• Energy Research

Transport-related activities represented 34% of the total carbon emissions in the UK in 2022 and heavy-duty vehicles (HGVs) accounted for one-fifth of the road transport greenhouse gas (GHG) emissions. Currently, battery electric vehicles (BEVs) and hydrogen fuel cell electric vehicles (FCEVs) are considered as suitable replacements for diesel fleets. However, these technologies continue to face techno-economic barriers, creating uncertainty for fleet operators wanting to transition away from diesel-powered internal combustion engine vehicles (ICEVs). This paper assesses the performance and cost competitiveness of BEV and FCEV powertrain solutions in the hard-to-abate HGV sector. The study evaluates the impact of battery degradation and a carbon tax on the cost of owning the vehicles. An integrated total cost of ownership (TCO) model, which includes these factors for the first time, is developed to study a large retailer's HGV fleet operating in the UK. The modelling framework compares the capital expenditures (CAPEX) and operating expenses (OPEX) of alternative technologies against ICEVs. The TCO of BEVs and FCEVs are 11% to 33% and 37% to 78% higher than ICEVs; respectively. Despite these differences, by adopting a longer lifetime for the vehicle it can effectively narrow the cost gap. Alternatively, cost parity with ICEVs could be achieved if BEV battery cost reduces by 56% or if FCEV fuel cell cost reduces by 60%. Besides, the pivot point for hydrogen price is determined at £2.5 per kg. The findings suggest that BEV is closer to market as its TCO value is becoming competitive, whereas FCEV provides a more viable solution than BEV for long-haul applications due to shorter refuelling time and lower load capacity penalties. Furthermore, degradation of performance in lithium-ion batteries is found to have a minor impact on TCO if battery replacement is not required. However, critical component replacement and warranty can influence commercial viability. Given the high costs, we propose financial incentives and vehicle tax reforms to reduce costs of critical components that will encourage the roll-out of zero emission HGVs.

The uptake of Electric Vehicles (EVs) is rapidly changing the landscape of urban mobility services. Transportation Network Companies (TNCs) have been following this trend by increasing the number of EVs in their fleets. Recently, major TNCs have explored the prospect of establishing privately owned charging facilities that will enable faster and more economic charging. Given the scale and complexity of TNC operations, such decisions need to consider both the requirements of TNCs and local planning regulations. Therefore, an optimisation approach is presented to model the placement of CSs with the objective of minimising the empty time travelled to the nearest CS for recharging as well as the installation cost. An agent based simulation model has been set in the area of Chicago to derive the recharging spots of the TNC vehicles, and in turn derive the charging demand. A mathematical formulation for the resulting optimisation problem is provided alongside a genetic algorithm that can produce solutions for large problem instances. Our results refer to a representative set of the total data for Chicago and indicate that nearly 180 CSs need to be installed to handle the demand of a TNC fleet of 3000 vehicles.

Dual fuel diesel and natural gas heavy goods vehicles (HGVs) operate on a combination of the two fuels simultaneously. By substituting diesel for natural gas, vehicle operators can benefit from reduced fuel costs and as natural gas has a lower CO2 intensity compared to diesel, dual fuel HGVs have the potential to reduce greenhouse gas (GHG) emissions from the freight sector. In this study, energy consumption, greenhouse gas and noxious emissions for five after-market dual fuel configurations of two vehicle platforms are compared relative to their diesel-only baseline values over transient and steady state testing. Over a transient cycle, CO2 emissions are reduced by up to 9%; however, methane (CH4) emissions due to incomplete combustion lead to CO2e emissions that are 50-127% higher than the equivalent diesel vehicle. Oxidation catalysts evaluated on the vehicles at steady state reduced CH4 emissions by at most 15% at exhaust gas temperatures representative of transient conditions. This study highlights that control of CH4 emissions and improved control of in-cylinder CH4 combustion are required to reduce total GHG emissions of dual fuel HGVs relative to diesel vehicles.

The high-resolution Global Aviation emissions Inventory based on ADS-B (GAIA) for 2019 – 2021: Low-resolution gridded outputs for 2019 - 2021 Roger Teoh, Zebediah Engberg, Marc Shapiro, Lynnette Dray and Marc E.J. Stettler These files contain the low-resolution monthly sum of the global flight distance flown, fuel consumption, and various pollutants from 2019 to 2021. The data is provided in a 4D grid with spatiotemporal resolution of 0.5° (longitude) x 0.5° (latitude), at altitude intervals of 1000 feet, and at a monthly temporal resolution. The global air traffic activity in GAIA was derived from Spire Aviation data. Non-commercial use and research purposes only. For further details, see README.txt Change log - 6-June-2023: The missing file "2021-08-monthly.nc" has been added and can be found in "Zenodo.zip"

Guangdong, a developed province of China, attaches great importance to CO2 emissions in transport these years, especially in road transport. To explore the way to achieve CO2 emission peak of road transport in such a typical province, multiple scenarios were designed, including a baseline scenario, four single mitigation scenarios, and three combined mitigation scenarios. The peaking regularity and scale of provincial CO2 emissions and mitigation potential until 2035 were quantitatively evaluated. The assessment results showed that CO2 emissions kept rapid growth without control and reached 315.4 Mt in 2035. The peak of CO2 emission by 2030 could not be addressed by single mitigation measures. But combination of four single mitigation scenarios could drive CO2 emissions to peak in 2030 at the level of 171.3 Mt. The peak appeared later at higher level of CO2 emissions compared with UK (30.5%) and Australian (45.6%). Therefore, the CO2 emissions from road transport in such a developed province should be constrained in the future. A strong policy combination to constrain provincial CO2 emissions is necessary for sharing the target of CO2 emission reduction in China.

It has been suggested that using liquefied natural gas as a fuel source for heavy goods vehicles could provide a reduction in greenhouse gas emissions. Various studies have investigated different aspects of the lifecycle emissions of natural gas heavy goods vehicles throughout the past decade, however, there has been little comparative analysis across these studies. This review provides a comprehensive examination of the well-to-wheel lifecycle emissions of liquefied natural gas for heavy goods vehicles in comparison to diesel, the current standard. A systematic selection criteria based on relevance to the defined well-to-wheel system boundary of liquefied natural gas as a fuel source for heavy goods vehicles, including greenhouse gas emissions, were augmented by the authors knowledge of the field. The various data are categorised by engine technology and model year (pre- and post-2015), average speed of the duty cycle, and then statistically analysed to identify clear trends and correlations in the emissions produced. The two primary factors affecting the well-to-wheel greenhouse gas emissions of natural gas heavy hoods vehicles are: (i) natural gas engine fuel efficiency relative to diesel, and (ii) methane leakage across the supply chain. Methane leakage rates are a significant uncertainty and range from 0.3 to 20 % of throughput. With long-term perspective of efficiency penalty (10 %) in natural gas engines, the well-to-wheel greenhouse gas emissions reduction of natural gas fuelled trucks against diesel is up to 10 %, which appears insufficient toward net zero emissions by 2050. The use of biomethane further reduces the greenhouse gas emissions by 34–66 % depending on the engine technology. Controlling fugitive methane emissions in the fuel production and supply chain remains critical.

The high-resolution Global Aviation emissions Inventory based on ADS-B (GAIA) for 2019 – 2021: High-resolution gridded outputs for 2021 - 2021 (Bi-monthly) Roger Teoh, Zebediah Engberg, Marc Shapiro, Lynnette Dray and Marc E.J. Stettler These files contain the high-resolution global flight distance flown, fuel consumption, and various pollutants that are provided bi-monthly for 2020 and 2021. The data is provided in a tabular format and can be converted to a 4D grid with a maximum spatiotemporal resolution of 0.05° (longitude) x 0.05° (latitude), at altitude intervals of 100.0 m, and at an hourly temporal resolution. The global air traffic activity in GAIA was derived from Spire Aviation data. Non-commercial use and research purposes only. For further details, see README.txt