Justin D.K. Bishop

Organic Architecture for Small- to Large-Scale Photovoltaic Power Stations

Increased widespread deployment of power generation from photovoltaics is consistent with binding agreements to reduce carbon emissions and increase the penetration of electricity from renewables and political aspirations to increase security of energy supply. However, in order for these generation facilities to compete in increasingly open power markets, they must be low cost and provide high-quality and high-quantity outputs. The organic architecture suggested in this paper proposes a solution that provides these advantages, using modular-power-electronic and energy-storage components, to facilitate scalable plants, from kilowatt to megawatt size. Specifically, the inclusion of power-conversion building blocks (PCBBs), grid-interactive power units (GPUs), and power-system control units allow efficient transfer of power from the point of energy conversion to the point of common coupling. A specific example of a 24-kW plant illustrates that, through optimum switching of PCBBs, the GPU can transfer 95.46% of the daily available energy to the transmission grid.

Using strong sustainability to optimize electricity generation fuel mixes

This work represents a contribution to the field of sustainable electricity system design by using an optimization tool to specify the final mix composition, subject to the constraints of: emissions that are within the biocapacity of the region; a diverse and robust electricity supply system; and supply that at least meets current demand. The 25-country European Union (EU-25) is used as a case study. All the goals, save diversity, can be met by re-structuring the current fuel mix, thus maintaining current consumption levels. The diversity target is only met when consumption is reduced by 10-15% and the constraint on maximum material throughput is relaxed. Re-structuring the mix and reducing consumption is insufficient to achieve a sustainable EU carbon footprint. However, the solution proposed singlehandedly allows the EU to meet its Kyoto emissions target as well as its 2007 policy of a reduction of 20% in greenhouse gas emissions by 2020.

Emissions, Performance and Design of UK Passenger Vehicles

ABSTRACT Consumer, legal, and technological factors influence the design, performance, and emissions of light-duty vehicles (LDVs). This work examines how design choices made by manufacturers for the UK market result in emissions and performance of vehicles throughout the past decade (2001–2011). LDV fuel consumption, CO2 emissions, and performance are compared across different combinations of air and fuel delivery system using vehicle performance metrics of power density and time to accelerate from rest to 100 km/h (62 mph, tz-62). Increased adoption of direct injection and turbocharging technologies helped reduce spark ignition (SI, gasoline vehicles) and compression ignition (CI, diesel vehicles) fuel consumption by 22% and 19%, respectively, over the decade. These improvements were largely achieved by increasing compression ratios in SI vehicles (3.6%), turbocharging CI vehicles, and engine downsizing by 5.7–6.5% across all technologies. Simultaneously, vehicle performance improved, through increased engine power density resulting in greater acceleration. Across the decade, tz-62 fell 9.4% and engine power density increased 17% for SI vehicles. For CI vehicles, tz-62 fell 18% while engine power density rose 28%. Greater fuel consumption reductions could have been achieved if vehicle acceleration was maintained at 2001 levels, applying drive train improvements to improved fuel economy and reduced CO2 emissions. Fuel consumption and CO2 emissions declined at faster rates once the European emissions standards were introduced with SI CO2 emissions improving by 3.4 g/km/year for 2001–2007 to 7.8 g/km/year thereafter. Similarly, CI LDVs declined by 2.0 g/km/year for 2001–2007 and 6.1 g/km/year after.

How Well Do We Know the Future of CO2 Emissions? Projecting Fleet Emissions from Light Duty Vehicle Technology Drivers

While the UK has committed to reduce CO2 emissions to 80% of 1990 levels by 2050, transport accounts for nearly a fourth of all emissions and the degree to which decarbonization can occur is highly uncertain. We present a new methodology using vehicle and powertrain parameters within a Bayesian framework to determine the impact of engineering vehicle improvements on fuel consumption and CO2 emissions. Our results show how design changes in vehicle parameters (e.g., mass, engine size, and compression ratio) result in fuel consumption improvements from a fleet-wide mean of 5.6 L/100 km in 2014 to 3.0 L/100 km by 2030. The change in vehicle efficiency coupled with increases in vehicle numbers and fleet-wide activity result in a total fleet-wide reduction of 41 ± 10% in 2030, relative to 2012. Concerted internal combustion engine improvements result in a 48 ± 10% reduction of CO2 emissions, while efforts to increase the number of diesel vehicles within the fleet had little additional effect. Increasing plug-in and all-electric vehicles reduced CO2 emissions by less (42 ± 10% reduction) than concerted internal combustion engines improvements. However, if the grid decarbonizes, electric vehicles reduce emissions by 45 ± 9% with further reduction potential to 2050.

Using Electric Vehicles for Road Transport

Road vehicles account for almost half of the energy used in all transport modes globally. Reducing energy use in vehicles is key to meeting the forecast increase in demand for transport, while improving energy security and mitigating climate change. Non-powertrain vehicle options may reduce fuel consumption by at least 15%. Electric motors are the significant powertrain option to reduce energy use in vehicles because they are more efficient than the internal combustion engine and can recover a portion of the vehicle kinetic energy during braking. Conventionally, batteries are used to meet both the power and energy demands of electric vehicles and their variants. However, batteries are well-suited to store energy, while ultra-capacitors and high-speed flywheels are better placed to meet the bidirectional, high power requirements of real-world driving. Combining technologies with complementary strengths can yield a lower cost and more efficient energy storage system. While pure and hybrid electric vehicles use less energy than internal combustion engine vehicles, their ability to mitigate climate change is a function of the emissions intensity of the processes used to generate their electricity.

Building Sustainable Cities of the Future

This book draws upon the expertise of academic researchers, urban planners and architects to explore the challenge of building the sustainable cities of the future.

Research data supporting "Quantifying the role of vehicle size, powertrain technology, activity and consumer behaviour on new UK passenger vehicle fleet energy use and emissions under different policy objectives"

Matlab .fig files to reconstruct figures used in the publication. Each file is labelled corresponding to the figure it recreates.