Process for optimising the service life of a bifacial multijunction photovoltaic module and photovoltaic module or panel suited to this process

Patent metadata

Field	Value
Publication number	US-12483190-B2
Application number	US-202218577735-A
Country	US
Kind code	B2
Filing date	Jul 6, 2022
Priority date	Jul 9, 2021
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

A lifetime optimization method for a two-sided photovoltaic module, which includes at least one multi-junction stack, where the stack's first junction layer is on the module's first side, which is exposed to the sun at the beginning of the module's life in the module's base position, and the stack's last junction layer is arranged under the module's second side, which receives diffused and reflected light and light passed through the stack. The method includes measuring the full module's output power (P FM ); calculating an estimated output power for the last junction layer (P LL ) as a function of the first irradiance in the module's turned over position, where the second side becomes its upper side; comparing the estimated P LL with the P FM when the first side is the upper side and recommending turning over the module when the base position's P FM becomes less than the turned over position's estimated P LL .

First claim

The invention claimed is:

1 . A method for lifetime optimization a two-sided photovoltaic module comprising at least one multi-junction stack, for which a first side of the module, under which is located a first junction layer of said stack, is exposed to the sun at the beginning of life of the module in a base position of the module, referred to as first-life position, and for which a last junction layer of said multi-junction stack, of two-sided type is arranged under a second side of the module not exposed to the sun receiving diffuse and reflected light under the module and also a part of light passing through the stack, wherein the method comprises:
(a) measuring a first irradiance IR up on the side of the module exposed to the sun and a second irradiance IR low on the side of the module not exposed to the sun, when the first side of the module is exposed to the sun; (b) measuring the output power P FM from the full module; (c) calculating the estimated output power P E1 of each junction layer of the multi-junction stack taken individually when the first side is the side exposed to the sun; (d) calculating an estimated output power for said last junction layer P LL of the module as a function of the first irradiance in a turned over position of the module, called second-life position, where the second side of the module becomes the side exposed to the sun and the first side of the module becomes the side not exposed to the sun; (e) comparing said estimated output power of said last junction layer P LL with the output power of the full module P FM measured when the first side is the side of the module exposed to the sun, to provide a recommendation for turning over the module when the output power of the full module P FM in the base position becomes less than the estimated output power of said last junction layer P LL in the turned over position of the module.

2 . The method of claim 1 , comprising, in base position, a comparison of the estimated output power from said stack of junctions P stack with initial output power data P ini from said stack of junctions with the same irradiance IR ref in order to determine a degradation of said stack of junctions.

3 . The method of claim 2 , wherein the initial output power data are irradiance/power IR ref /P ini pairs which can be obtained during a prior step of storing irradiance/resulting power pairs obtained for various irradiance values of said junction at the start of life of the module.

4 . The method of claim 1 , comprising a step of turning over the module.

5 . The method of claim 4 , comprising a period of monitoring the improvement of the yield from the turned over module and a step of validation or not of said turning over as a function of the improvement or not of said yield.

6 . A multi-junction photovoltaic module suited to the method of claim 1 , comprising a first stack of a first junction layer under a first side of the module and a last layer of bifacial junctions under a second side of the module, where said first layer allows a part of the light spectrum to pass towards said last layer or a second stack of a plurality of layers of junctions of decreasing bandgaps starting from said first side, for which the first layer is a first layer of the module arranged under said first side where said second stack is arranged under a final layer of bifacial junctions of the module and allowing a part of the light spectrum to pass from said first layer towards said last layer and in that it comprises an inhibition device at at least one of the output terminals of said last layer or of said plurality of layers of junctions of decreasing bandgaps except said last layer when the module is in turned over position with said last layer exposed to the sun.

7 . The photovoltaic module of claim 6 , wherein the junctions of the different layers have different surface areas or wherein the layers comprise a different number of junctions.

8 . The photovoltaic module of claim 6 , wherein the junctions of each of the layer are connected in series or series/parallel networks in order to implement networks with two output terminals per layer, where said series/parallel networks are suited for balancing the voltages of each of the layers when said networks are connected in parallel and when the first layer is exposed to the sun and the last layer is not exposed to the sun.

9 . The photovoltaic module of claim 6 , wherein the inhibition device is made up of a diode inserted between an output terminal of the network from the last layer and the output terminals from the one or more other layers of the multi-junction stack.

10 . The photovoltaic module of claim 6 , wherein the inhibition device is made up of a removable strap or a switch.

11 . The photovoltaic module of claim 6 , wherein the relative aging characteristics between the layers of the module are such that the last layer is suited, by turning the module over, to deliver a nominal power greater than the whole module when the yield curve is a function of time of the whole module becomes less than the yield of the last layer in position facing the sun.

12 . A photovoltaic panel comprising at least one photovoltaic module according to claim 6 and comprising output pads or contacts for the networks for the module(s) both on the upper surface and on the lower surface of the module.

13 . A photovoltaic panel comprising at least one photovoltaic module according to claim 6 and comprising a frame surrounding the module, for which the frame is provided with a symmetric profile provided with wings extending from both sides of the thickness of the module so as to make a low-profile frame limiting the shade cast by the frame both when the panel is in base position and when the panel is in turned over position.

14 . The photovoltaic panel according to claim 12 , further comprising a frame surrounding the module, for which the frame is provided with a symmetric profile provided with wings extending from both sides of the thickness of the module so as to make a low-profile frame limiting the shade cast by the frame both when the panel is in base position and when the panel is in turned over position, wherein the wings of the frame are provided with spaces for receiving a junction box suited for connection to both the output pads or contacts on the upper side of the module or to the output pads or contacts on the lower side of the module so as to limit covering of part of the side of the panel comprising the junctions by said junction box.

15 . The photovoltaic panel according to claim 12 , comprising a pair of irradiance sensors for each side of a plane of the panel.

16 . The photovoltaic panel according to claim 15 , wherein the pair of irradiance sensors is located on an arm on an outer side of the panel.

17 . A computer program comprising instructions for implementing the method according to claim 1 when this program is executed by a processor.

18 . A nonvolatile computer readable recording medium on which the program of claim 17 is recorded.

Assignees

• Electricite De France
• Centre National De La Rech Scientifique—Cnrs—
• Ecole Polytech
• Totalenergies Onetech
• Inst Photovoltaique Dile De France Ipvf

Inventors

• Puel Jean-Baptiste
• Julien Arthur

Classifications

• H02S40/34

  comprising specially adapted electrical connection means to be structurally associated with the PV module, e.g. junction boxes · CPC title

• Y02E10/544

  Solar cells from Group III-V materials · CPC title

• H02S50/15 Primary

  using optical means, e.g. using electroluminescence · CPC title