The interaction between different energy markets, such as natural gas or coal, and electricity markets is increasingly present in the energy sector. By reducing available reserves, dependence on imported gas in the future will surely rise, and this is a challenge that will require new solutions to maintain the safety of power system.Renewable energy sources’ share of power system production already plays a significant role, and according to many forecasts, a tendency for further growth is anticipated. Considering their volatility and impact on electricity market prices, it is clear that plant optimization will be more complex.
The primary objective of optimization is to meet the demand for heat energy but also to minimize fuel costs and include revenue from the sale of electricity and heat. The higher price of natural gas or lower electricity prices in the market is analysed long with the extent of their impact on the engagement of modeled power plants. The impact on the use of the gas system unit includes the supply of natural gas from gas pipelines to gas pipeline transport and the use of gas storage facilities.
The work includes the modeling of thermal power plants and cogeneration plants in the PLEXOS programming tool.
The model of cogeneration plants and gas system enables co-optimization of the gas and power system. Primarily, this option is used when connecting power plants that use natural gas as fuel directly to the gas grid. It is possible to consider the prices in the electricity market and the natural gas market, which definitely increase the range of possible solutions in model optimization.
The model was applied in the case of the Republic of Croatia and the work includes the modeling of thermal and cogeneration power plants in the HEP production d.o.o. The model and simulations contain units that are still in the construction and design phase. With this, the results of the budget show how the unit engagement would take place if all were built and run in the time observed in the simulations. In the gas system of the Republic of Croatia, the transport system and the underground gas storage is modeled with the most important characteristics: maximum and minimum capacity of injection and withdrawal.