Hi,
the formula for the Extractors energy consumption is: -16 * level * 1.1 ^ level
For me this would be: -16 * 28 * 1.1 ^ 28 = -6460.6 energy.
As you can see in this screenshot this is not the result in reality:
http://prntscr.com/o6ncv4The real result is based on the formula: -15 * 28 * 1.1 ^ 28 = -6056.8 energy. This matches the screenshot with -6057 Energy rounded down.
Please correct the shown formula to -15.
(Just to prove that I did not turn the percentage of production down:
http://prntscr.com/o6necd)