Hi Atanasius,
The results for 2017 are based on the data you entered in the Historical Production variable. LEAP calculates the supply for 2018 onwards (assuming that 2018 is the First Scenario Year in your model).
LEAP's supply calculations start from the top Transformation module to the bottom. It appears that you have the Electricity Generation module at the bottom, so any electricity demands are first met by the other modules that have electricity as their output fuel. Try rearranging the modules by moving the Electricity Generation module to the top using the blue arrow buttons above the tree.
If that doesn't help, ensure that you have electricity demands specified correctly in the Demand branches.
Hope this helps!
Emily