Abstract: An electricity automation application may automate control over an HVAC system in a consumer's home or other building to reduce or eliminate electricity consumption during a high-price or high-demand time interval. The consumer may grant authorization for the application to control the HVAC system at appropriate timepoints while maintaining an inside air temperature that is between minimum and maximum temperature setpoints set by the consumer. The application models temperature gains and losses for the home or building as a function of inside and outside temperatures and HVAC operating status. If a high-price or high-demand time interval is predicted, the application may determine a timepoint to precool or preheat the home or building to reduce or eliminate electricity use during the duration of the high-price or high-demand time interval.