Energy Infrastructure for Road Transport Electrification
Doctoral thesis, 2026
This thesis analyzes the interactions that occur between electricity and road transportation systems. It explores the infrastructure required for the indirect electrification of heavy transport using hydrogen as an intermediary energy carrier and the direct electrification of passenger vehicles. Multiple models were developed and applied to study the infrastructural requirements for the supply of hydrogen to refueling stations and the electricity grid capacity required for home charging of electric vehicles (EVs).
A comparison of the different hydrogen supply systems, all of which use electrolysis to produce hydrogen, reveals substantial differences in the costs for supplying hydrogen to refueling stations. For the Swedish case studied, a system in which electricity is supplied from the electricity grid with onsite production at the refueling station is found to be the least-costly option, as compared with centralized hydrogen production with transportation to the station. The most-expensive option is to produce hydrogen using local solar PV and/or wind power instead of connecting to the electricity grid.
A model of the Swedish low-voltage (LV) electricity grid was developed to study the impacts of EV home charging on the LV grid as the share of EVs increases, as well as the ways in which these impacts are influenced by different network tariff designs. The results show that the number of power system violations in the LV grid (defined as exceeding the operational limits for thermal capacity and voltage magnitude) increases as the share of EVs in the vehicle fleet grows. However, the number of occurrences with violations varies significantly across geographic regions in Sweden and across EV charging cases. Even with a high level of EV penetration, some areas have zero violations, while in other areas, violations are recorded already at small EV fleet shares.
Implementing different network tariff designs significantly impacts when and to what extent it is cost-optimal to charge EVs. Thus, there are impacts on the loading of the LV grid and the flexibility that EV charging can provide to the electricity system by adapting to variable electricity spot prices. Cost-minimizing EV charging with no network tariff or a tariff for the monthly peak power demand of individual households during daytime hours provides the highest level of flexibility for EV charging from the electricity systems' perspective, but also the highest loading on the LV grid. Having a network tariff based on the monthly peak power of individual households, including all hours of the day, results in the lowest loading on the LV grid, but also entails the lowest level of flexibility. Combining the results, a trade-off emerges between adapting EV charging to low electricity spot prices and reducing the loading on the LV grid. Implementing a network tariff for the combined peak power of all modeled households provides an alternative that lowers the loading on the grid, yet retains greater flexibility than when the cost is implemented at the household level.
Given that EV charging behavior strongly impacts the loading on the LV grid, different charging strategies in a fully electrified vehicle fleet lead to significant variation in the required transformer capacity and, thereby, the extent of LV grid reinforcement.
A comparison of the different hydrogen supply systems, all of which use electrolysis to produce hydrogen, reveals substantial differences in the costs for supplying hydrogen to refueling stations. For the Swedish case studied, a system in which electricity is supplied from the electricity grid with onsite production at the refueling station is found to be the least-costly option, as compared with centralized hydrogen production with transportation to the station. The most-expensive option is to produce hydrogen using local solar PV and/or wind power instead of connecting to the electricity grid.
A model of the Swedish low-voltage (LV) electricity grid was developed to study the impacts of EV home charging on the LV grid as the share of EVs increases, as well as the ways in which these impacts are influenced by different network tariff designs. The results show that the number of power system violations in the LV grid (defined as exceeding the operational limits for thermal capacity and voltage magnitude) increases as the share of EVs in the vehicle fleet grows. However, the number of occurrences with violations varies significantly across geographic regions in Sweden and across EV charging cases. Even with a high level of EV penetration, some areas have zero violations, while in other areas, violations are recorded already at small EV fleet shares.
Implementing different network tariff designs significantly impacts when and to what extent it is cost-optimal to charge EVs. Thus, there are impacts on the loading of the LV grid and the flexibility that EV charging can provide to the electricity system by adapting to variable electricity spot prices. Cost-minimizing EV charging with no network tariff or a tariff for the monthly peak power demand of individual households during daytime hours provides the highest level of flexibility for EV charging from the electricity systems' perspective, but also the highest loading on the LV grid. Having a network tariff based on the monthly peak power of individual households, including all hours of the day, results in the lowest loading on the LV grid, but also entails the lowest level of flexibility. Combining the results, a trade-off emerges between adapting EV charging to low electricity spot prices and reducing the loading on the LV grid. Implementing a network tariff for the combined peak power of all modeled households provides an alternative that lowers the loading on the grid, yet retains greater flexibility than when the cost is implemented at the household level.
Given that EV charging behavior strongly impacts the loading on the LV grid, different charging strategies in a fully electrified vehicle fleet lead to significant variation in the required transformer capacity and, thereby, the extent of LV grid reinforcement.
Transport electrification
Network tariffs
Hydrogen refueling infrastructure
Electric vehicles
Energy systems analysis
Hydrogen supply
Grid congestion
Low-voltage grid
HA1, Hörsalsvägen 4
Opponent: prof. Patrick Plötz, Fraunhofer Institute for Systems and Innovation Research ISI, Germany
Author
Therese Lundblad
Chalmers, Space, Earth and Environment, Energy Technology
An open data-based model for generating a synthetic low-voltage grid to estimate hosting capacity
Sustainable Energy, Grids and Networks,;Vol. 39(2024)
Journal article
Centralized and decentralized electrolysis-based hydrogen supply systems for road transportation – A modeling study of current and future costs
International Journal of Hydrogen Energy,;Vol. 48(2023)p. 4830-4844
Journal article
Lundblad, T, Perotti, E, Taljegard, M. & Johnsson, F. The role of network tariffs in steering electric vehicle charging and household peak power demand
Lundblad, T, Taljegard, M., Mattsson, N., Perotti, E, & Johnsson, F. Assessing the impact of fleet electrification on low-voltage grids: the role of network tariffs in mitigating power system violations
Electrifying road transportation requires more than just electric vehicles; it also requires new infrastructure to supply energy in different forms. This thesis models the infrastructure needed in Sweden for two different approaches to electrification: using hydrogen as a fuel and directly charging battery electric vehicles.
For indirect electrification by hydrogen, several ways of supplying hydrogen to refueling stations were compared. Producing hydrogen directly at the refueling station using electricity from the grid was found to be the cheapest option. This system is more cost-effective than either a system that produces hydrogen onsite in “island-mode” without being connected to the electricity grid or a system where hydrogen is produced at a central facility and transported to the refueling station.
For direct electrification, this thesis investigates how home charging of electric vehicles could affect local electricity grids. Electric vehicle charging was analyzed under electricity spot prices (that reflect the balance between electricity generation and demand in an electricity price area), combined with different network tariff designs (which are the fees households pay the grid owner to use the electricity grid). The results show that the risk of overloading in the local grid increases as the share of electric vehicles increases. However, the impacts vary greatly between different areas and are strongly dependent on how the vehicles are charged.
The modeling in this work shows that network tariff design has a large impact on when and to what extent it is cheapest to charge electric vehicles. Some tariff designs allow electric vehicles the flexibility to follow varying spot prices of electricity, but at the cost of increased loading on the local grid. Other designs limit the loading on the local grid but give vehicles lower flexibility to follow low spot prices. The results thereby reveal a tradeoff between adapting electric vehicle charging to low electricity spot prices and reducing loading on the local grid. A network tariff for the combined peak power of households provides a compromise that reduces the load on the grid, while still allowing for some flexibility.
For indirect electrification by hydrogen, several ways of supplying hydrogen to refueling stations were compared. Producing hydrogen directly at the refueling station using electricity from the grid was found to be the cheapest option. This system is more cost-effective than either a system that produces hydrogen onsite in “island-mode” without being connected to the electricity grid or a system where hydrogen is produced at a central facility and transported to the refueling station.
For direct electrification, this thesis investigates how home charging of electric vehicles could affect local electricity grids. Electric vehicle charging was analyzed under electricity spot prices (that reflect the balance between electricity generation and demand in an electricity price area), combined with different network tariff designs (which are the fees households pay the grid owner to use the electricity grid). The results show that the risk of overloading in the local grid increases as the share of electric vehicles increases. However, the impacts vary greatly between different areas and are strongly dependent on how the vehicles are charged.
The modeling in this work shows that network tariff design has a large impact on when and to what extent it is cheapest to charge electric vehicles. Some tariff designs allow electric vehicles the flexibility to follow varying spot prices of electricity, but at the cost of increased loading on the local grid. Other designs limit the loading on the local grid but give vehicles lower flexibility to follow low spot prices. The results thereby reveal a tradeoff between adapting electric vehicle charging to low electricity spot prices and reducing loading on the local grid. A network tariff for the combined peak power of households provides a compromise that reduces the load on the grid, while still allowing for some flexibility.
Driving Forces
Sustainable development
Areas of Advance
Transport
Energy
Subject Categories (SSIF 2025)
Transport Systems and Logistics
Energy Engineering
Energy Systems
DOI
10.63959/chalmers.dt/5851
ISBN
978-91-8103-394-6
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 5851
Publisher
Chalmers
HA1, Hörsalsvägen 4
Opponent: prof. Patrick Plötz, Fraunhofer Institute for Systems and Innovation Research ISI, Germany