Written Evidence Submitted by the Centre for Sustainable Road Freight
Response by Prof D. Cebon* and Dr D. Ainalis
Centre for Sustainable Road Freight, University of Cambridge
The Centre for Sustainable Road Freight (SRF) was founded in 2012 to help industry and Government minimise Carbon emissions from the road freight sector. The SRF brings together three of the UK’s leading academic groups: Cambridge University Engineering Department, Logistics Research Centre of Heriot Watt University and the Freight and Logistics Research Group at the University of Westminster, along with industry and government partners; to make road freight environmentally, economically and socially sustainable. The SRF receives funding from various UK Government sources, particularly UKRI (EPSRC), ETI, and InnovateUK, as well as from industry members.
This submission discusses the technical and economic challenges faced by hydrogen technologies in meeting the decarbonisation timescales needed, in comparison with the least cost, most efficient option - direct electrification.
Unless specified otherwise, this response is based on a series of articles comparing hydrogen and electrification, by D. Cebon: see references , , , and .
The Prime Minister Boris Johnson recently announced a new target to reduce UK carbon emissions by 68% (relative to 1990 levels) by 2030. This reduction is an admirable milestone on the way to the government’s ‘net zero’ Carbon emissions commitment by 2050. These targets highlight the fact that extreme measures need to be implemented rapidly (beginning within the current decade) to prevent using up the remaining Carbon budget – so as to avoid global warming exceeding 1.5°C. ‘Shovel ready’ solutions, with high Technology Readiness Levels (TRLs), and viable business cases are the only ones that can be implemented in time. There are myriad solutions on the table to reach these targets, primarily focused on the use of electrification and/or hydrogen. There are three application areas where use of hydrogen has been highly cited for meeting decarbonisation targets: 1) heavy goods vehicles (HGVs), 2) heating buildings, and 3) energy storage.
HGVs carry 90% of goods lifted  and produce 5% of the UK’s total greenhouse gas emissions . This represents a vital part of the economy, a significant source of Carbon emissions, and is a ‘difficult to decarbonise’ sector.
Hydrogen-powered trucks offers hauliers the benefit of fitting into the existing logistics system; they can be refuelled in approximately the same time as diesel trucks and can likely maintain similar operating ranges and patterns without significant change from current logistics practice. However, hydrogen is much more energy intensive than electricity and consequently is inherently more expensive for the economy, the environment and probably for the vehicle operator.
As 2/3 of HGV journeys (by vehicle-miles) are on the major road network, Electric Road System (ERS) technology could provide deep decarbonisation (approximately 90% from 2016 levels by 2040) with the lowest energy requirements . Such a system would distribute the electricity charging requirements around the UK land area, with consistent power requirements through the day, instead of major electricity hot-spots in depots at night, required by battery electric lorries. European trials have demonstrated that eHighway technology could be rapidly deployed around the UK’s major road network within the next 15-20 years at an estimated cost around to be about £20 billion .
Compared to direct electrification, via ERS, there are numerous challenges for hydrogen to overcome:
Heating buildings without carbon emissions poses a significant challenge to the UK’s net zero targets. There are three main options for heating using electricity or hydrogen: 1) heat pumps, 2) electric space heaters, and 3) hydrogen boilers. Electric space heaters are significantly more efficient than hydrogen boilers, delivering 90% more heat for the same input energy, and can utilise existing electrical infrastructure .
Heat pumps can deliver much more heat into a building than the electricity they use. Assuming a realistic Coefficient of Performance of 3.0, a heat pump can produce 3-times more heat than electricity input (see  for a good explanation of how heat pumps work).
Comparing hydrogen boilers to heat pumps, the challenges faced are:
It is unlikely that the infrastructure needed for Blue or Green hydrogen could be built in time for 2040, and to meet net-zero targets.
Government policy should promote and encourage heat pumps for heating new and retrofitted buildings. Heat pumps provide the most effective way to reduce carbon emissions from heating, and are available off-the-shelf, now.
A key issue in the low carbon future is electricity storage. Because of the variability of sustainable electricity (wind, solar) and its lack of synchronicity with the peaks of electricity demand, there is a need to store electricity at times of excess supply for use at times of high demand. Proponents of a Green hydrogen Economy propose to solve the electricity demand problem by using excess electricity to make hydrogen by electrolysis; storing it in underground salt caverns; and converting it back to electricity at peak times. In the renewable electricity future, the UK will need an estimated 65 GWh of intra-day storage and 16 TWh of inter-seasonal storage, both supplied at powers in the range 5-8 GW .
Challenges for hydrogen to store grid-scale energy include:
The time is rapidly approaching for the UK Government to ‘pick technology winners’ in this area. Without Government decisions on which technologies to support and the legislative and financial environments to support them, there is little chance of achieving the 2030 target. The challenges associated with hydrogen decarbonising the UK are:
 Cebon, D. ‘Blog: Long-Haul Lorries Powered by Hydrogen or Electricity?’, [online] available at: http://www.csrf.ac.uk/2020/02/blog-long-haul-lorries-powered-by-hydrogen-or-electricity/.
 Cebon, D. ‘Blog: Hydrogen for Heating, [online] available at: http://www.csrf.ac.uk/2020/09/hydrogen-for-heating/.
 Cebon, D. ‘Blog: Technologies for Large-Scale Electricity Storage’, [online] available at: http://www.csrf.ac.uk/2020/11/electricity-storage/.
 Cebon, D. ‘Blog: Electron or Hydrogen Economy’, [online] available at: http://www.csrf.ac.uk/2020/12/electricity-or-hydrogen-economy/.
 DfT (2018) Freight Statistics, TSGB0401: ‘Domestic freight transport by mode', [online] available at: https://www.gov.uk/government/statistical-data-sets/tsgb04-freight.
 BEIS (2020). "Final UK greenhouse gas emissions national statistics 1990-2018", [online] available at: https://www.gov.uk/government/collections/final-uk-greenhouse-gas-emissions-national-statistics.
 Ainalis, D.T., Thorne, C., and Cebon, D. ‘Decarbonising the UK’s Long-Haul Road Freight at Minimum Economic Cost’, Centre for Sustainable Road Freight, Technical Report CUED/C-SRF/TR17 July 2020. http://www.csrf.ac.uk/2020/07/white-paper-long-haul-freight-electrification/.
 Mackay, D. (2009), ‘Sustainable Energy Without the Hot Air’, pp.147-154, UIT Cambridge, England.