How to Store Solar Energy for Later Use

Storing solar energy is a great way to ensure you can benefit from the energy when the sun is shining even when you don’t have any electricity at the moment. There are a variety of ways to store solar energy, using both renewable and non-renewable sources, so you can choose which is best for your needs. Let’s dive into how to store solar energy and which option is best suited to you.

Best-Suited For Renewable Storages

If you’re looking to store solar energy for later use, you best suited for using a renewable energy source such as a battery or an airtight container. These storage methods do not require regular maintenance and can be charged up whenever there is energy available from the sun (meaningless at night, during cloudy days, or during winter), thus avoiding potential energy losses.

Batteries are very useful for storing energy, and while there are a variety of battery types available on the market, the perfect size and type to store solar energy is the sealed lead acid battery (SLA). These batteries are maintenance-free and can hold their charge for up to 10 years before needing to be replaced.

Best-Suited For Non-Renewable Storages

If you’re looking to store solar energy for later use and have a fixed energy requirement, you may be better-suited for using a non-renewable energy source such as a fuel-cell or a gas engine. These storage methods require regular maintenance and cannot be charged up whenever there is energy available from the sun, thus losing some of their stored energy whenever this happens.

A fuel-cell creates electricity and can be used to store energy just like a battery, but their efficiency significantly drops when they are not in use, sometimes down to 80%. The most efficient type of fuel-cell to store solar energy is the solid-state polymer electrolyte fuel-cell (SPEFC), which can maintain an efficiency above 90% even when it is not in use.

Considerations When Choosing a Storage Method

There are a variety of factors to consider when choosing the best storage method for your needs, including cost, reliability, and efficiency. For a free guide to choosing the right storage solution for your needs, download our free white paper here:

How to Choose the Right Storage Solution For Your Needs

When To Charge

To determine when you should charge up a storage device, you need to consider when there is likely to be the most energy available from the sun. You should charge up a storage device as soon as possible after the sun has risen and when it is still quite dark outside, to take advantage of the high-energy periods.

If you store too much energy when there is no solar energy available, you will struggle to generate enough electricity to use when the sun is shining, especially at night. This may mean you will resort to burning gas or using expensive batteries more frequently, which are less efficient as they lose some energy to heat up when charging.

Choosing the right location for your storage device is also important, as the farther you put it from the source of generation (i.e. the sun), the less likely it is to be affected by extreme weather conditions such as heavy winds or heavy rain, thus avoiding any unnecessary energy losses.


The size of your storage device will depend on your energy requirements. If you have a small space for which you need a small storage device, consider using an ultracapacitor which can store more energy than a regular capacitor and are more resistant to damage from high voltage spikes and spikes in current demand. If you have a large space for which you need a large storage device, consider using a traditional battery or a liquid-cooled fuel cell.

If you’re trying to save money, you may want to forgo purchasing a large storage device and opt for a smaller one, which will require less frequent charging. If your energy requirements are relatively low, then purchasing an ultracapacitor will be the cheaper option.

Also remember to consider the weight of your storage device when selecting an option, as the heavier it is, the more likely it is to be damaged if dropped. Batteries and similar storage devices are typically heavy, and while solid-state polymer electrolyte fuel cells are lighter, they are also much more expensive.


Depending on how long you want your storage device to last, you may want to select one that is more durable. While a standard capacitor can last for around 10 years before needing to be replaced, a lithium-ion battery will only last three to four years before suffering from significant degradation.

If you intend to use your storage device frequently and want it to last as long as possible, then a lithium-ion battery is the way to go. If you don’t need your storage device to last as long as possible, then an ultracapacitor, which can store more energy than a standard capacitor but are less durable, may be the better choice.


If you experience any difficulties with your storage device, especially if it is not working as it should, then you will need to consider what type of repairs are available. Batteries and similar storage devices are essentially robots that need to be maintained and monitored to ensure they continue operating as they should. If you experience difficulties with your battery or similar storage device, then you will need to either select one that is cheaper to fix or have it fixed by a professional.


The cost of your storage device will depend on a variety of factors, including what type of battery or similar storage device you use and how long it lasts, how many cycles it can perform before deteriorating, and the cost of the material itself. The cost of a lithium-ion battery, for example, includes the cost of the material itself along with the shipping fees if you are purchasing a fully-charged battery from a remote location. If you compare the cost of a lithium-ion battery to that of an ultracapacitor, you will notice the former is significantly higher. This is because while an ultracapacitor can be fully charged for less than the cost of a single lithium-ion battery, the latter needs to be replaced more frequently due to its shorter lifespan and higher failure rate. It is, therefore, more expensive to own an ultracapacitor than it is to own a lithium-ion battery.

It’s also worth considering the cost of the wiring and the space it takes up, as there is an increasing trend toward wireless devices and more electronics packed into smaller spaces, thus making more space desirable. If you can forgo having wires running all over your house, then you may save money in the long run.

To determine how much energy you need for your home, you can use one of the many free online calculators available, such as the one from

As the sun is a renewable resource and can be replenished when needed, the cost and durability of having solar energy stored is generally less than that of purchasing and operating traditional electricity generators on an as-needed basis. If you use solar energy whenever you can, then it makes sense to invest in a storage device to ensure you can take advantage of these high-energy periods when the sun is shining brightly and evenly throughout the year. This is why many homeowners choose to install a home solar power system – to store energy during the day when it’s abundant and to use it at night, when the sun is not providing enough energy for their needs.

Scroll to Top