No, solar energy systems only work during the day. This is because a best solar panel needs the power from the sun to turn light into electricity. But that doesn't mean you can't use solar energy to power your home day and night. Oh, really?
Even though solar panels don't make electricity at night, you can still use them to power your home or cut down on how much energy you use from the grid (and the cost that comes with it).
In this article, we'll talk about how solar panels work and how you can use them to power your home even when they're not making electricity.
How come solar panels don't work at night? An explanation of how it works
Solar panels are made up of solar cells, which are made of two thin wafers of semi conductive material, usually silicon. Since silicon by itself is not a very good conductor, each wafer is "doped" with impurities to make it work better.
Phosphorus is added to one wafer to make it have more free electrons, which makes it more negative. The boron in the other wafer makes it more positive because it has more places for electrons to go. This makes an electric field, in which free electrons move back and forth inside the solar cells.
Here is where the sun shines.
Photons, or packets of energy, are what light from the sun is made of. When a photon hits a solar cell, it moves an electron, making a space for another electron. The electron just wants to fill up the space, but the electric field moves the space to the positive side and the free electron to the negative side.
For the electron to get back, it has to take the long way around. Your photovoltaic (PV) system's current is made up of these moving electrons, and the voltage is made by the electric field. The electricity from the cells flows out of each panel, through the inverters, and into your home.
Without the sun's energy to move the electrons out of their happy state, there is no electron flow, no current, and no power to your home.
What about other light sources?
So, solar panels need light to work, and there are things that give off light at night, like streetlights, the moon, and the stars. Couldn't these be used to power solar panels at night?
In a technical sense, it's possible. Sunlight that bounces off the moon's surface is called moonlight. It is not as bright as direct sunlight, though. A small trickle of power is possible, but with small systems, the total current is unlikely to reach the minimum needed to turn on the system's inverter and turn the DC power into AC power that your home can use.
Other sources of light just don't give off enough light to make making electricity useful. There might be other ways to get solar panels to work at night, though.
In 2023, researchers at Stanford University changed a solar panel so that it could use the heat from the solar cells as they cooled down at night to make electricity. In their tests, they saw 0.05 Watts, or 50 milliwatts, of power being made per square metre at night.
Even though this is an interesting discovery, it isn't very useful for homeowners right now. Homeowners should stick with net metering and battery storage, which are already in place and make rooftop solar work even though the panels don't make electricity at night.
How to Use Solar Panels to Meet Your Energy Needs at Night?
At night, when solar panels can't make energy, there are two ways to meet energy needs: net metering or using a solar battery to store energy.
With net metering, you are connected to the power grid by a metre that works in both directions. It keeps track of how much electricity is coming in and going out. During the day, if your solar power system makes more energy than you need, the extra power goes into the grid. The utility pays for the energy that was transferred by adding credits or payments to the customer's electricity bill.
You can use energy from the grid to power your home appliances at night, when your solar power system isn't making electricity, or when there isn't enough electricity being made. The credits or electricity bill will be adjusted based on how much electricity was used from the grid.
When a home solar system is connected to net metering, there is a steady flow of electricity. It is a way for everyone to store the energy made by a solar power plant. With a net-metering plan, if there is a lot of sunlight during the day, it is possible to have no electricity bills at all.
Solar Battery Storage
The idea behind storing solar energy is pretty easy to understand. Most solar systems are carefully made to give you more energy during the day than you need. Solar panels store the extra power that is made during the day.
When your solar panels go to sleep at night, your home is powered by the energy stored in the solar battery. With his plan, some houses or buildings can even work off-grid, which means they don't need the utility at all.