1. Literature Review of “Energy Payback Time” for Renewable Energy Technologies
Aim:
To prepare for the School website, and potentially for publication, an authoritative and comprehensive review of the literature of life cycle assessment, and specifically, energy payback time of renewable energy technology.
Project Brief:
There are commonly expressed public concerns, some possibly mischievous and some genuine, about whether it is environmentally appropriate to use renewable energy technologies in place of fossil fuel or nuclear sources. Some members of the public seem to fear that some trick is being pulled by malevolent renewable energy companies, whose technologies are suspected as being less able to reduce greenhouse gas generation than is claimed.
In fact, for at least some renewable energy technologies, the energy payback time (ie. the operation period required to offset the presumed fossil-sourced energy invested in the production of the renewable energy equipment) has been studied extensively. There are also broader life cycle analysis (LCA) studies in existence. The supervisor is aware of a significant body of historical literature about energy payback times for photovoltaics.
The student’s task will be to produce a report or publishable paper reviewing the literature on these aspects for a range of renewable energy technologies, including but not restricted to, photovoltaics, wind power, hydro power, biomass/biofuels.
This topic links with several undergraduate courses, including SOLA1070, SOLA1055, SOLA1056, SOLA2053, SOLA3540, SOLA5053, SOLA5056, SOLA5052, MECH9720.
The School offers a vibrant and exciting research environment, with strong industrial interest in our research outputs and strong links to a rapidly growing global industry. As of Semester 1, 2007 the School has189 undergraduate, 14 postgraduate coursework and 42 postgraduate research students.
Supervisor: Dr Richard Corkish. r.corkish@unsw.edu.au Ph. 938 54068.
2. Crystalline silicon thin-film solar cells on glass
- cheap electricity from the Sun
Do you care about the environment? Do you have an engineering or science background and a strong interest in practical, hands-on work? Do you expect to achieve 1st class honours and do you aspire to do Masters or PhD research upon graduation? Would you be thrilled working in a high-tech laboratory, researching novel photovoltaic solar cells that, in the not-too-distant future, generate affordable clean electricity from sunlight? If your answer is “yes” to these questions, then why not join an active research team at The University of New South Wales (UNSW) in Sydney during the next summer break and participate in cutting-edge research towards efficient, low-cost crystalline silicon on glass thin-film solar cells? Such devices could become the next mainstream technology of the photovoltaics (PV) industry, which grows by more than 30% per year globally and is already a 10+ billion dollar/year business. UNSW is a world leader in silicon photovoltaics, holding numerous solar cell world records with wafer-based technology and having created a spin-off company (CSG Solar; formerly Pacific Solar) that is poised to become the first company, internationally, that mass-produces crystalline silicon on glass thin-film PV technology. Your work during next summer would be in the “Thin-Film Group” of UNSW’s prestigious “ARC Photovoltaics Centre of Excellence”, where you would join a 15+ team of senior researchers and postgraduate students working on the development of novel silicon thin-film solar cells. Your work could include the formation of silicon films on glass using various types of vacuum equipment, or the measurement of solar cell properties such as the energy conversion efficiency or the quantum efficiency. [Note to Engineering students: The work is expected to satisfy the Industrial Training requirements of your university].
More detailed information on the research work is available from the leader of the Thin-Film Group,
Supervisor: Prof. Armin Aberle phone (02) 9385 4031, e-mail a.aberle@unsw.edu.au
General information on our undergraduate and postgraduate education programs in the renewable energy sector is available from the School’s website at www.pv.unsw.edu.au.
3. Computing premixed bio-syngas combustion
Gasification of biomass to syngas is an extremely effective way to use biomass for energy. Waste biomass can be used, allowing co-existence with food crops, and the stable biochar by-product can provide long-term carbon sequestration. Syngas may be combusted in high efficiency combined cycle gas turbines. To reduce NOx emissions, lean premixed combustion is preferred; however it suffers from combustion instabilities leading to increased harmful emissions and mechanical damage. A particular difficulty of syngas is that the composition depends on the feedstock. Syngas consists of H2 and CO - gases that have vastly different flammability limits, flame speeds and diffusivities. Hence composition has a strong effect. Better understanding this effect will lead to improved combustor design.
Working directly with the supervisor, you will use detailed laminar flame simulations to map combustion and pollutant characteristics as a function of composition. The database will form a library that will be posted on the web for use in combustion models. Time permitting, you may perform unsteady flame-vortex interactions to examine effects of flame curvature and strain. Thorough work could result in a peer reviewed journal publication. A strong background in thermodynamics, chemistry and computing is desirable. For further details: http://evatthawkes.googlepages.com/classe.
4. Dual biofuels for efficient engines
Homogeneous Charge Compression Ignition (HCCI) engines combine the low emissions of spark ignition engines and the high efficiencies of compression ignition engines, and are being investigated as a next generation technology. Simultaneously, as petroleum resources are depleted and concerns about climate change grow, much interest exists in the use of biofuels for sustainable transport.
In true HCCI, combustion of the entire charge occurs nearly simultaneously. This leads to control difficulties at high load, when the rapid pressure rise causes engine knock. Deliberate charge stratification alleviates this problem. A particularly effective stratification technique may be the introduction of two fuels having significantly different ignition delay times. The second generation biofuels di-methyl ether and methanol exhibit this property, and both may be produced sustainably via the gasification and conversion to liquids of biomass, including waste biomass feedstocks that do not compete with food production.
Working directly with the supervisor, you will develop and use a simplified computational model of HCCI combustion to investigate the potential for reducing the rate of pressure rise by stratification using these fuels. Thorough work could form the basis of a peer-reviewed publication. A strong background in thermodynamics, chemistry and computing is desirable. For further details: http://evatthawkes.googlepages.com/classe.
Supervisor: Dr Evatt Hawkes - evatt.hawkes@unsw.edu.au
5. From fronts to flames – computing the transition
Supervisor: Dr Evatt Hawkes - evatt.hawkes@unsw.edu.au
New Homogeneous Charge Compression Ignition (HCCI) engines combine the low emissions of spark ignition engines and the high efficiencies of compression ignition engines. In true HCCI, combustion of the entire charge occurs nearly simultaneously, leading to control problems at high load. Deliberate charge stratification alleviates these problems. As stratification increases, the combustion transitions from “fronts” in which heat conduction is insignificant, to “flames”, in which heat is conducted from hot products to fresh reactants, accelerating ignition. Models assume the former mechanism is dominant. Many fuels for HCCI have a “negative temperature coefficient” regime in which, counter-intuitively, hotter regions take longer to ignite than cooler ones! The biofuel di-methyl ether, which can be produced sustainably from biomass gasification is one of the simplest molecules exhibiting this behaviour. The transition from fronts to flames has never been studied in this regime.
Working directly with the supervisor, you will use detailed one-dimensional simulations to compute the transition from fronts to flames. You will use the results to develop a general transition criterion, which will assist engine developers in the selection of combustion models. Good work could result in a peer reviewed journal publication. A strong background in thermodynamics, chemistry and computing is desirable. For further details: http://evatthawkes.googlepages.com/classe.
6. Biofuel production and utilisation
Concerns about climate change and the instability of oil supply set against rapidly increasing demand has led to great interest in fuels derived from biomass (biofuels). Biofuels have the potential to significantly reduce greenhouse gas emissions and dependence on oil. Biofuels may be produced by a range of processes and they include syngas (a mixture of H2 and CO), methane, methanol, ethanol, biodiesel (transesterified plant oils), dimethyl ether, and Fischer-Tropsch diesel. To produce and utilise biofuels we must overcome social, political, economic and technical barriers. In particular, it is imperative that biofuels should not cause more environmental damage than they offset through reduced fossil fuel consumption.
If you have an interest in the environment, and a strong engineering or physical sciences background, especially in thermodynamics, chemistry, fluid dynamics, mathematical modelling and/or computing, why not join us to work on research projects to realise sustainable biofuel technologies? Working with the supervisor and other summer students, projects could involve hands-on work such as the design and construction of a trailer-mounted biodiesel pilot plant, analytical work such as detailed numerical simulations of biofuel combustion, or more policy oriented work determining the potential and risks associated with biofuel technology. Students are welcome to suggest their own projects. For further details: http://evatthawkes.googlepages.com/classe.
Supervisor: Dr Evatt Hawkes - evatt.hawkes@unsw.edu.au
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