That chart is misleading because it shows consumption of all sources of energy, not just electricity. We don't use 28% of our electricity for transportation (yet!). Listings of electricity consumption by sector [1] show that the residential sector consumes the biggest share of electricity in the US. And the residential sector also has the highest seasonal variability in power consumption [2]. So better demand control for consumers might actually pay off pretty well.

[1] http://en.wikipedia.org/wiki/Electric_energy_consumption#Ele... [2] http://www.eia.gov/todayinenergy/detail.cfm?id=10211