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Do Solar Panels Work at Night?

Jun 21, 2018

Solar panels are made up of thousands of photovoltaic cells that convert sunlight into electricity. The panels work best on cloudless, sunny days, converting the Northern California sunlight into energy you can use in your home to power things such as your electronics and air conditioning. For the panels to work, there must be sunlight.

So, what happens to solar panels at night?

How to Use Solar Energy at Night

Running on solar energy alone is only practical during the day thanks to the constant supply of sunlight. At night, some form of energy banking is necessary. These are a few of options currently available to consumers:

  • Battery banks: Battery banks are designed to convert and store energy throughout the day for later use. They work best in smaller environments. If you need power at night, battery banks are a popular and effective method of energy storage.1
  • Net energy metering: Because solar energy systems are designed to produce more energy throughout the day than is needed, the extra energy is sent to a grid for solar owners to access for later use. In this setup, owners are issued credits for the extra energy their systems produce. They then use those credits to access energy at night.

Advancements in Solar Energy

While your solar panels may have leftover energy, by the time the sun goes down, they are not actively working to create more. Technically, then, the answer to the original question is no – solar panels don’t work at night because there is not enough sunlight available for them to convert into energy for use in your home.

Solar panels may absorb trace levels of energy from the sunlight reflected by the moon. However, this is not enough energy to power your home through the night.

Residential solutions for solar energy use and storage are viable since homes are relatively small and use less energy than commercial facilities. However, attempting to store massive amounts of energy for larger buildings would drive up costs.

Many solar experts believe a better solution may be heat storage. Heat is the driving generator of energy in a solar-thermal power plant, and storing it would be a way to essentially pause the energy conversion process. The idea is to heat something up and keep that thing hot until nightfall and then use that heat to generate steam to turn a turbine and generate energy.

The problem with storing heat is finding the right substance for solar power application. Here are a few of the conditions a substance would have to meet to be a viable option:

  • Stability at high temperatures (750 degrees Fahrenheit)
  • Affordability
  • Availability3

One solar plant in Granada, Spain may have solved this problem by utilizing something you probably have in your kitchen – salt.

Continuing Solar Power Experimentation and Innovation

Yes, salt. The Andasol 1 power plant is the first salt storage solar power plant. While they don’t use regular table salt you may use for flavoring popcorn and French fries, they do use a mixture containing a combination of sodium and potassium nitrate. The plant is packed with 30,865 tons of this mixture. These are a few reasons they use salt to store heat:

  • It remains stable at extremely high temperatures
  • It’s available in a virtually unlimited and low-cost supply
  • It only loses about seven percent of the energy put into it

Solar scientists are still experimenting with this concept and alternative heat storage materials. Some solar power plants are looking at sand as another potential material. Yet another group is attempting to create a system that mimics the molecular effects of photosynthesis to store solar power.

Who knows? Maybe one day your home will be powered at night by heat-storing salt!

Start Saving on Your Electric Bill This Summer!

If you’re ready to make the switch to cost- and energy- efficient solar PV panels, consult our residential solar experts at Energy Saving Pros in sunny Loomis, CA. Since 2008, we’ve been dedicated to renewable energy and helping our clients in the Sacramento area go solar. We offer a variety of energy-efficient services including expert solar panel installation.

Get your FREE quote by calling 866-497-6527 to speak with one of our Energy Advisors or by filling out our form online.

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1 https://synergypower.com/what-happens-to-solar-panels-at-night-and-on-cloudy-days/

2 https://blog.pickmysolar.com/do-solar-panels-work-at-night

3 https://science.howstuffworks.com/environmental/green-tech/energy-production/solar-energy-night2.htm


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