New snow removal technology uses electricity from exposed photovoltaic panels – pv magazine International

January 30, 2023 Emiliano Bellini

Scientists in China have developed a new snow removal system for off-grid and grid-connected photovoltaic systems that uses very little grid electricity.

The “domino-like snow removal system” (DSRS) uses electricity from uncovered photovoltaic modules to clear snow from solar panels, string by string.

“With high snow removal efficiency, it is almost energy-free,” said researcher Wen Liu PV magazine. “The snow removal principle has been verified to have no negative impact on the performance of PV modules by collaborative experiments with Chinese PV module manufacturer JA Solar.”

The researchers said that the rope that initially clears the snow provides energy for subsequent snow-covered ropes, in a sequence comparable to falling dominoes. The system uses only grid electricity with the first few panels, as the photovoltaic electricity is responsible for the subsequent snow removal.

The DSRS is connected to each of the PV system strings via T-type MC4 connectors and PV cables. It uses the thermal effect of the resistor to heat the entire PN junction area of ​​the PV modules evenly.

“The heat is transferred to the snow layer through the EVA film and the tempered photovoltaic glass, which causes the snow to melt,” said the Chinese team, noting that the system is based on a Maximum Power Point Tracker (MPPT) algorithm that initiates the removal process with high sunlight usage.

‘The snow melting process occurs on the surface of the PV modules, which is regarded as a one-dimensional heat transfer perpendicular to the surface of the PV modules,’ said the scientists.

Researchers tested a prototype system in a real winter snow cover environment and found that it can achieve “good” snow removal in environments with a minimum slope angle of 27 degrees, a minimum temperature of -14.8 C and a minimum fluctuating solar radiation of 248 W/m2 in off-grid mode.

“The DSRS can handle different types of snow, whose densities range from 121.05 kg/m3 to 480.10 kg/m3 with thicknesses varying between 15.5 mm and 32.5 mm,” they explained.

They said the system could cost between CNY 0.17 ($0.025)/W and CNY 0.29 CNY/W installed in PV systems ranging in size from 10 kW to 30 kW. The payback time is estimated between 2.9 and 4.3 years.

“The bill of materials (BOM) cost for this add-on box is less than $500, and its installation can be done with just a few extra electrical wires and three port connectors, so the cost is really low,” said Liu. “As far as I know, there is no low-cost solution for snow removal so far, and I believe this technology can be widely adopted.”

The research team presented the system in “A novel domino-like snow removal system for roof PV arrays: Feasibility, performance, and economic benefits”, recently published in Applied energy. The group includes academics from China University of Science and Technology, Xiong’an Innovation Institute and JA Solar.

“This paper presents a systematic work on the feasibility, performance and economic benefits of the domino-like snow removal system and confirms that it is a very good solution for removing snow from PV modules and has great potential to promote the deployment of PV where snow covers for a few months in winter,” concluded the group.