You’ve probably wondered what happens to solar panels at night or on cloudy days. In order for PV (Photovoltaic cells) to convert sunlight into electricity, you need to have sunlight. This is why solar panels work best during the summer season! So when solar panels aren’t generating enough electricity, are you still getting your money’s worth?
The great thing about solar is that the power can be switched to be drawn from the power grid at any time – and you can actually use solar power at the same time as the utility if necessary. The solar array system is wired into a home breaker box (electrical panel), which can then provide power to anything connected to the electrical circuit. Being connected to the power meter & the power grid at the same time allows for a “bidirectional” connection.
A bidirectional connection is like a standard electricity meter, except that it’s designed to measure electricity flow in two directions. When you install grid connected solar power system, you need a meter that can tell you not just how much energy you’ve consumed but also how much you’ve fed back into the grid.
Watch this short video on how bidirectional connection works (also known as “Net Metering”):
If you have a battery bank set up, you’ll be able to access the stored energy when needed. Many customers also like to get backup-batteries in case of emergency situations where power outages occur. Battery back-ups can be used for small scale cases such as residential solar as well as larger projects like commercial or utility-scale. In certain cases, battery back-ups may not even be necessary so it’s important to discuss this with your solar installer.
Even without a battery bank, a solar array will heavily reduce your utility bill. When looking at solar power from a financial perspective, you’ll be considering how much it produces over an entire year, not so much on a particular day. Some utility companies will compensate you at the end of the year for any extra power that you generate from your solar array system. This is one of the benefits of remaining tied to the grid; sharing power can be a win-win for you and your local power producer.
As with nighttime hours, the efficiency of a solar power system decreases on cloudy days since less sunlight reaches your solar panels. However, this does not mean that zero power is being produced. On a cloudy day, typical solar panels can produce 10-25% of their rated capacity.
Cloudy locations are still a good match for solar. For example, Portland is known for its bleak and rainy winters, and has cloudier weather than most cities. Yet over the course of a year, Portland gets about as much sunlight as the average U.S. city. The solar panels also benefit from having slightly cooler temperatures on average; because of the electronics inside, solar panels work best when they aren’t too hot. So in a city with extreme heat, solar is actually less efficient.
Mother nature has her days, and so every solar installation is made to optimize the potential of sunlight when it’s available. Cloudy days will hardly affect the return on investment of solar panels over the course of a year.
To learn more, contact your local solar installers at Southern Current today to request a FEE solar consultation for your property!