An energy cost optimization system for a building, the system comprising: - HVAC equipment which is heating, ventilation and air conditioning equipment, configured to operate in the building; and - a controller configured to: - generate a cost function defining a cost of operating the HVAC equipment over an optimization period as a function of one or more electric loads for the HVAC equipment, wherein the electric loads are decision variables of the cost function and comprise an electric load for each hour of the optimization period; - select particular hours of the optimization period as participation hours, wherein the participation hours indicate one or more hours that the HVAC equipment will participate in an economic load demand response (ELDR) program; - generate an ELDR term based on the participation hours, wherein the ELDR term indicates revenue generated by participating in the ELDR program; - modify the cost function to include the ELDR term; - perform an optimization using the modified cost function to determine an electric load for each hour of the optimization period; and - provide setpoints for the HVAC equipment based on the electric loads. - HVAC equipment which is heating, ventilation and air conditioning equipment, configured to operate in the building; and - a controller configured to: - generate a cost function defining a cost of operating the HVAC equipment over an optimization period as a function of one or more electric loads for the HVAC equipment, wherein the electric loads are decision variables of the cost function and comprise an electric load for each hour of the optimization period; - select particular hours of the optimization period as participation hours, wherein the participation hours indicate one or more hours that the HVAC equipment will participate in an economic load demand response (ELDR) program; - generate an ELDR term based on the participation hours, wherein the ELDR term indicates revenue generated by participating in the ELDR program; - modify the cost function to include the ELDR term; - perform an optimization using the modified cost function to determine an electric load for each hour of the optimization period; and - provide setpoints for the HVAC equipment based on the electric loads. - generate a cost function defining a cost of operating the HVAC equipment over an optimization period as a function of one or more electric loads for the HVAC equipment, wherein the electric loads are decision variables of the cost function and comprise an electric load for each hour of the optimization period; - select particular hours of the optimization period as participation hours, wherein the participation hours indicate one or more hours that the HVAC equipment will participate in an economic load demand response (ELDR) program; - generate an ELDR term based on the participation hours, wherein the ELDR term indicates revenue generated by participating in the ELDR program; - modify the cost function to include the ELDR term; - perform an optimization using the modified cost function to determine an electric load for each hour of the optimization period; and - provide setpoints for the HVAC equipment based on the electric loads.