HYDROGEN APPLICATIONS IN TRANSPORT HFCV VS EV VS ICE, PRODUCTION ROUTES, KEY CHALLENGES, ECONOMICS, TRANSITIONING COMPANIES AND PLANNED PROJECTS Cameron Rout, James Hammerton & Hu Li
SEPTEMBER 2019 Table of Contents:
Executive Summary ...... 6
1. An Introduction to Hydrogen Fuel ...... 7
1.1. A Brief Background ...... 7
1.2. Hydrogen vs Conventional Fuels ...... 8
1.3. Comparison of FC vs EV vs ICE vehicles ...... 9
1.3.1 Emissions ...... 11
1.3.2. Infrastructure ...... 12
1.3.3. Technology Maturity ...... 14
1.3.4. Driving Range ...... 16
1.3.5. Fuel Purity ...... 17
1.3.6. Overall Cost ...... 18
1.4. H2 Production Routes ...... 19
1.4.2. Reforming and POx ...... 19
1.4.3. Electrolysis ...... 21
1.4.4. Renewable Liquid Reforming ...... 22
1.4.5. Fermentation ...... 23
1.4.6. Photo Electrochemical (PEC) Water Splitting ...... 23
1.4.7. Photobiological ...... 23
1.4.8. Types of Production Facilities ...... 24
1.5. Key Challenges to H2 Implementation (Storage, Infrastructure Etc.) ...... 25
1.5.2. Storage ...... 25
1.5.3. Distribution and Delivery ...... 26
1.5.4. Infrastructure ...... 28
1.5.5. Standards and Safety: ...... 28
1.5.6. Cost: ...... 30
1.5.7. Public Response: ...... 30
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2. A Closer Look at Hydrogen Vehicles: ...... 31
2.1. Major Components of HFCVs and Operating Principles: ...... 33
2.2. Hydrogen Powered ICE Vehicles ...... 34
2.2.1. Hydrogen for Intermittent Use in ICE ...... 36
2.2.3. Dual-Fuel/Hydrogen Mixtures for ICE ...... 36
2.3. Conversion Efficiencies...... 37
2.4. The Market Position ...... 38
2.4.1. Global and UK Production and Consumption ...... 39
2.5. Manufacturing and Fuel Costs ...... 41
2.6. Lifespan and Range ...... 42
3. Planned and Approved Projects in the North/UK ...... 42
4. Current/Future Applications in Transport ...... 46
4.1. UK-Based Projects ...... 47
4.2. International Projects ...... 49
4.3. Non-Application International Projects ...... 52
5. Hydrogen Vehicle Fleets in the UK ...... 53
5.1. An Introduction to Hydrogen in the UK ...... 53
5.2. Public Access Fleets ...... 54
5.3. Governmental Fleets ...... 56
5.4. Fleet Transition Studies ...... 57
5.4.1. Knoxville Bus Fleet ...... 57
5.4.2. Policy Considerations ...... 60
6. Current and Future UK H2 Activity Map: ...... 60
6.1. All Existing and Planned UK Hydrogen Activities (Diagram and Table):Error! Bookmark not defined.
7. Proposed Actions and Objectives ...... 65
8. References: ...... 66
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List of Figures:
Figure 1 - Specific energy per unit mass of hydrogen and other fuels (Arup, 2019)...... 9 Figure 2 - Global warming potential of different vehicle types (Acar, C, 2018)...... 11 Figure 3 – All EV charging points around the Leeds region (ZapMap, 2019)...... 13 Figure 4 – The HFC tractor from 1959 (NMAH, 2019)...... 15 Figure 5 - Driving range of different vehicle types (Acar, C, 2018)...... 17
Figure 6 - SC-CO2 of different vehicle types (Acar, C, 2018)...... 19 Figure 7 - SMR process flow diagram (HydrogenEurope, 2019)...... 20 Figure 8 - Electrolysis of water to form hydrogen (energy.gov, 2019)...... 21 Figure 9 – A liquid hydrogen tanker truck (United Hydrogen, 2019)...... 27 Figure 10 - The invisible hydrogen flame (Okino, T, 2019)...... 29 Figure 11 - A typical HFC operating principle (SMMT, 2019)...... 34 Figure 12 Flammability limits of common engine fuels in terms of air-fuel ratio (λ). Note: Air-fuel ratio operation range from an engine would be narrower than shown as there are other limitations, such as flame speed and unburned fuel emissions...... 35 Figure 13 Typical variation of emissions of NOx with air-fuel ratio during homogeneous operation with hydrogen (Verhelst and Wallner, 2009; Wallner et al., 2008)...... 35 Figure 14 Improvement in the thermal efficiency of gasoline engines. From Takahashi et al. (2015) ...... 38 Figure 14 - Production and consumption of global hydrogen iMechE. (2019)...... 39 Figure 15 - Global demand for pure hydrogen (IEA, 2019)...... 40 Figure 16 - Policies supporting hydrogen transitions (IEA, 2019)...... 41 Figure 17 - Government budgets for hydrogen research over the past 15 years (IEA, 2019)...... 41 Figure 18 - Teesside's hydrogen campaign (McNeal, I, 2019)...... 43 Figure 19 - H21 North of England map Sadler, D. (2018)...... 44 Figure 20 - HyNet proposed cluster (Cadent, 2019)...... 45 Figure 21 - The 500 planned homes in Aberdeen (BBC News, 2019)...... 46 Figure 22 - Schematic of hydrogen trains operating principles (Burridge, T, 2019)...... 48 Figure 23 - Hydrogen double-decker buses in London (Barrett, T, 2019)...... 49 Figure 24 - Breeze hydrogen trains plan to come to the UK by 2022 (Alstom, 2019)...... 49 Figure 25 - Coradia iLint hydrogen train by Alstom (Alstom, 2019)...... 50 Figure 26 - Hydrogen fuel cell delivery truck by UPS (Mathews, L, 2019)...... 50 Figure 27 - Hype taxis in Paris (Roy, J, 2019)...... 51 Figure 28 - HY4 - World's first hydrogen aircraft...... 52
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Figure 29 - Skai flying taxi concept (Fish, T, 2019)...... 52 Figure 30 - Arcola Energy hydrogen bus maintenance facility (Fuel Cell Works, 2019)...... 56 Figure 31 - Toyota Mirai HFCV used by the Met Police (Fossdyke, J, 2018)...... 57 Figure 32 - Hydrogen vs conventional fuel bus data for 3 case studies (Langford, B, 2011)...... 58 Figure 33 - Knoxville bus fleet breakdown (Langford, B, 2011)...... 58 Figure 34 - Total dispensers used and associated refuelling times (Langford, B, 2011)...... 59 Figure 35 - UK hydrogen activity map...... 61
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List of Tables:
Table 1 - Opportunities and challenges of a hydrogen economy (Arup, 2019)...... 8 Table 2 - Typical emissions from all vehicle types...... 11 Table 3 - Technology maturity of ICE, EV, and HFCVs...... 16 Table 4 - Hydrogen safety pros and cons...... 29 Table 5 - Some thermochemical parameters of hydrogen and methane (Acar, C, 2018)...... 31 Table 6 Maximum power output with respect to gasoline of different fuels depending on the injection method ...... 36 Table 7 Conversion efficiencies of technologies for utilisation of hydrogen in transport ...... 37 Table 7 - Existing refuelling stations...... 62 Table 8 - Planned refuelling stations...... 62 Table 9 - Hydrogen projects...... 63 Table 10 - Hydrogen fleets...... 63
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Executive Summary
The transition towards hydrogen in the transport sector is a huge challenge, but also presents great opportunity for achieving both reduced emissions and improved air quality. Although there have been a number of studies and trials focused on hydrogen vehicles in the UK, targeted towards their performance and cost, these have been limited in their usefulness as they are based on specific fleets and locations. Other regions (such as the hydrogen corridor in the North of the UK) may not have the same resources available and this puts limitations on what these areas can achieve, for example.
This report covers the fundamentals of hydrogen for use as a future transport fuel and highlights some of the major reasons for using hydrogen in the future. In addition to this, multiple factors are discussed which must be considered in detail in the event of a transition period taking place. Some of these include hydrogen production routes, current market position, existing and planned UK projects and fleets, and advantages over conventional fuels, as well as challenges that must be overcome in order for it to compete with electrification and become a sustainable and viable alternative. These challenges include the limited refuelling infrastructure, safe storage and delivery of hydrogen fuel, production emissions, high cost, and public acceptance, for example. Also in this report is a mapped summary of the major UK hydrogen activity, and actions proposed with regards to further hydrogen research and innovation, along with potential industrial partners and refined research objectives.
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1. An Introduction to Hydrogen Fuel
1.1. A Brief Background As the population continues to soar and demand for products and services rises, it has led to an increase in energy consumption; the majority of which has been generated from fossil fuel based resources which are of course finite and lead to negative impacts including the release of greenhouse gas emissions, for example.
The transport sector is a major contributor towards greenhouse gas emissions, not only in the UK, but worldwide, with approximately one third of all carbon dioxide emissions in the UK coming from road transport in 2018 (DBEIS, 2019). Although these emissions figures have been falling in recent years thanks to the introduction of cleaner fuels and improvements in conversion efficiencies, it is still an area of concern with more awareness and pressure being put on reducing the rate of global warming. In addition to this, UK air quality has also been receiving more attention lately with the publishing of the Clean Air Strategy in 2019, aimed to lower pollutant concentration levels. On 27th March 2019, the government also issued a climate emergency in Leeds, stating that emissions must be reduced, and aimed to be carbon neutral by 2030.
In 2017, the transport sector was the largest energy consumer in the UK and represented 40% of final energy, up 0.9% compared to the year before, with road transport accounting for the majority of this, with approximately 73% (DBEIS, 2018). This has shown to slow however, with a rise of only 0.1% between 2016 and 2017, although electricity usage for road transport has increased sharply by 33% due to the growth of electric vehicles (EVs) (DBEIS, 2018). As a result, the transport sector has been much slower to decarbonise compared to other industries such as energy, for example.
The use of these alternative fuels and technological engineering advancements in the transport sector is now gaining momentum, driven greatly by the introduction of companies such as Tesla in 2003. These promote a transition towards more sustainable energy, specifically by bringing EVs to the mainstream market. However, it is not only these EVs which are predicted to overtake the fossil-fuel-dominant transport sector; hydrogen fuel cell vehicles (HFCVs) have also seen great developments in recent years and could be another major player in the future automotive industry. The use of hydrogen can alleviate some of the issues associated with fossil fuel use and there are a number of drivers for an overall wider hydrogen economy in the UK:
1. More hydrogen-related jobs available – and more tax to the government. 2. Reductions in GHGs and improvements in air quality and health. 3. More consistent price of energy – Takes advantage of renewable energy.
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4. A self-sufficient country – not dependent on other countries (high energy security).
However, although hydrogen presents a number of opportunities for decarbonising the future of the UK and several advantages compared to other energy vectors, it does still hold a number of challenges which must be overcome. These are currently under development and are outlined below:
Table 1 - Opportunities and challenges of a hydrogen economy (Arup, 2019). Opportunities: Challenges: Decarbonised gas network in city centres. Efficiencies are not high enough. Minimal GHG emissions. Lack of necessary infrastructure. High energy security and seasonal resistance. Public support is lacking. Energy storage easier than electricity. More storage space and tech needed. Safety aspects similar to natural gas. High cost. Fast vehicle refuelling and long range. Policies must be developed further. New job creation. UK can lead the global hydrogen transition.
1.2. Hydrogen vs Conventional Fuels Hydrogen is the most abundant element in the universe and is a major source of energy, making it a potential fuel for transport. It is incredibly light and versatile, giving it a very high specific energy by mass – nearly 3x as high as methane, but can rarely be found in pure form; it is almost always found as part of another compound. However, thankfully it can be produced in several ways, both sustainably and not, through processes such as steam methane reforming (SMR) and electrolysis, for example. However, as its use in fuel cells is still relatively new compared to other, more mature alternatives, it presents a series of challenges which must be overcome before it can compete in the marketplace.
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Figure 1 - Specific energy per unit mass of hydrogen and other fuels (Arup, 2019). Alternative fuels represent only a very small fraction of transport fuels in the UK, as the majority of cars on the road still run of traditional fossil fuels of petrol and diesel. 2018 saw roughly 38.2m vehicles registered on UK roads, with approximately 200,000 ultra-low emission vehicles (ULEVs), which was a 39% increase compared to 2017, representing 0.5% of total licensed UK vehicles (National Statistics, 2019). In addition, registered diesel vehicles dropped by 30%, and petrol vehicles rose 9%. Alternative fuel cars increased by 22% in 2018, with 59% of these being hybrid electrics (National Statistics, 2019).
ULEVs are those which use low carbon technology to emit less than 75g CO2/km and are growing in popularity according to statistics (SMMT, 2019). As these alternative fuels grow and develop, the use of diesel and petrol cars should decline in the future as a result, especially with the various government grants and incentives that are in place to promote their purchase and use, such as the ‘plug-in’ grant, for example.
The major difference between conventional fuels and more sustainable alternatives however is in their emissions. Typical fuels of petrol and diesel when combusted in an internal combustion engine (ICE) release harmful pollutants such as carbon dioxide, NOx, and carbon monoxide, for example. However, if hydrogen is used in a fuel cell, the process is net-zero, with emissions of only water and heat. Although this is highly dependent on the route chosen for the hydrogen as many production pathways include the release of greenhouse gases (GHGs), making the overall process less eco-friendly. So, renewable hydrogen sources must be used. Other differences include thermochemical qualities such as combustion/thermal efficiency, ignition values, diffusivity, and flammability, for example.
1.3. Comparison of FC vs EV vs ICE vehicles The current UK transport scene is a mix of different vehicle types, with the majority being made up of internal combustion engines (ICEs). However, these are highly polluting, and release large quantities of particulate matter, carbon monoxide, and NOx compounds which contribute towards poor air quality and negative health effects (Condliffe, J, 2017). As a result, the government introduced new policies and targets in 2017
9 and 2018 to have almost all cars and vans to be zero-emissions by 2050 and to reduce their numbers on the road, with the sale of new ICE petrol and diesel cars being stopped in 2040 (parliament.uk, 2019).
Alongside this, the government is pushing for a transition towards renewable alternatives such as electric vehicles (EVs) which are much cleaner to the environment, releasing zero emissions. This is being done through various financial grants and incentives, such as the plug-in grant, which offers £2,500-4,000 for certain EVs purchased, as well as the development and installation of more charging points, making infrastructure more readily available, promoting the growth of the EV market – the UK had approximately 3,800 publically funded points in 2018, although this must increase if EVs are to overtake the sale of ICEs in the future (House of Commons, 2018). With these actions taking place, it is predicted that by 2040, roughly 55% of new car sales will come from EVs (carbonfootprint, 2019).
Hydrogen fuel cell vehicles (HFCVs) are also gaining in interest by many as a potential transport option with growing concerns regarding climate change and the release of GHGs. Similarly to EVs, these emit zero emissions when renewable energy sources are employed to produce the hydrogen fuel, although this is not always the case. Their technology is also much less mature than that of EVs, with high costs for fuel cell production and a limited range of refuelling infrastructure, which demands further funding and development if public uptake is to improve in the future.
Kalghatgi et al investigated the future of ICEs in a world now moving towards EVs and low-carbon alternatives and stated that it would be several decades before these are fizzled out due to the lack of charging infrastructure and the shear quantities of electricity that would be required. It was also predicted that ICEs will be used and will continue to improve and develop further in the future, with low-carbon options playing a small role, making possibly only 10% of total transport energy demand by 2040 due to negative business cases and a low market uptake in the development stages. However as infrastructure becomes more readily available and costs reduce, this transition may take place more rapidly.
Acar et al investigated the potential of hydrogen as a sustainable alternative transport fuel and conducted several studies using integrated assessment models to examine the differences between HFCV, EVs, and ICEs respectively; a few of which will be shown in later sections of the report. However, the key takeaways from these tests showed that in terms of environmental impacts, the global warming potential of both HFCVs and H2ICEs was the lowest with approximately 7.10 and 6.40kg per 100km travelled, respectively (shown below in Figure 2). This suggests hydrogen can be a more eco-friendly option when compared to EVs and conventional ICEs for example, as these gave higher figures of 11.40 and 21.40kg respectively, although production stages must also be taken into account.
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Figure 2 - Global warming potential of different vehicle types (Acar, C, 2018). This section of the report is aimed to outline the key differences in each of these vehicle types, taking into account several factors such as emissions, cost, technology maturity, driving range, available infrastructure, and fuel quality respectively. These will also be discussed separately in greater depth with a closer focus on hydrogen throughout the report.
1.3.1 Emissions In 2017, transport accounted for approximately 28% of all UK GHG emissions, which was the largest proportion from any sector (House of Commons, 2018). The government has since re-emphasised and introduced a number of schemes and targets to improve these figures, including the Climate Change Act of 2008, which led to a big improvement in UK decarbonisation. This should see an 80% reduction in GHGs by 2050, compared to 1990 levels - though this has now been revised to a net-zero target. The Clean Air Strategy in 2019 also aimed to reduce pollutant concentrations such as PM, for example, limiting concentration levels to an average of no more than 10ug/m3 each year (Defra, 2019). Emissions therefore play a very important role nowadays in the introduction of new vehicles types. Table 2 below shows the potential emissions from all 3 vehicles types respectively:
Table 2 - Typical emissions from all vehicle types.
ICEs: EVs: HFCVs: Petrol and diesel cars emit EVs do not emit GHGs, unless When the hydrogen being
large quantities of CO2, CO, the electricity they use is used in FCVs is from
PM, NOx which are very generated in power plants renewable sources, the only harmful to the environment. from fossil fuel burning, for emissions are water and heat. example.
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They operate by burning fossil New methods of electricity If hydrogen is produced by fuel resources directly, which generation must be other means, emissions may are finite resources, leading developed in order to be released during the to their depletion soon in the improve the emissions production route. Examples future, which is not throughout the production include electrolysis and SMR, sustainable. route. Renewable sources which burn fossil fuels
must be used more releasing CO2. frequently. Their thermal efficiency is low Producing the battery for an A study found that a Toyota compared to EVs. EV can be a very energy- HFCV model produces
intensive process. ~120g/km CO2 over its lifetime when considering the manufacturing process (TheWeek, 2019). But this can be reduced massively if hydrogen is produced sustainably. Average emissions from Emissions equate to roughly SMR is the most common
driving 10,000 miles using an 83g/km of CO2. And when production method for ICE have been estimated at charging is taken into hydrogen. However this
2.99 and 2.88 CO2e in the UK account, it is 124g/km releases around 10kg CO2 for
for both petrol and diesel cars (TheWeek, 2019). every kg of H2 produced –
(carbonfootprint, 2019). roughly 62g CO2e per km (TheWeek, 2019). Average emissions from driving 10,000 miles using an EV have been estimated at
0.96t CO2e in the UK (carbonfootprint, 2019).
1.3.2. Infrastructure
The transition towards a low carbon economy will not take place unless there is sufficient infrastructure to support the use of EVs and HFCVs. Conventional ICEs have been in use for many years and have an extensive range of existing infrastructure. However, the development of EVs has seen a rise in charging points, with a large number located around Leeds (shown in Figure 3) and approximately 13,000 now available to the public across the UK (Rosamond, C, 2019). It is these which pose the biggest threat to the market, with many people still apprehensive as to whether they will be able to gain easy access to a charging station in their area or during a journey due to the limited range of current EVs, for example. These are continuing to grow
12 though, with government funding helping to open more points across the country, and even allow people to charge their vehicles from home and at work, promoting the transition. Further research is needed however on the total demand required to support the country in the future, and the associated costs of providing such a vast network of stations. In previous years, the charging was free in many cases, in order to help push the use of EVs, but now due to the rapid increase in users, charges are being applied which could discourage people slightly. Companies such as Tesco are planning to open over 2000 charging stations at their stores over the next few years and BP has made plans to become the UKs leading public network of EV charging stations (Sultan, F, 2019). This will mean people can more easily charge their vehicles, taking only approximately 20 minutes to fill the vehicles from empty, depending on the type of charging connector used. These are highlighted below:
1. Rapid Chargers: The fastest chargers available. These range between 43-50kW and can charge 80% of the battery between 30m-1 hour. 2. Fast Chargers: Ranges between 7-22kW and charge takes approximately 4 hours. These are considered the most common chargers currently available in the UK. 3. Slow Chargers: Can reach 3kW in power and require overnight charging. However, these chargers can operate with a normal 3-pin plug, typically used in UK homes.
Figure 3 – All EV charging points around the Leeds region (ZapMap, 2019).
In contrast however, the UKs HFCV infrastructure is much less developed. As the use of HFCVs is not as high compared to EVs, funding has been much less frequent and as a result, their costs are higher and there are 13 only a small number of refuelling stations scattered around the UK at the moment, with the majority based in London. There is however one station in Rotherham, but this still leaves a very sparse central region which may present difficulty to drivers when running low on fuel, for example. In order for ample hydrogen to be available to all during high demands in the future, renewable production routes must increase and the distribution and storage of this hydrogen must also develop.
There is a clear trade-off here between a lack of funding for infrastructure, which is restricting public uptake, and a lack of investor confidence in hydrogen due to low user volumes, for example. It seems something or someone must move first if the hydrogen economy is to really take off in the future, and this has to be related to funding. As a result, the Department for Transport recently gave £8.8m in funding towards the development of the hydrogen infrastructure in the UK, specifically 4 new refuelling stations and approximately 200 HFCVs for use by the MET police and others respectively (Corfield, G, 2018).
With plans to add new refuelling stations around the UK in the future, these challenges may fade. Tees Valley is opening two stations around Middlesbrough and Redcar, and providers ITM Power have also installed a hydrogen pump in a Shell petrol station on the M40 (joining Birmingham and London), which is uncommon and may help to generate a buzz among the public when filling up. Other companies are using HFCVs in their fleets, such as Yorkshire Ambulance Service and the Natural History Museum. Many regions are introducing new hydrogen fleet projects such as the Aberdeen and Liverpool Bus Project, for example, which may help improve public perception of hydrogen and spark an increase in its use among other companies in the future, which would call for a push on its infrastructure, for example.
1.3.3. Technology Maturity The technology behind all ICEs, EVs, and HFCVs vehicles differs due to many factors, including engineering advancements and government funding, for example. Technological developments and new prototype designs cannot be pilot tested unless companies secure funding to help support the projects.
As mentioned previously, the ICE is a well-established and mature technology, which has been in operation for many years and is the most common form of transportation in the UK. The first modern ICE was designed in 1876 and it was used in a commercial vehicle 10 years later. It still uses the same basic operating principles now as it did back then, however advancements in emissions control and efficiency have developed greatly, for example. ICEs can be used for a range of vehicle sizes, from small hatchbacks to large HGVs, and can transport a range of loads also. The same cannot be said for EVs however…
Like the ICE, EVs have been in use for centuries, with the first electric motor powered car being designed in 1828 (Robertson, M, 2019). After this, further developments were made and larger vehicles were being created all around the world, with EVs running on batteries. Since then, companies such as Tesla have taken 14 over the market and brought EVs to the public eye, with Roadster models proving a practical and sustainable alternative to the ICE. Although they do not emit harmful GHGs like that from ICEs when the electricity is produced sustainably, they do currently lack a big range which is one of the biggest technological roadblocks to their use, and the batteries used also limit the vehicles they are suitable for. For example, the batteries required to power a larger vehicle with a heavier weight and a higher load are very big and heavy and there simply is not enough storage space on board to make this practical. In addition to this, EV batteries are still expensive to purchase when compared to ICEs and have long refuelling times of >8 hours (Houses of Parliament, 2010). These shortcomings all need further development in order to generate higher public appreciation and approval.
HFCVs are the newest vehicles to hit the UK market, however, similarly to EVs, fuel cells have been in use for many years prior. The first working fuel cell was introduced in 1842, and employed a platinum catalyst to facilitate the reactions (Morus, I, 2017). However, in terms of fuel cells for transport, this wasn’t introduced until much later in 1959 when a tractor was fitted with one (NMAH, 2019). Since then, developments have continued and in 2013 the first commercially available HFCV was brought on to the market from Hyundai, swiftly followed by the Toyota Mirai in 2015. Now, further research and development is being carried out to introduce larger vehicles such as trains, boats, and trucks, fuelled using hydrogen fuel cells.
However, as this technology has not been commercially available for long, it has meant that the associated infrastructure required is not as readily accessible, which limits the public uptake. Though this is an obstacle to overcome, the actual technology of fuel cells has been around for some time now. The basic principles of fuel cell technology do not show many limitations other than improving the efficiency - instead, the major challenges arise in the cost, storage, and infrastructure of the technology itself.
Figure 4 – The HFC tractor from 1959 (NMAH, 2019).
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Table 3 - Technology maturity of ICE, EV, and HFCVs. ICEs: EVs: HFCVs: Most common engine type in the Limited range of vehicles Could be used for all vehicle world. Been in operation for available. types. Prototype planes, trains, centuries. and ferries all use HFC technology. Improvements have been made Currently not suitable for heavy Higher efficiency than ICE but in efficiency and emissions vehicles such as trucks, trains, still improving. reduction. and ships. Suitable for all vehicle sizes and Batteries required are still costly Major challenges are non- loads. and take a long time to charge. technology related.
1.3.4. Driving Range The distance that can be travelled using each of the technologies depends on the fuel properties and the on- board storage available, for example. Hydrogen typically takes the same amount of time to refuel as an ICE, and gives a much better driving range when compared to EVs. The Toyota Mirai is one of the most common FCVs and has a range of approximately 312 miles, whilst a high-end EV (the Tesla Model S) only manages around 294 miles, and the common Nissan Leaf manages 168 miles, whilst taking over 30 minutes to charge fully using the fastest chargers (Mok, B, 2017). ICEs running on petrol or diesel have a far higher range compared to both of these alternatives however, with some cars on the market being capable of travelling over 1000 miles per tank, such as the VW Golf (1,046 miles) and Ford Focus (1,112 miles), for example (Smith, L, 2019).
One study mentioned previously by Acar using integration models also assessed the driving range of different vehicles (Figure 5) and this showed poor results in the case of fuel cells. HFCV and H2ICEs were among the lowest with only 355 and 350km (second behind EVs at only 160km), and ICEs were the second highest behind hybrids with roughly 540km respectively. However, with the technology rapidly developing as new funding opportunities arise, these limitations may not be an obstacle for much longer.
Driving range is a major challenge for the EV industry, with many people worried about running out of fuel and not finding a refuelling station nearby, though work is being done to improve this soon in the future.
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Figure 5 - Driving range of different vehicle types (Acar, C, 2018). 1.3.5. Fuel Purity The most common and cheapest method for producing hydrogen currently is steam methane reforming followed by purification by pressure swing absorption (PSA) (Broda et al., 2013). Hydrogen contains several impurities such as carbon monoxide, carbon dioxide, nitrogen, noble gases, hydrocarbons, ammonia and sulphur compounds (Barthélémy, 2011; Relvas et al., 2018). For use in fuel cell electric vehicles, these need to be reduced significantly to maintain the lifespan of the cell, as well as to keep it operating at maximum power and efficiency (Murugan and Brown, 2015). There is currently a standard for the quality of hydrogen for fuel cells (ISO 14687-2) but none for use in internal combustion engines. Particular caution is made to the concentration of carbon monoxide and sulphur compounds which absorb onto the surface of the catalyst, impeding the electrode transfer process (Reshetenko et al., 2012). In the case of sulphur compounds, the catalyst can be permanently degraded by low concentrations in hydrogen (Kakati et al., 2016; Lee et al., 2018). Hence, the carbon monoxide and sulphur levels are kept to below 0.2µmol/mol and 0.0042µmol/mol respectively (International Organization for Standardization, 2012)
For internal combustion engines, fuel carbon monoxide impurities in hydrogen are not as stringent as HFC, the main reason for a limit being safety. Sulphur impurities in hydrogen for ICEs are still an issue as they damage diesel catalysts and contribute to SOx emissions (Li et al., 2012). However, the removal of sulphur impurities by PSA is less challenging than carbon monoxide (Ohi et al., 2016). The presence of inert impurities in hydrogen will have little effect on the combustion behaviour of hydrogen in an ICE. Overall, the amount of upgrading of hydrogen produced from steam methane reforming is less for use in an ICE than a HFC.
The lower purity requirements for ICE means that there is potential to reduce costs in the upgrading procedure. Currently, PSA is the most cost effective and widely used upgrading process used (Relvas et al., 2018; Li et al., 2016). The percent cost of a PSA unit for delivering fuel cell grade hydrogen has been estimated to be just 6% of the price, therefore the fuel cost benefit per kilogram for using a lower purity grade for ICE is negligible (Ohi et al., 2016). Also, considering that separate filling stations would have to be 17 purchased for a lower purity ICE grade hydrogen fuel, the savings in production costs are unlikely be enough to warrant this.
To make significant cost savings on fuel using hydrogen ICEs compared to HFCs would require blending with other gaseous fuels which are cheaper than hydrogen. Hythane, which is a mixture of 20vol% of hydrogen in natural gas is an example of a vehicle fuel which is considered by many of a more cost effective way of using hydrogen in transport (Middha et al., 2011).
1.3.6. Overall Cost The purchase cost of conventional vehicles is much lower compared to EVs and HFCVs. This is because of the development of the engineering technology involved, which is still taking place in the latter cases. ICE vehicles range from roughly £10,000 to over £500,000 depending on the engine size and specifications, for example, whereas EVs and HFCVs are much higher (covered in Section 1.5.5.). Using a quick calculation we can say that diesel costs approximately £1.32/litre and assuming a fuel consumption of 40mpg, this gives an overall cost of roughly £7.80/100km.
However, as technology maturity is relatively low for HFCVs, the cost of manufacturing the individual components is high and this leads to high purchase costs in order for profits to be made, for example. A typical PEM fuel cell has been estimated to cost at least $3,500 in the case of small vehicles, with larger trucks and so on costing much more. In addition to this, the hydrogen fuel is also very expensive as demand is low and there are limited refuelling stations and distribution facilities, for example. As a result, hydrogen costs roughly £12/kg, and when using a fuel consumption of 57 miles/kgH2 (given in Section 2.4.), this means a 100km trip will cost approximately £13, far higher than ICE vehicles (Auto Trader, 2018).
In the case of EVs, fuel consumption figures have been quoted at 14.3kWh/100km (Auto Trader, 2018). Using this as a guide, and the fact that 1kWh costs approximately 16p, a journey of 100km will only cost around £2.28, which is the cheapest option by some distance. However, although cheaper than ICE vehicles, their purchase costs are much higher and the availability of EV charging points are much lower so there is some trade-off present.
The social cost of carbon (SC-CO2) is also a monetary value used to measure the long-term damage caused by one tonne of CO2 emissions. These calculations are made using integrated assessment models but are difficult to achieve high levels of accuracy as they are relatively new and as things are so dynamic in real life, it is hard to model and account for these changes, for example. However, one model used a SC-CO2 of $60/t and calculated the costs for different types of vehicles and found the following results shown below:
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Figure 6 - SC-CO2 of different vehicle types (Acar, C, 2018).
From the figure it can be seen that conventional vehicles have the highest cost of approximately $1.28/100km, suggesting they are the most damaging towards the environment, for example. On the other hand, hydrogen ICE vehicles had the lowest at only $0.38. This is surprising as they still use some conventional fuels in their operation, however this must be compared to the other options of fuel cells and electric vehicles which are both fairly expensive and energy–intensive due to their lack of maturity and development at these early stages.
1.4. H2 Production Routes Hydrogen can be produced using a number of techniques from any primary energy source and many of these production techniques are both cheap and mature. The major challenges however lie in the storage and distribution of the hydrogen, which will be covered later in the report. The most common methods include production via fossil fuel feedstocks such as gasification, as well as renewable ones like electrolysis using wind energy. A number of conventional and newer technologies are outlined in this section with their basic operating principles, with pros and cons respectively.
1.4.2. Reforming and POx Hydrogen production through SMR is the most popular and mature production route for hydrogen today, with a low cost compared to other methods available. The largest SMR plant in the UK is based in Teesside by BOC, making it an attractive area to begin a hydrogen transition. However, as a trade-off to this, SMR is a damaging process as the upstream extraction and delivery of natural gas leads to carbon dioxide emissions. For this reason, CCS is becoming a more important aspect to collect the carbon dioxide emitted and reduce environmental damages, although if net-zero targets are to be achieved, this route is not suitable due to residual emissions released, for example (CCC, 2018). Here, natural gas (composed of mainly methane) is obtained from fossil fuels and is reacted with steam under high temperatures of roughly 700-1000°C, which is generated usually by burning part of the fuel source (to facilitate the endothermic reaction) (HydrogenEurope, 2019). The reaction also requires a catalyst (usually platinum) to produce a syngas 19 composed of hydrogen, carbon monoxide, and minor quantities of carbon dioxide (which can be captured for storage or use). The CO by-product can then be reacted with excess steam to increase the yield of hydrogen. This process can achieve efficiencies of between 70-82% (National Grid, 2019). The chemical reaction steps are outlined below:
CH4 + H2O → CO + 3H2
CO + H2O → CO2 + H2
Figure 7 - SMR process flow diagram (HydrogenEurope, 2019). The final stage of this process involves extracting the hydrogen and is called pressure swing adsorption (PSA), which is another mature technology available at high capacities, although it does come at an additional cost. As hydrogen for use in fuel cells has very strict requirements; currently at least 99.999% pure, a rigorous clean-up stage is required to ensure there are no contaminants in the final product stream (Walker, I, 2018). So here, the by-products of carbon dioxide and other impurities are removed to give pure hydrogen as a product. As an alternative stage, membrane-based purifiers or amine based systems could also be used. If the hydrogen produced was to be used for a different application, heat for example, then these stages may not be needed.
This reforming process can also be carried out using a different fuel (such as ethanol), which could potentially give higher efficiencies of hydrogen production compared to SMR due to the re-use of generated heat and the introduction of an oxygen stream into the reformer (CCC, 2018). In addition to this, using advanced reformers may also offer higher rates of CO2 capture as the majority of the CO2 released is held at the process pressure (which is easier to collect), and not at ambient temperatures, compared to SMR.
In a process similar to SMR, partial oxidation (POx) can also be used to produce hydrogen for use in fuel cells. The difference in this method is that it releases a lot of heat (i.e. is exothermic) as the fuel reacts in a limited amount of oxygen which is not enough to completely oxidise the hydrocarbons into carbon dioxide and 20 water. Instead, the products are the same as SMR: carbon monoxide and hydrogen, with minor traces of carbon dioxide. From here, the next step is called the water gas shift (WGS) reaction in which the carbon monoxide gas reacts with water to form carbon dioxide, hydrogen, and heat, shown in the chemical reactions below:
1 CH + O → CO + 2H + HEAT 4 2 2 2
CO + H2O → CO2 + H2 + HEAT
This method is also relatively mature compared to others available, and is very fast, however does not give a hydrogen yield as high as SMR. It still however relies on methane from fossil resources which is not sustainable, making it a CO2-intensive process, so it has downsides. In order to improve it for the future, it should be combined with renewable production techniques.
1.4.3. Electrolysis Hydrogen can also be produced via electrolysis, in which electricity splits water into its constituent atoms of hydrogen and oxygen respectively. Here, the electrolyser which is used consists of two electrodes (a positive anode and a negative cathode), attached by an electrolyte which can be made of various materials. The most common electrolysers however are the solid plastic polymer electrolyte membrane (PEM) and alkaline electrolyser. These can be relatively small, achieving efficiencies of 70-90% which also makes them well suited to local, on-site hydrogen production.
Figure 8 - Electrolysis of water to form hydrogen (energy.gov, 2019). Here, water reacts at the anode, forming oxygen and positively charged hydrogen ions:
+ − 2H2O → O2 + 4H + 4e
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From here, the electrons flow through an external circuit whilst positive hydrogen ions move through the membrane to the negative cathode. At this point, the hydrogen ions react with negative electrons to form hydrogen, shown below:
+ − 4H + 4e → 2H2
Other emerging electrolysers that can be used include solid oxide electrolysers. However, other less common options are not as mature and may have lower performance characteristics.
Electrolysis has a strong potential for hydrogen production for use in vehicles in the future as its purity is very high (99.999%), but the source of the electricity and its associated cost and efficiency must also be considered when evaluating its benefits (CCC, 2018). The process will only be classed as net-zero if the electricity being used is from renewable sources such as wind, nuclear, or solar, for example. If not, the GHG emissions will be higher and it won’t be considered a sustainable option for fuel cell uptake in the future. Current grid electricity in the UK is not suitable for hydrogen production as it is not produced sustainably, with GHG emissions being released at some stages during the process. It is therefore vital to try and incorporate other power generation systems such as wind farms into hydrogen production, and make electrolysis more economically viable through improving the efficiency of the conversion process and reducing costs as much as possible, as high electrolyser capital costs remain a barrier to adoption.
1.4.4. Renewable Liquid Reforming Renewable liquid fuels derived from biomass resources, such as ethanol can also be reacted with steam, similarly to SMR, to give hydrogen. As these liquids can be more easily transported compared to the raw biomass, it means the hydrogen could potentially be produced closer to the point of end use, and transported more easily to refuelling stations, with only minor infrastructure adaptations required, or simply reformed on site, for example. In addition to this, the raw biomass feedstocks can also be processed at larger facilities to take advantages of the economies of scale, saving on costs.
The 3 major stages for reforming biomass-derived liquid fuels is almost identical to SMR:
1. The fuel reacts with high temperature steam in the presence of a catalyst to form a mixture of carbon monoxide, carbon dioxide, and hydrogen. 2. This carbon monoxide is then reacted with excess steam to produce more carbon dioxide and hydrogen. 3. The last stage sees the hydrogen stream purified and removed.
Chemicals reactions are similar to SMR; this time with ethanol as the feedstock:
C2H5OH + H2O + HEAT → 2CO + 4H2 22
CO + H2O → CO2 + H2 + HEAT
This production route has a number of advantages including the fact that biomass feedstocks are plentiful and the transportation of the liquids is relatively simple. There will always be a large resource of biomass options for use in hydrogen production, and their consumption of carbon dioxide helps to ensure the process remains low in terms of GHG emissions. If this route is to be used to provide for an increasing demand of hydrogen for transport however, the reforming efficiency of larger compounds must be improved and the costs of both the liquids and the equipment must also be reduced.
1.4.5. Fermentation Hydrogen can be produced through microbial action in which biomass is converted into a sugar-rich feedstocks which are then anaerobically fermented. Here, microbes break down and digest the organic matter of the biomass to release hydrogen, and this method could be used for distributed, semi-central, or central hydrogen production scales respectively.
This organic matter can be in the form of refined sugars and wastewater, for example. In direct fermentation, microbes break down organics and the by-products can be combined with enzymes to produce hydrogen. For the future however, work is currently being done on improving the rate at which organics are broken down and how much hydrogen is produced (i.e. the yield) from the organic matter. Microbial electrolysis cells (MEC) can be used to capture the energy and protons generated by the microbial action and combined with an electric current, can produce hydrogen. This technology however is relatively new and immature, with a number of challenges that must be faced before implementation on the mass market, such as scaling up systems and increasing fermentation rates, for example.
1.4.6. Photo Electrochemical (PEC) Water Splitting This is an emerging technology in which water is dissociated into its constituent components of hydrogen and oxygen using sunlight and cheaper semiconductors surrounded in water-based electrolytes. It could be a potentially low-carbon route for hydrogen production in the future as it offers high conversion efficiencies and can produce relatively large quantities of hydrogen. However, as the process is not yet mature, there are still improvements associated with its efficiency and material costs which could be made.
1.4.7. Photobiological This production route employs the use of sunlight and microbes to break down water and organic matter into hydrogen. It is another technology which currently lacks maturity, yet offers good potential for green hydrogen in the future at a low cost. Its downsides however include low hydrogen production rates and low conversion efficiencies from solar energy.
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The basic principle when using water involves microbes utilising solar energy to break it down into hydrogen ions and oxygen. From here, these hydrogen ions can be joined together to form hydrogen gas. However as oxygen inhibits this stage, and the rate is still slow, challenges are present which must be overcome. In addition to this, oxygen and hydrogen may present some safety concerns when combined in specific concentrations, for example (energy.gov, 2019). In order for this route to improve, more research must be done on improving the rate of breakdown (and hence hydrogen production), and scaling the process up to support higher demands in the future.
1.4.8. Types of Production Facilities Hydrogen can be produced in a range of facilities, depending mainly on who the consumer is and where the hydrogen is going to be used, for example. The production route also has an influence on which facility is most suitable. The 3 major types are outlined in the table below:
Table 2 - The 3 major hydrogen production facilities (energy.gov, 2019).
Distributed Production: Centralised Production: Semi-Central Production: Hydrogen is produced in When hydrogen demand This is a mid-range small local units, close to the increases in the future, larger production facility which is point of end-use, such as facilities will be needed to relatively close to the point refuelling stations. keep up. of end-use. This is a more cost-effective Third-party delivery may be These have a reasonable cost approach in the early stages beneficial initially when associated and do not require as hydrogen demand is demands are low. However extensive transportation. currently very low and transportation of the fuel will They are capable of transport costs are avoided. be expensive and could lead producing between 5,000- to additional emissions. 50,000kg/day. These are capable of producing 750,000kg/day, taking advantage of economies of scale. This approach is more expensive compared to distributed, and requires additional hydrogen delivery infrastructure.
As the UK currently has a low hydrogen demand for transport, with fuel cell vehicles considered a rarity and only a handful of refuelling stations available, it makes sense to produce hydrogen through only distributed facilities at this early stage. In addition to this, as the infrastructure required to transport this hydrogen is still not yet available, centralised facilities will be a long way off development. However, there may be 24 potential to transport a small amount of hydrogen from an existing plant for use in a refuelling station, from petroleum refineries which use hydrotreatment processes such as hydrodesulphurisation and hydrogenation of crude oil, for example (Fraile, D, 2015).
1.5. Key Challenges to H2 Implementation (Storage, Infrastructure Etc.) There are a number of challenges associated with hydrogen as a potential transport fuel for the future. These must be clearly identified and further research must be carried out in order to overcome these difficulties and push towards the transition. It is clear that without successful interplay of several factors (such as ecosystems, technology, institutions, business cases, and user practices), this transition will be limited. A number of these challenges are listed below, with a few of the most important ones being discussed in greater depth.
1. Renewable production routes must be increased. 2. Safe and secure long-term storage needed. 3. Cheap distribution to the consumer. 4. Refuelling infrastructure is very limited. 5. Cost reduction pathways needed. 6. Standards and safety requirements needed – purity required depends on use. 7. Integration among other sectors such as wind and electricity. 8. Public support of hydrogen is not present - lack of large scale demonstration projects.
1.5.2. Storage Energy storage is a very important aspect of the future hydrogen economy. With many renewable energy sources being dependent on weather conditions (such as wind and solar energy), leading to large fluctuations in grid stability, for example, it has highlighted the need for storage options in times when energy production is low. The storage of hydrogen poses a challenge as metal embrittlement can occur and leakages can take place, and due to the flammable nature of hydrogen, could lead to harmful results because of its low energy ignition, for example. For these reasons, hydrogen storage is one of the most important aspects to consider.
Hydrogen can be stored both in physical form and material-based form, and a few available options are outlined below:
1. Pipelines – Compressed hydrogen can be stored in adapted pipelines as ‘linepack’ when pressures are increased. This has a very low cost and helps to provide the energy needed during short term surges in demand, for example. However, as hydrogen has a low volumetric energy density, less energy is held in each pipeline compared to natural gas so these periods of high demand may not be met fully. 25
2. Underground – Large quantities of compressed hydrogen can also be stored in underground salt caverns and geological rock formations, for example. This can help with seasonal variations in supply and also allows more storage space for other energy forms elsewhere. In addition, this shows lower gas losses when compared to other options. 3. Cryogenic Storage – Stores of liquid hydrogen are also options, however it must be taken into account that there is a greater loss of energy due to warming periods and transportation. This makes it less suitable for long-term storage as losses must be minimised. 4. Chemisorption – Materials such as Graphene can physically absorb hydrogen into its structure and release it later when needed (Tozzini, V, 2019).
Although there are options available for hydrogen storage, the overall storage efficiency, volumetric energy density, and input/output response times are vital factors limiting the progression of the hydrogen economy.
1.5.3. Distribution and Delivery When producing hydrogen, it must be considered how it will be distributed and delivered to the consumer, whether it be to a large scale plant or a local refuelling station, for example. Currently in the UK, there are only 17 hydrogen refuelling stations in operation which provide compressed hydrogen for cars and buses, with two of these being located at universities for research purposes, and not available for public use (Hydrogenics, 2019). Although there are others planned to be constructed in the future, including two in the Tees Valley region, this is still not enough to convince people to purchase a HFCV.
Distribution options have been previously mentioned in Section 1.4.7, however there are a number of ways in which the produced hydrogen can be delivered, through various pipelines, trucks, and dispensers, for example, and there are also a number of challenges which must be solved prior to large scale use in the UK.
Hydrogen is most commonly transported and delivered in the following forms:
1. Pressurised Gas – As hydrogen is so light, it must be highly compressed in order to transport large quantities of it to the end-user. Refuelling stations in the UK currently deliver hydrogen in a compressed form at either 350 or 700 bar, and it can be transported from the production point via pipelines or ‘tube trailers’, which carry gaseous hydrogen on trucks on the road (BOC, 2019). However, these trucks are not capable of carrying large volumes which limits their use during times of high demand, and the use of pipelines can lead to impurities contaminating the gas, reducing its purity leaving it unsuitable for use in some instances.
2. Liquid Hydrogen – Hydrogen is transported in the liquid form when larger volumes are required. As this can’t be done through pipelines, it is stored and transported using tanks and insulated liquid 26
tanker trucks. However, in order to liquefy the gaseous hydrogen, it must be cooled below -253°C before it is stored in tanks and vaporised prior to distribution (energy.gov, 2019). This method has downsides though, as approximately 30% of the hydrogen’s energy is lost through the liquefaction process, and it is a much more expensive method compared to gas transport (Arup, 2019). Both of these limitations must be improved if liquid hydrogen is to be used on a larger scale in the future.
Figure 9 – A liquid hydrogen tanker truck (United Hydrogen, 2019).
A few of the major hydrogen carriers are also outlined below:
1. Transmission and Distribution Pipelines – These are used for high volumes of hydrogen gas and can transport them great distances. However, there are challenges in using existing pipework currently used for natural gas. These are made from steel and as hydrogen is such a small molecule, it can diffuse into other materials and lead to embrittlement which can lead to fractures in the metals, leading to potential leaks, for example.
2. High-Pressure Tube Trailers – These are special tanks designed to carry compressed gas to specific areas of demand. They are capable of transporting 1,000kg per trip though this figure could increase in the future to 1,500-5,000kg if the gas can be pressurised further (CCC, 2018). However, these are better suited towards small volumes, and as the quantity that can be transported increases, the cost of transport also rises alongside.
3. Cryogenic Hydrogen Road/Rail Tankers – These are used to transport medium quantities to specific areas, similarly to tube trailers. However during the transport, the slow heating of the liquid leads to energy losses which makes the process inefficient and more costly unless cooling of the load is somehow available.
Once hydrogen is delivered to a refuelling station, for example, the process of refuelling a HFCV is identical to standard petrol stations, taking only a few minutes to fill up the tank using the dispensing equipment.
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In order for hydrogen to become commercially available for use in FCVs, equipment must be standardised and fuel must be measured in order to ensure all vehicles use hydrogen of the same quality and purity, for example. In addition to this, there are a number of challenges associated with the transport and delivery of hydrogen which must be worked on, including:
Reducing hydrogen energy losses during liquefaction processes. Minimising leakages during transport through pipelines and road transport. Minimising contamination and ensuring high purity hydrogen is delivered. Reducing delivery costs. Increasing the number of available refuelling stations.
1.5.4. Infrastructure In order for alternative transport fuels to compete with conventional ones, there must be a large infrastructure readily available to support their production, distribution, and use. It must be cheap, accessible and easy for the customer to purchase and use, otherwise the sustainable transition will not take place as quickly as it is needed. The lack of infrastructure is a major challenge to overcome for hydrogen transport and it is unlikely to change until demand rises, but saying this, demand will not rise until the infrastructure matures, leaving a negative trade-off.
1.5.5. Standards and Safety: As the hydrogen transport industry begins to develop, it is important to highlight the dangers of hydrogen use and work towards minimising the risks associated in order to replace fossil fuels in the future. Various standards and codes of practice are needed to ensure hydrogen use and the construction of fuel cells is carried out safely and securely, in specialised infrastructure and facilities, with no risk to humans and the environment. For example, standards must be met regarding the purity of the hydrogen when used in fuel cells, otherwise it will not operate efficiently (or at all). These cells require very high purity and this can be a challenge in the production stage as well as adding a substantial cost to the process. Some other safety aspects of hydrogen are outlined below:
1. Dispersion – Hydrogen is very buoyant when compared to air which means it disperses very rapidly and dissipates when released. This is a big safety advantage as it is uncommon for large concentrations to be clustered in one area, leading to hazard risks, for example. 2. Explosive Limit – Hydrogen has a better lower explosion limit (LEL) compared to petrol, at 4.1% in air as opposed to only 1.2% (Goal Zero, 2019). This means a small hydrogen leak is less likely to lead to an explosion if a spark is ignited. The value for hydrogen is also very similar to natural gas, so little changes will be needed in terms of explosion safety features, for example. Similarly, the lower and
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upper flammability limits are 4% and 75% for hydrogen, which is a wider range than conventional fuels used in ICEs for example. This appears to be a drawback for hydrogen, however it allows for a leaner air/hydrogen mixture which can lead to more complete combustion and subsequent
improvements in fuel economy (Acar, C, 2018). 3. Public Opinion – Many people still consider hydrogen to be a dangerous fuel after historical events such as the Hindenburg disaster. However, it is not made clear enough that the safety measures and knowledge during this period were lacking, with storage and safety precautions much less established when compared to today. 4. Flame Characteristics and Odour – Hydrogen burns with a colourless flame and it has no odour which can make it difficult to detect. It also releases a lower amount of heat from its flame which reduces the chance of the surroundings catching fire, although it makes it less noticeable which is dangerous. For this reason additives are used to help in the case of leaks and improve detection via smell and flame detectors can also be used.
Figure 10 - The invisible hydrogen flame (Okino, T, 2019). The safety advantages and disadvantages of hydrogen are briefly summarised in Table 4:
Table 4 - Hydrogen safety pros and cons.
Pros: Cons: Hydrogen is non-toxic. Highly flammable at a range of concentrations. Low density so dissipates quickly in air. Low ignition temperature. No degradation issues. Odourless and colourless, making leaks hard to detect.
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1.5.6. Cost: The location of hydrogen production and the size of the facility at which it is produced has a big influence on the price. For example, many central, large scale production plants make hydrogen in high quantities which lowers the price, but the trade-off with this is that the hydrogen usually has to be transported further in order to be delivered to its end-use location, and this is more expensive. The same is true in the case of a local hydrogen production facility which does not require lots of transport; the production costs are usually higher as volumes required are much smaller.
In addition to this, as the technological maturity of fuel cells is still relatively low and use is limited currently by the lack of infrastructure and subsequent public uptake, it has meant that the cost of fuel cells and hydrogen vehicles in general is still very high. For example, there are only 3 HFCV on the market in the UK currently; the Toyota Mirai, Honda Clarity, and the Hyundai ix35 respectively, and all cost far more than an average ICE vehicle, at approximately £66,000, £60,000 and £53,000 (RAC, 2018). As these costs are far higher than other available models on the market (especially more mature EVs), it has led to a negative business case in the early stages of a hydrogen transport economy as the public response has been low. However, the main reason why HFCV are so expensive at the moment is due to the fuel cell itself, which can have very high costs, and until this technology is made cheaper, it seems HFCVs will not come down in price. It is this downside that must initially be overcome in order to reap the benefits of hydrogen however, as governments will not feed high funds into hydrogen without public backing and the development of a wider hydrogen infrastructure will only happen when there is a higher demand.
1.5.7. Public Response: One final challenge related to hydrogen implementation which has already been touched on is public response. Although hydrogen poses a number of benefits that will help ease climate change, improve air quality, and possibly save money, the fact is you cannot force people to use something they don’t want to. In the 1960’s and 70’s there was a transition from towns gas to natural gas in which people were simply told things were changing and that’s how it was (TPP, 2019). There was a level of compulsion surrounding those days where nobody complained and people just accepted the changes being made. However, we now live in a time now where everyone has a voice and people will refuse to do something they don’t want to do for example. If hydrogen doesn’t appear beneficial to the consumer, they will not approve of the switch and this will make it much harder to transition away from harmful fossil fuels, for example.
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2. A Closer Look at Hydrogen Vehicles:
Hydrogen can be used as an alternative transport fuel in a number of applications, including use in fuel cell vehicles or in modified internal combustion engines, for example. Here, hydrogen can be introduced into spark ignition (SI) engines in 2 different ways:
1. Direct injection – Hydrogen is fed through an injector inside the combustion chamber during the intake and/or compression stroke 2. Port injection – Hydrogen is transferred to the inlet manifold using valve control and mixed with the intake air.
Table 5 below shows the different characteristics of hydrogen and methane:
Table 5 - Some thermochemical parameters of hydrogen and methane (Acar, C, 2018). Parameter: Hydrogen: Methane: Diffusivity in Air (cm2/s) 0.61 0.16 Flammability Range (vol %) 4-75 5-15 Auto-Ignition Temp (°C) 585 450 Minimum Ignition Energy (mJ) 0.02 0.29 Lower Heating Value(MJ/kg) 120 50 Flame Velocity (m/s) 1.85 0.38
From this table it can be seen that hydrogen has a number of qualities that make it attractive for use in ICE transport vehicles. This combination of conventional technology and new alternative fuels gives higher efficiencies and a potential for emissions reductions in the near future.
The low minimum ignition energy of hydrogen helps to give a quick ignition of the fuel and allows a much leaner fuel mix to be used, for example. However, alongside these pros, there are cons, with this also potentially leading to early-ignition, which could waste fuel and lead to sudden and dangerous heat and pressure releases. Hydrogen also has a higher auto-ignition temperature of 585°C which helps to improve the efficiency of the engine as higher compression ratios can be used without the risk of ignition, for example. In addition to this, its high diffusivity in air yields a safety feature as leaks can quickly diffuse without the risk of harming people or the environment.
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There have been several papers published covering the differences between hydrogen internal combustion engines (H2ICEs) and HFCVs, along with the future of low-carbon transport options with regards to their practical and technical qualities. Attempts to explain why H2ICEs have not been adopted by car manufacturers as a bridging method towards a hydrogen economy have also been outlined.
Verhelst et al stated that H2ICEs are currently far cheaper compared to HFCVs in terms of their construction and fuel costs, as fuels required do not have to be of such a high purity. As a result, these are more affordable options for developing countries as expensive purification stages can be avoided. They are also capable of operating on both hydrogen and conventional fuel, which lowers driver anxiety when running low on fuel and the need for refuelling stations respectively. However, Langford et al argues that although H2ICE vehicles are more cost effective at the moment, this will not be the case forever as fuel cell technology is predicted to dramatically decrease in cost over the next few years, making it more economically viable.
Sorokanich et al also highlighted the drawbacks of H2ICEs by covering the technical limitations of the fuel. Here, the low energy density means that a higher quantity of fuel is required to carry out the same amount of work compared to more conventional fuels, and when this is combined with a relatively low conversion efficiency of 25-30% for ICEs, the results are not impressive. In addition to this, hydrogen combustion emits harmful NOx compounds which contribute towards poor air quality and global warming, for example. Both of these factors are enough to deter automakers from designing H2ICE vehicles and move directly on to HFCVs. Cockcroft et al also found that in the case of a long term hydrogen infrastructure where buses operated using fuel cells, the life cycle cost is lower when compared to the diesel and H2ICE alternative respectively, so fuel cells not only have lower emissions but also more competitive costs overall, making them a more desirable option.
In Kalghatgi et al’s paper, HFCVs were considered the obvious choice when compared to H2ICEs as they have a much higher efficiency. However, there were still many references to the well-known drawbacks associated with these vehicles in the current market. The cost of the storage tank alone falls within the region of $3000- 4000 and the vehicles are much more expensive when compared to ICEs, as well as the shortage of refuelling stations (Kalghatgi, G, 2018). In addition to this, the low volumetric energy density of hydrogen compared to conventional fuels means it must either be cooled to a liquid below -253°C or compressed highly at 700 bar; both of which can present safety issues when stored on a vehicle, along with its wide flammability range. This required fuel storage space can also reduce the space inside the vehicle for passengers and cargo, which makes them slightly less practical compared to alternatives.
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The remainder of this section is targeted specifically towards fuel cell vehicles however, outlining their major engineering components and operating principles, the current market position, operating efficiencies, costs, and challenges respectively.
2.1. Major Components of HFCVs and Operating Principles: Fuel cell vehicles work by using electricity to power the wheels and this section is going to cover the use of PEM fuel cells as these are the most common. Here, this electricity is generated using hydrogen in a fuel cell stack on board, which can be produced through a number of different processes, some sustainable and some not. This fuel cell stack is essentially a number of layered cells where the chemical reactions take place. It is where hydrogen reacts with oxygen (in the air) to form electricity and water.
The major components of a fuel cell are listed below:
Bipolar Plates – These can be made from metal, carbon, or composite and are added in between individual fuel cell stacks in series in order to separate them. They help to add strength to the overall structure, evenly distribute the hydrogen gas and oxidant, conduct electricity between the different cells, remove heat, and help to prevent gas leakage, for example (energy.gov, 2019). Catalyst Layers – A fine layer of platinum particles are added along with a carbon support, with a very high surface area. This is then mixed with ionomer which conducts ions and is placed between the membrane and gas diffusion layers. Membrane – The PEM conducts only positive ions and stops electrons passing respectively. It is vital that it allows only the wanted ions to pass between the anode and cathode otherwise the reactions would not take place. This membrane is also incredibly thin at only approximately 20µm (energy.gov, 2019). Gas Diffusion Layers – These help transport the reactants into the catalyst layer and facilitate the removal of water. The layers are typically made up of very thin carbon fibres and the gases diffuse through the pores. Here, water retention and release is constantly adjusted in order to maintain conductivity and promote gas diffusion. Gaskets – These are needed in between fuel cell stacks to prevent gas leakages. They are made of rubber polymers and provide gas-tight seals.
The reaction chemistry is slightly similar to that of electrolysis in which PEM are used; hydrogen attaches itself to the anode and is activated by a platinum catalyst whilst oxygen gathers at the cathode. This dissociates the hydrogen and releases positive and negative ions and electrons. From here, the membrane allows the positive ions to pass over to the cathode whilst the electrons travel through an external circuit
33 generating electricity. At the cathode, the hydrogen ions (i.e. protons), oxygen, and electrons then react to form water.
+ − 4H + 4e + O2 → 2H2O
Figure 11 - A typical HFC operating principle (SMMT, 2019). 2.2. Hydrogen Powered ICE Vehicles Hydrogen has several properties that makes it interesting as a fuel for internal combustion engines. One of the most important is the wide range of flammability limits of hydrogen, which is in contrast to gasoline which is narrow (Lanz et al., 2001). Figure 12 shows the flammability limits of some common fuels expressed in terms of air fuel ratio. The significantly wider range of hydrogen means that spark ignition (SI) engines can operate at much leaner conditions, reducing the need for throttling, a source of efficiency losses (Wang et al., 2014).
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Figure 12 Flammability limits of common engine fuels in terms of air-fuel ratio (λ). Note: Air-fuel ratio operation range from an engine would be narrower than shown as there are other limitations, such as flame speed and unburned fuel emissions.
Another advantage of lean burning hydrogen is the lower cylinder temperatures leading to reductions in NOx emissions. Figure 13 shows that the NOx emissions from hydrogen combustion at an air-fuel ratio of 2 or higher (which is not possible with gasoline) is close to zero. However, stoichiometric combustion of hydrogen is known to cause much higher NOx emissions than gasoline as the flame temperature is higher (Alliche and Chikh, 2018). There are several options to overcome this such as permanently running lean and supercharging to compensate for power loss, use throttling to avoid the peak NOx emissions at roughly λ=1.3, exhaust gas recirculation, and lean NOx trap catalytic after-treatment systems (Park et al., 2010; Roy et al., 2011; Salvi and Subramanian, 2016).
Figure 13 Typical variation of emissions of NOx with air-fuel ratio during homogeneous operation with hydrogen (Verhelst and Wallner, 2009; Wallner et al., 2008).
One of the main challenges in utilising hydrogen as a fuel for ICEs is the low activation energy requirement which can lead to knocking and pre–ignition of the mixture (Kawahara and Tomita, 2009; Shudo and
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Nabetani, 2001; White et al., 2006). Pre-ignition has been avoided by running lean, using cold spark plugs or injecting hydrogen late in the cycle (Mathur and Khajuria, 1984; Mohammadi et al., 2007; Sopena et al., 2010). Li and Karim (2004) found that compression ratio and intake temperature were the main parameters affecting knock in hydrogen SI engines.
The low density of hydrogen creates issues relating to maximum power in port injection engines. This is because a significant amount of the inlet air charge is displaced by the fuel gas. The maximum power of a port injected hydrogen ICE is just 86.4% compared to gasoline (Table 6). The derating with the use of hydrogen is similar to that of compressed natural gas engines. The theoretical maximum power of a direct injection (DI) hydrogen engine is significantly higher than other fuel options because the lower heating value on a mass basis is high. The higher theoretical maximum power means that a hydrogen DI engine can also run leaner compared to other fuels for the same output power.
Table 6 Maximum power output with respect to gasoline of different fuels depending on the injection method.
Maximum power (with respect to
Gasoline) %
Fuel Direct injection Port injection Hydrogen 120.8 86.4 Diesel 106.2 - Biodiesel 103.8 -
Ethanol 103.9 97.5 CNG 94.8 87.9 LPG 101.3 99.2 Propane 100.7 98.7
Ammonia 107.3 85.6
2.2.1. Hydrogen for Intermittent Use in ICE The ability to run an ICE very lean and the low storage energy density of hydrogen has led to designs where it is utilised at low loads before reverting back to gasoline for the majority of operation. This means that the overall fuel tank space remains low as only a small amount of hydrogen is used. This approach has been used to reduce idling emissions and fuel consumption of gasoline engines (Ji and Wang, 2010). Hydrogen has also been utilised to reduce cold start emissions as three way catalysts common to gasoline engines must increase in temperature before they start to operate properly (Hao et al., 2016).
2.2.3. Dual-Fuel/Hydrogen Mixtures for ICE Using hydrogen fuel mixtures or two separate injection systems for two different fuels is an approach commonly used to overcome some of the difficulties with hydrogen, especially at high engine loads, as well as to reduce fuel costs. Ji et al. (2010) investigated the addition of 3% hydrogen to a gasoline port fuel injection (PFI) SI engine operated at 1400rpm and at two excess air ratios: 1.2 and 1.4. The addition of 36 hydrogen increased indicated thermal efficiency but reduced indicated mean effective pressure. The addition of hydrogen reduced the coefficient of variation, and emissions of carbon monoxide (CO) and hydrocarbons (HC). Emissions of NOx initially increased with the use of hydrogen but, by retarding the spark timing, NOx was successfully reduced below the baseline.
Natural gas is often mixed with hydrogen and is sometimes sold as hythane when the proportion of hydrogen is no less than 20% by volume. Unlike hydrogen, natural gas has high knocking resistance with an octane number reported in the range of 110-130 (Liu et al., 2013). Natural gas is a relatively clean burning fuel, with low particulate emissions and can run lean (Wang et al., 2009). Methane and ethane, the two main constituents of natural gas are the lowest specific CO2 emitters of the alkanes. The lower flame temperature of natural gas helps to reduce NOx at near stoichiometric conditions (Di Iorio et al., 2016). Storing hydrogen and natural gas as a mixture is generally considered the best option, rather than two separate tanks and injection systems, as the benefits of being able to continually alter the hydrogen fraction are negligible (Bauer and Forest, 2001). The main disadvantage of this hydrogen approach is that energy density of the mixtures is low compared to gasoline and other liquid fuels.
Other hydrogen dual fuel/mixtures investigated include hydrogen-ammonia, which is produced from hydrogen by the Haber process. It is of interest because ammonia has low flame speeds, reducing NOx emissions when added to hydrogen, high octane number and can be thermally decomposed to hydrogen and nitrogen or split by electrolysis on-board to hydrogen (Gill et al., 2012; Hanada et al., 2010; Zacharakis- Jutz, 2013; Zamfirescu and Dincer, 2009). Furthermore, as ammonia condenses at 8.6 bar, it can be stored on-board as a liquid relatively cheaply (Zamfirescu and Dincer, 2009). Hydrogen-LPG systems have also been researched as a low emission alternative to gasoline (Han, 2018; Kacem et al., 2016; Ravi et al., 2017).
2.3. Conversion Efficiencies
Table 7 Conversion efficiencies of technologies for utilisation of hydrogen in transport.
Technology Efficiency Gasoline SI engine Road vehicle engines typically 30-40%1,2 Hydrogen SI engine 45%1,3 Diesel engine Road vehicles 35-45%4,5. Up to 55% for marine type6 Diesel-hydrogen dual fuel engine 33%7 PEM fuel cell 60%8,9 Electric motor for drive 95%10 Steam methane reforming 80-90%11 Water electrolysis 70-90%12 1(Vancoillie et al., 2012), 2(Takahashi et al., 2015),3(Welch et al., 2008),4(Kogo et al., 2016),5(Thiruvengadam et al., 2014)6(Mrzljak et al., 2017),7(de Morais et al., 2013),8(Hwang, 2013),9(Hwang, 2012),10(Gao et al., 2016),11(Peng, 2012),12(Zhang et al., 2010) N.B. Thermal efficiency of producing electricity for the process not considered 37
Table 7 shows some efficiencies important to the utilisation of hydrogen in transport. The efficiency of gasoline engines has slowly risen from 25-30% in the 1960s to 30-40% in the present day (Figure 14). It has been suggested that efficiency improvements can be made to SI engines with the use of hydrogen as the fuel instead of gasoline. A hydrogen SI engine has been demonstrated to have a brake thermal efficiency of 45% (Welch et al., 2008). Compression ignition engines generally have higher thermal efficiencies than SI ranging from 35-45% for road and up to 55% for large stationary and marine engines. Studies have shown that the use of hydrogen in a dual fuel diesel engine can reach similar efficiencies. Whilst a mature technology, ICE are still improving efficiency-wise. Unlike fuel cells which are modular, efficiency of ICEs are higher for larger models.
Figure 14 Improvement in the thermal efficiency of gasoline engines. From Takahashi et al. (2015)
PEM fuels cells have an efficiency advantage over even the most efficient ICE currently available. Electric motors convert the electricity from fuel cells very efficiently. The fuel cost of a FCEV is therefore less than a pure hydrogen ICE vehicle. For ICE to be a cheaper option in terms of running costs, hydrogen would have to be used in conjunction with a cheaper fuel. For hydrogen powered marine vehicles, using an ICE is an interesting option as the efficiency would approach that of fuel cells. Furthermore, freight is a very cost sensitive, making full conversion to more expensive hydrogen difficult. Being able to use hydrogen as part of a fuel mixture is another advantage of the ICE.
The most common hydrogen production pathway of steam methane reforming demonstrates a similar efficiency to electrolysis. However, the efficiency estimate for electrolysis does not consider the efficiency in producing the electricity required, which can be in the region of 50% for combustion power stations.
2.4. The Market Position Conventional transport methods of the ICE are still by far the most commonly used on the market today. However, with climate change accelerating at a rapid pace, and new government targets being set such as
38 net zero and a ban on the sale of petrol and diesel cars by 2040, this may change in the near future as EVs and HFCVs receive more attention.
EVs have been in operation for a few years and are developing steadily along with the growing network of charging infrastructure, for example. In Q1 of 2018, battery car sales increased 84%, and accounted for 1.5% of total European car registrations. But hydrogen vehicles are still far behind with a number of challenges still needing to be solved. The hydrogen market is currently very small with only around 1,400 HFCVs registered in Europe at the end of 2018 (Gurzu, A, 2019). This deters customers and government backing is only just beginning to warm up, with new funding opportunities arising more frequently now as new targets are set. This section aims to summarise the current UK hydrogen transport market and outlines predictions for the future respectively.
Currently in the UK, there are only 3 hydrogen fuel cell cars available to purchase; the Toyota Mirai, Honda Clarity, and the Hyundai ix35. This is very limited when compared against the EV market which has over 50 models available commercially. In addition to this there were only 13 refuelling stations in the UK in 2018 compared to 11,000 charging stations for EVs. However there have now been proposals to introduce 65 stations in total by 2020 and 1,100 by 2030 in order to facilitate a hydrogen transition (CCC, 2018).
2.4.1. Global and UK Production and Consumption
Figure 15 - Production and consumption of global hydrogen iMechE. (2019). The majority of global hydrogen is currently produced by carbon-intense steam methane reforming, which makes up approximately 49% as shown in Figure 14 above. As of 2019, roughly 70m tonnes of hydrogen are produced (around 75% of which comes from natural gas), which results in approximately 830m tonnes CO2e
39 being emitted each year (IEA, 2019). From the figure, there are very few renewable production routes, with electrolysis only accounting for 4% of global supply. Alongside this, approximately 6% of global natural gas and 2% of coal is used to produce hydrogen (IEA, 2019). In terms of consumption, the food industry, fertilisers, and oil and gas refining dominate, with transport not even registering on the scale, with <1% of today’s hydrogen produced being used for transport purposes. This is because of the current lack of a hydrogen economy, with HFCVs only just starting to make an appearance on the market. This must change in the future if hydrogen stands a chance at being an alternative transport fuel alongside electricity.
Figure 16 - Global demand for pure hydrogen (IEA, 2019). In terms of UK production, approximately 0.74 million tonnes are produced each year, with over half of this being produced around the Tees Valley regions of Middlesbrough and Redcar through SMR (Vaughan, A, 2019). It has been said that in order for the UK to transition towards a hydrogen economy and potentially replace heating via natural gas, this production value must increase significantly to account for the high demands, and that carbon capture and storage (CCS) technologies are essential for keeping emissions low.
Figure 16 below shows the total policies in place by mid 2019 globally, with a breakdown of the incentives and/or targets associated. It can be seen that out of the 50 or so policies, passenger cars lead the
40 investments, with refuelling stations and buses close behind. However, this is still a relatively small number considering the scale of hydrogen implementation if it is to compete with fossil fuels, for example.
Figure 17 - Policies supporting hydrogen transitions (IEA, 2019). Figure 17 also shows the government budgets for hydrogen and fuel cell research over time. From this, it can be seen that US funding has decreased since 2005 to only approximately $150m. However, China has recently started to add funding since 2015, slowly increasing its budget each year as hydrogen shows greater potential for low-carbon options. As for Europe, budgets have remained similar each year. The general trend however shows that overall budgets are lower when compared to a decade or so previously as 2008 still holds the highest global budgets.
Figure 18 - Government budgets for hydrogen research over the past 15 years (IEA, 2019). 2.5. Manufacturing and Fuel Costs Obviously the cost of producing hydrogen as a fuel is dependent on the production route chosen and the end-use application. Different routes vary in their maturity and some of the technologies are more established than others, offering better economics, such as SMR for example, although this must be carefully balanced with carbon emissions.
When operating a HFCV, compressed hydrogen can be refuelled either at 350 or 700 bar. As there are only 3 models of HFCV in the UK, information regarding fill up costs are quite limited. The most popular however, the Toyota Mirai, has a tank size of 4.7kg H2 and has a fuel consumption figure of roughly 57 miles/kgH2, which equates to approximately 26mpg in its ‘petrol equivalent’, though this depends on the driving style (Middleshurst, T, 2017). In addition to this, the cost of hydrogen at a fuelling station is roughly £12/kg in the UK, which means a typical fill up will come to around £55 (Auto Trader, 2018).
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The cost of the individual fuel cells used in hydrogen vehicles however is still very expensive and is one of the main reasons why HFCVs cost so much when compared to ICE vehicles, which acts as a deterrent for the consumer. The US DoE published literature focused on the cost of PEM fuel cell systems for small and medium sized vehicles and showed that the overall estimated cost is a combination of several factors, shown below (US DoE, 2018):
Estimated Cost = (Materials Cost + Processing Cost + Assembly Cost) × Markup Factor
These calculations also took into account the production numbers each year and business structure. As a result, figures published showed estimates of around $46/kW in 2018 and $38 in 2025 for smaller vehicles of around 80kW. For the larger ones (~160kW), estimates were approximately $97 and $80/kW for 2018 and 2025 respectively (US DoE, 2018). From these values, it can be seen that a fuel cell assembly can cost ~$3,500 in the cheapest case which is still very high. This means the overall purchase cost of the vehicles is made high in order to regain the expenses used during the manufacturing stages.
2.6. Lifespan and Range The range of HFCVs has been mentioned previously already, however will be briefly covered in this section also. One of the key advantages of HFCVs over EVs currently is their driving range, which can reach approximately 350/400 miles before refuelling is needed. EVs achieve much lower figures at only 100-200 miles for basic models, and the most expensive high-end models still only just break over 300 miles (Mok, B, 2017). HFCVs also refuel much faster when compared to EVs, taking the same amount of time as conventional methods, whereas electric vehicles take at least 30 minutes when using the fastest chargers available.
3. Planned and Approved Projects in the North/UK
As the push towards a hydrogen economy increases, more work is being done to overcome the challenges restricting the transition (particularly infrastructure and larger scale demonstration projects), and as the government offers more funding to support companies in the UK, we are seeing more projects appear as a result. This section of the report briefly highlights a number of UK-based projects which are aimed to accelerate the hydrogen transition respectively. It should be noted that this list is not exhaustive. There are a number of other projects taking place in the UK to help support decarbonisation. These include the NWaste2H2 project, the H100 project in Scotland, HyHy, and Waste2Tricity, for example.
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1. Tees Valley Hydrogen Corridor
Tees Valley is currently one of the UK’s biggest hydrogen producers, with over 50% of the UK supply, and won a £1.3m project on 5th February 2019 to improve the hydrogen economy (McNeal, I, 2019). This project aims to introduce a new fleet of hydrogen vehicles and two refuelling stations around Middlesbrough. It also plans to develop the hydrogen corridor project further, in which the people responsible are trying to secure government funding of anywhere between £10-50m via the ‘Strength in Places Fund’, and place themselves at the centre of the hydrogen revolution in the UK, which could potentially add £7bn to the region’s economy and provide 1000 people with new jobs by 2050 (TVCA, 2019). On top of this, the government has also identified Teesside as a potential region for the first introduction of hydrogen trains, as an alternative to diesel-fuelled ones on non-electrified railways, in a bid to improve air quality and reduce pollution further (iMechE, 2019). The Tees Valley has excellent rail connections, a large port, and multiple airports which make it a very attractive region for these future developments.
Figure 19 - Teesside's hydrogen campaign (McNeal, I, 2019).
2. Low-Carbon Hydrogen Supply Competition
The BEIS Energy Innovation Programme opened a competition for £20m which was targeted towards improving the supply of low-carbon bulk hydrogen across all sectors of power, transport and industry, for example (BEIS, 2018). A number of techniques have been considered, including reforming with CCS and electrolysis, along with import infrastructure and storage, and it aims to improve user confidence in reliability of supply at affordable prices. This is essential if hydrogen is to be used in the future as a replacement to fossil fuels, and if net zero targets of 2050 are to be reached.
3. H21 Leeds City Gate
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This project is aimed at assessing the technical and economic feasibility of converting the existing gas network in Leeds to 100% hydrogen. Natural gas produces approximately 180g/kWh CO2, compared to zero for hydrogen, which means carbon dioxide reduction could be achieved relatively easily if the fuel switch took place, assuming the hydrogen used is produced through renewable sources (Leeds City Gate, 2018). As the infrastructure is already in place, it offers a low-cost option, with minimal disruption to the city during the transition period which could provide people with heat and also fuel for HFCVs, strengthening the hydrogen corridor, creating a strong link from Leeds to Middlesbrough, for example.
4. H21 North of England
This project was introduced in November 2018 for a similar reason as the Leeds City Gate project – to reduce carbon emissions via heating. Many homes and businesses use natural gas for heating, however this project aims to switch over to renewable hydrogen (with by-product CO2 being stored in aquifers and caverns), with at least 3.7m homes taking part in the transition (Equinor, 2018). Plans are due to start in 2028 across many northern regions such as Leeds, Middlesbrough, Newcastle, and York, for example, and there is potential to extend this range to 12m more homes by 2050.
Figure 20 - H21 North of England map Sadler, D. (2018). 5. HyDeploy
This project is similar to the H21 projects previously mentioned; aimed at cutting carbon emissions from home cooking and heating through the use of hydrogen. However, this project plans to assess the use of hydrogen when blended with natural gas up to 20%. This is a more cautious approach, but can lead to important reductions nevertheless. It currently has approval to run 12-month trials through private gas networks at Keele University, with future plans in early 2020s to move towards public networks if all goes well and testing shows positive results (HyDeploy, 2019).
6. HyNet
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This aims to create the first low-carbon or even zero-carbon cluster network in the UK, using hydrogen with CCS. Its goal is to reduce carbon emissions from all sectors and promote the use of more sustainable feedstocks whilst helping to support economic growth in the region. The first cluster is based around Leeds, Manchester and Liverpool, with a network of pipelines transporting hydrogen, production facilities using natural gas, refuelling stations, and storage facilities, in addition to the creation of new jobs, for example (Cadent, 2019). It also has good potential to be extended if it proves successful, especially with so many other projects planned for the north.
Figure 21 - HyNet proposed cluster (Cadent, 2019).
7. Aberdeen Bus Project
Aberdeen is keen to become a world leader in low carbon technology and has made plans to increase its hydrogen fleet by introducing the bus project. This has made it the world’s largest demonstration of HFC buses. Here, people from industrial and public sectors have come together to provide funding for the development of the hydrogen economy in the city. The project is divided into two separately funded endeavours, with High Vlo City funding four buses and HyTransit funding six, all with support from FCHJU.
The hydrogen will be produced by electrolysis using a 1MW electrolyser and commercial hydrogen refuelling stations will be constructed to support the growing vehicle fleet (H2 Aberdeen, 2019).
8. Project Cavendish
This project started in February 2019 and was partnered with Arup and aimed to assess the potential of using existing infrastructure for hydrogen production and storage. It was developed to see how the current infrastructure could provide London and the surrounding area with hydrogen, for example. 45
9. Hydrogen Homes in Aberdeen
A new project has been planned in Aberdeen in late July 2019 aimed to construct 500 new homes on the outskirts of the city. However, some of these houses may be powered using fuel cell technology respectively. The company responsible are called Cognito Oak are aiming to install roughly 30 hydrogen-powered homes in this cluster as a pilot project, which is a first for Scotland and helps hold them high in the ranks at hydrogen related projects, for example. By doing this, they plan on collecting data which may help identify trends when compared to other low carbon technologies and may help determine whether fuel cells in the home is a viable option for the future on a larger scale.
Figure 22 - The 500 planned homes in Aberdeen (BBC News, 2019).
4. Current/Future Applications in Transport
Since hydrogen shows good potential for use as an alternative transport fuel, its applications span much wider than simply replacing gas for heating in existing networks, for example. There are also a number of projects in development (or now existing) which have used hydrogen for transport.
The government recently set aside £25m of funding for 22 winning projects to try and help reach a low- carbon economy by encouraging ground-breaking zero emission technologies for new vehicles (DfT, 2019). This is a crucial part of the Industrial Strategy. The government also recently said that all new cars and vans should effectively be zero-emission by 2040, with approximately 200,000 ULEM vehicles currently on UK roads in 2018, making up 0.5% of all vehicles (Press Association, 2019).
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One act the government has done is hand out a number of Toyota Mirai HFCVs to companies to reduce emissions and help with low carbon transport. These include the Natural History Museum, Imperial College London, and University College London respectively (Toyota, 2019).
Similarly to Section 4, a number of these application projects have been summarised in this part of the report, with UK and international projects outlined respectively.
4.1. UK-Based Projects
1. ZERRO (Zero Emission Rapid Response Operations) - Hydrogen Ambulance 2019, Sheffield:
This project is being led by the ultra-low emission mileage company ULEMCo and it is one of the 22 winning schemes that received a share of £25m in government funding (IML, 2019). The exact amount of funding given was approximately £1.9m (OLEV, 2019). Plans are starting with it being trialled in Sheffield, where hydrogen is sourced from local stations (the closest is located in Rotherham).
2. INEOS Grenadier – Hydrogen Fuel Cell 4x4:
This project is another winner of the governments funding competition, with roughly £125,000 received. The aim of this work is to investigate the feasibility and production of a 4x4 powered using a fuel cell. Petrochemical company Ineos is leading this research.
3. Yorkshire Ambulance Service – Hydrogen Vans:
The Yorkshire Ambulance Service has a goal to reach net-zero by 2050. As a result, this is the first service in the UK to introduce green support vehicles, with the aim of making its whole 1200-vehicle fleet as eco- friendly as possible by carbon reductions (Ryan, A, 2019). The vans are powered by electric motors using energy from the battery and a hydrogen fuel cell. The battery recharges from a power supply and the
47 hydrogen is sourced from refuelling stations. This is also linked to the hydrogen ambulance project mentioned previously.
4. Arcola Energy – Hydrogen Bus Project:
Liverpool is the first place in the North that is planning to trial hydrogen buses after winning a £6.4m bid to the government’s Office for Low Emission Vehicles. The bus maker is Alexander Dennis and they are working with companies including BOC and Arcola Energy to organise the project and see up to 25 buses on the roads, helping to cut carbon emissions and improve air quality in the process. To fuel the fleet, there are also plans to install refuelling stations at the BOC Plant at St Helens, and trials are expected to begin in 2020 respectively (Arcola Energy, 2019).
5. Hydroflex – Britain’s First Hydrogen Train:
Hydrogen trains do not yet exist in the UK. A quarter of trains currently operate using diesel fuel, but the government is keen to remove these by 2040 to reduce carbon emissions. However, the majority of UK rail lines lack the overhead cabling which electric trains need to operate, which means diesel is still needed. Currently, the only two hydrogen passenger trains in active service in Europe are held in Germany, by company Alstom. However, the UK is now looking to become one of the next countries to start using them, and the Hydroflex is one example where the technology is being tested. Here, bi-mode trains can be powered by either electricity from hydrogen or from overhead cables. These tests are due to begin in March of 2020 (Burridge, T, 2019). It is hoped that these hydrogen trains will be able to carry passengers in the UK in two years.
Figure 23 - Schematic of hydrogen trains operating principles (Burridge, T, 2019).
6. Wrightbus – Hydrogen Bus Fleet in London:
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Similarly to this, Transport for London has also paired with Wrightbus and planned to introduce 20 new hydrogen buses in 2020, which will operate on 3 main routes around the city. Wrightbus currently operate hydrogen buses in Aberdeen, which is the only other city in the UK to do so. The investment has cost £12m with the associated refuelling stations required to power them. More than £5m in funding is also being provided by the EU and £1m from the Office of Low Emission Vehicles.
Figure 24 - Hydrogen double-decker buses in London (Barrett, T, 2019).
In addition to these are Breeze trains which Alstom are introducing by converting older 321-class diesel trains to run on hydrogen in 2022, ULEMCo are introducing a zero-emission truck in Liverpool, and HySeas III which is the world’s first hydrogen powered passenger ferry, planned for 2021.
Figure 25 - Breeze hydrogen trains plan to come to the UK by 2022 (Alstom, 2019).
4.2. International Projects 1. Coradia iLint, Germany– World’s First Hydrogen Passenger Train:
This project is based in Germany and is led by Alstom, designed to be the first train to run on hydrogen fuel cells in an attempt to reduce the number of diesel trains on the rails. It was first introduced in 2016 and its first operation was in 2018 and has shown good promise in the public eye, contributing towards sustainable train operation (Alstom, 2019). Here, hydrogen is stored in a tank on the roof of the train, along with the fuel
49 cell, and the batteries are underneath the train, providing an even weight distribution. This is shown more clearly in Figure 11 below.
Figure 26 - Coradia iLint hydrogen train by Alstom (Alstom, 2019). 2. UPS, USA – Hydrogen Delivery Trucks:
The delivery company UPS, has made conscious efforts to reduce its emissions by introducing electric vans to its existing vehicle fleet. However, they are now adding a number of HFCVs to this which are planned to be in use by the end of this year. The trucks being used are manufactured partly by Toyota and Kenworth, with Shell also supporting the project since its start in 2017, by building two refuelling stations to help improve the ease of use. These vehicles have been built with the focus on short-range driving, although they still have a relatively healthy range of approximately 300 miles (Mathews, L, 2019).
Figure 27 - Hydrogen fuel cell delivery truck by UPS (Mathews, L, 2019). 50
3. Memphis Airport – HFCV Fleet:
An airport in Memphis began a project in 2013 to introduce a number of HFCVs into its fleet by 2018. It consists of 15 cargo tractors which have an approximate run time of 4 hours, thanks to a new accessible refuelling station to provide the fuel to power the vehicles. The project uses liquid hydrogen and was given $5m in funding to support the transition (Petrecky, J, 2017).
4. Hype, Paris – HFCV Taxi Fleet:
Taxi company Hype have plans to grow their fleet of HFCVs by 2020 in an attempt to reach a zero-emission taxi sector by 2024 in France. They currently already have 100 Hyundai hydrogen-powered taxis, now with plans to introduce 500 Toyota Mirai models (Roy, J, 2019). The project is led by a host of companies, including Air Liquide, Idex, and Toyota, who are supplying the cars. In support of this, there will also be a number of refuelling stations opening up around Paris, with 4 currently available, and plans for this number to triple next year.
Figure 28 - Hype taxis in Paris (Roy, J, 2019).
5. HY4, Germany– World’s First Hydrogen Plane:
Aircraft makers Pipstrel have teamed up with hydrogen experts Hydrogenics to design the first hydrogen fuel cell plane. This is a 1.5 tonne, 4 seater aircraft which uses electricity via hydrogen to travel at speeds of over 100mph and gives a range of approximately 930 miles (HY4, 2019). It is also a hybrid, as it relies on battery power during take-off and landing stages. However, with good existing infrastructure already in place around Germany, this helps support the transition and innovation towards renewable air travel.
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Figure 29 - HY4 - World's first hydrogen aircraft.
6. Alaka’i Technology, USA – Hydrogen Powered Drones:
The ‘Skai’ is a hydrogen powered flying drone prototype which has the potential to become a ‘flying taxi’ in the future, with 6 motors, enough seats for 5 people, a range of 400 miles, and speeds of up to 120pmh (Fish, T, 2019). It was first unveiled in Los Angeles earlier this year and the use of fuel cells make it very light compared to electric batteries. It could also be used as a cargo carrier to transport heavy goods, or a flying ambulance, for example.
Figure 30 - Skai flying taxi concept (Fish, T, 2019). 4.3. Non-Application International Projects
1. New Electrolysis Plant in Germany:
The UK has planned to build the world’s largest electrolysis plant in Wessling for the production of clean hydrogen. The project will see the construction of a 10MW plant with a capacity of 1,300 tonnes H2/year, and is being led by ITM Power, with plans for it to be completed by mid-2020 (Njoroge, T, 2019). This is being done in Germany as they have excess electricity which cannot be stored in the grid and must be used – unfortunately the UK does not have this problem and so cannot build its own.
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2. Chinese Hydrogen – First Commercial Liquid H2 Plant:
A new hydrogen liquefaction plant has been agreed to be built by Zhejiang Jiahua Energy Chemical Industry Co and Zhejiang Energy Group Co, with plans to start operation later in 2019. The hydrogen gas will be
3 3 provided at approximately 99.9972% purity and will treat 19,200Nm of gas each day, giving 1m /H2 of liquid hydrogen as a result (Leung, V, 2019).
3. Coal-to-Hydrogen Plant in Australia:
A new pilot project has started in Victoria in which brown coal is to be converted into hydrogen. Kawasaki Heavy Industries and other Japanese and Australian companies are working on the project which plans to produce 3m tonnes of liquid H2/year, with support from both the Victorian and Australian government, each contributing $50m. It plans to construct a hydrogen liquefaction terminal to support a wider hydrogen energy supply chain project by June 2020 (Hosie, E, 2019). This plans to convert brown coal into liquid hydrogen for transport to Japan using specially-built marine carriers. Coal is abundant in Victoria so is a great way of adding value to the reserves. This is going to be gasified to produce syngas which is composed of CO and H2.
5. Hydrogen Vehicle Fleets in the UK
Early fleet adoption is one potential way to introduce hydrogen vehicles into the public eye in the UK, slowly feeding them into the transport sector by replacing a small number of older, more polluting vehicles such as buses, which operate on specific routes in limited regions, for example. Not only will this improve air quality, but it will also increase public exposure to hydrogen as a transport fuel, helping to break down existing misconceptions and negative responses, for example. This has been shown in previous studies by Molin et al in which public willingness to use hydrogen buses was very high, even though their knowledge on the subject is low. In addition, Shaheen et al also found that the more exposure the public had to hydrogen, the more accepting they were of it. This section of the report is focused on highlighting the current hydrogen fleets in the UK, including public access and government vehicles respectively, and also includes a brief literature review of existing studies aimed towards transitioning older conventional-fuel fleets to hydrogen.
5.1. An Introduction to Hydrogen in the UK The UK is one of the leading countries in terms of hydrogen development for a low-carbon future. The UK’s hydrogen infrastructure however is still very underdeveloped, with only a handful of hydrogen vehicle fleets scattered around the country and refuelling stations few and far between, with approximately 17 in the UK for cars and/or buses. The major hydrogen vehicle fleets in the UK are located in Aberdeen, Tees Valley, 53
Liverpool, Birmingham, and London, with many new projects up and coming to develop the hydrogen economy and build on the hydrogen corridor, for example. As the public pushes towards sustainable alternatives, reductions on climate change, and the government gives more funding opportunities for hydrogen projects, these fleets will continue to grow and improve in the future, and refuelling stations will become more accessible.
This section of the report aims to identify the major hydrogen vehicle fleets in the UK, giving a brief outline of their size, vehicle types, and future projects associated with them, for example. It must be noted that this list is not exhaustive and other smaller fleets are in operation. However for the purpose of this report, only the major fleets have been covered.
5.2. Public Access Fleets The government has started to increase its funding for low-carbon transport and alternative fuel technology by opening more competitions, for example, and as a result there are a number of hydrogen vehicle fleets emerging which aim to provide services to the public. Although there are limited refuelling stations in the UK, many fleets operate on a ‘return-to-base’ basis and so don’t require extensive infrastructure. A few of these are outlined in this section, but this list is not exhaustive:
1. Aberdeen:
The Aberdeen City Region Hydrogen Strategy 2015-2025 has been developed in order to encourage hydrogen developments and promote a low-carbon economy through various new projects and fleets, for example.
The hydrogen bus project mentioned in Section 3 saw the deployment of 10 hydrogen buses in the city to help promote a low-carbon transition and make Aberdeen global leaders in hydrogen. However since then, the addition of 10 more buses to the fleet has been proposed earlier this year after £3m of funding was supplied by the Scottish government. This will put Aberdeen’s hydrogen vehicle fleet in the region of approximately 60 vehicles in total by the end of 2019 (Haslam, D, 2019). In addition to this, car rental company Co-Wheels Car Club based in Aberdeen added two Toyota Mirai HFCVs to its fleet in April 2019 for the public to hire in an attempt to improve public perception and develop the hydrogen economy further. There are also plans to add another Mirai soon in the future which will be used at Robert Gordon University as part of its fleet (Townsend, R, 2019). Aberdeen has also introduced the world’s first hydrogen road sweeper in 2018 which was provided by ULEMCo. The sweeper is a diesel/hydrogen hybrid and reduces emissions by approximately 30% when compared to conventional alternatives (Aberdeen City Council, 2018).
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The company Wrightbus also secured approximately £7.5m in funding in July 2019 for the introduction of new hydrogen fuelled double decker buses to Aberdeen’s existing fleet (McKeown, G, 2019). This will provide 15 HFC buses, each costing around £500,000 to the city which will operate on specific routes later on in the year.
2. Teesside:
The hydrogen plans at Tees Valley have been covered multiple times previously in this report and therefore will not be mentioned again. However, after winning a portion of £14m of government funding towards hydrogen vehicles, it will now add a new fleet of 5 hydrogen vehicles which will be supported by the two new refuelling stations planned for construction. Alongside this, there are currently pilot plans to trial hydrogen trains in the region, though this will not be available for many years yet (Redfern, J, 2019).
3. Crawley: The DfT has awarded a total of approximately £48m in funding to various applicants in order to provide 263 low emission buses around the UK (Bastable, B, 2019). Crawley and Gatwick was one of those regions and has secured £4.4m to introduce 20 new single-decker hydrogen buses to selected high-demand 24h public routes to reduce emissions and improve air quality. Brighton and Hove Buses and Metrobus are the joint leaders of this project and are planning to reach zero-emission fleet conditions by 2030. A group comprising ITM Power, Toyota, and Hyundai also won a portion of £14m government funding in 2019 which was aimed to develop HFCVs and associated refuelling infrastructure (approx. £3.1m) (Shrestha, P, 2019). The Hydrogen Mobility Expansion Project will now open a new refuelling station in Crawley and a fleet of 51 HFC cars are to be introduced in the near future.
4. Liverpool:
Liverpool have recently received 25 double decker hydrogen buses in 2019 after £6.4m government funding support was secured from OLEV (Arcola Energy, 2019). The buses are going to be in use by 2020 and the project also includes the construction of a refuelling station at St Helens to support their use. This is the first city in the north to trial hydrogen buses and to help, Arcola Energy are building a manufacturing and support facility for the buses to keep them well maintained and operating to a high standard.
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Figure 31 - Arcola Energy hydrogen bus maintenance facility (Fuel Cell Works, 2019). 5. Birmingham:
A new scheme is planned to reduce dangerously high levels of NO2 pollution in Birmingham by introducing a new fleet of 22 hydrogen buses costing approximately £500,000 each. The buses are planned to operate on major network routes and the scheme will cost a total of £13.4m (Elkes, N, 2019). The project will also see the development of refuelling facilities, which will be set up at Tyseley Energy Park.
6. Abergavenny, Wales:
A hydrogen car manufacturer Riversimple, in Wales won approximately £1.25m in funding from the governments OLEV to support the production of a test fleet of 20 of their vehicles. There are 3 existing vehicles and this funding will help manufacture 17 more to create a new fleet for a 12-month trial around the local region (Figg, H, 2019). This trial will involve over 200 users, operating the vehicles in a range of environments and for a range of uses including households and businesses. This will help to give further information that will refine the models and develop the company further, for example.
5.3. Governmental Fleets 1. Metropolitan Police:
In 2018 the Met joined with ITM Power to increase the number of hydrogen fuel cell vehicles in its fleet. In 2017 it also trialled Suzuki HFC scooters and aimed to add roughly 550 ultra-low emission vehicles to its fleet by 2020. Toyota also made a deal with the Met and gave them 11 Toyota Mirai’s in March 2018 which can be easily refuelled thanks to nearby stations at Teddington and Rainham respectively (Date, W, 2018). In
56 addition to these the fleet also has 11 BMW C Evolution scooters, and 50 Nissan e-NV200 vans, both of which are low carbon electric vehicles (Fleet News, 2018).
Figure 32 - Toyota Mirai HFCV used by the Met Police (Fossdyke, J, 2018).
2. London Fire Brigade:
In 2016 the fire brigade decided to use electric vehicles, with the frontline car fleet comprising 57 plug-in hybrids and range extender vehicles respectively. This was made possible through £790,000 funding provided 75% by OLEV and 25% by Chargemaster, who specialise in EV charging (Smith, C, 2016). However, although they don’t currently have any hydrogen vehicles in their fleet, they are now considering a swap to hydrogen for use in their vans as the limited range of the current EVs is restricting their use, and the vans also pass through several routes which have nearby refuelling stations. The fire brigade is also a member of Hydrogen London and has been “keeping a close eye on the prospect of the technology in its own fleet” (Smith, C, 2016).
5.4. Fleet Transition Studies
5.4.1. Knoxville Bus Fleet Langford et al investigated the transition of a bus fleet in Knoxville to hydrogen fuel, with particular focuses on resulting fleet size requirements, hydrogen production, storage, and distribution to provide refuelling for the changeover. In this study, data was collected from existing bus projects using hydrogen around the US in order to better estimate transition requirements for the Knoxville fleet of 12 hydrogen buses. This data included the original bus fleet, facilities, and personnel, all sourced via interviews with staff and records.
Previous demonstration projects from Santa Clara Valley Transport and SunLine Transit Agency were used as teaching tools to gain a better understanding of the availability and cost of hydrogen buses before Knoxville’s transition. Here, it was found that the average availability of the hydrogen buses was lower when compared to original bus types, with only 55-66%. It was deduced that this low value was due to technical issues associated with the fuel cell technology and batteries, for example. In addition to this, as the hydrogen 57 buses were only used on specific routes under limited operating hours, their total mileage was registered lower also, with fuel cells less than half when compared to conventional fuels in all case studies, shown in Figure 32 below.
Figure 33 - Hydrogen vs conventional fuel bus data for 3 case studies (Langford, B, 2011).
In terms of cost, the fuel cell buses also showed much higher total costs per mile compared to diesel and CNG alternatives. This may be due to the fact that diesel fuel has been on the market for decades and is a well-known and mature fuel when it comes to its production, for example. However in the case of hydrogen, things are not as developed and costs are higher due to lower demands and production knowledge. Total maintenance costs were also higher for hydrogen buses because of their lower availability caused by technology-related issues. This data collected has shown that in order for existing bus fleets to be converted to hydrogen, increases in fleet size may be required to compensate for these downsides in the current hydrogen market. Average fuel cell bus availability is 60% and in order to achieve an assumed desired 85%, this fleet size must increase by 1.4x.
The Knoxville Area Transit (KAT) is the case study fleet under scrutiny, and consists of 93 buses and vans which operate on 25 fixed bus routes and 3 express routes accordingly, covering the University of Tennessee by designating 20 vehicles respectively. The fleet breakdown is given below:
Figure 34 - Knoxville bus fleet breakdown (Langford, B, 2011).
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Another factor that played a role in the transition towards hydrogen fleets included the space that fuel cell technology takes up in the vehicle itself. This led to a reduced volume of free space inside the vehicle for passengers which meant less people could be transported on routes, for example, leading to further demands for higher fleet sizes.
The Knoxville fleet case study of 93 buses was amended assuming a fuel cell transition using the equation below and calculations showed that 132 buses would be needed to achieve the same availability and results as the existing fleet. It was assumed that bus demand would remain the same and that with fuel cell technology improving at a rapid pace, these numbers could potentially reduce in the future if a short and steady conversion were to take place.
Z N = C (1 + ) (1 + X) A
N = number of hydrogen buses required.
C = size of current bus fleet.
Z = availability goal for the fleet.
A = average availability expected.
X = % planned fleet size expansion.
In terms of cost, the study also recorded total fleet consumption over the year was around 850,000 gallons of diesel and gasoline, and found that when using hydrogen produced from SMR, the cost of running the bus fleet increased by approximately $0.03-0.15/mile compared to diesel. Hydrogen from electrolysis would increase costs by $0.50/mile, as the technology is less developed. In addition to cost considerations, calculations were also made regarding refuelling requirements for the fleet. Here, it was noted that using one dispenser would take approximately 6.6 hours to fill the entire fleet, compared to only 2 hours when 3 are used (Figure 32). This was deemed a more practical option as the buses could be fuelled before and after service times. Finally, with an increased fleet size due to the switchover, it was estimated that 17 additional maintenance bays would be required to carry out essential works, with other factors also needing consideration such as infrastructure for hydrogen storage and production, for example.
Figure 35 - Total dispensers used and associated refuelling times (Langford, B, 2011). 59
5.4.2. Policy Considerations Another study by Hans et al focused on the importance of a policy mix in order to reduce emissions, improve air quality, and public health in Belgium, through the introduction of cleaner vehicles. It has been said that without this, expected CO2 emissions are likely to increase as specific targets are not made and clear paths towards achieving them are also lacking which leads to a delayed action and more people opting for the cheaper conventional alternative. As a result, some policy initiatives have been introduced including reduced purchase prices for alternative fuel vehicles and incentives for more charging infrastructure, for example.
6. Current and Future UK H2 Activity Map:
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Figure 36 - UK hydrogen activity map.
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Table 8 - Existing refuelling stations
# Location: Operator: H2 Provided: Suitable For: 1 Kirkwall Orkney, Scotland ITM Power 350/700 Bar. Car 2 Aberdeen, Scotland Linde AG 350/700 Bar. Car 3 Aberdeen Cove, Scotland Hydrogenics Corp. 350/700 Bar. Car and Bus 4 Rotherham, England ITM Power 350/700 Bar. Car 5 Uni of Birmingham - 350/700 Bar. Car 6 Coventry University - 350/700 Bar. Car 7 Abergavenny, Wales - 350/700 Bar. Car 8 Port Talbot, Wales - 350/700 Bar. Car 9 Swindon, England ITM Power 350/700 Bar. Car 10 Swindon, England Linde AG 350/700 Bar. Car 11 Beaconsfield, England ITM Power 350/700 Bar. Car 12 Hatton Cross Station, England - 350/700 Bar. Car 13 Hendon, England - 350/700 Bar. Car and Bus 14 Lea Interchange, England - 350/700 Bar. Bus 15 Teddington Station, England ITM Power 350/700 Bar. Car 16 Cobham Surrey, England ITM Power 350/700 Bar. Car 17 Rainham Essex, England ITM Power 350/700 Bar. Car
Table 9 - Planned refuelling stations.
# Location: Operator: 1 Tees Valley, England - 2
3 Liverpool Bus Station, England Linde AG
4 Derby, England ITM Power 5 Birmingham, England ITM Power 6 Greenford, England -
7 London, England ITM Power 8 9 Gatwick, England ITM Power
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Table 10 - Hydrogen projects.
## Project: Summary: 1 £1.3m funding secured in 2019.
Tees Valley H2 Corridor 2 refuelling stations and new vehicle fleet. Aims to win more funding from ‘Strength in Places’ fund. 2 Converting existing gas network to 100% hydrogen. Leeds City Gate Infrastructure already in place. Small changes needed only.
Will strengthen the H2 corridor between Teesside and Leeds. 3 Aims to blend hydrogen with natural gas at 20%. HyDeploy 12-month run trials in operation at Keele University. Plans to move to public networks in early 2020s. 4 HyNet Aimed to create a low-carbon cluster network. Proposed between Leeds, Manchester, and Liverpool. Includes hydrogen production, storage, and transport etc.
Table 11 - Hydrogen fleets.
# Location: Comments: 1 Two more Toyota Mirai’s added to Car Club rental service. £21m Hydrogen Bus Project 2013 (fleet of 10). In 2017 this fleet was doubled to 20. 17 Mirai’s and 4 Renault Kangoos added to local authority fleets in 2019. New Bus Fuel Project. Aberdeen, Scotland Introduction of HFCV fleets (60 HFCVs predicted in operation by end of 2019). JIVE 1 and 2 received £50m from the EU in 2018 for 12 HFC buses to be used in Dundee to create an integrated energy park with hydrogen buses and RFS. £7.5m funding in July 2019 for introduction of 15 HFC double deckers. Funding was sought by Wrightbus. 2 Tees Valley, UK £1.3m funding secured in Feb 2019.
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New hydrogen infrastructure proposed. Two refuelling stations and a fleet of HFCVs with a 300+ mile range planned. Refuelling stations will be suitable for cars and buses and lorries. Arriva are also looking to build a major facility to run 10 hydrogen trains. 3 OLEV £6.4m funding was won in 2019. Liverpool, UK Plans to bring 25 HFC double decker buses to the city and a new refuelling station is planned for support. 4 £13.4m funding was sought for hydrogen buses. 22 new buses each costing £500K are planned for late 2019 along Birmingham, UK with a refuelling station. The university also has a refuelling station and a fleet of 100 EV, hybrids, and HFCVs for research purposes. 5 Hydrogen ambulance won funding in 2019. 5 hydrogen vans added to council fleet in 2019. Sheffield, UK Already an existing refuelling station in Rotherham nearby. YAS added two more Renault Kangoos and 3 hydrogen vans in 2017 and 2019. 6 50 Mirai’s added to taxi fleet ‘Green Tomato’s’. 8 hydrogen buses in operation for 6 years. 5 refuelling stations around the city. Plans for 20 hydrogen double deckers to come online in 2020. London, UK Hydrogen produced from wind and costing £12m. TfL operates 165 zero-emissions buses. 60 FCEV taxis incoming. Part of a £22.8m project between Paris, London, and Brussels. 11 Toyota Mirai vehicles added to Met Police fleet in 2018. 7 Hydrogen vehicle manufacturer Riversimple won £1.25m in Abergavenny, Wales funding from OLEV to produce 17 more. This pushes their fleet up to 20 so now trials can be carried out.
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7. Proposed Actions and Objectives
Refined objectives and proposed projects:
Based on the above analysis, the future projects are proposed should any funding be secured. Objectives are determined. The scope of the work stream 2 - transport is defined.
Scope of the WS2:
The WS2 will utilise the strengths in the region, i.e. an existing large scale of hydrogen production in the Tees Valley, many industrial fleets (road, off-road and trains) and an extensive bus network and a clear determination for decarbonisation in the Leeds city region, to investigate the potential of hydrogen in decarbonisation and improving air quality for transport sector. The aim is to identify key challenges for the hydrogen transition through case studies, e.g. fuel and powertrain options (ICE and fuel cell) and fleet suitability (distance, load etc), and provide scalable cost benefit analysis models on operability, cost, environmental impacts and design a transition strategy in the Teesside industrial cluster and Leeds city region.
Objectives:
• Determine the scope for hydrogen based transport including fuel options (compressed and liquefied hydrogen and hydrogen derived fuels such as methanol and ammonia), powertrain options and associated infrastructure in the region.
• Carry out detailed case studies with key stake holders, some of which may be implementation based, to conduct scalable life cycle cost/benefit analysis.
• Determine the implications of hydrogen transport networks for regional emissions and air quality.
• Formulate a hydrogen transport transition strategy.
Proposed projects:
• Scoping potential roles of H2 for transport in the corridor region.
• Leeds Bus Network case study.
• Determining the air quality impacts of a hydrogen transition in regional and micro-environments.
• Further case studies with regional stakeholders in other sectors, especially HGV, off-road vehicles and train fleet operators.
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• Integrated multiuser hydrogen hub for transport and heat.
• FCEV deployment to meet end user requirements.
• Hydrogen conversion to methanol by reacting with CO2. This avoids the need for expensive hydrogen fuel tanks and a hydrogen distribution system for transport.
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