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Controlling electricity usage with an online measurement system

Target group

Students from 14 to 18 years.

Learning aims

The electricity bill for the Geschwister Scholl Grammar School in Düsseldorf was €35,000 in 2005. The measures that they had already tried to save energy were not a resounding success.

By carrying out the project described here the school wanted to find out the main reasons of their high electricity usage.

Short description

With the support of the Düsseldorf public services the school installed the online measurement system from deZem (Berlin). Measuring devices were installed at 20 different points in the school energy network, which measured the consumption and transmitted the values to the central computer via the internet. The measurement results were prepared in such a way that consumption curves were created for individual electricity circuits and/or rooms in the school and the proportional electricity costs could be calculated.


The project led to surprising results

It arose that in the investigation period approx. 17% of the electricity usage occurred in the assembly hall even though it was only used rarely for events and/or individual lessons. The cause of this was not the lighting, but rather the ventilation system which regulated the room temperature.

Additionally it was discovered that the electricity usage of the whole school on a holiday was just approx. 15% below that of a school day. From this we can conclude that the majority of the electricity usage comes from devices such as heating pumps or fans that run around the clock or are controlled according to a fixed time schedule. Contrary to expectations the pupils and teachers can only influence a small part of the electricity usage themselves – e.g. for lighting, computer or the copier, although it is precisely these devices that receive the most attention regarding saving energy in schools.

The project raised a lot of questions, but it was an important step on the way to more energy efficiency in the Geschwister-Scholl grammar school. In the school year 2006/2007 the school was able to save approx. €5,500 on electricity.

More information

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