At the press conference on 21.03.2023, the German Weather Service (DWD) presented its collected Climate values from 2022. According to this, the Average global radiation 2022 in Germany 1230 kWh/m². This record value since measurements began in 1983 is also due to the high number of hours of sunshine in 2022. At 2,024 hours, this value was also 31 % higher than the average value for the reference period 1961-1990, giving all PV system operators an extremely profitable year.
Annual increase of 3.35 kWh/m² on average
The global radiation values have risen by an average of 3.35 kWh/m² per year since they were recorded. The radiant energy that hits the earth's surface from the sun has risen on average from 1,005 to around 1,140 kWh/m² between 1983 and today. It is made up of direct radiation (also known as direct irradiation), which hits the earth's surface directly from the sun, and diffuse radiation (also known as scattered radiation), which is scattered by the atmosphere. Both types of radiation are characterized by modern solar modules into electrical energy, so that high global radiation values further improve the efficiency of photovoltaic systems.
Important variables for renewables: wind speed & global radiation
Like all weather data, global radiation also varies: In poorer years for PV system operators, such as 2013, it was still 1045 kWh/m² on average. In the so-called summer of the century in 2003, for example, it was 1,195 kWh/m² or around 1,210 kWh/m² in Germany in 2018. The record level of global radiation in 2022 contrasts with an average wind year: Wind turbines benefited from an annual average of 5.6 m/s, which roughly corresponds to the average for the reference period (1961 - 1990).
Reasons for the increase in global radiation
The fluctuating values of global radiation are due to solar activity and the degree of atmospheric pollution, the intensity of which is constantly changing. However, experts attribute the constant increase over decades to climate change. Warmer temperatures allow the atmosphere to absorb and store more energy from the sun, which leads to higher or increasing global radiation overall.