Our project uses a CHP plant where the heat form the natural gas generator (GG) is supplied to Exhaust Gas Boiler(EGB), from which the steam is supplied to VAM Chiller that is used for space cooling and the electrical consumption of project is less than CHP generated energy
Here the unit cost of design case electricity is calculated by dividing the total cost of natural gas by the total electricity produced by the generator. This cost is about 0.04 USD / kWh. Also REB is used as a back up source of electricity . Hence as per CHP guidelines market electricity cost is taken as baseline energy cost. However the market electricity cost is 0.124USD / kWh. This is 66% higher than the design case energy cost. In this case should we follow the CHP guidelines and use market cost as baseline or consider the design case cost (Gas cost/kWh) for both base case and design case?