Using photovoltaic systems to generate solar power is an increasingly popular method of meeting your own energy needs and at the same time contributing to environmental protection. While photovoltaic systems produce electricity using solar energy during the day, self-consumption is often limited. The electricity produced is not always used immediately - especially when the sun is shining and electricity demand is low. This is where power storage comes into play: it enables excess solar power to be stored and used at a later date. In this guide, you will learn how to store your solar power efficiently and make the most of the advantages of power storage.
1. Why is power storage useful?
Power storage offers numerous advantages. Without storage, the unused electricity is fed into the public grid, for which a feed-in tariff is paid. However, this tariff has fallen continuously in recent years, making it less and less financially attractive to sell the power you generate yourself. With an electricity storage system, you can maximize your own consumption because you don't feed the electricity into the grid, but can use it when you actually need it - for example in the evening or at night when there is no sunlight.
By storing and later using your own solar power, you can significantly reduce your electricity costs and become less dependent on rising electricity prices in the long term. In addition, using an electricity storage system makes your household more self-sufficient because you are less dependent on the public power grid.
2. How does an electricity storage system work?
A photovoltaic electricity storage system, often also referred to as a battery storage system, stores the excess solar power produced by your photovoltaic system and releases it when needed. The storage process is usually fully automatic as soon as more electricity is generated than can be consumed.
The most common electricity storage technologies are based on lithium-ion batteries, which are characterized by high efficiency, durability and low losses during charging and discharging. However, there are also alternatives, such as lead-acid batteries, which are cheaper to purchase but have a shorter lifespan and efficiency. Modern lithium-ion storage systems achieve efficiency values of over 90%, which means that only a small part of the stored energy is lost during use.
3. What size should the electricity storage system be?
The optimal size of the electricity storage system depends on several factors. The following are particularly important:
- The size of your photovoltaic system: The more solar power your system produces, the more storage space you need to be able to use the surplus effectively.
- Your electricity consumption: Higher electricity consumption usually also requires greater storage capacity. Households with electric cars, heat pumps or other energy-intensive devices often need larger storage units.
- Your goal for self-consumption: If you want to use as much of the electricity you generate yourself as possible, you need a sufficiently dimensioned storage unit. As a rule, electricity storage units are dimensioned for daily needs, which means that they should be able to store the electricity that is not needed during the day and release it during the night.
The capacity of a battery storage unit is given in kilowatt hours (kWh). As a rule of thumb, around 1 kWh of storage capacity is useful for every 1 kWp (kilowatt peak) of installed photovoltaic power. A typical single-family household with a 5 kWp photovoltaic system could therefore benefit from a power storage unit with around 5 kWh.
4. How can the power storage be used efficiently?
There are several ways to use your power storage efficiently:
- Optimizing your own consumption: Many modern household appliances can be operated on a timer. Use times of high solar radiation to operate energy-intensive devices such as washing machines, dishwashers or charging stations for electric cars.
- Intelligent energy management: Modern photovoltaic systems are often equipped with energy management systems that automatically ensure that solar power is used and stored optimally. These systems monitor your consumption and control when power is stored or withdrawn.
- Night operation: The stored power is used in the evening and at night when the sun is not shining. An efficient storage system should be able to cover energy requirements overnight and only be recharged the next day when the sun shines again.
5. Is the combination of a photovoltaic system and electricity storage worthwhile?
The purchase of an electricity storage system is an investment that is profitable for many households. However, the benefit depends on several factors, such as the level of your electricity consumption, the size of the photovoltaic system and the current electricity prices. However, due to the decreasing feed-in tariff and rising electricity prices, it is becoming increasingly attractive to store your own solar power and use it yourself.
The environmental aspect also plays an important role: the more solar power you use yourself, the less electricity has to be obtained from fossil energy sources, which significantly reduces your ecological footprint.
Conclusion
An electricity storage system is the ideal addition to a photovoltaic system in order to use the solar power you generate yourself efficiently and to maximize your own consumption. By storing the excess electricity, you increase your independence from the public power grid, reduce your energy costs in the long term and make an important contribution to the energy transition. Whether the investment is worthwhile for you depends on individual factors such as your electricity consumption and the size of your photovoltaic system.