Do flat plate collectors still work effectively with heavy snow cover?

Impact of Snow on Flat Plate Collector Performance

Flat plate collectors are designed to capture solar radiation through a transparent glass or plastic cover, but heavy snow cover can block this radiation, reducing the collector’s efficiency. Studies have shown that a 2-inch (5 cm) layer of snow can reduce the collector’s efficiency by up to 50%. However, collectors with a high snow-melt rate or those with a low emissivity surface can recover faster from snow cover.

Strategies for Improving Performance under Snow Conditions

Several strategies can help mitigate the impact of snow on flat plate collector performance. These include using a low-e coating on the collector’s surface to reduce thermal losses, implementing a snow-melt system to clear snow from the collector surface, and installing a wind shield to reduce wind-induced snow drifting. For example, a low-e coating with an emissivity of 0.04 can reduce thermal losses by up to 20%.

Comparison with Evacuated Tube Collectors

Evacuated tube collectors, commonly used in solar hot water systems, are less susceptible to snow cover due to their design. These collectors use sealed glass tubes that are evacuated to create a vacuum, reducing thermal losses and allowing them to maintain performance even under heavy snow cover. In contrast, flat plate collectors rely on a transparent cover to capture solar radiation, making them more vulnerable to snow cover. However, flat plate collectors are often less expensive and can still provide effective performance under light to moderate snow cover.