DETROIT If youve noticed your DTE bills are higher than normal this summer, youre not alone. We reached out to DTE to find out why some customers are seeing higher bills. There are three main reasons:Its been a hot summerDTE says one of the biggest reasons bills are higher is the hot summer. Arcadia found that residents of major metro areas can expect to spend between $20 and $40 more on their monthly energy bills this summer. Estimated billsThe less-likely issue with your higher bill is that its being estimated.