Can Solar Energy Be Stored?


There are a lot of great things to be said about solar energy. Firstly, it’s a clean form of energy, and it’s endlessly renewable. Plus, you can use solar energy for a wide variety of applications.

Just recently, solar energy also gained another feather in its cap when it came to affordability. In October of 2020, Popular Mechanics reported on how solar energy had already become the cheapest form of energy in history.

We all know the basic premise of how solar energy works. The rays of the sun, they shine down on a solar panel that ‘magically’ turns them into electricity to power our electric devices. But what happens when there is no sunlight? After all, there are only so many hours a day when the sun is out. All of this begs the critical question: Can solar energy be saved? The answer is YES.

You can indeed save solar energy in batteries, just as you would save electricity from any other source. If you think about it, saving solar energy is a necessity. It wouldn’t be feasible as a source of energy if it simply cut off at night when the sun’s gone!

Having said that, it’s safe to say that one of the most significant limitations of solar energy systems is the part that’s concerned with storing the energy it’s captured. To understand why that is, let’s dive a little deeper into the topic.

Overview Of Solar Energy Systems

In our journey to understand the saving or storage of solar energy, let’s start with a broad view. It would help you a lot to know how solar energy systems work as a whole.

The system starts with solar panels (also known as photovoltaic or PV panels). That’s the component that most people already know. Then, the other three key components are the inverter, the racking system, and of course, the battery system.

The purpose of the solar panels is to convert sunlight into Direct Current or DC energy. When sunlight hits the solar panels, it stimulates electrons to move through the solar cells. That process results in the production of electricity.

That DC electricity then flows to the inverter. Its primary purpose is to convert DC energy to AC or Alternating Current energy. Why does that matter? Well, it’s because all of the electric devices and appliances that we use rely on AC energy, not DC.

The racking system is the least complicated part of the entire solar energy system. There needs to be a place to mount all of the solar panels you’re using. Plus, they need to be mounted facing the sun, so it captures sunlight for as many hours as possible each day.

Whether you’re using solar energy for your home, a factory, or even an office building, you’d typically place the racking system on the roof. However, if you have a wide-open space available, you can also put those racks on the ground.

Lastly, we come to the component that’s the main focus of this article: the battery system. That system is where solar energy is stored to ensure continuity. Whether it’s night time, a day with bad weather, or if your solar panels stop working for whatever reason, an efficient battery system ensures that you’ll have an uninterrupted energy supply at least for a while.

Solar Energy Batteries

Now, let’s take a closer look at solar energy batteries. The main criteria that set solar energy batteries apart from each other are their storage capacity. Simply put, the higher the storage capacity, the longer the system can provide you with power while the solar panels aren’t capturing any sunlight.

Suppose you’re using a solar power system for your home. You’ll need a battery with enough capacity to provide energy overnight until the sun comes back out. If the capacity is too small, you’ll end up with no electricity for a few hours, or you’ll have to rely on (and pay for) electricity from the national power grid.

In terms of the types of batteries available on the market, there are three different types from which you can choose. Solar system batteries either use lead-acid, lead-gel, or lithium-ion to store energy. Lately, lithium-ion batteries have become the most widely used type among the three.

Whatever battery you choose to go with, it’s important to remember that they’re not just plug-and-play types of batteries. You can’t just buy it off a shelf at a store and plug it in at home. Instead, installing new batteries as part of your solar energy system requires additional work like technical and electrical changes, or maybe even an inverter replacement.

Remember: you can approach some home improvement tasks as a DIY project. But when it comes to solar energy tasks, it’s always best to hire an expert. They’ll get the job done in a jiffy, and you won’t have to worry about accidentally blowing anything up!

How Long Do Solar Batteries Last?

If you know anything about batteries, you’ll see that they don’t last forever. Car batteries need changing after two years or so. Even your smartphone and laptop batteries lose their efficiency after a while. The same is true for your solar energy batteries.

What happens to solar batteries after a few years? Well, don’t worry, they won’t just stop working altogether. However, they gradually lose their ability to store energy efficiently over time.

For example, a brand new battery will charge up to 100%, but over time its maximum may drop down to say 90% or lower. Again, that’s true for all batteries, regardless of their purpose.

In the case of solar batteries, remember what was said earlier. There are generally three types of batteries: lead-acid, lead-gel, or lithium-ion. Typically, solar batteries will last anywhere from 5-15 years before you need to replace them.

Keep this in mind: solar systems generally last 25-30 years overall. That means that throughout the lifespan of your solar system as a whole, you’ll probably need to replace your batteries at least once or twice.

Is there a way to extend the lifespan of solar batteries? Yes, indeed there are.

How To Extend The Lifespan Of Solar Energy Batteries

You may have seen tips online on how to extend your phone’s battery life. Well, here are a few critical tips on how to extend the lifespan of solar energy batteries.

  1. Limit The Number Of Batteries You Use – Believe it or not, more isn’t better when it comes to solar energy batteries. In any solar energy system, people often use several batteries at the same time. Together, these batteries form a ‘bank’, and their purpose is to increase the total amount of energy stored.

    However, having too many batteries in a bank will waste energy. Each battery has connections, and these connections put up a small amount of resistance. The more batteries there are in a bank, the higher the total resistance there is. When that happens, the overall efficiency of the system drops.
  2. Rotate Your Batteries – Just like rotating the tires on your car, you should also rotate the batteries in your battery bank. The reason for this is pretty straightforward. Batteries towards the middle and the end of the battery might not get charged as much as the ones right at the front.

    It’s almost like how you need to rotate the tires on your car; it’s to ensure that the wear on each tire is at least somewhat even. The same is true for your batteries. When you rotate them from time to time, the batteries will wear out more evenly. That will allow you to maximize their lifespans.
  3. Use Larger Battery Interconnecting Cables – Here, we have another tip that’s aimed at reducing resistance. This time, we’re looking at the battery interconnecting cables. As the name suggests, these are the cables that connect all of your batteries together within the battery bank.

    Simply put, when it comes to these cables, larger is better. Larger cables will have less resistance, keeping the flow of electricity much more efficient. Never leave batteries uncharted solar batteries are like muscles; use them or lose them! That’s quite an accurate way to describe them, as leaving batteries uncharged for extended periods will cause them to deteriorate. So, make sure that you plug your batteries in at all times.

    If you have additional batteries for whatever reason, you have to make sure that you use them from time to time. You can combine tip number 2 from earlier and rotate your batteries. Keep the additional ones to the side, but rotate them into your solar energy system on a scheduled basis. That way, all of your batteries charge and discharge equally.
  4. Use The Appropriate Batteries For Your Needs – Last but not least, use batteries with capacities that are sufficient for your needs. That means don’t use batteries that have too little or too much capacity for your home or office.

    Let’s look at this tip a little closer. If you use batteries that have too little capacity, they will run out quicker. Over the span of many years, you would have put those batteries through a higher number of charging cycles, thereby wearing them out a lot quicker. However, if you use batteries that have too much capacity, you might never be able to charge them up completely. They’ll charge to some extent during the day, but when there’s no sunlight the charging stops!

    So, try to figure out what your energy needs are before deciding what battery capacities you need. Then, use a trial and error approach to ensure you only have the necessary amount; not too much, and not too little.
Infographic Covering the Info Above…who doesn’t love a good infographic?

Can Solar Work Without Batteries?

With all the importance that we place on solar energy batteries, many people have another question to ask: Can solar energy systems work without batteries? The answer is YES. As long as the system has solar panels and inverters, your solar system will still fulfill its purpose. Not everyone needs to store the energy generated by their solar systems.

For some people, using their solar energy systems during the day and then switching over to using grid energy at night is perfectly fine by them. That’s sort of taking a ‘hybrid’ approach to the use of solar energy. 

Overall, people who use a combination of solar and grid power still spend less money on their power bills every month. That’s especially true for people who live in countries where electricity is cheap. Don’t forget: more and more countries are using affordable solar energy to power their national grids, as well! When that’s the case, grid power supply essentially becomes like a giant battery for your home solar energy system.

The only situation where solar energy batteries might be compulsory and necessary is if you’re choosing to live entirely off the national power grid. Being disconnected from the power grid, you’ll need batteries to make sure that you receive uninterrupted power all-day and all-night.

Is It Worth Getting Solar Batteries?

So, all-in-all, is it worth getting solar batteries? The answer is another yes.

There’s a couple of simple reasons for getting solar batteries. Firstly, even if you’re using a hybrid system, the national power grid isn’t perfect. Whenever you do use grid power, you’ll have to pay money to the power company. So, you’re better off investing in batteries for your solar system so that you don’t have to use grid power at all.

Plus, if you’re in a disaster-prone area, the grid might break down and leave you without electricity. Your solar energy system will work during the day, but you’ll need batteries to power your home appliances through the night.

Second, solar batteries are affordable, and they’re improving every single day. More and more companies are entering the renewable energy market and producing batteries that are more efficient and even more affordable than before.

Regardless of the battery that you might have right now when the time comes to buy a replacement, you’ll find that they’ll be more efficient and much cheaper in the future!

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