Robust Optimal Operation Strategy for a Hybrid Energy System Based on Gas-Fired Unit, Power-to-Gas Facility and Wind Power in Energy Markets

Abstract

Gas-fired power units (GFUs) are the best technology in recent years due to lower natural gas prices, higher energy transformation performance, and lower CO2 emission, as compared to the conventional power units (CPUs). A permanent storage facility called power-to-gas (P2G) technology can provide adaptation of ever-increasing renewable energy sources (RESs) fluctuations in power system operations, as well as reduce dependency to buy natural gas from the gas network. High investment and utilization expenditures of state-of-the-art P2G technology do not lead to economically effective operation individually. Therefore, in the present paper, an integrated GFUs-P2G-wind power unit (WPU) system is proposed to determine its optimal bidding strategy in the day-ahead energy market. A robust optimization approach is also taken into account to accommodate the proposed bidding strategy within the electricity price uncertainty environment. This problem was studied by using a case study that included a P2G facility, GFU, and WPUs to investigate the effectiveness and capability of the proposed robust bidding strategy in the day-ahead energy market. Simulation results indicate that the obtained profit increase by introducing the integrated energy system, and the P2G facility has a significant effect on participating GFUs, which have gas-consumption limitations in order to achieve maximum profit. Moreover, as it can be said, the amount of purchased natural gas is decreased in the situations, which do not have any gas-consumption limitations. Furthermore, the proposed system’s operation in the robust environment provides more robustness against electricity price deviations, although it leads to lower profit. In addition, deploying P2G technology causes about 1% incrementation in the introduced system profit.

Economic‐environmental stochastic scheduling for hydrogen storage‐based smart energy hub coordinated with integrated demand response program

“…All linearized constraints relevant to the minimum up and down-time of gas-based power units are determined with ( 16) to (19) and ( 20) to (23), respectively. 47 Minimal up-time limitations express that these units cannot be turned off for particular hours after the unit is turned on. Likewise, minimum down-time limitations are specified that the unit cannot be turned on until a certain number of shut-down hours is completed.…”

“…Equation ( 46) indicates the hourly stored hydrogen, restricted to the minimum and maximum capacity of the system stated in (47). The equalization of stored hydrogen in the first and final hours is expressed in (48).…”

A hybrid robust‐stochastic approach for optimal scheduling of interconnected hydrogen‐based energy hubs

“…In the following constraints, electrical energy storage (ESS) must be charged in low-price hours while being operated in discharge mode in high-price hours to reduce the total imported electric power from the main grid. Therefore, constraints (30) and (31) illustrate the charging and discharging electric power limited by their maximum and minimum charging and discharging power values. This action must not occur at the same time, as illustrated in Equation (32).…”

“…Also, in order to consider the gas storage system (GSS), constraints (42)-(47) are outstanding and determine the charging and discharging power of GSS for each hour and scenario [22,31]. are the charging and discharging gas power of GSS unit at time t and scenario s; G min,chr,GS and G max,chr,GS are the minimum and maximum state of charging power and also G min, dischr,GS and G max, dischr,GS are the minimum and maximum state of discharging gas power by GSS unit; I chr;GS t;s and I dischr;GS t;s are the binary decision variables for charging and discharging power by GSS unit at time t and scenario s; η chr, GS and η dischr,GS are the efficiencies of charging and discharging gas power modes; E min, GS and E max, GS are the minimum and maximum gas energy stored level; Δt is the interval time for calculating gas energy level of GSS unit; E GS t;s is the level of stored gas energy in GSS unit at time t and scenario s.…”

“…Also, in order to consider the gas storage system (GSS), constraints (42)–(47) are outstanding and determine the charging and discharging power of GSS for each hour and scenario [22,31]. …”