovoltaic (PV) receiver, wherein the PV receiver is configured to convert the transmission beam into electrical power based on a conversion efficiency response having a peak conversion efficiency wavelength; and controlling a beam emission wavelength of the transmission beam based on changes in the peak conversion efficiency wavelength due to changes in the temperature of the PV receiver during the beaming period.

2. The power beaming method of claim 1, wherein the transmission beam is a laser beam.

3. The power beaming method of claim 1 or 2, wherein at least one of the beam transmitter or the PV receiver is spacebome.

4. The power beaming method of any one of claims 1 to 3, wherein at least one of the beam transmitter or the PV receiver is landbome, waterborne, or airborne.

5. The power beaming method of any one of claims 1 to 4, wherein the PV receiver comprises an array of PV cells.

6. The power beaming method of claim 5, wherein the PV cells comprise single-junction PV cells.

7. The power beaming method of claim 5 or 6, wherein the PV cells comprise multi-junction PV cells.

8. The power beaming method of any one of claims 1 to 7, wherein the PV receiver comprises a semiconductor material having a bandgap energy, and wherein the changes in the peak conversion efficiency wavelength are due to temperature-induced changes in the bandgap energy.

9. The power beaming method of any one of claims 1 to 8, wherein the beam transmitter and the PV receiver are separated from each other by a beam transmission distance ranging from about 40 km to about 200 km.

10. The power beaming method of any one of claims 1 to 9, wherein the beam emission wavelength lies within a waveband ranging from about 400 nm to about 2500 nm.11 . The power beaming method of any one of claims 1 to 10, wherein the beaming period has a duration ranging from about one minute to about ten minutes.

12. The power beaming method of any one of claims 1 to 11, wherein the changes in the temperature of the PV receiver are due at least in part to beam heating.

13. The power beaming method of any one of claims 1 to 12, wherein the changes in the temperature of the PV receiver are due at least in part to ambient heating or cooling.

14. The power beaming method of any one of claims 1 to 13, wherein: the transmission beam has a non-uniform irradiance profile with stronger intensity at a center of the transmission beam and radially decreasing intensity away from the center; and the beam emission wavelength is controlled based on changes in the peak conversion efficiency wavelength in a region of the PV receiver illuminated by the center of the transmission beam.

15. The powerbeaming method of any one of claims 1 to 14, wherein controlling the beam emission wavelength of the transmission beam comprises managing heat generation within the PV receiver in order to regulate heat transfer between the PV receiver and an asset coupled to the PV receiver.

16. The power beaming method of claim 15, wherein the asset comprises fixed equipment.

17. The power beaming method of claim 15 or 16, wherein the asset comprises mobile equipment.

18. The power beaming method of any one of claims 1 to 17, wherein controlling the beam emission wavelength comprises: varying the beam emission wavelength during the beaming period to reduce a mismatch between the beam emission wavelength and the peak conversion efficiency wavelength as the peak conversion efficiency wavelength changes over time due to the changes in the temperature of the PV receiver.

19. The power beaming method of claim 18, wherein varying the beam emission wavelength comprises shifting the beam emission wavelength by about 10 run to about 100 nm over the beaming period.

20. The power beaming method of claim 18 or 19, wherein varying the beam emission wavelength comprises adjusting the beam emission wavelength in increments ranging from about 0. 1 nm to about 10 nm.21 . The power beaming method of any one of claims 18 to 20, further comprising: providing wavelength variation information about an expected variation in the peak conversion efficiency wavelength over time during the beaming period; and varying the beam emission wavelength according to the wavelength variation information.

22. The power beaming method of claim 21 , wherein providing the wavelength variation information comprises performing a calibration operation to determine the expected variation in the peak conversion efficiency wavelength over time.

23. The power beaming method of claim 21 or 22, wherein providing the wavelength variation information comprises providing a model predicting the expected variation in the peak conversion efficiency wavelength.

24. The power beaming method of any one of claims 18 to 23, wherein varying the beam emission wavelength comprises adjusting the beam emission wavelength at a rate proportional to an intensity of the transmission beam.

25. The power beaming method of any one of claims 18 to 24, further comprising: monitoring the temperature of the PV receiver over time during at least part of the beaming period; and varying the beam emission wavelength based on the monitored temperature.

26. The power beaming method of any one of claims 18 to 25, further comprising: monitoring a parameter of the conversion efficiency response of the PV receiver over time during at least part of the beaming period; and varying the beam emission wavelength based on the monitored parameter.

27. The power beaming method of claim 26, wherein the monitored parameter comprises the peak conversion efficiency wavelength.

28. The power beaming method of any one of claims 18 to 27, wherein varying the beam emission wavelength comprises continuously adjusting the beam emission wavelength during all or part of the beaming period.

29. The power beaming method of any one of claims 18 to 27, wherein varying the beam emission wavelength comprises intermittently adjusting the beam emission wavelength during all or part of the beaming period.

30. The power beaming method of claim 29, wherein intermittently adjusting the beam emission wavelength comprises changing the beam emission wavelength at a single point or interval during the beaming period.31 . The power beaming method of claim 29, wherein intermittently adjusting the beam emission wavelength comprises changing the beam emission wavelength at multiple distinct points or intervals during the beaming period.

32. The power beaming method of any one of claims 18 to 31, wherein varying the beam emission wavelength comprises increasing the beam emission wavelength as the peak conversion efficiency wavelength increases due to an increase in the temperature of the PV receiver.

33. The power beaming method of any one of claims 18 to 31, wherein varying the beam emission wavelength comprises decreasing the beam emission wavelength as the peak conversion efficiency wavelength decreases due to a decrease in the temperature of the PV receiver.

34. The power beaming method of any one of claims 18 to 33, wherein varying the beam emission wavelength comprises varying the beam emission wavelength linearly as a function of time.

35. The power beaming method of any one of claims 18 to 34, wherein varying the beam emission wavelength comprises reducing the mismatch between the beam emission wavelength and the peak conversion efficiency wavelength during the entire beaming period.

36. The power beaming method of any one of claims 18 to 34, wherein varying the beam emission wavelength comprises reducing the mismatch between the beam emission wavelength and the peak conversion efficiency wavelength during a portion of the beaming period.

37. The power beaming method of claim 36, wherein the portion of the beaming period begins after the start time of the beaming period and ends at the end time of the beaming period.

38. The power beaming method of any one of claims 18 to 37, wherein varying the beam emission wavelength comprises minimizing the mismatch between the beam emission wavelength and the peak conversion efficiency wavelength.

39. The power beaming method of any one of claims 1 to 17, wherein controlling the beam emission wavelength comprises, at or prior to the start time of the beaming period: setting the beam emission wavelength to match the peak conversion efficiency wavelength expected at a later time of the beaming period.

40. The power beaming method of claim 39, wherein the later time is the end time of the beaming period.

41. A power beaming system, comprising: a beam transmitter configured to transmit a transmission beam during a beaming period; a photovoltaic (PV) receiver configured to receive the transmission beam from the beam transmitter and convert the transmission beam into electrical power based on a conversion efficiency response having a peak conversion efficiency wavelength; and a transmitter controller operatively coupled to the beam transmitter to control the beam emission wavelength, the transmitter controller comprising a processor and a non-transitory computer readable storage medium having stored thereon computer readable instructions that, when executed by the processor, cause the processor to perform operations comprising controlling a beam emission wavelength of the transmission beam based on changes in the peak conversion efficiency wavelength due to changes in the temperature of the PV receiver during the beaming period.

42. The power beaming system of claim 41, wherein the beam transmitter comprises a laser source configured to emit the transmission beam as a laser beam.

43. The power beaming system of claim 41 or 42, wherein at least one of the beam transmitter or the PV receiver is configured for spacebome operation.

44. The power beaming system of any one of claims 41 to 43, wherein at least one of the beam transmitter or the PV receiver is configured for landbome, waterborne, or airborne operation.

45. The power beaming system of any one of claims 41 to 44, wherein the PV receiver comprises an array of PV cells.

46. The power beaming system of claim 45, wherein the PV cells comprise single -junction PV cells.

47. The power beaming system of claim 45 or 46, wherein the PV cells comprise multi-junction PV cells.

48. The power beaming system of any one of claims 41 to 47, wherein the PV receiver comprises a semiconductor material having a bandgap energy, and wherein the changes in the peak conversion efficiency wavelength are due to temperature-induced changes in the bandgap energy.

49. The power beaming system of any one of claims 41 to 48, wherein the beam transmitter and the PV receiver are separated from each other by a beam transmission distance ranging from about 40 km to about 200 km.

50. The power beaming system of any one of claims 41 to 49, wherein the beam emission wavelength lies within a waveband ranging from about 400 nm to about 2500 nm.

51. The power beaming system of any one of claims 41 to 50, wherein the beaming period has a duration ranging from about one minute to about ten minutes.

52. The power beaming system of any one of claims 41 to 51, wherein the changes in the temperature of the PV receiver are due at least in part to beam heating.

53. The power beaming system of any one of claims 41 to 52, wherein the changes in the temperature of the PV receiver are due at least in part to ambient heating or cooling.

54. The power beaming system of any one of claims 41 to 53, wherein: the beam transmitter is configured to emit the transmission beam with a non-uniform irradiance profile with stronger intensity at a center of the transmission beam and radially decreasing intensity away from the center; and the beam emission wavelength is controlled based on changes in the peak conversion efficiency wavelength in a region of the PV receiver illuminated by the center of the transmission beam.

55. The power beaming system of any one of claims 41 to 54, wherein the operation of controlling the beam emission wavelength of the transmission beam comprises managing heat generation within the PV receiver in order to regulate heat transfer between the PV receiver and an asset coupled to the PV receiver.

56. The power beaming system of claim 56, wherein the asset comprises fixed equipment.

57. The power beaming system of claim 55 or 56, wherein the asset comprises mobile equipment.

58. The power beaming system of any one of claims 41 to 57, wherein the operation of controlling the beam emission wavelength comprises: varying the beam emission wavelength during the beaming period to reduce a mismatch between the beam emission wavelength and the peak conversion efficiency wavelength as the peak conversion efficiency wavelength changes over time due to the changes in the temperature of the PV receiver.

59. The power beaming system of claim 58, wherein the transmitter controller is configured to shift the beam emission wavelength by about 10 nm to about 100 nm over the beaming period.

60. The power beaming system of claim 58 or 59, wherein the transmitter controller is configured to adjust the beam emission wavelength in increments ranging from about 0.1 nm to about 10 nm.

61. The power beaming system of claim 60, wherein the operations performed by the processor further comprises: providing wavelength variation information about an expected variation in the peak conversion efficiency wavelength over time during the beaming period; and varying the beam emission wavelength according to the wavelength variation information.

62. The power beaming system of claim 61, wherein the operation of providing the wavelength variation information comprises performing a calibration operation to determine the expected variation in the peak conversion efficiency wavelength over time.

63. The power beaming system of claim 61 or 62, wherein the operation of providing the wavelength variation information comprises providing a model predicting the expected variation in the peak conversion efficiency wavelength over time.

64. The power beaming system of any one of claims 58 to 63, wherein the transmitter controller is configured to adjust the beam emission wavelength at a rate proportional to an intensity of the transmission beam.

65. The power beaming system of any one of claims 58 to 64, further comprising a monitoring device operatively coupled to the transmitter controller and configured to monitor the temperature of the PV receiver over time during at least part of the beaming period, and wherein the transmitter controller is configured to vary the beam emission wavelength based on the monitored temperature.

66. The power beaming system of any one of claims 58 to 65, further comprising a monitoring device operatively coupled to the transmitter controller and configured to monitor a parameter of the conversionefficiency response of the PV receiver over time during at least part of the beaming period, and wherein the transmitter controller is configured to vary the beam emission wavelength based on the monitored parameter.

67. The power beaming system of claim 66, wherein the monitored parameter comprises the peak conversion efficiency wavelength.

68. The power beaming system of any one of claims 58 to 67, wherein the transmitter controller is configured to vary the beam emission wavelength continuously during all or part of the beaming period.

69. The power beaming system of any one of claims 58 to 67, wherein the transmitter controller is configured to vary the beam emission wavelength intermittently during all or part of the beaming period.

70. The power beaming system of claim 69, wherein the transmitter controller is configured to vary the beam emission wavelength intermittently at a single point or interval during the beaming period.71 . The power beaming system of claim 69, wherein the transmitter controller is configured to vary the beam emission wavelength intermittently at multiple distinct points or intervals during the beaming period.

72. The power beaming system of any one of claims 58 to 71, wherein the transmitter controller is configured to vary the beam emission wavelength by increasing the beam emission wavelength as the peak conversion efficiency wavelength increases due to an increase in the temperature of the PV receiver.

73. The power beaming system of any one of claims 58 to 71, wherein the transmitter controller is configured to vary the beam emission wavelength by decreasing the beam emission wavelength as the peak conversion efficiency wavelength decreases due to a decrease in the temperature of the PV receiver.

74. The power beaming system of any one of claims 58 to 73, wherein the transmitter controller is configured to vary the beam emission wavelength linearly as a function of time.

75. The power beaming system of any one of claims 58 to 74, wherein the transmitter controller is configured to vary the beam emission wavelength to reduce the mismatch during the entire beaming period.

76. The power beaming system of any one of claims 58 to 74, wherein the transmitter controller is configured to vary the beam emission wavelength to reduce the mismatch during a portion of the beaming period.

77. The power beaming system of claim 76, wherein the portion of the beaming period begins after the start time of the beaming period and ends at the end time of the beaming period.

78. The power beaming system of any one of claims 58 to 77, wherein the transmitter controller is configured to vary the beam emission wavelength to minimize the mismatch between the beam emission wavelength and the peak conversion efficiency wavelength.

79. The power beaming system of any one of claims 41 to 57, wherein the operation of controlling the beam emission wavelength comprises, at or prior to the start time of the beaming period: setting the beam emission wavelength to match the peak conversion efficiency wavelength expected at a later time of the beaming period.

80. The power beaming system of claim 79, wherein the later time is the end time of the beaming period.81 . A power beaming method, comprising: transmitting a transmission beam from a beam transmitter during a beaming period, the transmission beam having a beam emission wavelength; receiving the transmission beam at a photovoltaic (PV) receiver, wherein the PV receiver is configured to convert the transmission beam into electrical power based on a conversion efficiency response having a peak conversion efficiency wavelength; and varying the beam emission wavelength during the beaming period to reduce a mismatch between the beam emission wavelength and the peak conversion efficiency wavelength as the peak conversion efficiency wavelength changes overtime in response to temperature variations in the PV receiver.

82. The power beaming method of claim 81, further comprising steps or features of any one of claims 1 to 38.

83. A power beaming system, comprising: a beam transmitter configured to transmit a transmission beam during a beaming period, the transmission beam having a beam emission wavelength; a photovoltaic (PV) receiver configured to receive the transmission beam from the beam transmitter and convert the transmission beam into electrical power based on a conversion efficiency response having a peak conversion efficiency wavelength; and a transmitter controller operatively coupled to the beam transmitter, the transmitter controller comprising a processor and a non-transitory computer readable storage medium having stored thereon computer readable instructions that, when executed by the processor, cause the processor to perform operations comprising controlling the beam transmitter to vary the beam emission wavelength during the beaming period to reduce a mismatch between the beam emission wavelength and the peak conversion efficiency wavelength as the peak conversion efficiency wavelength changes overtime in response to temperature variations in the PV receiver.

84. The power beaming system of claim 83, further comprising features of any one of claims 41 to 78.

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