Future electricity demand and grid connections of electric road systems for heavy transport
Typ
Examensarbete för masterexamen
Program
Sustainable energy systems (MPSES), MSc
Publicerad
2020
Författare
Front, Robin
Raisse, Martin
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
This thesis investigates the potential implementation of electric road systems (ERS), a
novel technology created with the purpose of electrifying future transport in order to
reduce greenhouse gas emissions. Using this technology, electricity is delivered from the
electricity grid to the road and further onto the vehicles travelling on the road. This
thesis considers the implementation of an ERS for heavy transport such as heavy trucks
and buses.
More specifically, the purpose of this thesis is to study how the connection points (electrical
substations) from an ERS can be placed along the road and how the varying electricity
demand from the road will affect the dimensional requirements of the equipment used. This
was studied via a case study of the E6 route in Sweden assuming three different vehicle
electrification scenarios derived from climate goals as well as electrification trends and
statistics: 40%, 70% and 100% electrification. The average and peak electricity demand
of the vehicles were calculated using a mathematical model. Three cases of substations
placement were assumed; the first case was based on a previous proposition from the
report Slide-in Electric Road System where the electrical substations are placed with a
40 km distance between each other, the second case was based on assuming there is
available capacity in existing substations and connecting the ERS to these, the third case
was based on the geographical load distribution of the ERS by making an investment cost
optimization based on cost of cables and substation equipment. This was done assuming all
substations were dimensioned by the same power and the optimization model was created
to find out the optimal substation dimension, balancing the number of substations and
their investment cost against the cost of the cables connected to the road between the
stations.
It can be concluded that if spare capacity in existing substations is sufficient it would
obviously be the least cost alternative to use these substations. However, data regarding
existing capacity is classified making it difficult to draw any conclusions. But generally
the grid strength is weaker in southern parts of route E6 where demand is high and
production is low, possibly making current substations unsuitable. Therefore, if additional
substation capacity is required a cost optimization will lead to best return of investment.
The substation dimensions for the three scenarios based on the cost optimization were 45
MWfor the 40% scenario and 48MWfor both the 70% and the 100% scenario, for route E6.
At larger dimensions, the cable costs are increasing rapidly while the investment cost of the
substations are low. As the cables make up most of the total cost, the solution is defined by
the balance of cable versus substation cost at these dimensions. Another conclusion is that
the expected peak electricity demand is a large factor when dimensioning the substations,
as traffic during peak hours can be 3-4 times higher than the average yearly traffic. If usage
of the ERS during the worst peak hours can be avoided, large dimensioning requirements
can be cut and the investment costs can be reduced by a considerable amount. For the
cases with low electrification, the model resulted in few substations along route E6, making
the distance between stations very long which can have negative effects related to voltage
drop and power losses.
Beskrivning
Ämne/nyckelord
Electric road system , ERS , Electricity grid , Electrical substations , Ramp-up , Climate target , Cost optimization