cooling

The proposed technique is based on radiative cooling and consists of a glass coating made with a two-dimensional subwavelength nanostructured grating, which is imprinted in soda-lime glass and has enhanced mid-infrared emissivity, and a micro-structured grating. The temperature decrease provided by the nano-micro-grating coating was found to be approximately up to 5.8 degrees Celsius.

New research from Australia has shown that vortex generators and glass texturing have so far proved to be the most effective solutions among the novel methods explored for lowering the temperature of solar panels.

Researchers in Spain have compiled a list of key performance indicators intended at evaluating not only the quality of a heat pump or a PV generator; but also the quality of their integration. pv magazine spoke to research co-author Celena Lorenzo about the potential and challenges of this combination. According to her, heat pumps powered by PV alone are efficient enough for both cooling and heating.

Researchers in the Middle East have proposed a new passive technology to cool off solar modules, based on highly conductive porous materials.

Researchers in the Netherlands and Singapore have measured irradiance-weighted average temperatures of floating PV systems in both countries and have compared the results with reference rooftop and ground-mounted PV systems. They have discovered that floating PV systems with open structures, which allow wind to pass beneath the modules, can provide a higher heat loss coefficient.

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%.

Scientists in the United States have tested soda-lime glass radiative coolers in a CPV system and claim these can reduce the device operating temperature by 5 to 36 degrees Celsius. This may result in an increase in the solar cell’s open-circuit voltage of between 8% and 27%.

South African scientists have used a PV system to keep tomatoes in cold storage. They linked an air-cooling system and evaporative cooling tech to a 3.5 kW array and 12 batteries and tested it for 28 days in September.

Indian and Malaysian scientists have developed a new cooling system featuring an assembled back-channel attached on the rear sides of solar panels, to channel flows of titanium oxide and water. They used a 0.6% nanofluid concentration – the optimum value of nanoparticle concentration in water.

An international research team has tested change material heat sinks for heat management on a concentrator photovoltaic system. It found that increasing over height ratios lowers the formation of stratified liquid layers, which in turn reduces the potential hot spots in the upper part of the solar cell.