The transition away from SF6-based insulation in high-voltage equipment has accelerated interest in alternative gas mixtures with lower environmental impact. One such mixture is CO2/O2 (70%/30%), which is used as a carrier gas in C4-FN based mixtures but is also being explored for stand-alone insulation applications. To enable detailed characterisation of partial discharges (PDs) in such alternative gases, a high-bandwidth measurement setup was developed. The setup is based on a custom designed test compartment that uses a needle-to-plane electrode configuration to generate corona discharges and applies a high-frequency current transformer (HFCT) as a measurement impedance.
Initial measurements using a conventional IEC 60270 configuration revealed a resonance frequency of 3.5 MHz, which limited the effective bandwidth of the system. By eliminating the traditional coupling capacitor and instead using the inherent capacitance between the conductor in the bushing and the grounded enclosure as a coupling path, the resonance frequency was shifted to 144 MHz. Aside from the significant increase in bandwidth, this also improved sensitivity. The frequency response of each segment of the measurement circuit was characterised, allowing the derivation of the PD current from the measured voltage and enabling calibration-free charge estimation. The setup was used to study the PD behaviour in a CO2/O2 (70%/30%) mixture at pressures ranging from 0.2 to 0.4 MPa and voltages up to 1.5 times the PD inception voltage. A novel phenomenon was observed: certain PDs were rapidly followed by another discharge, after which a longer interval was required for the next event.
Multiple charge estimation methods were adapted to suit the measurement circuit. After evaluation, the modified frequency domain method demonstrated the strongest correlation with peak current, especially at low discharge magnitudes. These results demonstrate that the developed measurement setup is suitable for detailed PD analysis in alternative gases and that it is able to offer new insight into the behaviour of alternative gases.

This study presents a comprehensive Life Cycle Assessment (LCA) comparing HyET Solar's Powerfoil modules to conventional Passivated Emitter Rear Contact (PERC) technology. Through both current and future scenario analyses, utilizing tools like Integrated Assessment Models (IAMs) and Shared Socioeconomic Pathways (SSPs), the research examines key impact categories, including Global Warming Potential (GWP), Terrestrial Acidification, Land Use, and Material Resources.
Current scenario findings reveal that PERC modules exhibit significantly higher environmental impacts across most categories. The GWP of PERC modules is notably high at 50.1 grams CO2-equivalent per kWh, primarily driven by energy-intensive processes in inverter and silicon wafer production. Powerfoil modules, especially the triple-junction architecture, demonstrate reduced impacts with emissions as low as 23.8 grams CO2-equivalent per kWh.
Future scenario findings project even greater environmental benefits for Powerfoil modules by 2050. Efficiency improvements and material optimizations, including the replacement of existing top encapsulant and reducing the carrier foil thickness, could bring down the emissions to 6.2 grams CO2-equivalent per kWh, which is almost 70% lower than PERC modules.
The study also identifies critical hotspots in the Powerfoil modules’ lifecycle, providing a quantitative analysis of environmental impacts after replacing these hotspots in future scenarios. Furthermore, the Global Sensitivity Analysis highlights that module efficiency and solar irradiation are critical factors influencing environmental outcomes. These findings highlight the potential of Powerfoil modules as a more sustainable alternative in photovoltaic technology, with substantial implications for reducing the environmental footprint of energy systems.

This master’s thesis investigates the design, challenges, and protection mechanisms of electrical power distribution systems on ships with a particular emphasis on DC distribution systems. A key focus is on the challenges of DC systems, including protection difficulties and unique characteristics, as well as their environmental benefits and contribution to sustainability. The thesis dedicates a significant portion to the technical analysis of short-circuit currents in DC grids, offering methodologies for their calculation and protection devices like fuses and circuit breakers. Relevant standards such as IEC 61660 and IEC 60269-1 ground these discussions, ensuring their practical relevance. The thesis includes a detailed simulation model of the DC grid of a vessel, developed using MATLAB-Simulink. The simulation analyses several scenarios, including short circuits and different operational modes, by examining crucial system components such as generators, IGBTs, batteries, drives, and link capacitors. The simulations  showcase the efficacy of protective measures by examining the performance of fuses and circuit breakers in different scenarios. The simulation results of the DC grid's performance under different short circuit scenarios, with and without protective measures, provide valuable information for optimising these systems for maritime applications. The thesis concludes with an improved Simulink model incorporating enhanced battery protection, demonstrating the potential for increased safety and reliability in shipboard DC power distribution systems.

In an era defined by the rapid evolution of energy technologies and the necessity of sustainable power generation, effective voltage control is a critical component in optimizing the performance of the power distribution grid and the seamless integration of renewable energy sources. This thesis presents the development and evaluation of an adaptive voltage control policy for high voltage to medium voltage transformers aimed at mitigating voltage limit violations in modern power distribution networks.

The motivation for this research arises from the increasing integration of distributed energy resources and the growing complexity of power grids, which require dynamic and robust voltage management strategies. The proposed policy utilizes a voltage control curve, optimized using a genetic algorithm, which systematically identifies the best parameters for the curve to ensure voltage stability and minimize violations across diverse grid configurations.

The methodology involves quasi-dynamic simulations performed on 30 real-world distribution grids, which test the effectiveness of the voltage control curves in maintaining grid stability under varying load and generation conditions. This was done by setting a stricter ±3% voltage limit for the medium voltage grid. Results show an average reduction of 88.54% in voltage limit violations and a 17.19% decrease in the maximum difference between the maximum and minimum voltage levels in the medium voltage grid throughout a complete year (2023). This study highlights the importance of a grid-specific voltage control curve, as every distribution grid exhibited unique voltage regulation needs.

Furthermore, the policy was evaluated under projected grid scenarios, demonstrating sustained effectiveness across two future timeframes: one set five years and the other ten years into the future. In the first scenario (2028), an 80.06% reduction in voltage limit violations was achieved, while the second scenario (2033) still showed a reduction of 62.25%.

Through the genetic algorithm optimization, the voltage control policy adapts to fluctuating grid dynamics, contributing to improved power quality and the successful integration of distributed energy resources. While effective in medium voltage grids, further research is needed to explore the policy’s applicability to low voltage networks and in environments with limited data availability.

The simplicity and universality of the proposed adaptive voltage control strategy make it a practical solution for real-world deployment, as it can be implemented on existing hardware. In contrast, the proposed strategy alone will not be enough to completely eliminate all the voltage stability problems in distribution grids and additional measures are necessary. However, by minimizing voltage violations and improving grid resilience, this work offers a robust framework for voltage management in modern, evolving power distribution networks, particularly in the context of the global energy transition towards sustainable energy sources.