Long, long ago in a galaxy far, far away...
Energy efficiency was once seen as a lower-cost technique to avoid new
generating facilities
Across the country, it was argued that:
consumers were not getting the right price signals from regulated
rates, and
As a result, consumers were underinvesting in efficiency and
overinvesting in electricity consumption
utilities needed to provided incentives to consumers to change the
relative prices between electricity and efficiency in order to induce
them to change their  energy consuming behavior
It was variously  known as “demand-side management”, or “least-cost
planning” or “integrated resource planning”
It was argued that utilities saved money by paying for reductions, rather
than building expensive new plants, thus holding rates lower than they
would otherwise have been.