Efficiency restoration in a photovoltaic cell

Patent metadata

Field	Value
Publication number	US-9515215-B2
Application number	US-201314027657-A
Country	US
Kind code	B2
Filing date	Sep 16, 2013
Priority date	Oct 12, 2011
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

The electrical output efficiency of a photovoltaic thermal system can be restored from degradation due to light exposure by annealing a photovoltaic thermal cell at an elevated temperature. The elevated temperature at the photovoltaic thermal cell can be provided by redirecting the flow of a heat exchange fluid to bypass a heat exchanger unit. A boiler unit may be employed to provide additional heating of the heat exchange fluid during the anneal. Further, a variable configuration lid can be provided over a front surface of the photovoltaic thermal cell to control ventilation over the front surface. During the anneal, the position of the variable configuration lid can be set so as to trap heat above the front surface and to elevate the anneal temperature further.

First claim

What is claimed is:

1. A photovoltaic thermal (PVT) system comprising:
a photovoltaic thermal (PVT) cell configured to generate electricity and to provide a thermal output;
an in-cell pipe located within said PVT cell and configured to transport a heat exchange fluid inside said in-cell pipe;
a boiler unit for heating said heat exchange fluid;
a heat exchanger unit within which said heat exchange fluid loses heat;
a heat exchanger inlet-side pipe connecting said boiler unit to said heat exchanger unit;
a PVT cell inlet-side pipe connecting said PVT cell to said heat exchanger unit;
a PVT cell outlet-side pipe connecting said PVT cell to said boiler unit; and
a heat exchanger bypass pipe connecting said heat exchanger inlet-side pipe to said PVT cell inlet-side pipe,
wherein said PVT system operates in a first circulation path or a second circulation path; a first valve located at a common node between said portion of said heat exchanger inlet-side pipe and said heat exchanger bypass pipe configured to switch between said first circulation path and said second circulation path; said first circulation path transports said heat exchange fluid from said boiler unit to said heat exchanger bypass pipe, from said heat exchanger bypass pipe to said PVT inlet-side pipe, from said PVT inlet-side pipe to said in-cell pipe, from said in-cell pipe to said PVT outlet-side pipe and from said PVT outlet-side pipe back to said boiler unit wherein said boiler unit heats said heat exchange fluid so as to heat a photovoltaic material within said PVT cell to a temperature greater than 130 degrees C. to anneal said photovoltaic material; and said second circulation path transports heat exchange fluid from said PVT cell inlet-side pipe to said in-cell pipe, from said in-cell pipe to said PVT outlet-side pipe, from said PVT outlet-side pipe to said boiler, from said boiler to said heat exchanger inlet-side pipe, from said heat exchanger inlet-side pipe to said heat exchanger unit and from said heat exchanger unit back to said PVT cell inlet-side pipe.

2. The PVT system of claim 1 , further comprising an automatic control device configured to provide control instructions to said boiler unit for raising said temperature of said photovoltaic material above 130 degrees C.

3. The PVT system of claim 2 , further comprising a temperature sensor located at said PVT cell and configured to measure a temperature of said photovoltaic material of said PVT cell.

4. The PVT system of claim 3 , wherein said automatic control device is configured to monitor said measured temperature of said photovoltaic material.

5. The PVT system of claim 3 , wherein said automatic control device is programmed to monitor said measured temperature of said photovoltaic material from said temperature sensor and to provide an instruction to heat said heat exchange fluid employing said boiler unit.

6. The PVT system of claim 1 , wherein said PVT cell includes a variable configuration lid configured to provide at least two different levels of ventilation over a front surface of said PVT cell.

7. The PVT system of claim 6 , wherein said variable configuration lid is attached to a body of said PVT cell by a hinge around which said variable configuration lid can rotate, wherein a rotation of said variable configuration lid provides different levels of ventilation to said front surface of said PVT cell.

8. The PVT system of claim 6 , wherein said variable configuration lid is configured to slide in a plane that is substantially parallel to said front surface of said PVT cell, wherein a sliding of said variable configuration lid in said plane provides different levels of ventilation to said front surface of said PVT cell.

9. The PVT system of claim 6 , wherein said variable configuration lid is configured to move in a direction substantially perpendicular to said front surface of said PVT cell, wherein a movement of said variable configuration lid in said direction provides different levels of ventilation to said front surface of said PVT cell.

Assignees

• IBM

Inventors

• Chae Young T
• Hong Augustin J
• Kim Jeehwan
• Lee Young M
• Sadana Devendra K

Classifications

• H02S40/44

  Means to utilise heat energy, e.g. hybrid systems producing warm water and electricity at the same time (directly associated with the PV cell or integrated with the PV cell H10F77/67) · CPC title

• Y02E10/60

  Thermal-PV hybrids · CPC title

• Y02E10/50

  Photovoltaic [PV] energy · CPC title

• F28F1/32

  the means having portions engaging further tubular elements · CPC title

• H01L31/03767

  Electricity · mapped topic