Optimal heat and electric power flows in the presence of intermittent renewable source, heat storage and variable grid electricity tariff

Abstract

To decarbonize and increase the flexibility in the heating and electricity sectors, large heat pumps, combined heat and power plants, renewables and storage technologies are increasingly being installed. This results in a tighter coupling between the electricity and heat distribution networks. Hence, the two networks need to be operated in an integrated way so that their synergies can be exploited. The main challenge in that regard is the lack of suitable tools that can capture the detailed operating parameters of both networks simultaneously. This paper proposes a population-based optimal power flow model for integrated heat and electricity distribution networks. An extended energy hub approach is used to model the components of the integrated energy system in a modular form. Active and reactive power balances, heat power balance and optimal management of storage technologies in the presence of intermittent renewables and variable tariffs are considered. The proposed method is then tested using a case study of highly coupled electricity and heat distribution networks consisting of a heat pump, a gas boiler, a combined heat and power plant, a wind turbine and a thermal storage together with a variable electricity tariff. It is found that above 97% of the surplus production from the wind power plant is effectively used in the system and 10.35% of the heat demand is effectively shifted from the peak hours to the cheap-electricity hours. The results show that the proposed method can be used as a decision support tool that can be used for the optimal integration of heat and electricity distribution networks. It also maximizes the synergy that can be captured from the multi-energy systems in general and from the heat and electricity distribution networks in particular.