IEC Issues New Standard for Testing Resistance of Solar Modules to Heavy Snow

The method determines how well a solar module performs mechanically under the influence of inclined non-uniform snow loads


The International Electrotechnical Commission (IEC) has issued a new standard – the IEC 62938:2020 – to test the resistance of solar photovoltaic modules to large amounts of snow piling up on their surfaces.

The IEC defines the test standard as a method for determining how well a framed PV module performs mechanically under the influence of inclined non-uniform snow loads.

It said that this standard was introduced based on how previous market experiences have shown the need for a specific test method for measuring resistance to snow loads as needed. Previously, the IEC 61215-1:2016 was the closest equivalent to this test, and it contained various test methods to induce mechanical stresses to measure how well solar modules could withstand different loads.

The older test, however, was constrained as it could only be used to assess uniform loads on a horizontal plane, unlike the new one which can test non-uniform loads on a sloped pane. The IEC said that there were several reports of bent and misaligned modules in areas with heavy snow.

It said that this was observed at large systems in mountainous areas where modules in the lower rows of sloped installations were affected. Because modules are installed at an inclined position, snow will slide down the panel and accumulate unevenly at the bottom edge of the frame. As a result of this, the lower part of the module needs to withstand greater stress. The IEC also noted that ice might also accumulate between the frame and glass, applying even more stress on the module.

The IEC noted that this standard was applicable only for framed modules with framed protruding beyond the first glass surface on the lower edge after installation, as this is what stops snow from sliding off the edge. This standard does not apply to other kinds of modules with back rails formed in frames, on the side, top, and lower edges which will not create an additional snow barrier.

Recently, a team of research scientists led by the University of New South Wales, in collaboration with the University of Sydney, have, for the first time, produced a new generation of experimental solar energy cells that have passed the International Electrotechnical Commission (IEC) testing standards for heat and humidity.

A little earlier, the Ministry of New and Renewable Energy also decided to set up a Renewable Energy Standardization Cell. The objectives of the cell are to identify the areas in renewable energy where standards need to be developed and identify international standards such as International Organization for Standardization (ISO) and International Electrotechnical Commission (IEC) for applications in Indian climatic conditions. India’s northern region, especially Leh, Ladakh, and parts of Himachal Pradesh, experiences heavy snowfall in the winter season.

Image credit: 1010 Climate Action / CC BY (2.0)