Optimal operation of energy hub with the presence of electricity to gas technology and hydrogen loads, considering demand response programs and air pollution

Energy supply is the most important need of human societies because life is impossible without energy. Therefore, the operation of energy resources is a substantial subject in the management of these resources. On the other hand, energy resources are often interdependent, which can help their management. In other words, the integrated operation of energy resources can be useful in energy management. In this regard, “the energy hub” has been introduced as a new concept for the integrated operation of energy resources. Using the concept of an energy hub, this paper tries to reduce the energy supply costs of consumers and manage these resources by integrated and simultaneous operation of electricity, natural gas, and water. In modeling, various pieces of equipment, such as energy storage devices, combined heat and power systems, and renewable sources, are used. Power-to-gas technology is also used to produce hydrogen and natural gas from water and electricity to supply hydrogen loads and inject the natural gas produced into the gas network. Power-to-gas technology uses excess electricity produced by renewable sources to produce hydrogen, which is obtained from the breakdown of water molecules. Given that the technology requires carbon dioxide to produce natural gas, this can reduce air pollution. In addition, a demand response program is implemented to shift a part of the electricity and heat consumption from peak hours to off-peak hours in order to reduce operating costs. Load transfer can be done with different methods, such as incentive plans or load management on the demand side. This modeling is a mixed integer linear programming. As mentioned, the model presented in this article is linear, so it is necessary to linearize the nonlinear equations. In this modeling, a method called "the Cartesian" method is used for linearization. After linearization of the nonlinear equations, this problem has been solved by GAMS software using the CPLEX solver. The results show that the proposed model has a significant impact on reducing operating costs and air pollution. In other words, devices such as electric heaters, combined heat and power, and power-to-gas units could reduce operating costs by 22% by converting energy carriers into different forms of energy, thereby significantly reducing pollutant emissions into the air so that, in the presence of the power-to-gas unit, the amount of pollution in the air can be decreased by 26%.