If you have a photovoltaic system, there are two options, you can either feed the excess green electricity into the public grid or store it. In the last few years, the remuneration for feeding into the public power grid has steadily decreased. It is therefore worthwhile in many cases to store the electricity generated so that it can be used again at a later date.
Some establish a solar island to be completely self-sufficient with electricity. Such systems have no connection to the public power grid. Rather they have solar batteries with a large storage capacity. This enables the highest degree of independence.
Although there are many different types of energy storage, there are only a few that are suitable for solar energy news storage. These are batteries specially designed for storing solar power that can help you to get the maximum yield from your solar system. Strictly speaking, these storage systems are not batteries, but rechargeable batteries because only these can be recharged. Because the battery is often used as an umbrella term, we use a solar battery and solar accumulator here as a synonym.
What criteria do you have to consider when buying a solar battery?
When choosing a solar. list battery, it is important to consider the following aspects. Cheaper is not always better, but in most cases means that you have to compromise on one of these aspects. In the long term, this is reflected in additional costs. These are the criteria:
- Storage capacity
- Efficiency
- Maximum depth of discharge
- Lifespan and number of charging cycles
- Coupling
Use a photovoltaic system with or without a solar battery?
Your PV system produces the most electricity during the day when solar radiation is greatest. However, since nobody is often at home at this time, little can be used for this electricity. During the day, electricity is usually only required for the refrigerator and freezer. The surplus electricity is then fed into the public grid for a small income. The feed-in tariff is currently around 11 cents / kWh.
In the evening, however, most people are at home and use a variety of electrical devices. The stove, microwave, and dishwasher are used for cooking. After that, you might want to use the TV, lights all over the house, and charge cell phones and laptops. A lot of electricity is also used for washing and drying clothes. The power consumption is therefore significantly higher in the evening than during the day.
If you have already fed all of the excess electricity into the public grid, there is no more electricity left for your own evening consumption. This means that you now have to obtain electricity from the public grid, which currently costs around 30 cents / kWh. If you integrate a solar battery into your solar system, you can save significant costs. You store the excess energy generated during the day, use it 100% – and free of charge. So in the evening less or even no external electricity has to be bought.
