Through its network of experts (BMDV), the DWD once again published its annual review for the year under review at the end of March. Energy weather 2023 has been published. According to this, the average values for global radiation and wind speeds for the past year are once again at record levels. At 1,144 kWh/m², global radiation fell slightly by 86 kWh/m² in 2023, but the average wind speed rose from 5.62 m/s in 2022 to 5.98 m/s in 2023. Long-term view these are again Peak values for renewable energies. (Cf. Global radiation 2022)
What is the energy weather?
Energy weather plays a crucial role in forecasting and optimizing energy production from renewable sources. Two important parameters that must be taken into account when determining the energy weather are the Global radiation and the Wind speed.
Global radiation refers to the total solar radiation that reaches the earth's surface. It is made up of direct solar radiation and diffuse sky radiation. Global radiation is a decisive factor in predicting the generation of energy from Solar systems. The higher the global radiation, the more energy can be obtained from sunlight.
In addition to global radiation, wind speed also plays an important role in predicting energy generation from Wind turbines. The wind speed determines the amount of wind energy that can be generated by the wind turbines. The higher the wind speed, the more energy can be generated from wind.
Global radiation as a factor for the energy weather
Global radiation is influenced by various factors, including the Solar altitudewhich Cloudinesswhich Air pollution and the Geographical location. The altitude of the sun determines the angle of incidence of the sun's rays on the earth's surface. The higher the sun is in the sky, the more direct the sun's rays are and the higher the global radiation. Cloud cover and air pollution, on the other hand, reduce global radiation as they reduce the amount of sunlight that reaches the earth's surface.
Global radiation is measured with the help of Pyranometers which measure the entire solar radiation. These instruments are designed to measure both the direct sunlight as well as the Diffuse sky radiation can measure. The data is recorded continuously and is also used in the solar cadastre or in energy weather forecasts. In addition to the pyranometers, other measuring devices such as Solar radiation sensors and Weather stations to obtain precise data on global radiation.
Global radiation is subject to various trends and patterns that are important for energy weather forecasting. For example, there are Seasonal or weather-related Fluctuations in global radiation that are related to the position of the sun and the tilt of the earth. In some regions there are also Long-term trendswhich are attributable to climate change or changes in atmospheric conditions. The analysis of these trends and patterns helps to make accurate predictions about global radiation and to optimize energy production from solar installations.
At 1,144 kWh/m², global radiation in the 2023 energy weather was the second lowest of the last six years, but the sixth strongest In some months, including February, May, June, July, September and October, global radiation was higher than in the reference period 1991-2020. September in particular was the most radiant since 1991 with 124 kWh/m². June was also very strong. Autumn 2023 was the most radiant since 1991. Winter 2022/2023 showed a slight negative anomaly, with January in particular being significantly weaker than usual. The center of Germany had the highest positive anomaly, while the southern edge of the Alps showed a slightly negative anomaly.
Wind speed as a factor for the energy weather
The wind speed is also influenced by various factors, including topographical featuresgeographical location and Atmospheric conditions. Mountains and hills can obstruct the wind flow and lead to lower wind speeds. Geographical location also influences wind speed, as coastal areas and open landscapes tend to have higher wind speeds. In addition, atmospheric conditions such as differences in air pressure and temperature gradients can influence wind speed.
It is measured with the help of anemometersthat record the air flow. These instruments record wind speed in real time and provide accurate data for energy weather forecasting. In addition to the anemometers, other measuring devices such as Wind direction sensors and weather stations to obtain precise data on wind speed. The German Weather Service measures the meteorological parameters at a height of 100 meters and averages the annual values for the whole of Germany.
The DWD experts calculated an average wind speed of 5.98 m/s across Germany in 2023. That is the highest for 16 years. Some months, including January, November and December, had particularly high wind speeds, while September was one of the windiest months since 1950. Spring and fall were windier than average, while winter was slightly above average. The distribution of the percentage deviation in wind speed in 2023 showed a positive trend in the south of Germany, while it weakened towards the north and east and became slightly negative in some areas.
Global radiation and wind speed complement each other
Global radiation and wind speed correlate and complement each other during a year in Germany to a good energy weather mix. For example, high global radiation leads to a warming of the air, which in turn leads to an increase in wind speed. Conversely, a high wind speed can break up the cloud cover and lead to an increase in global radiation. The precise analysis of these interactions and correlations is also used for short-term forecasts of the energy weather.
Overall, it can be seen that the higher global radiation in summer and the increased wind speeds in winter optimal for a relatively Consistent energy generation by wind and solar power plants. Germany is no exception. With the exception of the eastern Mediterranean region, global radiation throughout Europe in 2023 was above the average for the reference period. There were positive deviations in the average wind speeds in a broad strip from northern France, the Alps, Italy and the Balkans to the Black Sea.
Conclusion
The energy weather in 2023 once again set new records for renewables. Both global radiation and wind speeds were at a high level. Although global radiation was slightly lower than in the previous year, it was still above average, particularly in some months such as September and June. Winter saw a slight decrease, especially in January. Wind speeds, on the other hand, reached their highest level in 16 years at 5.98 m/s. January, November and December were particularly strong, while September was comparatively windless.
The energy weather takes two key factors into account: global radiation and wind speed. Global radiation, which comprises the total solar radiation on the earth's surface, is decisive for solar power generation. Wind speed, on the other hand, determines the amount of wind energy that can be generated. The measurements and analyses of these parameters help to make precise predictions for energy generation from renewable sources and to optimize them.
The interactions between global radiation and wind speed are of particular importance here. High global radiation can increase the wind speed and vice versa. This contributes to the balance of energy production throughout the year. In Europe, the values for global radiation and wind speed in 2023 were above average overall, which offers positive prospects for the use of renewable energies.