Solar batteries: is it possible to store renewable energy?

From Helios, Ra and Tonatiuh, to Kinich Ahau, the pantheons of ancient civilisations believed it took a divine being to possess and control the power of the Sun. But now, we are in the era of electrification. An era in which the combination of innovation and sustainability enables us to harness the potential of renewable energies and create devices with the capacity to store the sun's energy, such as solar batteries.

Energy storage is seen as a cornerstone of the energy transition and the decarbonisation of the electricity system. Unpredictability is a factor that affects renewable sources, such as solar or wind, hence the need for storage systems in this type of environment. Solar panel batteries are one of many solutions which can be employed to keep things running smoothly; their main purpose being to store electric power until it is needed, allowing for greater efficiency and reliability throughout the system. 

How can I store solar energy for my own consumption?

There are currently various energy storage systems. The solar panel battery is one of the best known. There are many types of batteries, but in general they can be divided into three groups: monobloc, stationary and lithium. The main difference between them is the technology used in their manufacture. As a result, their lifespan varies and so does their price.

When it comes to self-consumption, monobloc batteries are the most commonly used because they do not require high power. The disadvantage is that their lifespan is shorter than other types of batteries, as they usually last between four and ten years. However, this also makes them the most economical alternative. Among monobloc batteries, AGM batteries and GEL batteries stand out. The main difference between the two is that the latter respond better to voltage compared to discharge.

The next type we find are stationary batteries, although in this case they are no longer geared towards self-consumption. They are usually used in photovoltaic systems with medium and high consumption, so their life cycle is also usually longer than the previous ones, up to 20 years. This group includes OPZS batteries, OPZV batteries and TOPZS batteries.

Finally, there are also lithium batteries. These are currently the best when it comes to storing energy generated by solar panels. They are the most cost effective in the long run as they are very durable and require very little maintenance. However, they are also more expensive.

Beyond solar panel batteries

As we have already seen, solar batteries are an excellent storage system. However, the development of new technologies over the years has given way to other systems that can efficiently convert and store energy.

When we focus on end users and their self-consumption, we should also keep, supercapacitors and flywheels in mind as well as solar batteries. Supercapacitors store electricity in the form of electrostatic charges and can be charged and discharged in seconds. Flywheels, on the other hand, are a mechanical storage system capable of conserving electricity in kinetic form through a metal disc.

As we have already mentioned, there are also systems that can store energy on a large scale. In this case, three stand out: electric pumps, compressed air systems and thermal storage. Currently, the first of these systems is undoubtedly the most efficient in operation.

Storage for self-consumption in Spain

Storage is the ideal complement for self-consumption systems, as it gives them more flexibility and allows generation and consumption to be matched, maximising the use of renewable energy.

The growth of photovoltaic solar energy is unstoppable. According to the Spanish Photovoltaic Union (UNEF), self-consumption installations grew by 101.8% in 2021 compared with 2020. Now, the challenge in 2023 for this type of energy will be storage.