CHP Heat Heat Heat Heat Pump District Heating Network Heat Demand Heat Pump Heat Storage (a) Waste Water Store Waste Water Waste Water Digesters Boiler Demand District Heating Network Heat Heat Demand Heat Demand Storage (b) Storage Demand Heat Demand Boiler Heat Pump Gasometer Gas Production Electricity Distribution Network Boiler (c) Feedwater Fuel (Natural Gas) Gas Boiler Recovery Boiler HP Steam Public Power Grid Fuel (Black Liquor) Generator Turbine MP Steam Steam Accumulator LP Steam Blow Off Production Facility (d) figure 4. Real-world MES case studies. (a) Centralized DH: ACS and Mälarenergi, (b) decentralized DH: HOFOR and Paris-Saclay, (c) EMUASA: wastewater treatment plant with biogas production, and (d) paper mill: diagram of the steam system with a steam accumulator installed. LP: low pressure; MP: medium pressure; HP: high pressure. 80 ieee power & energy magazine july/august 2021 Bypass (HP→LP) Electricity Demand Heat Demand CHP CHP CHP Bypass (HP→MP)