The Effects of El Niño on Solar Production

With the constant rainfall and overcast weather Northern California has been experiencing lately, and with El Niño persisting, it seems like the perfect time to talk about solar power. But wait, shouldn’t solar energy be discussed when the sun is out all the time? Well, yes and no. Since solar panels are powered by the sun, sunny and cloudless days are wonderful for producing loads of energy. However, solar panels still produce energy when the sun is hidden behind clouds. In other words, it’s always a great time to have solar.

Simply put, solar panels are designed to convert sunlight into a form of energy that can be used to power a load (a house, for example). Since the sun is shining from dawn to dusk, there is a long period of time everyday in which solar panels can work. On days that are sunny and cloudless, panels will receive a constant stream of direct sunlight for the majority of the day. While this is an ideal circumstance for the panels, it is not the only circumstance in which they will work and produce a sufficient amount of energy.

A commonly known characteristic about light is that it reflects off of white or lightly colored surfaces — this is why the sun is so blinding in places where there is a lot of snow. It is also the reason why it is possible to get a sunburn on cloudy days; sunlight is still able to affect people and places when they are not receiving full blasts of direct sunlight. One of the things that diffused and reflected sunlight is able to affect is, you guessed it, solar panels. Although energy output will be slightly reduced, there will still be a substantial amount of energy produced on cloudy days. The same can be said about rainy days; solar panel efficiency can drop depending on how heavy the rain is. While there is a possibility for a high drop in energy efficiency, it is important to remember that a significant drop only occurs during intense weather conditions, which usually don’t affect California. Furthermore, the energy generated on days when the sun is out and shining makes up for the days when solar conditions are not ideal. This is why a place like Germany, which is known for being overcast and rainy, is able to be one of the world leaders in solar energy.

Besides diffused and reflected light, which positively affect solar energy, there is one other interesting cloudy day phenomenon that increases the amount of energy produced called the “Edge of Cloud” effect. On days when there are clouds constantly moving in the sky, there are moments when the sun is able to peek out from behind the clouds and wash direct sunlight over us. When that happens, the sudden switch between diffused light and direct sunlight causes a surge of energy to be produced. It’s a similar reaction to when a light switch is constantly being turned on and off; the change between no energy flow to energy flow causes the energy usage to temporarily spike, which results in more energy used than if the switch was just kept on for an extended period of time. In the case of solar, however, the surges of direct sunlight will result in money saved rather than spent.
With all of this in mind, and with the sporadically poor weather conditions still among us, it should be comforting to know that the rain and clouds won’t stop homeowners from saving money on their electricity bills.


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