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How Does Solar Energy Work at Night?

Just because solar panels need sunlight to generate power doesn’t mean they’re useless after dark. In this article, I’ll walk you through how solar panels remain part of the energy cycle even at night – and the ways they can still help power your home once the sun goes down.  

Do Solar Panels Work at Night?

Solar panels don’t work at night – that’s the simple answer. Solar panels use a process called the “photoelectric effect,” where sunlight hits the panel and excites electrons to create an electrical current. So, without sunlight, there’s no energy to produce.

If we were to be a bit more technical, the reality is that any source of light can be absorbed by solar panels to generate electricity – streetlights and moonlight, for example. 

However, they’re not remotely as powerful as direct sunlight. They don’t even come close to reaching the minimum threshold to get your inverters to work, let alone power your home.…

How Do Homes With Solar Panels Still Have Power at Night?

While your solar panels “sleep” at night, solar energy continues to work and benefit you via these two methods:

Solar Batteries

With solar batteries, any excess energy your solar panels generate during the day can be captured and stored, ready to run your appliances, lights, and electronics later at night. 

It works much like a water tank, storing up water for emergencies or when the supply line is interrupted.

Don’t worry about producing “excess energy.” As far as I know, solar systems are designed with a conservative approach in mind – at least that’s how we do things here at Avail Solar when we plan for and install home solar systems.

This means your solar panels will generate excess energy on particularly sunny days, and throughout the year, you’ll build up a positive net energy balance that helps offset low production on cloudy days and seasonal changes.

Speaking of seasonal changes, solar batteries also help you make the most of time-of-use rates.

In winter, for instance, when sunlight is weaker and solar production drops, you can charge your battery during off-peak hours (usually late at night) when electricity is cheaper. You can then use that stored energy during peak hours, on top of what little your solar panels generate during the day.

When you factor in a solar battery’s lifespan, on top of the advantages we just discussed, it’s an investment that really pays off over time.

Rolling back a few years ago, many of our customers started asking whether we also installed batteries – and that told me they saw exactly how valuable this addition could be for their homes.

Net Metering

Net metering is a pricing arrangement where you send excess energy back to the grid, and in exchange, you earn “energy credits” from your utility company.

So, at night when your solar panels aren’t producing, you can use those credits to pull power from the grid without paying the full price – thanks to the excess energy your solar panels generate during the day.

In that sense, the grid serves as a sort of storage system that works just like a solar battery, although it operates on a different scale and with different mechanisms in place.

If I had to point out a difference that could be a deal breaker for many, it’s that with net metering, you’d still be subject to any price increases your utility imposes. 

Whereas with a solar battery added to a solar system that’s bought outright or financed (not leased or under a PPA contract), your investment remains at a flat rate for years, which means more predictable savings.

Are There Any Developments in Nighttime Solar Technology?

How awesome would it be if solar panels worked just as well at night as they do during the day, right? We’re not really there yet, but attempts have been made to make nighttime solar panels a reality.

Professor Jeremy Munday, one of the researchers at UC Davis who have explored the use of thermoradiative cells, explained that they function much like how typical PV cells would, but only in reverse…

Instead of absorbing sunlight, these cells would capture infrared radiation at night and convert it into electricity. 

So far, they’ve successfully generated power, but more refinements are needed before they become practical for large-scale use. That means, for now, the best ways to ensure reliable solar power at night are solar batteries and net metering.

Other Ways to Make the Most of Solar for Nighttime Use

Being one who likes to dig into all the possibilities and juice out every bit of value, here are a few ways you can really maximize the two main options – solar battery use and net metering – to make your solar system work harder for you at night.

Regular Solar Panel Cleaning

Dirt and dust can build up on your panels over time, which can impact how much energy your panels generate, ultimately affecting how much is stored for nighttime use. 

We’ve covered how to properly clean your solar panels in a previous article, and trust me, it’s likely easier than you might think.

Optimize Energy Consumption

One of the simplest tips to mention, but often hard to put into practice, is using your energy wisely. Consider how often the TV is left on when no one’s watching, or how much power your air conditioning unit consumes when it’s running in a room that’s completely unoccupied.

If you could track these habits, you’d realize how much excess solar energy you could be storing on your battery – or even selling back to the grid via net metering.

To get a clearer picture, you can review your load profile to identify where and when you’re using the most energy.

Other ways to optimize include investing in programmable appliances (such as smart thermostats) and using Energy Star-rated devices, which are more energy-efficient.

Monitor Your System’s Performance

Many home solar systems come with apps or dashboards that track energy production and storage. By keeping an eye on these metrics, you can quickly spot any issues and have them addressed by a professional asap, ensuring your system runs smoothly and generates the most power possible.

If you choose microinverters for your system, you’ll be able to keep tabs on each panel individually. On the other hand, if you’re sticking with the traditional string inverter setup, you’ll need to invest in power optimizers to be able to track each panel’s performance on its own.

Enjoy Solar Savings Even at Night

As I mentioned, just because your solar panels are in sleep mode at night doesn’t mean the savings stop when the day ends.

At Avail Solar, we create a solar design that takes advantage of net metering arrangements and maximizes your solar battery investment, so you can slash those electric bills and turn them into savings instead.

Request a quote today or reach out to one of our solar experts!

Posted in Solar 101