Wie viel Strom erzeugt eine Solaranlage?

The generation of electricity from solar systems is key to a sustainable energy supply in Germany. However, the amount of electricity generated depends on various factors that need to be taken into account. Here we explain in detail how the weather, the location, the season and the orientation and inclination of the solar modules influence electricity generation. For every 1 kWp of installed photovoltaic power, a photovoltaic system generates approx. 1,000 kWh of electricity per year. This is an annual average of 2.7 kWh per day or 112.5 Wh per hour. On detached houses, standard photovoltaic systems have an output of 5 to 10 kWp.

Weather conditions

The weather plays a decisive role in the electricity production of solar systems. Sunlight is of course the most important factor, with direct sunlight being more effective for generating electricity than diffuse light on cloudy days. However, modern solar modules can also generate electricity efficiently in cloudy and diffuse light conditions, albeit less than on clear, sunny days. These values are average annual values for Germany. In reality, a solar system does not produce exactly 2.7 kWh of electricity per kWp every day. Around 70% of the electricity produced is generated in the summer months. Furthermore, solar radiation and the weather vary depending on the location and time of day. For this reason, the daily and hourly values are not very meaningful.

Weather	Global radiation	Power
Sunny	1000 W/qm	1000 Watt
Slightly cloudy	400 W/qm	400 Watt
Very cloudy	150 W/qm	150 Watt
Rainy	50 W/qm	50 Watt

Location and overview of federal states

Geographical location is another important factor that influences the performance of a solar installation. In Germany, there are significant differences between the federal states: Northern Germany (e.g. Schleswig-Holstein, Lower Saxony) tends to receive fewer hours of sunshine than the south, resulting in lower average electricity generation. Southern Germany (e.g. Bavaria, Baden-Württemberg) benefits from more hours of sunshine, especially in the Alpine regions, which favors solar energy generation. Eastern and western Germany have similar hours of sunshine, although local conditions such as altitude and microclimate can influence efficiency.

You can find a detailed overview on the Radiation map of the German Weather Service

Bundesland	Specific yield
Baden-Württemberg	1.070 kWh/kWp
Bayern	1.060 kWh/kWp
Berlin	910 kWh/kWp
Brandenburg	990 kWh/kWp
Bremen	930 kWh/kWp
Hamburg	959 kWh/kWp
Hessen	1.018 kWh/kWp
Mecklenburg-Vorpommern	1.014 kWh/kWp
Niedersachsen	985 kWh/kWp
Nordrhein-Westfalen	987 kWh/kWp
Rheinland-Pfalz	1.037 kWh/kWp
Saarland	1.063 kWh/kWp
Sachsen	1.035 kWh/kWp
Sachsen-Anhalt	1.004 kWh/kWp
Schleswig-Holstein	1.002 kWh/kWp
Thüringen	1.021 kWh/kWp

Seasons

The time of year is decisive for the amount of electricity generated. In summer, when the days are longer and the sun is higher, electricity production is at its highest. In winter, on the other hand, when the days are shorter and the sun is lower, the energy yield is significantly lower. The most productive months are from April to August. Here, an average of up to 145 kWh of electricity is generated per month. In the winter months, on the other hand, it is only 15-40 kWh.

Period	Possible photovoltaic yield
January	20,5 kWh/kWp
February	31,6 kWh/kWp
March	80,3 kWh/kWp
April	138,5 kWh/kWp
May	146,0 kWh/kWp
June	139,3 kWh/kWp
July	146,0 kWh/kWp
August	124,0 kWh/kWp
September	93,16 kWh/kWp
October	41,0 kWh/kWp
November	26,5 kWh/kWp
December	13,7 kWh/kWp
Gesamtjahr	1000,8 kWh/kWp

Alignment and inclination of the solar modules

The orientation (azimuth angle) and inclination (elevation) of the solar modules are essential for optimizing power generation. Ideally, the modules should face south in order to make maximum use of the solar radiation throughout the day. The optimum inclination depends on the geographical latitude; in Germany it is usually between 30° and 38°.

Modular types

Solar modules, also known as photovoltaic modules, are the heart of every solar system that converts sunlight into electrical energy. There are three main types of solar modules, which differ in terms of their composition, efficiency, cost and areas of application: monocrystalline, polycrystalline and thin-film solar modules.

Monocrystalline solar modules

Monocrystalline solar modules consist of solar cells that are made from a single, continuous crystal lattice. These cells have a typical dark, almost black color and a uniform surface. Monocrystalline modules are known for their high efficiency, as the continuous crystal lattice allows electrons to move more easily, resulting in higher power generation. Due to the more complex manufacturing process and higher efficiency, they are generally more expensive than other types of solar module. They are particularly suitable for applications where space is limited as they can generate more energy in a smaller area.

Polycrystalline solar modules

Polycrystalline solar modules consist of solar cells made up of silicon crystals that form many small, different crystal lattices when cooled. These cells have a blue color and a speckled appearance, which is created by the many small crystals. Polycrystalline modules are cheaper to produce than monocrystalline modules as the process produces less waste and is simpler. However, they are also less efficient as the irregularities in the crystal lattice can disrupt the flow of electrons. They offer a good balance between cost and efficiency and are a popular choice for residential buildings and projects with more available space.

Thin-film solar modules

Thin-film solar modules differ fundamentally from monocrystalline and polycrystalline modules. They are produced by applying one or more thin layers of photovoltaic material to a substrate. The materials can include cadmium telluride (CdTe), amorphous silicon (a-Si) and copper indium gallium selenide (CIGS). Thin-film modules are less efficient than crystalline modules, but have the advantage of being flexible, lightweight and easier to install. They are particularly suitable for large commercial applications or for locations where the modules need to be mounted on curved surfaces. They are cheaper to produce and less prone to performance degradation at high temperatures.

Conclusion

Generating electricity from solar installations in Germany is a complex interplay of various factors. While the weather and the seasons are factors that cannot be influenced, the choice of location and careful planning of the orientation and inclination of the solar modules can make a significant contribution to increasing efficiency. By taking these factors into account, owners of solar installations can maximize their electricity production and thus make an important contribution to the energy transition in Germany.

We would be happy to advise you. Please contact us.

How much electricity does a solar system generate?