The reason why the maximum supply power is different between summer and winter is that a periodic test for the power stations is carried out in winter with less power demand in {HEAD ~ preparation} for {TAIL ~ summer} with more power demand 
The reason why the maximum supply power is different between summer and winter is that a periodic test for the power stations is carried out in winter with less power demand in { HEAD ~ preparation } for { TAIL ~ summer } with more power demand
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