Photovoltaic thermal hybrid solar collector
Encyclopedia
Photovoltaic thermal hybrid solar collectors, sometimes known as hybrid PV/T systems or PVT, are systems that convert solar radiation into thermal
and electrical energy
. These systems combine a photovoltaic cell, which converts electromagnetic radiation
(photon
s) into electricity, with a solar thermal collector
, which captures the remaining energy and removes waste heat from the PV module. Photovoltaic (PV) cells suffer from a drop in efficiency with the rise in temperature due to increased resistance. Such systems can be engineered to carry heat away from the PV cells thereby cooling the cells and thus improving their efficiency by lowering resistance.
, typically water, glycol or mineral oil
is then piped through these pipes. The heat from the PV cells are conducted through the metal and absorbed by the working fluid (presuming that the working fluid is cooler than the operating temperature
of the cells). In closed-loop systems this heat is either exhausted (to cool it), or transferred at a heat exchanger
, where it flows to its application. In open-loop systems, this heat is used, or exhausted before the fluid returns to the PV cells.
Internal energy
In thermodynamics, the internal energy is the total energy contained by a thermodynamic system. It is the energy needed to create the system, but excludes the energy to displace the system's surroundings, any energy associated with a move as a whole, or due to external force fields. Internal...
and electrical energy
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
. These systems combine a photovoltaic cell, which converts electromagnetic radiation
Electromagnetic radiation
Electromagnetic radiation is a form of energy that exhibits wave-like behavior as it travels through space...
(photon
Photon
In physics, a photon is an elementary particle, the quantum of the electromagnetic interaction and the basic unit of light and all other forms of electromagnetic radiation. It is also the force carrier for the electromagnetic force...
s) into electricity, with a solar thermal collector
Solar thermal collector
A solar thermal collector is a solar collector designed to collect heat by absorbing sunlight. The term is applied to solar hot water panels, but may also be used to denote more complex installations such as solar parabolic, solar trough and solar towers or simpler installations such as solar air...
, which captures the remaining energy and removes waste heat from the PV module. Photovoltaic (PV) cells suffer from a drop in efficiency with the rise in temperature due to increased resistance. Such systems can be engineered to carry heat away from the PV cells thereby cooling the cells and thus improving their efficiency by lowering resistance.
System types
A number of PV/T collectors in different categories are commercially available and can be divided into the following categories:- PV/T liquid collector
- PV/T air collector
- PV/T concentrator (CPVT)
PV/T liquid collector
The basic water-cooled design uses conductive-metal piping or plates attached to the back of a PV module. A working fluidCoolant
A coolant is a fluid which flows through a device to prevent its overheating, transferring the heat produced by the device to other devices that use or dissipate it. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, and chemically inert, neither causing nor...
, typically water, glycol or mineral oil
Mineral oil
A mineral oil is any of various colorless, odorless, light mixtures of alkanes in the C15 to C40 range from a non-vegetable source, particularly a distillate of petroleum....
is then piped through these pipes. The heat from the PV cells are conducted through the metal and absorbed by the working fluid (presuming that the working fluid is cooler than the operating temperature
Operating temperature
An operating temperature is the temperature at which an electrical or mechanical device operates. The device will operate effectively within a specified temperature range which varies based on the device function and application context, and ranges from the minimum operating temperature to the...
of the cells). In closed-loop systems this heat is either exhausted (to cool it), or transferred at a heat exchanger
Heat exchanger
A heat exchanger is a piece of equipment built for efficient heat transfer from one medium to another. The media may be separated by a solid wall, so that they never mix, or they may be in direct contact...
, where it flows to its application. In open-loop systems, this heat is used, or exhausted before the fluid returns to the PV cells.
PV/T concentrator (CPVT)
A concentrating system has the advantage to reduce the amount of solar cells needed. It also can get very good solar thermal performance compared to flat PV/T collectors. The main obstacles are to provide good cooling of the solar cells and a durable tracking system.See also
- Solar air conditioningSolar air conditioningSolar air conditioning refers to any air conditioning system that uses solar power.This can be done through passive solar, solar thermal energy conversion and photovoltaic conversion . The U.S...
- Zenith SolarZenith SolarZenith Solar is an Israeli solar energy company based in Ness Ziona. It was founded in 2006 by Roy Segev and Bob Whelen, who is also its chief executive....
- SolimpeksSolimpeksSolimpeks is a Turkish company dedicated to manufacture and market solar thermal and photovoltaic thermal hybrid solar collectors worldwide. The company's broader product line is exported to 60 countries, with European Union countries comprising about 70% of sales.Solimpeks PV-T products are the...