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Solar panels with battery storage? Here are the answers to all your questions
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The near future of the electricity world belongs to wind and solar energy. However, one of the main challenges for renewable energy sources is their instability. In other words, wind energy can only be generated when the weather is windy and solar energy only when the weather is sunny, and if you have neither, you have no electricity.

The solution to this problem lies in energy storage – part of the generated energy is stored for periods with no wind or sunlight.

By opting for Eesti Energia's solar solutions, owners of private houses interested in the production of green electricity can now store the electricity by using a battery, in order to reduce their electricity costs, environmental footprint, and contribute to the green revolution in Estonia by supporting the wider implementation of renewable energy.

A solution consisting of solar panels and a battery allows you to be your own master in energy. Solar panels and batteries become a green home power plant, reducing your electricity costs, and allowing to earn income.

Storage is good for two reasons. First, it is possible to consume more of the electricity you have produced yourself and thus save costs. Secondly, electricity supply is guaranteed if there is an interruption in the power network.

How does a solar panel and battery storage solution work?

  • Solar panels consist of photovoltaic cells that convert light energy into electrical energy.
  • The electricity generated by the panels flows into an inverter with the function of converting the direct current into alternating current suitable for the power network.
  • When the electricity generated by solar panels is not used, it is stored in a storage device – a large lithium-ion battery. The stored electricity can be used in the evenings or with a backup power switch during power outages. Without a battery, the solar system will switch off during interruptions. The lithium-ion storage devices provided by Eesti Energia are safe, reliable, small in size, and 95% recyclable.
  • If the electricity produced by solar panels is currently consumed, it will flow directly from the inverter through the electrical switchboard to the home electrical system. An electrical switchboard helps to distribute electricity in a low voltage building.
  • An electricity meter is an instrument for measuring the electricity consumed or generated. The meter keeps track of how much electricity you have bought from the power network and how much of your own electricity you have sold there. The solar electricity generated by the panels only moves into the power network when the battery is full and there is not much consumption at home. It is possible to earn income by selling electricity to the power network, but as network fees and state taxes apply to electricity purchased from the network, it is always more profitable to consume as much own produced electricity as possible.
  • How much can be saved?

    According to long-term expert forecasts, the price of electricity is on the rise, and the more expensive the price of electricity in the network, the faster a home solar power plant will pay off.

    Battery prices have fallen steadily, making storage more affordable. Ideally, it is possible to reduce electricity bills by up to 70% per year, but as each home and consumption varies, the savings vary according to the project.

    Sample solution: Terraced house of a single family
    Annual consumption 5,000 kWh
    Solar electricity solution 18 panels, capacity 6.48 kW
    Inverter 6 kW
    Storage solution 10 kWh
    Annual output 6,500 kWh
    Average savings on electricity costs per year 60%

    The savings change seasonally - the electricity bill can decrease by almost 95% in summer, but much less in winter. The peak productivity of the panels is usually between March and late August. The months with the best output are usually April and May, because the sun is high, and the temperatures are cooler. In winter, the sun is low, and productivity is smaller, but not completely non-existent.

    The idea that solar panels do not pay off in Estonia is a myth. True, there is less direct sunlight in Estonia than in southern countries, but compared to Germany, for example, the productivity of our solar panels is the same. However, lower-than-average air temperatures speak in favour of Estonia by increasing the efficiency of solar panels.

    Would you like to save nature, save on electricity costs, and increase the value of your real estate? If the answer is yes, you might want to consider installing solar panels and a battery solution. Those interested can quickly calculate the approximate annual output of the planned home power plant, added benefit of storage and cost of the system by using Eesti Energia’s solar energy calculator.

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