Electric and hydrogen buses: Shifting from conventionally fuelled cars in the UK

May combine two claims.

At 50% capacity, CFB emissions are 32.5 gCO2 km-1 per person in 2017 and 28.5 gCO2 km-1 per person in 2050.

“However, at 50% capacity, emissions from a CFB would almost half that of CFVs at 32.5 gCO 2 km -1 per person in 2017.However due to minimal technological advances if a CFB was at 50% capacity in 2050, emissions would be expected to be 28.5 gCO 2 km -1 per person.”

May combine two claims.

CFB emissions are projected to peak in 2030 and by 2050 be 0.02 MtCO2 higher than in 2017.

“Emissions for CFBs are expected to peak in 2030 before decreasing, however by 2050, emissions are expected to be 0.02 MtCO 2 higher than in 2017.”

May combine two claims.

A standard four-person car at 100% capacity produced 30 gCO2 km-1 per person in 2017 and could decrease to 21.7 gCO2 km-1 per person by 2050.

“Fig. 1 demonstrates that a standard four-person car produced 30 gCO 2 km -1 per person at 100% capacity in 2017.Due to technological advances, emissions per person could decrease to 21.7 gCO 2 km -1 per person by 2050.”

The quote only partly states this claim.

At the average CFV occupancy rate of 1.6 individuals per vehicle, carbon emissions per person are significantly more than for 25% capacity CFBs.

“Carbon emissions for this CFV capacity are significantly more than that of 25% CFBs.”

May combine two claims.

A bus at 25% capacity produces 65.2 gCO2 km-1 per person in 2017, decreasing to 56.9 gCO2 km-1 per person.

“A bus at 25% capacity would produce 65.2 gCO 2 km -1 per person in 2017, decreasing to 56.9 gCO 2 km -1 per person.”

May combine two claims.

Under the steady progression scenario, hydrogen bus emissions decrease by 78% over 2017-2050, with a secondary peak in 2030.

“Under the steady progression scenario, emissions decreased by 78% over the studied period, though the decrease was not linear and contained a secondary peak in 2030.”

• AssumptionThe authors state this as an assumption: The hydrogen production process is electrolysis.

May combine two claims.

CFV emissions are projected to peak in 2020 at 41.5 MtCO2 and then decrease to 7.3 MtCO2 below 2017 levels.

“Emissions for CFVs are expected to peak in 2020 to 41.5 MtCO 2 before decreasing by 7.3 MtCO 2 below 2017 levels.”

May combine two claims. The quote only partly states this claim.

A car at 25% capacity could produce 120 gCO2 km-1 per person in 2050, decreasing to 87 gCO2 km-1 per person by 2050.

“Whereas a car could produce 120 gCO 2 km -1 per person in 2050, decreasing to 87 gCO 2 km -1 per person by 2050.”

May combine two claims.

In 2017, CFVs produced 5 times more emissions than CFBs; by 2050, CFVs produced 4.5 times more emissions than CFBs.

“Emission predictions indicate that in 2017, CFVs under both scenarios produced 5 times more emissions than CFBs.By 2050, emissions are 4.5 higher.”

May combine two claims.

Under the two-degree scenario at 50% capacity in 2017, CFV emissions per person are almost double those of HBs and six times those of EBs.

“Results indicate that under this scenario, the gCO 2 km -1 per person for CFVs at 50% capacity are almost double that of HBs and six times that of EBs in 2017.”

• AssumptionThe authors state this as an assumption: The hydrogen production process is electrolysis.

Probably not a substantial claim: may not pass S3 (load-bearing).

Table 6 indicates that EVs produce less gCO2 km-1 per person than HBs in 2050.

“Table 6 indicates that EVs produce less gCO 2 km -1 per person than HBs in 2050, this remains unlikely as 100% EVs by 2050 is not likely achievable.”

• AssumptionThe authors state this as an assumption: The hydrogen production process is electrolysis.

May combine two claims.

At 50% capacity, CFVs produce the highest level of emissions in gCO2 km-1 per person, followed by EVs, then all bus types.

“Emissions at 50% capacity demonstrate that CFVs produce the highest level of emissions in gCO 2 km -1 per person, followed by EVs, then all bus types”

May combine two claims.

At 50% capacity, hydrogen bus emissions are 15.6 gCO2 km-1 per person, while electric bus emissions are almost half at 6.4 gCO2 km-1 per person.

“Under 50% capacity, emissions from HBs were 15.6 gCO 2 km -1 per person with emissions from EBs at almost half this level producing 6.4 gCO 2 km -1 per person.”

• AssumptionThe authors state this as an assumption: The hydrogen production process is electrolysis.

May combine two claims.

HBs use 1.8 kWh km-1, EBs use 1.2 kWh km-1, and EVs use 0.17 kWh km-1.

“Through comparison of kWh km -1 , HBs use 1.8 kWh km -1 , EBs use 1.2 kWh km -1 , whereas EVs use 0.17 kWh km -1 .”

May combine two claims.

The worst-case hydrogen bus scenario remains 5.7 MtCO2 lower than CFB production, with CFBs producing around four times more emissions in total in 2050.

“The worst-case scenario remains 5.7 MtCO 2 lower than the CFB productions, with CFBs producing around four times more emissions in total in 2050.”

• AssumptionThe authors state this as an assumption: The hydrogen production process is electrolysis.

May combine two claims.

Without CCS, hydrogen bus emissions using steam methane reforming are 11 times higher and using coal gasification are 19 times higher than with CCS.

“Without CCS, emissions using steam methane reforming was 11 times higher and for coal gasification, emissions were 19 times higher.”

May combine two claims.

Electrolysis using CCS would produce 15 gCO2 kWh-1 and result in emissions of 0.25 MtCO2 in 2018.

“As a more advanced technology, electrolysis using CCS would produce 15 gCO 2 kWh -1 (CCC, 2018).This would result in emissions produced of 0.25 MtCO 2 in 2018.”

• cites CCC, 2018Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• AssumptionThe authors state this as an assumption: The hydrogen production process is electrolysis.

May combine two claims.

By 2050, even with technological improvements, CFVs remain the highest emitting transport mode, producing 55 times more emissions than EBs and 14 times more than HBs.

“By 2050, even with technological improvements CFVs remain the highest operating emitting transport mode producing 55 times more emission than EBs and 14 times more emission than HBs.”

• AssumptionThe authors state this as an assumption: The hydrogen production process is electrolysis.

May combine two claims.

Cumulative emissions of EVs are substantially higher than for both bus types, due to the higher number of EVs and distance travelled projected between 2017 and 2050.

“Results indicate that the cumulative emissions of EVs are substantially higher than for both bus types which is due to the higher number of EVs and distance travelled projected between 2017 and 2050.”

May combine two claims.

At 75% capacity, hydrogen bus emissions are 10.4 gCO2 km-1 per person, while electric bus emissions are 4.3 gCO2 km-1 per person.

“For 75% capacity, HB produced 10.4 gCO 2 km -1 per person, with EBs producing 4.3 gCO 2 km -1 per person.”

• AssumptionThe authors state this as an assumption: The hydrogen production process is electrolysis.

May combine two claims.

CFB emissions at 50% capacity remain relatively constant over the time frame and are almost half of CFV emissions in 2017.

“CFB emissions remain relatively constant at 50% capacity within the time frame at almost half of CFV emissions in 2017.”

May combine two claims.

At 25% capacity, hydrogen bus emissions are 31.2 gCO2 km-1 per person, while electric bus emissions are almost three times lower at 12.8 gCO2 km-1 per person.

“Results indicate that under the 25% capacity emissions from HBs are 31.2gCO 2 km -1 per person, whereas for EBs emissions are almost three times lower at 12.8 gCO 2 km -1 .”

• AssumptionThe authors state this as an assumption: The hydrogen production process is electrolysis.

May combine two claims.

Under the consumer evolution scenario, hydrogen bus emissions decrease by 69%, with a secondary peak in 2031 at 3.5 MtCO2 before decreasing to 1.84 MtCO2.

“The consumer evolution scenario saw the lowest decrease in emissions of 69%, with emission levels having a secondary peak in 2031 at 3.5 MtCO 2 before decreasing to 1.84 MtCO 2.”

• AssumptionThe authors state this as an assumption: The hydrogen production process is electrolysis.

Probably not a substantial claim: may not pass S3 (load-bearing).

This paper does not directly consider the embedded carbon costs of vehicles including the decommissioning of CFVs and the construction of vehicles.

“This paper does not directly consider the embedded carbon costs of vehicles including the decommissioning of CFVs and the construction of vehicles.”

Probably not a substantial claim: may not pass S3 (load-bearing).

No single technology can make transportation carbon neutral.

“Although no single technology can make transportation carbon neutral (Mathiesen et al., 2015), this paper will focus on the environmental operating emissions of EBs and HBs.”

• cites Mathiesen et al., 2015 sourceNot checked — no full text of the source

May combine two claims.

The UK is one of the best suitable locations for CCS implementation as there are suitable carbon sinks and appropriate offshore infrastructure.

“Furthermore, the UK is one of the best suitable locations for CCS implementation as there are suitable carbon sinks (depleted oil and gas reservoirs and aquifers) with appropriate offshore infrastructure (BEIS, 2019d).”

• cites BEIS, 2019dNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

May combine two claims.

Approximately 99% of the H2 produced and consumed within industry is generated by natural gas reforming, producing high levels of CO2 as by-products.

“Approximately 99% of the H 2 produced and consumed within industry is generated by natural gas reforming (Hosseini and Wahid, 2016;Mohammadfam and Zarei, 2015;Ozalp, 2008) producing high levels of CO 2 as by-products (National Academy of Engineering, 2004).”

• cites Hosseini and Wahid, 2016 sourceNot checked — no full text of the source
• cites Mohammadfam and Zarei, 2015 sourceNot checked — no full text of the source
• cites Ozalp, 2008 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

May combine two claims.

The projected increase in CFB emissions by 2050 relative to 2017 is due to a 19% increase in the number of buses and a 3% decrease in total distance travelled.

“This is due to a 19% increase in the number of buses and 3% decrease in the total distance travelled.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The Paris Agreement has set a target to limit global warming to less than 2°C above pre-industrial temperatures and to pursue efforts to limit the temperature increase to 1.5°C above pre-industrial temperatures within this century.

“The Paris Agreement has set a target to limit global warming to less than 2 °C above pre-industrial temperatures and to pursue efforts to limit the temperature increase to 1.5 https://doi.org/10.1016/j.trd.2020.102350°C above pre-industrial temperatures within this century (Pietzcker et al., 2014).”

• cites Pietzcker et al., 2014 sourceNot checked — no full text of the source

May combine two claims.

EBs and HBs offer key advantages over CFBs and CFVs because they do not produce emissions directly from operation since their emissions are produced upstream.

“Both EBs and HBs offer key advantages over conventionally fuelled buses (CFBs) and other conventionally fuelled vehicles (CFVs), as they do not produce emissions directly from operation since their emissions are produced upstream (Correa et al., 2017;Mekhilef et al., 2012).”

• cites Correa et al., 2017 sourceNot checked yet

  Checked before — its earlier verdict is held back until a new check runs.

• cites Mekhilef et al., 2012Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

GHG emissions will need to reach optimum levels and decline as fast as possible to meet the Paris targets.

“In addition, GHG emissions will need to reach optimum levels and decline as fast as possible to meet these targets (Pietzcker et al., 2014).”

• cites Pietzcker et al., 2014 sourceNot checked — no full text of the source

May combine two claims.

To use H2 for fuel, significant infrastructure improvements are needed as currently there are low numbers of H2 vehicles in use within the UK.

“To use H 2 for fuel, significant infrastructure improvements are needed as currently there are low numbers of H 2 vehicles in use within the UK (Southall and Khare, 2016).”

• cites Southall and Khare, 2016 sourceNot checked — no full text of the source

May combine two claims.

SMR is one of the most widespread and least expensive methods of H2 generation.

“SMR is one of the most widespread and least expensive methods of H 2 generation (Ogden et al., 2000).”

• cites Ogden et al., 2000 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based).

Expanding and learning from policies in areas that have seen increases in public transport use, such as London, would further increase the emissions decrease seen across the country.

“Expanding and learning from policies in areas that have seen increases in public transport use, such as London, would further increase the emissions decrease seen across the country.”

May combine two claims.

At least 20 CFVs could be taken off the road if buses were fully utilized, significantly reducing road transport emissions and congestion.

“By assuming the maximum capacity of an average bus is 80 and a small CFV is four, as least 20 CFVs could be taken off the road if buses were fully utilized, significantly reducing road transport emissions and congestion.”

May combine two claims.

If increased use of public transport is achieved by 2050, there is a reduced need for the number of small EVs on the road, which can help decrease transport emissions and partially mitigate increases in power generation, congestion, safety and reduction of CFV and EV infrastructure.

“If increased use of public transport is achieved by 2050 there is a reduced need for the number of small EVs on the road which can help decrease transport emissions as well as partially mitigate increases in power generation, congestion, safety and reduction of CFV and EV infrastructure.”

May combine two claims.

HBs use more electrical energy due to conversion and storage losses, and are expected to produce a higher level of operating emissions than battery powered EBs.

“HBs use more electrical energy due to the energy required to convert electricity to H 2 and back to electricity with the potential for loss in storage; therefore, it is expected they will produce a higher level of operating emissions than battery powered EBs (Shinnar, 2003).”

• cites Shinnar, 2003 sourceNot checked — no full text of the source

May combine two claims.

The projected decrease in total CFV emissions is due to technological improvements and a 9% decrease in distance travelled despite a 25% increase in the number of vehicles between 2017 and 2050.

“For CFVs, this decrease in total emissions is due to technological improvements, a decrease of 9% in the distance travelled despite a 25% increase in the number of vehicles between 2017 and 2050.”

Classified as probably not a substantial claim.

To ensure consistency between the different fuel type models, the number of buses and distance travelled remained constant.

“To ensure consistency between the different fuel type models, the number of buses and distance travelled remained constant (Appendix A).”

May combine two claims.

The projected decrease in distance travelled by each bus is because distance projections are based upon the need to fulfil demand, which is estimated partly upon projected decrease in population size, resulting in a decrease in the need for public transport.

“This is since distance projections are based upon the need to fulfil demand, which in turn is estimated partly based upon the projected decrease in population size, resulting in a decrease in the need for public transport.”

May combine two claims.

The UK currently faces the 'chicken and egg problem' as although commercial H2 vehicles exist, future development is dependent upon widespread fuelling infrastructure to enable sales of H2 vehicles.

“The UK currently faces the 'chicken and egg problem' as although commercial H 2 vehicles exist, future development is dependent upon the widespread fuelling infrastructure to enable sales of H 2 vehicles (Kriston et al., 2010).”

• cites Kriston et al., 2010 sourceNot checked — no full text of the source

Classified as probably not a substantial claim.

If the UK is to meet its emission targets, the travelling public need to move away from individual transport towards sustainable public transport.

“Results from this study, particularly in Fig. 5, indicate that if the UK is to meet its emission targets, the travelling public need to move away from individual transport towards sustainable public transport.”

Probably not a substantial claim: may not pass S4 (based).

EBs are more suited to shorter routes within cities such as London.

“Due to current technological advancements, EBs are more suited to shorter routes within cities such as London”

Probably not a substantial claim: may not pass S4 (based).

Without a modal shift towards public transport, the UK will be unlikely to meet its net zero emissions target.

“Without a modal shift towards public transport, the UK will be unlikely to meet their net zero emissions target.”

Probably not a substantial claim: may not pass S2 (checkable).

If HBs are to be more widely utilised, then the preferred method of hydrogen generation would be electrolysis using renewable energy technologies.

“If HBs are to be more widely utilised, then the preferred method of hydrogen generation would be electrolysis using renewable energy technologies”

May combine two claims.

Widespread utilisation of HBs or EBs will be required if the UK is going to meet national emission targets, because technological advances are not a strong enough mitigating factor for CFBs to meet targets and neither is a simple switch to personal EVs.

“Results from the analysis presented in this paper indicate that widespread utilisation of HBs or EBs will be required if the UK is going to meet national emission targets, as technological advances are not a strong enough mitigating factor for CFBs to meet targets and neither is a simple switch to personal EVs.”

• AssumptionThe authors state this as an assumption: The hydrogen production process is electrolysis.

May combine two claims.

If an HB has more than 10 passengers and an EB has more than 7, the bus has less emissions than a full electric car.

“So, if an HB has more than 10 passengers and an EB has more than 7, the bus has less emissions than a full electric car.”

Classified as probably not a substantial claim. May combine two claims.

The results do not take into consideration life cycle emissions and assume that all electric modes of transport are electric from 2017.

“Results do not take into consideration life cycle emissions and assume that all electric modes of transport are electric from 2017, therefore although”

May combine two claims.

Bus operating costs per person are likely to be higher unless fares subsidies are implemented, which could result in fewer passengers.

“Bus operating costs per person are likely to be higher, unless fares subsidies are implemented, which could result in fewer passengers.”

Probably not a substantial claim: may not pass S4 (based).

It is unlikely consumers will use the bus system more if faced with higher fares and cheaper unsustainable transport options.

“To reduce total costs, more individuals will need to use the bus system, however it is unlikely consumers will do this if faced with higher fares and choose cheaper, unsustainable transport options.”

Probably not a substantial claim: may not pass S4 (based). May combine two claims.

HBs have a larger range and may be suited to longer distances between cities and rural services.

“where as HBs have a larger range and may be suited to longer distances between cities and rural services.”

May combine two claims.

Hydrogen buses are less efficient than direct electric transport because H2 generation requires electricity to be converted to H2 and back again.

“This is to be expected as H 2 generation requires electricity to be converted to H 2 and back again and will therefore be less efficient than direct electric transport.”

• AssumptionThe authors state this as an assumption: The hydrogen production process is electrolysis.

May combine two claims.

The additional costs of HBs and EBs are due to electric mechanisms and above all lack of mass production.

“The additional costs are due to the electric mechanisms, for example, the battery package, electric motor and auxiliary system, but above all lack of mass production (Feng and Figliozzi, 2013;Mahmoud et al., 2016).”

• cites Feng and Figliozzi, 2013 sourceNot checked — no full text of the source
• cites Mahmoud et al., 2016 sourceNot checked — no full text of the source

May combine two claims.

Without CCS implementation, the positive effects on dropping emissions from SMR would be dampened by the GHG emissions of SMR, furthering the likelihood of the UK missing its emissions targets of net zero.

“without CCS implementation the positive effects on dropping emissions would be dampened by the GHG emissions of SMR, furthering the likelihood of the UK missing its emissions targets of net zero.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

HBs can be fuelled through electrolysis using excess renewable energy and with H2 generation from SMR using natural gas combined with CCS for low emissions.

“HBs can be fuelled through electrolysis using excess renewable energy and with H 2 generation from SMR using natural gas combined with CCS for low emissions.”

May combine two claims.

Currently HBs cost around one million euros per bus, a standard EB costs 450,000 euros compared to a standard CFB of 250,000 euros.

“Currently HBs cost around one million euros per bus, a standard EB costs 450,000 euros compared to a standard CFBs of 250,000 euros (Hydrogen Europe, 2017).”

• cites Hydrogen Europe, 2017Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

May combine two claims.

Both HBs and EBs are expected to produce significantly lower levels of emissions compared to CFBs by 2050, but this is dependent on the energy generation method.

“Both HBs and EBs are expected to produce significantly lower levels of emissions compared to CFBs by 2050, however this is dependent on the energy generation method.”

• AssumptionThe authors state this as an assumption: The hydrogen production process is electrolysis.

Probably not a substantial claim: may not pass S2 (checkable).

CCS is required to reduce emissions as far as possible whilst infrastructure is being implemented to achieve complete decarbonisation of electricity generation.

“As technology currently isn't in place for 100% renewable electricity generation and gas generation will be required as dispatchable power, CCS is required to reduce emissions as far as possible whilst infrastructure is being implemented to achieve complete decarbonisation of electricity generation.”

• AssumptionRests on an assumption: Technology is not currently in place for 100% renewable electricity generation.
• AssumptionRests on an assumption: Gas generation will be required as dispatchable power.
• AssumptionRests on an assumption: CCS will help to mitigate some of the emissions produced from fossil electricity generation that provide dispatchable power when renewable generation is low.