.jpg)
Among all the elements of a photovoltaic installation, batteries play a key role. They are responsible for storing surplus energy that is not going to be consumed immediately, so that the user can make use of it when needed. Currently, users can choose between two types of batteries: virtual and physical, depending on the use they want to make of the surplus. In this blog, we give the keys to learn more about the characteristics of each of them, as well as their main benefits.
What is a virtual battery
A virtual battery is a storage system for surplus solar energy that stores the economic amount equivalent to the energy that has not been consumed at the time; that which could not be returned to the grid for economic compensation.
During daylight hours, solar panels collect the energy produced by the sun. Part of this energy is used directly to supply the consumer's installations or home, and the surplus can be returned to the electricity grid through a surplus compensation tariff. The surpluses that cannot be compensated are those that can be accumulated, in the form of an economic balance, in virtual batteries. This balance is stored digitally for the owner to use when needed. In addition, if the owner has more solar installations in his name, he can manage and make use of his stored energy in the one he prefers. Thus, private users or companies that decide to have a self-consumption installation will see how their electricity bills are reduced.
Virtual batteries are especially interesting for users who consume seasonally, for those who have second or third homes or for self-consumption projects that generate a high amount of surplus.
And they are truly beneficial and profitable for those who make use of them, as they do not require maintenance -since they are not physical devices-; they allow access to better energy rates, being able to use energy when its market price is high; they are easy to handle and, thanks to them, they contribute to the use of clean energy and to the stability of the electricity grid.
What is a physical battery
On the other hand, a physical battery is a system that stores surplus electricity from the solar installation and releases it when needed. This technology promotes savings both day and night and avoids variations in energy prices, as well as contributing to the reduction ofCO2 emissionsinto the atmosphere.
When choosing the ideal battery for a solar installation, it is necessary to take into consideration its storage capacity, performance and battery life. Currently, the industry standard has turned to lithium batteries as the main alternative for medium-term energy storage (on the order of several hours).
Within lithium batteries, there are several chemistries, which are selected based on their performance for their intended applications. The same performance is not required for handheld electronics (such as cell phones, cameras or tablets) as for mobile applications (such as cars, bikes or electric scooters), so the same chemistry is not used. In particular, for stationary energy storage applications, such as hybridization with photovoltaic installations, the most commonly used chemistry is Lithium Ferro Phosphate or LFP.
With these batteries, several strategies can be followed to achieve savings for the user:
- Load-shifting: This is an arbitrage or displacement of consumption, i.e., taking advantage of off-peak price hours to charge the batteries to cope with peak hours by discharging the batteries, thus consuming less from the grid during expensive hours.
- Peak-shaving: This strategy is used to counteract an often forgotten element of the electricity bill: the power term. This term is a fixed payment that is made for having the right to demand a certain power and is independent of each month's consumption. By taking advantage of the battery to cover peak demand, the contracted power can be lowered (without incurring penalties), thus saving on the fixed costs of the bill.
- Surplus storage: In the case of hybridizing the battery with a photovoltaic installation, the surplus of the latter (i.e. the energy produced that cannot be consumed at that moment) can be used to charge the batteries with energy that would otherwise have been lost or sold to the grid at a very low price. This energy can be discharged when it is most convenient, complementing the two previous strategies.
As for their benefits, the following stand out: the energy independence they offer the user to consume the energy generated, even when there is no sunlight; they allow direct control over the energy that is stored, as they do not depend on the electricity grid; they contribute to sustainability by making the most of the energy produced; they reduce long-term costs and help to save money.
To find out which is the best option regarding the choice of batteries for your photovoltaic installation, do not hesitate to contact us for the best advice.
