During the operation of AC mains power supply, grid losses are inevitable. Through the electric resistor in the cables parts of the electricity is converted into heat. The amounts of grid losses grow alongside the distance the power has to travel. Grid operators regulate those losses by feed-in management measures. With the goal to predict grid losses more precisely and eventually be able to purchase additional energy for a better price, 50Hertz has developed a new model that relies on Artificial Intelligence (AI).
In 2018, 50Hertz, who is the responsible TSO for the North and the East of Germany, has transported a capacity of 117 Terawatt hours (TWh). During this phase, grid losses of 2.5 TWh occurred which equals two percent. What is particularly relevant in the 50Hertz grid area is the high amount of integrated renewable energy. This type of energy is often produced far away from where it is eventually needed and has to travel long distances.
An artificial neural network allows 50Hertz now to calculate the estimated grid losses for the next day. This calculation results in lower costs for the additional energy that 50Hertz has to purchase on the market. 50Hertz spent 70 Million Euro on electricity purchases in 2018 to cover up the losses. Those costs are aimed to be reduced with the new IA model by up to one percent.
The technique used until now worked as follows: the predictions for losses were based on the prognosticated integration of wind and solar power. This was then compared to similar days in the past. For the new method, 50Hertz made use of a bigger set of data. Every 15 minutes numbers on wind- and solar power integration, the strength of the wind and the sun and the temperatures at 70 different places in the grid area are gathered. This forms the base on which the artificial neural network learns to predict the grid losses – also for the time span of 15 minutes for the following day.
During the training phase, the artificial neural network compares its predictions with the actual results and the algorithm aligns with that. This procedure happens repeatedly. The artificial neural network literally learns new complex coherences resulting in more precise grid loss predictions. One great example is that the model acquires knowledge in regards to the issue that when strong winds occur the generated power needs to travel long distances to reach the consumer as it cannot be fully used where it is first generated. This leads to higher grid losses.
50Hertz worked together with Fraunhofer Institute of Optronics, System Technologies and Image Exploitation (IOSB) in Ilmenau (Thuringia) on this project. The prototype already improved the accuracy in comparison with the old technique by about seven percent. 50Hertz-experts then implemented the system into their own infrastructure. The trial phase started at the end of June 2019. Since then a solid database has been created and the prognosis has steadily improved. On December 9, 2019, it is fully applied in the system operation at 50Hertz.
