Energy efficiency increases should contribute to the reduction of energy consumption. Studies show, however, that despite improvements in efficiency, energy consumption often does not fall as much as expected - rebound effects occur.
The switch to renewable energies is not an energy efficiency measure as such, but also leads to a reduction in fossil energy consumption and thus to a reduction in resource consumption. If the residents subsequently consume more energy than before - or are less motivated to take further efficiency measures than they would have if they hadn’t started using renewable energy - the positive environmental effects can be eroded.