The following article addresses the problematic of electrification of heavy duty vehicles. The content was prepared by electro company, providing services for energy generation from renewable energy sources (Elektro Ljubljana RES, Ltd) and supported by BSC, Ltd, Kranj (RDA of Gorenjska), for the preparation of the training material for public authorities, in the scope of e-SMART project. The challenge is much more demanding, than for electrification of passenger cars and at the moment we are still way from the ideal solutions.
Since there are many unanswered problems still related with wide introduction of battery-based e-HDVs mentioned in previous slides, there is a lot of space for alternatives. Hydrogen and so called synthetic gases are promising technologies that are solving the range problem by eliminating need for heavy batteries. But on the other side, they are not so energy efficient, since the total cycle of use has so far low efficiency and synthetic gases are not totally CO2 emission free. Lower total cycle efficiency requires therefore more energy from renewable clean sources.
Will at the end prevail battery based e-HDVs or alternative power train vehicles based on hydrogen or synthetic gases is difficult to say now. It is important, that equal support is given to both developments and that politics just set up the rules, what is acceptable in terms of carbon emissions and environmental care, while they leave the final decision of which fuel is viable to the users of such vehicles. They are the only ones that can give the objective answer.
From the distribution perspective, e-HDV charging is a special challenge due to high power required. We cannot expect that local RES will be always available when needed, so power will need to be transferred from other locations too. This is not possible with weak medium voltage distribution networks that we have now. Smart charging is not acceptable except for depot charging, since trucks should be on the road and not waiting for sufficient power from the network. To avoid very high investment costs, charging locations will have to be located where power network is strong enough. And in order to return investment and to be economically viable, they need to be used a lot, so they should be located in the main logistic nodes to provide enough consumption. For compatibility with RES, high capacity energy storages need to be attached, which even increase needed investment.
To conclude this article, starting point of e-HDV electrification is probably in battery based EVs with manual charging systems with cables and standardized plugs and communication, as it is done in the case of passenger cars. Depot is the right starting point, since decision for electrification can be met by only one company and power required is still manageable. For higher power charging locations, busiest transit nodes with strong electric power network connections are the first candidates. In the case of Slovenia, this could be the existing petrol station Ljubljana Barje with its central location on the crossroad of both main transit corridors of the country and 110 kV network almost at the location.
However, investment in high power charging infrastructure is really high and before very wide standardization and consent about technical solutions of electrification of the freight transport is met; investment in these facilities is quite risky.
Hydrogen based powertrains could be a good alternative, since they solve problem of range and energy storage, however they have so far very low total cycle efficiency.