ICE – A hard habit to break by Mark Matchett
With the phrase “Low Carbon” being used so often today and with the reputation of the Internal Combustion Engine (ICE), being hindered in recent times by events such as the emissions scandal, what future remains for combustion engines in road transport? Additionally following Brexit, with ambiguity around the role of the EU, how do UK developers of engines and new engine concepts plot the course ahead?
Whatever your thoughts on the EU, you can’t easily ignore the work carried out by the host of technical working groups, which offer informed opinion and develop roadmaps for the future of tech and industries in wide range of sectors. The roadmap on ICE Powertrains recently published by European Road Transport Advisory Research Council, (ERTRAC) is a great example of this good work, predicting that at least 60% of new passenger cars will utilize ICE in some form out to 2040.
As good as Diesel?
Future mobility solutions need to be sustainable, yet the changes required also need to be accepted by consumers to ensure uptake; in many ways new solutions need to be “as good as diesel” from a user experience perspective.
However, the need to switch isn’t purely driven by the need for a low carbon future. From a European and UK perspective, “energy security” - including the use of sustainable energy from renewable sources - also counts. Optimisation of the use of transport assets – via connectivity and automation - will also play a considerable part, but what ever the propulsion or transport systems end up looking like, if the initial energy source isn’t sustainable, then in my book, it simply isn't low carbon.
Against that background, the roadmap on ICE Powertrains still predicts at least 60% of new passenger cars will utilize ICE in some form out to 2040. It lists hybrid and range extended powertrains as well as natural gas engines as parts of the future mix.
The roadmap outlines a 4 pillar concept of the elements that contribute to low carbon low emission transport economy.
Figure 1.1 ERTRAC systems approach with pillars for decarbonisation and emission reduction
Whilst the authors of the roadmap play on its informative role to European Funding Programmes such as Horizon 2020, (helping to direct investment in research) less obvious is its importance and its ability to cement the investment case for many small or medium sized enterprises (SME’s) working in areas of new ICE powertrain research; with the EU targeting a 40% cut in Green House Gasses, (GHG) by 2030, there’s enormous opportunity for innovators in this sector, many of which exists in the UK. SMEs are well advised to refer to the roadmap when seeking investment funding, as it sets out the requirements and rationale useful to developing a business case.
But what about fuel?
The roadmap sees fossil based fuels dominating road transport until at least 2030, with renewable liquid fuels, methane, and electricity contributing heavily beyond this. The ICE is seen as being predominantly fuelled by fossil derived fuels, but increasingly complimented by synthetic fuels, power to liquid and gas, (PtX) as well as advanced bio fuels and, natural and biogas. PtX are fuels which store carbon in an energy dense synthetic fuel which can then be combusted much the same way petrol, diesel and natural gas is today, with the major difference being that it requires electricity to power the process.
Figure 2.2 The evolution of passenger road transport energy towards 2040
Two step pathway
The predicted engine / fuel combinations will be developed in order to optimise not only tail pipe performance, but also, crucially, the Well-to-Wheel performance. According to the roadmap, a second pathway to decarbonisation - electrification - will evolve at a quickening pace. The roadmap predicts new ICE concepts appearing, to satisfy differing needs; the need for transient performance (efficiency when the engine speed and load is constantly changing) is not a requirement for ICE in a range extender as it is for todays conventional vehicles.
While electrification will dominate inner city and urban scenarios its still predicts that vehicles used for longer distance journeys will be the lions share of the fleet and will continue to use more traditional ICE powertrains.
In Heavy Duty freight transport, where the loss of payload that electrification would bring adversely impacts emissions per tonne of freight carried (because more trucks would be needed to haul the same payload) it predicts decarbonisation will be more dominated by ICE and advanced and alternative / bio fuels than on electrification.
Mmmmm, Hydrogen .
With regards to hydrogen, the road map sees progress on system cost and renewably produced hydrogen being likely negated by advances in battery technology (in electrified propulsion systems), and improvements in the availability of re-charging infrastructure that is the current Achilles heel of full electric vehicles. The roadmap concludes that ultra efficient ICE and low carbon fuels such as gas, will play a major role up to 2040 and possibly beyond.
So where is the smart money
So, armed with the conclusions drawn from these respected EU predictions, developers of new ICE technologies and advanced low carbon fuels will be able to convince potential investors or funders of the value of continued investment in ICE technologies. Internal combustion engines will not go away with the rise of electrification, they will simply become more complementary. The road map continues to outline the synergy of ICE in a hybrid powertrain; electric propulsion operates efficiently in transient conditions, but the ICE can outperform in high power scenarios and where range is a key factor, especially if designed in combination with novel transmissions and braking systems.
So there’s also an opportunity for system integrators. Other opportunities highlighted in the report include reducing heat and friction losses, waste energy recovery systems and the contribution of advanced materials.
The report also strengthens the case for investment into scalable production of PtX, with Power to Liquid having a particular attraction as an energy carrier with drop in potential to decarbonise existing vehicles in existing fleets (an “as good as diesel “ solution).
In addition, the recent EU communication, “A European Strategy for low-Emission Mobility” (Com(2016) 501 for those that want to look it up), begins to show the direction of political thinking.
Regarding fuels, the EU strategy document expresses concerns about transport's reliance on oil, (94% of transport energy in the EU). It uses as an example possible legislation to mandate blends including advanced bio fuels and synthetic fuels (Power to X). The EU, the document suggests, will focus on the phased replacement of food based bio fuels with advanced bio fuels, also promising to consider the investment required to make this possible. Amongst the options, it quotes lorries and coaches being well suited to advanced bio fuels as well as gas and synthetic methane (Power to Gas technologies). The document of course also emphasises existing directives on alternative fuel infrastructure roll out making strong reference to electric recharge points for EV’s but also acknowledges the need for improvements in combustion engines and that low emission vehicles will complement zero emission vehicles as part of Europe’s fleet.
But what about the user?
For a variety of reasons today's fully electrified vehicle doesn’t satisfy the user experience demands of many of today's motorists. Efforts by innovators and vehicle manufacturers continue to chase this up the curve such that the uptake of electrified vehicles takes off. In parallel, advocates of the convenience factor and innovators of Thermal Propulsion Systems, (the new term used by the UK Automotive Council for internal combustion engines) also continue to look for new options. Both pathways however have the same head wind of cost to contend with.
One recent study “Alternative Fuels in the well to wheel debate” by FVV offers some perspective on how the apparent contradiction between user experience and low emissions might be resolved. Using a German example, the report sets out to demonstrate the feasibility of storing sustainable electricity in liquid or gaseous fuels which can be used to fuel a thermal propulsion system rather than stored completely in a battery (in a fully electric vehicle). The variety of propulsion systems, conventional ICE, hybrid or fully electrified are really just ways of converting energy into motion, each having different convenience, cost, and emission characteristics. The basic problem with conventional hydrocarbon fuels is that the creation of these natural resources, their use, the subsequent carbon releases and reabsorption by nature are on massively different time scales..... Enter global warming and climate change.
What does this do for carbon emissions?
There are 2 major advantages of using renewable power to create liquid or gaseous fuels.
1. It provides the energy dense fuels needed by many forms of transport to provide range and convenience to users, and combined into a hybrid electric propulsion system can also enable low emission vehicles with a user experience good enough to drive uptake by consumers, in turn delivering the air quality improvements demanded in our cities.
2. It creates the timely closure of the carbon cycle, where the carbon released by the burning of the synthetic fuels is exactly the same amount as the carbon (being extracted from ambient air), subsequently re synthesised into a renewable liquid or gas using PtX processes and renewable power. Almost like a circular carbon economy.
So from a technological view the solution to carbon emissions is renewable power, not just electricity produced in a conventional way. Taking a big picture view, the challenge is to find a way to store it with sufficient density as to provide the user experience required driving uptake; and that isn’t necessarily going to be a battery on its own.
Convenience, Cost, and Emissions.
So, having talked about Convenience and Emissions, what about Cost. The FVV report mentioned above goes into some detail when considering future scenarios of transport demand and the mix of propulsion systems in play. These scenarios are created in the first place to profile estimates of the infrastructure costs involved to support these via renewable power and PtX, and secondly to characterise the likely unit costs for these alternative fuels at the pump. In all scenarios (based again on a German example), a target for 100% renewably powered transport is set at 2050. When the numbers are crunched the report suggests investment of between €600bn and €1400bn would be required for the necessary infrastructure. Between 70 to 80% of this investment, it is predicted, would be in renewable power plants, representing between 5 and 15 times the existing German installed capacity. Taking a middle scenario of €1000bn amortised over the 35 years to 2050 equates to low single digit percentages of the German national GDP, a figure which the report suggests is manageable.
So, with the economic cost in context, what about the cost to the consumer. For the purpose of this analysis the FVV report references a separate piece of work by Ludwig- Bölkow-Systemtechnik GmbH. The analysis is based on a 2050 oil price of $100 per barrel and estimated costs for energy and annual opportunity for renewable power generation based on a German example. The output from the analysis suggests that for a variety of fuel types (synthetic gas or liquid fuels excluding taxes) a price of of around €2.5 per diesel equivalent litre where 80% of this is the renewable power required in the process. Compared to €0.61 for diesel based on $100 oil, this is a significant difference, but one that seems surprising low to me considering the environmental benefits it could produce. The report goes on to suggest that new business models such as the use of concentrated carbon dioxide directly from process industries eroding the difference, as could the relative natural advantages of one country to the next (opportunity for renewable generation).
What does it all add up to?
My take on this is that in the long term, users will have a strong influence on the switch to low and zero emission mobility and that as a result one size probably won't fit all. The result will most likely be a mixture of propulsion technologies to fit the pocket preferences and needs of individuals and businesses. Thermal Propulsion will almost certainly retain a significant role in vehicle propulsion due to its flexibility, and like many other technologies - including hydrogen fuel cells, and batteries for electrification - will continue to improve. But it’s the role of renewable power that is the common enabler of low and zero emissions mobility, not just electrification. New ways to reduce the cost of converting this into increasingly dense stores will influence user preference, producing many unexpected twists and turns along the way.
The full FVV report is available on the FVV website: www.fvv-net.de