Solar energy is an abundant source of clean energy. If used well, it can surpass the output from many conventional sources of energy at a much cheaper cost.
High temperatures reduce the power output of the PV cells due to voltage drop. Thus, a cool sunny day is a lot better condition for the optimal functioning of the solar panels.
Contrary to popular opinion, solar panels still generate electricity on cloudy/rainy days or in foggy weather—they are just not producing as much energy as they do on bright, sunny days.
While a thick layer of snow can certainly affect the energy production of the PV cells, a bit of snow is not that bad for the panels as some sunlight can still pass through.
Although modern panels are designed to withstand winds up to 90 mph, poorly designed panels may not perform that well. Dust and flying debris are other elements that can affect the panels in windy conditions.
For instance, a direct lightning strike can even melt the panels. Indirect lightning strikes, which are more common than direct strikes, can result in voltage surges causing damage to several components of the system.