High power charging is a necessity for the electrification of heavy vehicles such as long-haul trucks, maritime vessels, electric flights and for a “fully” electrified car fleet. The amount of power needed and the effects on a system level are not fully known.
The project “High power charging – when, where and how” investigates possibilities, limitations, and show different charging scenarios. Christoffer Aalhuizen is PhD student in the project.
What is your background Christoffer?
I have a dutch surname, Aalhuizen, from my grandfather but I’m born and raised in Dala-Järna, hometown of the legendary Swedish cross-country skier Gunde Svan. I have studied both engineering and economics at Uppsala University where I now conduct my PhD studies. In between I worked for the municipality and companies calculating costs for transitioning to a fossil-free vehicle fleet, something that I found very interesting and is one of the reasons that I now pursue a PhD within this area.
Explain what the project is about
Heavy vehicles used in commercial transporation and industry have battery sizes from 600 kWh or higher. They also need to be charged fast to be economically competitive, preferably no longer than 45 minutes which is the stipulated resting time for truck drivers. Fast charging of long-haul heavy vehicles will likely require chargers capable of providing more than 1 MW, yet how this fast charging affects the power system is something that we don’t have any reliable models for today. The aim is to investigate how the grid can meet the requirements from the vehicles and how the vehicles can meet the requirements from the grid, and what possibilities they have to strengthen each other. We will focus on the interface between grid and vehicle and vehicle to vehicle and on the charging infrastructure needed in weak grids, where we are going to do simulations in combination with fast charging, local production and storage.
What are the main challenges?
Fast charging with high power requires a high voltage output with significant peaks and drops that affect the whole systems. The presumption is that the closer a charging stations is to the power source the better. Many transportation routes follow the same pattern which leads to charging “hot-spots”. Finding suitable locations for these “hot-spots” is one challenge. Other locations like harbours, airports and mines are rather fixed and are often found far out in the grid. Then we must perhaps have other types of local flexible solutions.
Why not just use bigger cables?
Haha, well, bigger cables makes things easier with power output, but it’s also very costly so I don’t see that as a pragmatic solution, at least not short-term. We will probably need different types of storage and auxiliary solutions to handle the large variations. This project is mainly about modelling requirements so we don’t have all the solutions right away. What we hope to achieve is to establish common grounds for vehicles and grid to enable high power fast charging.
When are you presenting your findings?
I’m currently finishing up drafts for two papers, one about potential power peaks at airports with electrical aircrafts and one of a model estimating power requirements from the power grid for charging long-haul heavy duty electric trucks. On a similar note you can also read this article where I collaborated with RISE where we estimated the effects from implementing charging of electric aircrafts, photovoltaics and a small airport a battery energy storage at a small airport: https://doi.org/10.1016/j.apenergy.2023.121946