Advantages and disadvantages of batteries in photovoltaic solar systems

Should we install a battery in our photovoltaic solar system ? This is a question that we all must ask ourselves when we buy a photovoltaic solar system for our homes.

Energy storage technologies have been around for decades. Batteries to store the energy produced in photovoltaic solar systems are relatively new on the market.

There are many advantages that solar batteries guarantee, such as economic benefit, but on the contrary they have a great disadvantage, their price is still very high!

Is it worth investing in solar batteries?

When batteries for energy storage are installed in a solar photovoltaic system, we can store the extra energy produced by the solar panels that is not consumed, instead of sending it to the grid.

With solar batteries, the use of electricity generated by the photovoltaic system is maximized. This stored electricity is the electricity produced during production peaks that is not used in the house, so this excess is stored and can be used later!

Let us remember that when the electricity production market for self -consumption emerged , the states initially financed customers with great incentives to invest in photovoltaic panels. Incentives that included payment based on the MW sent to the electricity grid, as well as state incentives to invest in these systems.

But over time, these incentives dwindled and it is not currently worth sending the electricity to the grid for collection. Now, instead of sending it to the grid, the electricity is stored in solar batteries for later consumption.

Advantages of investing in solar batteries.

Investing in an energy storage system has more pros than cons, especially when it comes to solar PV. It should also be borne in mind that the advantages depend on the type of photovoltaic system installed, whether it is connected to the electricity grid or not.

It serves us as a reserve.

If the photovoltaic solar system is connected to the electricity grid, it will produce energy during the day to be consumed by household appliances. Any excess power is sent to the grid, so some of the electricity is “wasted”.

With a solar battery this does not happen. The electricity accumulated during the day can be used at night, or as a supplement at times when production cannot be matched.

energy independence.

Sunlight is only available during the day, when we are not at home. Since most of us consume more energy at night. With a solar battery we will store excess electricity for later use.

Another advantage is that we save on the electricity bill, because the electricity consumed from the network will be less at night, since we are using the electricity accumulated during the day in the batteries.

Helps reduce the ecological footprint.

Fossil fuels are the main source of electricity, so by opting for solar batteries, we will reduce the need to use electricity from the grid. This reduces carbon dioxide emissions.

Part of the virtual network.

In the last 100 years, electrical networks have changed a lot. If we think about the current electrical network, it is obsolete.

By installing solar batteries, we are fostering innovation, investing in the smart grid, where we can have more information and be more efficient.

In addition, having solar batteries allows consumers to store energy for themselves, but also to generate and distribute their clean energy to the grid.

Independence from the electrical network.

Choosing a system with solar batteries allows you to be self-sufficient in terms of energy. Because you no longer consume 100% from the electricity network at night, but only from the batteries and, only in extreme cases, you may need to consume electricity from the network.

In addition, the development of batteries has increasingly ensured a greater storage capacity. There are even batteries that allow us to self-consume for several days (2 to 3 consecutive days without sunlight).

Disadvantages of investing in solar batteries.

Like everything else, the bet on solar batteries for a photovoltaic system also has disadvantages.

High cost.

Perhaps the main reason why few choose to install solar batteries in their photovoltaic systems.

Since solar battery technology is still in full development, to ensure greater storage capacity and greater reliability, they remain expensive and can cost as much as the entire photovoltaic system (panels, inverters, power optimizers).

Before opting for this solution, the ideal is to see the cost-benefit of investing in batteries. This way you will know if it is worth the investment.

It is true that the costs have been falling, and every month there are new developments in this field, but it is not yet at “palatable” values. It is believed that a few more years and solar batteries for photovoltaic systems will reach values ​​that will quickly compensate the investment. Although this market is very active and can change in months, some are already anticipating and talking about a residential storage boom .

Installation complexity.

The installation of a solar battery system increases the complexity of your photovoltaic solar system. This means that more things can go wrong, from the design to the installation and operation of solar batteries.

Therefore, it is crucial that during the installation phase, the battery system is correctly dimensioned for the needs, as well as the other installations to be carried out (cables, switches, devices, etc.).

More maintenance.

Solar photovoltaic panels are easy to maintain, but if a solar battery system is added, the maintenance of the entire system will increase. However, this maintenance directly depends on the type of batteries installed.

If we think about deep cycle sealed lead-acid batteries, the water levels must be checked periodically, and the terminals must be kept clean.

Battery chemicals are dangerous and corrosive, so care must be taken when performing maintenance.

If we opt for lithium ion batteries, they are easier to maintain.

Useful life.

The useful life of a battery will depend on the type of battery to be used and its discharge capacity.

Sealed lead-acid batteries can only be discharged to 50% of their capacity, any more than that reduces the life of the batteries.

While lithium-ion batteries can be discharged up to 80%!

Also keep in mind that during the lifetime of the solar PV system (20-25 years), you may need to replace the solar batteries at least once.