PhD Projects

PhD Projects

Geothermal systems such as open and closed systems are amongst the most energy efficiency means to provide space heating and cooling (and hot water), however still face high capital costs. A geothermal system typically uses the ground and/or the groundwater as a heat sink or cooling source taking advantage of its stable year-round temperature. A heat pump upgrades the heat with the help of a compressor typically running on electricity. For example, ground source heat pump (GSHP) systems include ground heat exchangers that can be placed vertically or horizontally. The latter requires large land availability, and thus is more suitable for rural environments.

Simulation and optimisation of geothermal systems are necessary for technical and economic feasibility studies and also crucial for the process understanding of the systems such as thermal mixing by dispersion. KIT will develop simulations tools such as analytical models that will be verified by UoM researchers through simulations and be validated in the field. Unique to this project is the combined expertise of researchers from existing geothermal installations at both institutions. The analyses and simulations will be accompanied by holistic cost, risk and life-cycle studies. One route to minimise running costs in geothermal systems may be to use cheaper horizontal ground heat exchangers in areas/sectors, where energy infrastructure is lacking or to develop hybrid systems or to store energy in the ground by using aquifer thermal energy (ATES) systems instead of only direct use To increase the awareness and acceptance of geothermal energy harvesting, its integration in rural and urban energy planning will be also explored including the evaluation of the heating and cooling demands in cities.

 

Groundwater provides a significant proportion of the drinking water and agricultural water in Australia as well as Germany. This contribution is expected to further rise due to climate change as the availability of surface water resources become more and more variable. Shallow and unconfined alluvial aquifers are particularly vulnerable to contamination and to extreme climatic events, such as droughts and floods, which can have strong impacts on both water quantity and quality.

A large number of Victoria’s wetlands, also referred as Groundwater Dependent Ecosystems (GDE) are important in sustaining biodiversity at a regional, national and international scale and are highly recognized for their environmental significance. They provide habitat for threatened species and communities. According to DEWLP in 2016, of the threatened native species in Victoria, 499 (24%) depend on wetlands for their survival. Some of these wetlands are dependent on unconfined alluvial aquifers for their ecological interactions. Such groundwater-fed wetlands that are located in proximity to agricultural lands face ecological threats from cumulative impacts of fertilizers and pesticide used in the Agriculture industry. As the pressure on croplands increases the use of fertilizers and pesticides, the occurrence of nutrients such as nitrate and other agrochemicals in groundwater might increase as well leading to greater potential of contaminant migration from groundwater to surface water and vice versa. These interactions will further be impacted by the increasing variability of extreme climate events. This project aims to understand the nature and extent of such interaction and contaminant pathways through a combination of field-work, laboratory program and modelling to provide greater understanding for better management of these chemicals in the field.

When undertaking water resource planning, ecological needs are often predicted based upon long-run average expectations of responses to water availability and run-off regimes. Climate change is causing background trends in water resource availability (both reductions and increases), but also greatly increasing variability in year-to-year resource availability. Furthermore, climate change can influence water quality due to increased temperature causing e.g. acceleration of microbial activities, algal blooms and a changing aquatic biotope. This calls into question the previous practice of assuming (and modelling) long-term average expectations. How can we make sensible predictions to inform management decisions in this increasingly dynamic and changing future?

This research will develop new approaches to modelling environmental responses to water resource availability that better encompass the ‘new normal’ of shifting baselines in climatic systems. Innovation is provided by the extension or redesign of current approaches that are based on assumptions that long-term averages from the historic record are a reliable estimate of future conditions and can be used to set objectives.

Global probabilistic climate projections, mitigation pathways and the goals of limiting global warming to 1.5°C or 2°C under consideration of aerosol radiative forcing uncertainties. This project is a synthesis exercise to capture CMIP6 insights and analysis of aerosol influence on cloud radiative effects, e.g. via CMIP representations of cloud properties and changes relative to insights gained from satellite observations.

Cloud processing of aerosols during their lofting in convective clouds - resulting microphysical properties of aerosols in the TTL and their impact on cirrus formation. Understanding the role of tropical ocean aerosols on cloud and precipitation processes. This project links with Year of the Maritime Continent logistics.

The Melbourne University Renewable Energy Integration Lab is a model for simulating the least cost combination of electricity generation technologies to meet a given demand profile for a given emission target. The model has been configured and run to find pathways to a low carbon electricity sector for the National Electricity Market in Australia. This project proposes to configure the same model for Germany, adapting the transmission network, resource maps (wind and solar), technology cost assumptions and demand profiles.

This task will make use of the existing energy system models PowerACE and PERSEUS for the German electricity system. As a basis, an in-depth techno-economic analysis of  the future energy technologies, such as heat pumps, PV, local storages and electric vehicles, in the decentralized electricity systems is undertaken, which focuses on the individual generation costs and the potential to provide flexibilities on the decentral level (which makes the given demand cost-sensitive). The German model will also consider electricity exchanges with neighbouring countries.

District energy systems are an essential part of many cities, circulating heat or electricity from renewable and non-renewable sources. With the forecast growth of urban populations over the coming decades, there is significant potential for district energy systems to provide low carbon energy solutions for cities. However, the design of district energy systems is typically focused only on their operational performance, e.g. their heat demand or peak power. A review of models used to design and evaluate district energy systems found that only 1 of 25 considers embodied energy. With district energy systems requiring energy-intensive materials, such as concrete, steel, polymers, and copper, as well as regular maintenance, it is essential that these systems are optimised across their entire life cycle.

This project focuses on developing a model for the life cycle energy analysis of district energy systems (e.g. district heating/cooling, embedded electricity networks, district energy network, etc.) for buildings. The project will use the advanced Path Exchange Hybrid method to quantify embodied energy, allowing a more holistic understanding of the energy performance of various district energy systems. The model will allow designers to evaluate and optimise the life cycle energy performance of district energy systems.

 

Light-weight, mechanically flexible, colored, cost-efficient and optionally semi-transparent organic solar cells offer a plethora of advantages over established solar technologies and open up avenues to new applications, formerly only insufficiently addressed by the ubiquitous silicon solar cells. Their unique properties render them ideal devices for building integrated photovoltaics. Organic solar modules can be integrated into arbitrarily shaped facades or windows. Printing and coating processes in roll-to-roll plants are widely considered enablers for future lowest fabrication costs.

Within the last five years, methylammonium lead iodide (MAPbI3) perovskite solar cells showed an unprecedented fast improvement towards power conversion efficiencies beyond 20%. Their technology appears to be fully process-compatible with organic solar cells, so that processes for the fabrication of all solar cell elements other than the light-harvesting layers can be exchanged.

 

This project intends to develop a platform for printable organic and perovskite solar cells and modules. The partners will investigate printable electrodes, charge carrier transport layers, device architectures and designs to be used with both technologies. With their background in chemistry, the researcher at UoM will design new materials to be incorporated into the solar cells, while the researcher at KIT have expertise on the deposition of the delicate organic and perovskite light-harvesting layers and their characterization. The PhD candidate at UoM will investigate organic solar cells whereas the PhD candidate at KIT will advance perovskite solar cells. Their exchange between the institutions will be the basis to build the process platform and enable both to use this platform for their purposes. For the fabrication of the light-harvesting layers and all other functional layers of the solar cells, the project team strives for using industry-compatible printing and coating processes as well as eco-compatible printing agents, both of which are not naturally used in today’s solar cell fabrication. Yet, the eco-friendly device fabrication will be an important asset when assessing the overall performance of different solar technologies and their life-cycles. Associated PhD candidates at KIT and UoM will complete the project by investigating the microstructure-property relation of the light harvesting layers and by performing life-cycle analyses of the newly developed solar cells.