With version 1.8.0 the YAML configuration structure will change. Don't worry the old structure will be supported for a bit and the migration should be very easy. Only a few minutes work depending on the amount of sensors you have.
See https://homeassistant-powercalc.readthedocs.io/en/latest/configuration/new-yaml-structure.html for more information.
Changes
- #1736 Change YAML structure to remove sensor platform support @bramstroker