Micro-gas-turbine powered electric car competitiveness compared to full electric and present-day hybrid vehicles
Khanal, Basanta (2025)
Diplomityö
2025
School of Energy Systems, Sähkötekniikka
Kaikki oikeudet pidätetään.
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe2025053056110
https://urn.fi/URN:NBN:fi-fe2025053056110
Tiivistelmä
This study examines the feasibility and benefits of implementing a hybrid electric vehicle (HEV) equipped with a low-power micro gas turbine (MGT) as an alternative to conventional battery electric vehicles (BEVs) and contemporary hybrid electric vehicles (HEVs). The proposed system comprises a hypothetical 25 kW MGT operating at 40% electrical efficiency, a 10-kWh battery, and a 100-kW electric propulsion system. The analysis assesses energy efficiency, material sustainability, and environmental impact in comparison to existing vehicle technologies.
The material and energy efficiency of different vehicles is studied starting from the manufacturing impact. The proposed HEV with MGT reduces battery dependency up to 80–90% by utilizing only a 10-kWh battery, significantly cutting down manufacturing emissions compared to BEVs, which typically require 50-100 kWh battery packs. BEVs rely on resource-intensive materials such as lithium, cobalt, and nickel, whereas the HEV with MGT minimizes reliance on these scarce materials.
The hypothetical MGT system, using hydrogen or biomethane, integrates combined heat and power (CHP) for improved thermal efficiency, making it more efficient in cold environments without additional battery drain.
The proposed HEV with MGT achieves a well-to-wheel efficiency of around 35% due to the high efficiency of the micro gas turbine. BEVs have an efficiency of 42-72% when powered by renewable sources but suffer from substantial energy losses in charging, grid transmission, and battery degradation.
Traditional hybrid vehicles, using internal combustion engines (ICEs), experience inefficiencies at lower speeds and variable loads, with peak ICE efficiencies typically at 30-40% but much lower in real-world driving conditions. In addition, delivering fuels to the ICEs add the environmental burden of these vehicles. So-called e-fuels are, in principle possible but not available now.
The proposed vehicle offers an estimated range of 50 km on battery alone and 523 km with the MGT-powered generator and a 90-l methane tank, making it competitive with conventional ICE and hybrid vehicles in terms of long-range usability.
Unlike BEVs, which require extensive charging infrastructure, the HEV with MGT can refuel quickly using existing fuel infrastructure for methane or hydrogen, reducing dependency on developing charging networks.
BEVs provide zero tailpipe emissions but face sustainability challenges due to battery production, possibly emitting power generation and end-of-life recycling issues. Conventional HEVs still depend on ICEs, which operate very inefficiently at low loads, leading to unnecessary fuel consumption. The HEV with MGT bridges this gap, offering a sustainable alternative with lower emissions, better fuel flexibility, and improved overall efficiency.
The HEV with MGT presents a compelling alternative to both BEVs and traditional hybrids, combining electric propulsion with a highly efficient, fuel-flexible micro gas turbine. It mitigates resource scarcity issues linked to battery production, reduces dependency on charging infrastructure, and enhances efficiency through CHP principles. Additionally, by enabling the use of e-hydrogen or biomethane as fuel sources, this hybrid system provides a pathway toward a low-carbon transportation future. As the automotive industry moves toward sustainability and carbon neutrality, the HEV with MGT stands out as a promising, efficient, and environmentally responsible solution.
The material and energy efficiency of different vehicles is studied starting from the manufacturing impact. The proposed HEV with MGT reduces battery dependency up to 80–90% by utilizing only a 10-kWh battery, significantly cutting down manufacturing emissions compared to BEVs, which typically require 50-100 kWh battery packs. BEVs rely on resource-intensive materials such as lithium, cobalt, and nickel, whereas the HEV with MGT minimizes reliance on these scarce materials.
The hypothetical MGT system, using hydrogen or biomethane, integrates combined heat and power (CHP) for improved thermal efficiency, making it more efficient in cold environments without additional battery drain.
The proposed HEV with MGT achieves a well-to-wheel efficiency of around 35% due to the high efficiency of the micro gas turbine. BEVs have an efficiency of 42-72% when powered by renewable sources but suffer from substantial energy losses in charging, grid transmission, and battery degradation.
Traditional hybrid vehicles, using internal combustion engines (ICEs), experience inefficiencies at lower speeds and variable loads, with peak ICE efficiencies typically at 30-40% but much lower in real-world driving conditions. In addition, delivering fuels to the ICEs add the environmental burden of these vehicles. So-called e-fuels are, in principle possible but not available now.
The proposed vehicle offers an estimated range of 50 km on battery alone and 523 km with the MGT-powered generator and a 90-l methane tank, making it competitive with conventional ICE and hybrid vehicles in terms of long-range usability.
Unlike BEVs, which require extensive charging infrastructure, the HEV with MGT can refuel quickly using existing fuel infrastructure for methane or hydrogen, reducing dependency on developing charging networks.
BEVs provide zero tailpipe emissions but face sustainability challenges due to battery production, possibly emitting power generation and end-of-life recycling issues. Conventional HEVs still depend on ICEs, which operate very inefficiently at low loads, leading to unnecessary fuel consumption. The HEV with MGT bridges this gap, offering a sustainable alternative with lower emissions, better fuel flexibility, and improved overall efficiency.
The HEV with MGT presents a compelling alternative to both BEVs and traditional hybrids, combining electric propulsion with a highly efficient, fuel-flexible micro gas turbine. It mitigates resource scarcity issues linked to battery production, reduces dependency on charging infrastructure, and enhances efficiency through CHP principles. Additionally, by enabling the use of e-hydrogen or biomethane as fuel sources, this hybrid system provides a pathway toward a low-carbon transportation future. As the automotive industry moves toward sustainability and carbon neutrality, the HEV with MGT stands out as a promising, efficient, and environmentally responsible solution.