BEV, PHEV, ICE vehicles and the role of hydrogen storage and carbon capture and storage for decarbonisation of private transport

Panel: 6. Transport and mobility

This is a peer-reviewed paper.

Authors:
Marcel Clemens, OMV Exploration & Production GmbH, Austria
Torsten Clemens, OMV Exploration & Production GmbH, Austria
Markus Zechner, Stanford University / OMV E&P, USA

Abstract

We compared CO2 emissions of Battery Electric Vehicles (BEV), Plug in Electric Vehicles (PHEV) and Internal Combustion Engine Vehicles (ICE). We defined user profiles for small car users and commuters. We looked into three different electricity generation mixes: coal-dependent countries, natural-gas dependent countries and hydropower dependent countries to determine breakeven times for CO2 emissions and total CO2 emissions of the respective cars. We investigated the sensitivity of various parameters and the impact of Carbon Capture and Storage (CCS) and hydrogen storage on total CO2 emissions for the various cases.

The results show that to be able to compare CO2 emissions of various vehicle types, additional information to the Worldwide harmonized Light vehicle Test Procedure (WLTP) is required: battery production related CO2 emissions, CO2 intensity of the energy mix in the respective country, electrical consumption (for PHEVs electrically driven only), and fuel consumption (for the PHEV driven with petrol only). For PHEVs, it has to be estimated which total percentage is driven electrically (Electrical UTility – EUT) to determine the actual CO2 emissions.

In countries dependent on coal for electricity generation, the emission reduction by driving EVs instead of ICEs is limited. In particular larger battery sizes even increase CO2 emissions compared with ICEs for the cases investigated here. For gas dependent countries, CO2 emissions can be reduced by 30 % when BEVs are driven instead of ICEs. Dependent on battery size and EUT, driving PHEVs leads to higher or lower emissions than BEVs for these countries. Substantial CO2 emission reduction can be achieved for hydropower dependent countries. For these countries, BEVs with small batteries result in 70 % lower CO2 emissions than the respective ICEs.

The analysis shows that reduction of the CO2 emissions from electricity generation has the highest sensitivity on CO2 emissions from EVs in coal dependent countries. Carbon Capture and Storage (CCS) can be retrofitted and would lead to substantial reductions in CO2 emission per kWh produced. In gas and hydropower dependent countries, hydrogen storage could contribute to deep decarbonisation (Sustainable Development Scenario of the IEA) of private transport. To store energy, electricity from fluctuating renewable energy sources could be converted into hydrogen and the hydrogen could be injected into salt caverns or porous media. CCS could be used to geologically store CO2 which is generated when hydrogen is produced from hydrocarbon gas.

For deep decarbonisation, CO2 emissions related to battery production need to be addressed, as those are dependent on the energy mix in the country in which the batteries are produced. CCS or hydrogen storage will be required to decrease those CO2 emissions.

Watch presentation