cooling technique

Researchers in Iran have tested four different two-layer PCMs across several cooling system configurations and have found that the payback time of the proposed cooling tech is still far from reaching commercial viability. The system, however, was able to improve PV power generation by more than 3% and produce hot water with a temperature of up to 48 Celsius degrees from the solar module’s excess heat.

A British-Indian research group has developed an active cooling technique that is claimed to improve a PV system’s yield by around 0.5%. The system could be used in residential solar arrays and the water heated by the PV modules may be fed into a solar water heating system.

Saudi scientists have tested several cooling technologies for solar panels and have found that active techniques work better than passive ones under harsh climatic conditions. The most effective one consists of a system based on four heat pipes immersed in a box of liquid, as liquid bulk, integrated with the back of the solar panel.

British scientists have developed an experimental compressed air system for the simultaneous cleaning and cooling of PV modules. The system was built with a compressed-air unit which was made of a compressor, an air tank, and an airflow regulation valve, and a series of nozzles. The technique was tested on a PV system located in northwestern India.

A French-Lebanese research group has proposed a way to cool down PV modules by using air exhausted from heating, ventilation, and air conditioning (HVAC) systems. They showed that array performance improves when the cooling load rises.

Iranian scientists have assessed a new active approach for solar module cooling based on water spraying. Water sprayed from different angles can reduce the operating temperature of PV modules, with limited water consumption. However, the team noted that they have yet to assess the economic viability of the system.

Malaysian researchers have proposed a new passive technology for solar module cooling based on fin heat sinks. The tech ensures lower PV system payback times and reduces operating module temperatures by up to 26 C.

Iraqi researchers have demonstrated the technical and economical feasibility of using shallow geothermal energy to cool PV systems. They tested two different techniques – a closed-loop system and an open-cycle system – to reduce power losses from 30% to up to 4.1%.

The novel technique consists of a PVC pipe with 20 holes that is placed on the top of a PV module and is able to maintain a constant discharge of water. It was demonstrated on an experimental photovoltaic-thermal PV system in which the PV panel was not integrated with the solar collector but connected to it via pipes.

Researchers in Israel have suggested the use of regasification of liquefied natural gas to reduce the operating temperature of PV modules in solar parks located at gas terminals. According to them, the feasibility of such a cooling solution could be strengthened by the fact that both the PV systems and the LNG regasification systems are, separately, mature, economical technologies.