Traditional wastewater treatment methods have become aged and inefficient, meaning alternative methods are essential to protect the environment and ensure water and energy security worldwide. The use of microbial electrolysis cells (MEC) for wastewater treatment provides an innovative alternative, working towards circular wastewater treatment for energy production. This study evaluates the factors hindering industrial adoption of this technology and proposes the next steps for further research and development. Existing pilot-scale investigations are studied to critically assess the main limitations, focusing on the electrode material, feedstock, system design and inoculation and what steps need to be taken for industrial adoption of the technology. It was found that high strength influents lead to an increase in energy production, improving economic viability; however, large variations in waste streams indicated that a homogenous solution to wastewater treatment is unlikely with changes to the MEC system specific to different waste streams. The current capital cost of implementing MECs is high and reducing the cost of the electrodes should be a priority. Previous pilot-scale studies have predominantly used carbon-based materials. Significant reductions in relative performance are observed when electrodes increase in size. Inoculation time was found to be a significant barrier to quick operational performance. Economic analysis of the technology indicated that MECs offer an attractive option for wastewater treatment, namely greater energy production and improved treatment efficiency. However, a significant reduction in capital cost is necessary to make this economically viable. MEC based systems should offer improvements in system reliability, reduced downtime, improved treatment rates and improved energy return. Discussion of the merits of H₂ or CH₄ production indicates that an initial focus on methane production could provide a stepping-stone in the adoption of this technology while the hydrogen market matures.

Installations of decentralised renewable energy systems (RES) are becoming increasing popular as governments introduce ambitious energy policies to curb emissions and slow surging energy costs. This work presents a novel model for optimal sizing for a decentralised renewable generation and hybrid storage system to create a renewable energy community (REC), developed in Python. The model implements photovoltaic (PV) solar and wind turbines combined with a hybrid battery and regenerative hydrogen fuel cell (RHFC). The electrical service demand was derived using real usage data from a rural island case study location. Cost remuneration was managed with an REC virtual trading layer, ensuring fair distribution among actors in accordance with the European RED(III) policy. A multi-objective genetic algorithm (GA) stochastically determines the system capacities such that the inherent trade-off relationship between project cost and decarbonisation can be observed. The optimal design resulted in a levelized cost of electricity (LCOE) of 0.15 EUR/kWh, reducing costs by over 50% compared with typical EU grid power, with a project internal rate of return (IRR) of 10.8%, simple return of 9.6%/year, and return on investment (ROI) of 9 years. The emissions output from grid-only use was reduced by 72% to 69 gCO₂e/kWh. Further research of lifetime economics and additional revenue streams in combination with this work could provide a useful tool for users to quickly design and prototype future decentralised REC systems.

Samples of Ethylene-Vinyl Acetate (EVA) were doped with particles of Boron Nitride (BN) in concentrations ranging from 0-60% w/w. Thermal conductivity was measured using a Differential Scanning Calorimetery (DSC) technique. The thermal conductivity of parent EVA was increased from 0.24W/m ⋅ K to 0.80W/m ⋅ K for the 60% w/w sample. Two PV laminates were made; one using the parent EVA the other using EVA doped with 50% BN. When exposed to a one directional heat flux the doped laminate was, on average, 6% cooler than the standard laminate. A finite difference model had good agreement with experimental results and showed that the use of 60% BN composite achieved a PV performance increase of 0.3% compared to the standard laminate.

The present work involves the development of a novel method for the fabrication of zirconium nickel (Zr_(x)Ni_(y)) alloy used as a nanocatalyst to improve the hydrogen storage properties of the Mg/MgH₂ system. The catalyst was fabricated through the high-pressure reactor and activated under hydrogen prior to being mechanically milled with the MgH₂ for 5 h under argon. The microstructure characterisation of the samples was determined via SEM-EDX (scanning electron microscope analysis–energy dispersive X-ray spectroscopy), XRD (X-ray diffraction) and FE-HRTEM (field emission high resolution transmission electron microscopy), and the desorption characteristic of the nanocomposite (10 wt.% Zr_(x)Ni_(y)–MgH₂) was determined via TPD (temperature-programmed desorption). The nanostructured MgH₂ powder milled with 10 wt.% of the activated Zr_(x)Ni_(y) based nanocatalyst resulted in a faster hydrogen release—5.9 H₂-wt.% at onset temperature 210 °C/peak temperature 232 °C. The observed significant improvement in the hydrogen desorption properties was likely to be the result of the impact of the highly dispersed catalyst on the surface of the Mg/MgH₂ system, the reduction in particle size during the ball milling process and/or the formation of Mg_0.996Zr_0.004 phase during the milling process.

Activated alloys synthesized by arc-melting were examined as catalysts for improving the hydrogen sorption characteristics of nanostructured magnesium hydride, proposed as a reversible hydrogen storage material. The MgH2- catalyst absorbing materials were prepared by ball milling of pure MgH2 with hydrided Zr47Ni53, Zr9Ni11, and other alloys investigated. The nanostructured MgH2-intermetallic systems were tested at 250°C and catalyst addition of eutectoid Zr47Ni53 resulted in the fastest desorption time and highest initial desorption rate. The catalyzed Mg-hydride with activated Zr9Ni11 and Zr7Ni10 phases showed fast desorption kinetics. Moreover, the results demonstrated that the composition of dispersed ZrxNiy catalysts has a strong influence on the amount of accumulated hydrogen and desorption rate of Mg-nanocomposite. Part two covers advanced micro-channels hydrogen storage module design based on the results of semi-empirical computer simulations of heat and mass transfers in the container. The micro-channels reservoir concept offers many advantages over the conventional metal hydride hydrogen storage system. It is a micro-structured system that can pack a lot of power into a small space and dissipate effectively the heat of the sorption reactions. This review summarize recent patents related to CNTS.