As solar energy is a very important component of the energy balance, it is important that we all have a good understanding of this technology. Questions arise: where to get electricity at night, when the solar panels do not work, or from what light do the panels generate energy?
Let’s look at these and other questions to find out what is happening in the panels at night.
What light does the photovoltaic panel generate energy from?
Many people think that the fuel for photovoltaic panels is sunlight, but in fact, it is just daylight. This is an important difference because it is this property that determines the place of installation of the panels on our home or plot. Solar panels can be installed in places where there is no direct sunlight and will still generate energy because they create energy from the photons contained in natural daylight.
While the panels achieve the highest efficiency in sunny places, they will also generate electricity in the shade. This gives us a lot of room for maneuver when choosing where to install the panels.
However, in fact, on cloudy days, using the panels will not produce as much energy as on sunny days. It is estimated that when it is fully cloudy, the panels generate only 40 percent of the energy generated on sunny days, and this must be taken into account when designing a photovoltaic installation. This situation could change as scientists devise ways to generate electricity not only from sunlight but also from the ultraviolet light that is normally absorbed by the earth.
How do solar panels work?
Usually, people are surprised to hear that the idea of using the sun’s rays goes back to 1839 when French scientist Edward Becquerel discovered that some materials generate electricity when sunlight shines on them. This effect was called the photoelectric effect. The first photovoltaic cells capable of producing electricity were developed at the end of the 19th century.
However, photovoltaic (PV) cells resembling those of today were not created until the 1950s. Scientists added silicon to PV cells and found that they can convert 4 percent of the energy of the sun’s rays into usable electricity. Of course, the solar panels that are purchased today are much more efficient.
Contemporary solar panels have built-in reflective layers that increase the amount of sunlight reaching them. This is especially useful on cloudy days or in shady locations as it increases the amount of light that is acquired.
What happens to the solar panels at night?
As you can easily deduce, the solar panels do not produce electricity at night. Since there is no light to power the panel, it goes into sleep mode until dawn. Fortunately, the panels are not useless then, as the energy generated during the day can be stored and used in many ways.
If we have ever used solar garden lamps, we know how energy storage works. The solar panel produces energy during the day and charges the batteries installed in the lamp. At night, the lamp switches to battery power and starts to glow.
Where to get electricity at night?
There are many ways to power devices at night with the panels in sleep mode. To choose the best option, you should consider what we expect from photovoltaic panels.
First, you need to answer the question: do we want to power the house from panels 24 hours a day or switch between panels and electricity from the power plant, when the need arises? Do we have a large budget or do we want to start using photovoltaics spending little to start? Do we have room for extra batteries at home or in the office to keep them powered up at night?
When we answer these questions, we can decide where we want to get electricity at night. We can use electricity from a power plant or store the energy generated by the panels in batteries. Let us consider both of these approaches.
Using electricity from a utility company
We may dream of completely cutting off the standard power grid, but we may not be ready for such a revolutionary step yet. Or maybe we just want to use solar energy in the simplest possible way? Either way, we can design our electrical installation so that the photovoltaic power supplies the house or office during the day, and then the system switches to electricity from the utility company at night.
Taking into account the fact that a large part of the energy is consumed by air conditioning, in this way we are still able to generate significant savings by using a photovoltaic installation during the hottest times of the day. It is also the least complex way of using photovoltaics.
Solar panels are an excellent tool for reducing carbon dioxide and helping the environment. Photovoltaics can also help us reduce electricity bills! As we explained in this article, there are ways around the problem of no sun for panels at night.
We can use the panels during the day, and at night or on cloudy days, we can draw electricity from the power grid. We can also install batteries and store the generated energy. In both variants, we are able to achieve our goal, i.e. use photovoltaic panels to generate electricity for our needs.