The generation and use of electrical energy from renewable sources represent a viable solution to counteract the pollution produced by energy production based on the burning of fossil fuels, and to combat climate change due to the concentration of greenhouse gases.

However, the storage of this energy also represents a great challenge, and together with the high costs involved, have been the major barriers to the mass adoption and implementation of these technologies.

Solar energy: procurement and storage

Specifically, solar energy is intermittent, i.e., it can only be obtained when the day is sunny. Its storage represents a difficulty for its efficient use, which is fundamental for us to make the transition to this type of environmentally friendly energy.

The storage of solar energy is achieved by means of solar batteries, capable of containing the photovoltaic energy, coming from the solar radiation that was captured by means of solar panels composed of solar cells that perform this function.

The solar battery is composed of electrochemical cells, whose function is to transform the sun’s chemical energy into electrical energy to be stored in this battery.

Each battery is composed of two electrodes, one positive and one negative, and electrolytes. They make the energy flow in the form of current to fulfill its objective of energizing from the public lighting to our homes.

Types of batteries

• Monoblock batteries. They are mainly found in home installations, which are usually the most common for self-consumption purposes. They are of low to medium power, sufficient for lighting and use of low power appliances. Their duration is shorter in terms of deep discharge cycles.
• Stationary batteries. They are not very different from the previous ones in terms of structure and functionality; however, these batteries are more used in medium to high consumption sites, and their financial cost is higher.
• Lithium batteries. Nowadays they are the best option since their high efficiency is combined with low maintenance requirements, moderate cost, and high durability, also in deep discharge cycles.

Over time, the energy storage capacity of solar farms has increased. They have gone from 214 MW to 899 MW on average per day in a moderate-sized farm. It is expected that as technology advances this capacity could increase to 2,500 MW by 2023.

In addition to existing technology, solutions such as hydrogen cells are under development to obtain greater energy capacity from electrolysis. 

This is the mechanism for separating water molecules. The idea is to take advantage of this reaction, releasing oxygen into the environment and using the energy from burning hydrogen to generate power.

The transition to clean energies is vital, therefore, it is important that we are aware of the evolution of the storage of this non-polluting energy, to stop depending on conventional energy from fossil fuels.