What is a solar cell battery?
A solar battery works like a regular rechargeable battery that is supplied with solar from a solar cell system. Since a photovoltaic system can not store electricity by itself, the excess electricity that the property does not use will be charged in the battery.
With a solar battery, you can use more of your self-produced electricity and thereby reduce the need to buy electricity from the electricity company.
Is it profitable to store solar energy?
Well the answer is Yes & No.
However, it can be practical in certain situations, such as in the event of a power outage or when the property is completely off grid .
Since they are relatively expensive at the same time as the lifespan is about 5-15 years, over time you will not be able to make any major savings as it looks today.
You can instead make the comparison by storing your surplus on the electricity market until you need to use it and then buy back the electricity from the electricity company.
However, given that you receive a tax reduction on the sale of your surplus electricity, the price of the batteries and the life of the batteries, an investment in a solar battery will not be directly profitable over time.
When can a solar battery be a good choice?
If you want to be able to store electricity to be able to use during the evening and night, a solar battery can be a good solution.
If you choose to buy a solar battery to use together with your solar cell system, you get the opportunity to use more of your self-produced electricity.
You also have the opportunity to use the stored electricity in connection with power outages, which makes you less sensitive to external factors.
However, the prices for these batteries are still quite high. This means that you do not make much money from storing your surplus electricity compared to selling it on the electricity market and then buying it back as the solar do not produce electricity.
Then you need to keep in mind that the lifespan of solar batteries is less than the lifespan of a solar system, which is between 25 to 30 years.
A photovoltaic battery needs to be replaced at least once during the life of a photovoltaic system. This means additional costs after about 15 years, or every 5 years if you choose a lead-based battery instead of a lithium battery.
What is the lifespan of solar batteries?
The lifespan of a solar battery depends on several different factors. The normal life of a lead-based solar battery is about 5 to 7 years. For a lithium battery, the lifespan is about 15 years.
Other factors that affect a battery’s life include weather and wind. In addition, a battery that is often discharged will have a shorter life over time.
Since a photovoltaic system has a lifespan of about 25 to 30 years, you will have to buy a new storage battery at least once. This means that there is an additional cost after about 15 years, if you choose a Solar lithium battery.
Since solar batteries are a relatively new product, compared to solar cells, future developments will contribute to the batteries having a longer lifespan and greater capacity.
This may in the long run make it more profitable to invest in a solar cell battery at a later time when prices have fallen.
What should you choose for storage capacity?
The storage capacity of a solar cell battery depends on how large a solar cell battery you choose. There are today solar cell batteries with a storage capacity of between 4 to 9 kWh and the price is between 20,000 up to 100,000 kronor, depending on the type of battery and size.
For a medium-sized villa that has remote-controlled heating or that has an alternative source for heating, a solar cell battery with a storage capacity of 4 kWh is normally sufficient to provide the electricity used during the evening and night. If you also need electricity for heating, a larger battery is required.
How much storage capacity you need depends on how big a photovoltaic system you have. In order to be able to store solar energy more efficiently, it should be possible to store 1 kWh for every kW a solar cell plant emits. This means that if you have a photovoltaic system of 8 kW, you should have a storage capacity of 8 kWh so that the battery is constantly charged.
You should also keep in mind that a battery can only store electricity for a short time, often between 1-3 days, which means that you can not store electricity for any longer period.
Advantages & disadvantages of battery for solar cells
There are both advantages and disadvantages to getting a battery to store the excess electricity from your photovoltaic system.
However, there is a constant further development of batteries, which over time will mean that the batteries will have better storage capacity, longer life and that prices will fall.
Benefits of solar cell battery
1. An advantage of obtaining a solar cell battery is that you can use some of the excess electricity that the solar cells produce during the times when the solar cells do not produce any electricity. This means that the electricity that is not used during the hours that the sun is up can be stored and used during the evening and night when the solar cells do not produce any electricity.
2. By using more of their own electricity, you contribute to a better environment.
3. If you have a solar cell battery, you can still use the stored electricity during a power outage, which means that you are less exposed.
Disadvantages of solar cell battery
1. Solar batteries are still expensive while the lifespan is shorter than the lifespan of the solar cells. This means that you need to invest in a new storage battery at least once more during the lifetime of the solar.
2. The savings you make with the help of a solar cell battery are relatively low because today you can get a tax reduction for the electricity you sell. This means that an investment in a solar cell battery will not contribute to any profitability.
3. The time that a battery can store electricity is limited to 1 or 2 days. This means that you can not store electricity during the summer and then used it during the winter, when you need it the most.