Bone Song by John Meaney.

This is a detective story set in a world where zombies and wraiths walk the streets and are taken for granted. The bones of the dead contain necrotic energy which is harvested and used much as we use electricity. Despite the setting this is not a horror story. It is very definitely a detective story and sadly not as good as it should have been. The plot is too loose and there are too many things not properly explained. A follow up might be better if Meaney focusses more on the plot and less on developing his unusual setting.