Authors: Rade M. Ciric, Sasa N. Mandic
Serbia faces challenges in the energy sector due to its high dependence on fossil fuels and poor energy efficiency. The government has made efforts to promote renewable energy sources and increase energy efficiency but still relies on energy imports, with electric energy imports accounting for 18% of demand. The country’s energy policy focuses on infrastructure development, diversification of energy sources, modern technology adoption, reducing consumption growth, increasing energy efficiency, and boosting renewable energy use. Serbia is obligated to increase its share of renewable energy in total consumption from 21.2% to 27% by 2020 under an agreement with the EU, but it is not on course to achieve this target.
EPS Distribucija-Novi Sad operates in Vojvodina, Serbia, supplying over 2308 GWh of electricity and providing 902 MW of heat capacity. CHP “Plant West” in Novi Sad generates 256.3 MW of heating, 38 MW of water heating, and 9.98 MW of electrical power using natural gas. It has three gas power motors and three generator units and is connected to a substation via an underground cable.
Combined Heat and Power (CHP) on the grid has challenges and operating conflicts, including:
• Inadvertent islands could occur when the utility feeder breaker opens.
• Interference with utility equipment.
• Power quality problems: The impedance of service transformers hinders the ability of DG to provide any relief to other loads on the same feeder.
• Conflicts with utility fault-clearing requirements and reclosing of the breakers.
To connect CHP to the grid, certain criteria need to be met, including:
• The maximum power of generating units must not exceed the maximum allowable value of the short circuit current (power) of the equipment.
• DG should not cause the voltage increase at any point exceeding limits for a given voltage level.
• Only synchronous machines with 2/3 pitch can be used in some transformer connections.
The article also discusses the application of power quality monitoring in a CHP (Combined Heat and Power) plant in Serbia. The integration of the combined heat and power (CHP) plant in Novi Sad, Serbia, has been successful despite initial technical issues. The CHP plant has helped achieve the country’s energy policy objectives by diversifying energy sources, introducing modern technologies, and increasing energy efficiency. The experience and lessons learned from the project should be shared with future stakeholders, and the government should provide real incentives to encourage investment in energy efficiency projects. This would have positive socio-economic effects, such as promoting employment and increasing the national GDP.