Adjusted consumption
The correction method for temperature is based on data from Eurostat, the statistical office of the European Union. The correction is based on the number of degree days and the share of natural gas used for heating. The number of degree days in a day is defined as 18º Celsius minus the average outside temperature for that day. The assumption is that heating is required, if the outside temperature drops below 18º Celsius. The share of natural gas used for heating houses is set at 80 percent. The remaining 20 percent is used for cooking, showering, etc. The share for heating in manufacturing industry is set at 15 percent.
Example: In a particular year, the number of degree days was 3,300, adjusted to 2,950 degree days, the average over the period 1981-2010. If households use 1,000 m³, then 0.80 * 1,000 m³ = 800 m³ is used for heating and 200 m³ for cooking, etc. In that case. the corrected volume is 2,950 / 3 300 * 800 m³ = 715 m³ + 200 m³ = 915 m³.