Do solar power systems work at night?
As a general rule of thumb, solar power systems are most effective during bright, sunny days with clear skies, but how do they work at night? The short answer is that they don’t, because obviously, there is no sunlight in the evening. The longer answer is more nuanced, mostly due to the presence of solar storage through batteries. To get a proper idea of how they become useful when the sun is nowhere in sight, we need to understand the basics.
How solar power systems work
Solar power systems take in energy from the sun and convert this energy into direct current (DC) power. The inverter within your model will then change this to alternating current (AC) power, allowing the use of various devices and appliances in your home.
There are two kinds of solar power systems that enable them to be effective irrespective of the time of day.
- Net metering setups
- Storage setups
Solar power systems using net metering are perhaps the most common around the world. These models are connected to the electricity grid so that you export energy when there’s an excess supply, and import energy when there’s a deficiency. Given this structure, you can build up energy credits when you loan electricity to the grid, and it’s these credits that get used up first when your model is not producing any electricity.
Solar power systems don’t produce electricity at night, but through net metering, they do work at night by allowing you to use energy credits created during the day. This process can also be extrapolated from its daily application to a seasonal scenario. Conceivably, you could build up significant credits during the summer, and apply these for use during the winter when sunshine hours drop down, allowing your electricity bill to drop dramatically throughout the year.
If you’re looking for a more detailed explanation of net metering, check one of our previous blog posts on the topic.
It’s only recently that storage batteries have become more viable options, as previously, the initial investment alone was enough to scare people away. Times have changed, and now they’re more affordable and worthy additions to solar power systems.
Battery storage works in a way that is similar to net metering. During the day, your panels absorb PV energy, and the inverter transforms this to electricity which is used up by your home. The excess energy in this case, though, is fed to the battery, rather than the grid. As a result, when it’s cloudy, rainy, or dark, your house relies on the battery to power household uses, rather than the main grid. When the battery storage is depleted, only then will you turn back to the grid for electricity.
A storage structure might be more appealing than a net metering installation since the former reduces the reliance on the main power grid. In some cases, this dependency is cut back by 80%, so you could conceivably find yourself in a position of minimal power grid usage.
Yes, even with the downward trajectory of battery prices, the cost of the equipment can still be several thousands of dollars. To remedy the situation, you can access several financing options these days, even opting for loans or monthly payments on your setup, bringing your charge to less than $50 a month.
If you’re looking to purchase a battery, you should consider getting a lithium-ion setup. They are light, compact, and have a longer lifespan and depth of discharge when compared to lead-acid batteries. Depth of discharge refers to the percentage of a battery that’s been discharged, relative to its total capacity, with a higher value signifying your ability to utilise more of a cell.
While solar power systems don’t produce electricity at night, through a couple of mechanisms, they’re able to provide and facilitate the use of electricity in the evening. With net metering and storage models, these renewable energy setups become more than sufficient in the absence of sunlight.
While Earthsave currently does not offer battery cells, our list of panels and inverters can form an essential part of any home’s renewable energy plan. Choosing the right inverter is crucial, as it’ll set the stage for you to benefit from both your panel and the main grid.