The first thing that comes to the mind when talking about solar panels is that they are the renewable energy power generation units that are only suitable for summer time, and that the higher the temperature the better results. However, that is rather not the case, as solar energy is just like electronics such as smartphones and computers, where overheating does not help with the operation efficiency, and the cool weather during winter time actually helps to elevate the power generation volume of solar panels, thus the degree of insolation remains to be the essential element.
A reduction in the overall power generation volume of solar energy during winter is primarily caused by the decrease in the hours of insolation and rainy weather, and the accumulation of snow on modules is also a significant challenge in snowy areas, especially with the inclined angle design of existing solar panels, which is prone to accumulation of gravel and snow at the bottom of the bezel, and is less concatenated with the temperature. Various development has been seen from technical advancement and the proliferation of experience, such as bifacial solar panels that are able to absorb the reflect light from the bottom, and the installation of heaters to melt the accumulated snow on the panels.
Undoubtedly, modules will not generate power under rainy weather, or that the solar panels are often covered by snow. Take northern Taiwan, as well as Yilan and Hualien, as an example, the areas did not see the sun for several days during early December due to the impact of the northeast monsoon, and instead experienced the rainy weather that laundry stays wet the whole time. According to the climate forum “Taiwan Typhoon BBS”, areas including northern Taoyuan, Yilan, and Hualien had exposed to less than 5 hours of sunlight during early December, with less than 20 minutes on average per day, where Yilan has sustained an even lower insolation. Most insolation had occurred during the warm day of December 13th, and the difference in the total hours of insolation between the north and the south in the period of December 1st to 15th was 58 times.
▲ Load curve on December 25th 2020. (Source: TPC)
Hence, the solar power generation over the past several days had been supposed by northern Taiwan, which provided a certain level of power generation volume during noon. The data of TPC indicates that the solar power generation ratio at 12:40 pm on December 15th had reached to 7.50%, which was higher than that of nuclear energy at 7.09%. The power generation for today (25th) is shown in the above diagram, where the solar power generation volume at the exact time had reached to 2.05MW, with a power generation ratio of 7.95%.
(Cover photo source: Flickr/SteFou! CC BY 2.0)