THEElectricity that is generated by a photovoltaic installation can be stored through the use of special batteries installed in the system itself. This accumulated electricity can be used later at any time we need it. In this way, solar energy storage systems make it possible to take advantage of all the energy from the sun and not waste anything .
The electricity consumption needs of a home or business vary depending on various factors, such as the period of the year, the time of day, etc. For this reason it is very interesting to have systems that accumulate this electrical energy to be able to use it when it is needed. On the other hand, through the use of solar batteries, energy independence from the network is obtained, which has increased its prices exponentially in the last year.
Let’s see below what a photovoltaic battery consists of, as well as the different types that we can find on the market today.
Photovoltaic battery and operation
A photovoltaic battery is a device that allows you to store the energy that is generated through the use of solar panels during daylight hours . This energy can be used later when energy production is not possible (the solar panels are not working), as occurs, for example, on cloudy days or at night. In this way, thanks to the use of batteries we can have electricity at any time .
A solar battery is made up of one or more electrochemical cells through which chemical energy is converted into electricity . The cells have a positive and a negative electrode, as well as electrolytes that allow the movement of ions between the two electrodes to facilitate the flow of current out of the battery.
The ability to accumulate energy and generate electric current is determined by the following parameters:
- Upload/download speed. Rate at which the accumulator is filled and emptied. The more discharge cycles, the shorter the battery life.
- loading depth. Amount of electrical energy that can be introduced into the solar battery in each charge. The greater the depth, the shorter the life of the accumulator. It is not recommended to download them more than 50%. It should be noted that lithium batteries have a depth of discharge that can reach 100% without such a strong impact on battery life as occurs with other technologies.
There are various types of batteries for solar panels that are classified according to the technology used in their manufacture, as well as according to the power or number of volts of the battery . Depending on the type of photovoltaic installation that we have, it will be interesting to place one type or another of solar battery. Choosing a good battery is essential for the solar installation to be more profitable and efficient.
Let us now look in greater depth at the various types of batteries for the storage of solar energy based on their manufacturing technology.
Monoblock or Monoblock batteries
These types of batteries are high performance and are usually used in solar installations for self-consumption that do not require great power, where simple electrical devices are used and do not use a motor.
Monoblock batteries are batteries made up of several 2V cells forming a single block with two connection terminals, one positive and one negative. The output voltages of the monoblock batteries are usually 6v and 12v and the capacities range from a few amp hours to about 800Ah.
Their duration is more limited than other types of batteries ( about 5 years ), although they are the cheapest alternative on the market.
Batteries commonly used in photovoltaic installations of medium and high consumption and that offer a longer life cycle , which can reach up to 20 years. They need a charge regulator to work properly, since they must always be charged. They usually need maintenance.
These batteries are more expensive than the previous ones , but much more profitable in the long run.
The different types of stationary batteries that exist are:
- OPZS batteries. For large photovoltaic installations due to its high storage capacity and durability. They need maintenance cycles of two years.
- OPZV batteries. Similar to OPZS, but do not require maintenance every two years. They offer a lower shelf life.
- TOPZS batteries. They are OPZS with a shorter useful life, but with a much cheaper price.
Lithium batteries are the most widely used today as they offer high durability and require very little maintenance . They are also the most profitable in the long term due to their greater depth of loading and unloading.
They have a useful life of about 13 to 15 years , including a guarantee that ranges between 7 and 10 years. In addition, they are the least heavy , do not emit polluting gases as they are sealed and can be completely discharged without being damaged .
The only disadvantage they present is that they have a higher price .
Together with POWEN , choose the type of photovoltaic energy storage that best suits your needs and achieve maximum savings and profitability from your solar installation, efficiently sizing the systems according to the characteristics of your home. In addition, there are various grants and subsidies that POWEN can inform you about, as is the case of state aid charged to European Next Generation funds . POWERit meets all the requirements for you to be able to obtain these aids: a minimum guarantee of 5 years, not including lead technology and that the installed capacity is at most twice the installed peak power.