Cost implements the cost function. One of it’s properties is price of the electricity (kW−h). We suppose that all electric energy is transformed to heat energy. Also, usually we have price for (kW−h), but in our model we have (J), so we transform between them using 1kW−h= 3.6e6J.
The output value of Cost component is accumulated cost of the house heat- ing/cooling. The input is the heat flow from heater/cooler.