• Energy Research
• 2025-2025close
• Open Access close
• Restricted close
• Embargo close
• GB close

Abstract In the next 25 years an unprecedented number of new marine artificial structures, over 75,000 offshore wind turbines alone, are planned to meet global net zero targets. Structures are required to last for multiple decades in the hostile marine environment; where the largest cost across their whole lifecycle is on operations and maintenance dependent on accessibility in calm seas. However, the role of climate change on accessibility, and thus operational cost, has not been resolved. Here we provide the first study of future accessibility; evaluated from global climate model driven wave modelling, using the high emission scenario (RCP8.5). We found that climate change drives significant regional variation in accessibility, with the northern hemisphere benefiting from a 6% increase in operating windows whilst accessibility in parts of the southern hemisphere is reduced by 6-9%. These findings will help offshore developers and stakeholders incorporate adaptions to climate change as part of strategic planning practices.

Climate change is driving many species to shift their geographical ranges poleward to maintain their environmental niche. However, for endemic species with restricted ranges, like the Critically Endangered whitefin swellshark (Cephaloscyllium albipinnum), endemic to southeastern Australia, such dispersal may be limited. Nevertheless, there is a poor understanding of how C. albipinnum might spatially adjust its distribution in response to climate change or whether suitable refugia exist for this species in the future. Therefore, to address this gap, this study utilised maximum entropy (MaxEnt) modelling to determine the potential distribution of suitable habitat for C. albipinnum under present-day (2010–2020) climate conditions and for future conditions, under six shared socioeconomic pathways (SSP1-1.9, SSP1-2.6, SSP2-4.5, SSP3-7.0, SSP4-6.0 and SSP5-8.5) for the middle (2040–2050) and end (2090–2100) of the century. Under present-day conditions (2010–2020), our model predicted a core distribution of potentially suitable habitat for C. albipinnum within the Great Australian Bight (GAB), with benthic primary productivity and surface ocean temperature identified as key distribution drivers. However, under all SSP scenarios, future projections indicated an expected range shift of at least 72 km, up to 1,087 km in an east-southeast direction towards Tasmania (TAS). In all future climate scenarios (except SSP1-1.9 by 2100), suitable habitat is expected to decline, especially in the high-emission scenario (SSP5-8.5), which anticipates a loss of over 70% of suitable habitat. Consequently, all future climate scenarios (except SSP1-1.9 by 2100) projected a decrease in suitable habitat within a currently designated marine protected area (MPA). These losses ranged from 0.6% under SSP1-1.9 by 2050 to a substantial 89.7% loss in coverage under SSP5-8.5 by 2100, leaving just 2.5% of suitable habitat remaining within MPAs. With C. albipinnum already facing a high risk of extinction, these findings underscore its vulnerability to future climate change. Our results highlight the urgency of implementing adaptive conservation measures and management strategies that consider the impacts of climate change on this species.

AbstractFerroelectric semiconductors can exhibit extraordinarily long charge carrier lifetimes following photoexcitation. However, it remains unclear whether these long‐lived charge carriers are available to participate in the necessary solar water splitting redox reactions. Presented here are coupled transient optical and photoelectrochemical measurements that demonstrate the correlation between photo‐generated hole lifetimes, photocurrent density, and the energetic driving force associated with enhanced performance in ferroelectric BaTiO3 porous photoanodes with induced polarization states. For the first time, a three‐fold increase in photocurrent density following water‐oxidation‐preferential poling is correlated with a three orders of magnitude increase in hole lifetime in comparison to an un‐poled film. Transient absorption and photocurrent measurements demonstrate the polarized films benefit from reduced charge carrier recombination, enhanced charge carrier separation, increased hole population, and more efficient electron extraction over the water oxidation relevant timescales of µs to tens of seconds. Photoelectron spectroscopy and Kelvin probe measurements elucidate the effect of the presence and polarity of a ferroelectric polarization on core and band‐edge positions and work function values, ultimately revealing energy level differences of 300–400 meV that are found to be the driving force behind the associated lifetime and photocurrent gain.

Large-scale energy storage systems typically withdraw electricity from the grid and transform it into another form for storage. When the grid is unable to meet demand, the process is reversed and the stored energy is transformed back into electricity. Instead of this traditional approach, the following thesis explores the concept of ‘generation-integrated energy storage’, in which a generator’s existing energy conversion pathway is used to store energy in an intermediate form. This has two benefits: (i) the hardware used for generation can be exploited to reduce storage costs and (ii) fewer energy transformations are required when compared to traditional ‘electricity-in-electricity-out’ forms of storage. This means a high effective (exergetic) round-trip efficiency can be achieved at low cost. Specifically, this thesis focuses on the integration of thermal energy storage with the feedwater heating system of steam plant. (In modern energy systems this is likely to be nuclear-powered.) In the proposed system, the plant’s electrical output is flexed whilst maintaining constant reactor power. During charge, the plant’s electrical power output is reduced below its normal full-capacity level, and during discharge, it exceeds this level. This approach provides the equivalent of an electricity storage system and facilitates the adoption of a load-following role for nuclear plant. By allowing the reactor to operate constantly at maximum power output, the system also avoids the economic constraints and practical problems of part-load operation, which currently favour the use of nuclear plant for baseload only. An important feature of the proposed system is that the wet steam turbine bleed flows automatically provide good thermal matching with the feedwater temperature profile. This means that heat can ultimately be transferred to and from sensible-heat thermal-storage media with high exergetic efficiency. Various options are discussed for the thermal stores, including pressurised water tanks, thermal oils, and packed beds. This thesis is focused on the engineering research and development of the feedheat- integrated energy storage system and how this technology would be valuable in a modern energy system. The following contributions have been made: (i) Thermodynamic analysis – Detailed thermodynamic analysis is presented for an elec- tricity storage system in which thermal stores are integrated with the feedwater heating system of steam plant. The findings indicate that a round-trip efficiency greater than 80% is likely and that the plant’s power output can be varied between 85–113%. The analysis is also extended for heat cogeneration applications, for which the effective COP is estimated to be approximately 8 for modern district heating and 4 for industrial process heat. (ii) Off-design steam plant operation – A detailed off-design steam plant model is created. It is shown that the plant performs sufficiently well when operated off-design, and is able to efficiently transfer work to heat and then heat back to work. (iii) Capital cost estimation – A comprehensive cost analysis of the proposed system is undertaken, with an emphasis on the marginal cost of oversizing existing compo- nents. Costs for a well-designed system are approximately 250–1000 $/kWe and 15–20 $/kWhe. (iv) Thermo-economic optimisation – Parametric studies and a genetic algorithm optimisa- tion method are used to determine the optimal trade-off between efficiency and cost, and inform best design practices. (v) Steam turbine operation – A streamline equilibrium throughflow method is used to numerically validate Stodola’s ellipse law, and to explore the unusual off-design conditions caused by the storage system. Throughout this thesis, these contributions are routinely placed in the context of the modern energy system. It is demonstrated that integrated systems which perform multiple roles – electricity generation, energy storage, and possibly heat cogeneration – will be highly valuable for the transition to a low-cost, secure, and decarbonised energy system.

Within China's decentralized governance framework, the reform of converting counties into municipal districts (County-to-District Reclassification, CDR) facilitates the upward shift of environmental responsibilities, offering an opportunity to explore how environmental centralization drives firms' green transformation. Using this exogenous quasi-natural experiment, we apply the Dynamic Slack-Based Measure (DSBM) model to estimate green total factor productivity (GTFP) as a proxy for green transformation. Our findings show that CDR significantly enhances firm green transformation, a result that remains robust across sensitivity tests. Mechanism analysis reveals that CDR improves GTFP through enhanced environmental regulation and optimized resource allocation. The positive effects are more pronounced for district- and county-level enterprises, capital-intensive firms, and industries with high external financing dependency. Firms in non-two control zones, non-capital cities, and regions with strong policy continuity experience more significant green productivity gains. Additionally, regions with stronger city dominance over counties exhibit a greater green transformation effect than those with stronger county autonomy. Further analysis reveals that firms at the borders of reformed counties experience more substantial positive impacts, supporting the internalization of environmental externalities through centralization.

Security and stability challenges in future power systems with high penetration Inverter-Based Resources (IBR) have been anticipated as one of the main barriers to decarbonization. Grid-following IBRs may become unstable under small disturbances in weak grids, while during transient processes, system stability and protection may be jeopardized due to the lack of sufficient Short-Circuit Current (SCC). To solve these challenges and achieve decarbonization, the future system has to be carefully planned. However, it remains unclear how both small-signal and transient stabilities can be considered during the system planning stage. In this context, this paper proposes a coordinated planning model of different resources in the transmission system, namely the synchronous condensers and GFM IBRs to enhance system stability. The system strength and SCC constraints are analytically derived by considering the different characteristics of synchronous units and IBRs, which are further effectively linearized through a novel data-driven approach, where an active sampling method is proposed to generate a representative data set. The significant economic value of the proposed coordinated planning framework in both system asset investment and system operation is demonstrated through detailed case studies.

Ozone (O3), a major air pollutant, can negatively impact plant growth and yield. While O3 impacts have been widely documented in crops such as wheat and soybean, few studies have looked at the effects of O3 on sorghum, a C4 plant and the fifth most important cereal crop worldwide. We exposed grain sorghum (Sorghum bicolor cv. HAT150843) to a range of O3 concentrations (daytime mean O3 concentrations ranged between 20 and 97 ppb) in open-top chambers, and examined how whole plant and leaf morphological traits varied in response to O3 exposure. Results showed no significant impact of realistic O3 exposure on whole plant biomass and its partitioning in sorghum. These findings suggest that sorghum is generally resistant to O3 and should be considered as a favourable crop in O3 polluted regions, while acknowledging further research is needed to understand the mechanistic basis of O3 tolerance in sorghum.

Dust accumulation on photovoltaic (PV) modules significantly reduces their performance, especially in desert environments. Cleaning can be costly or not feasible. This paper presents a comprehensive study of PV modules performance in a desert environment, focusing on the impact of dust on power output reduction at various tilt angles to determine the optimal angle in uncleaned conditions. Seven pairs of PV modules were installed on the roof of the Faculty of Engineering in Jeddah City at angles of 0°, 15°, 25°, 45°, 60°, 70°, and 90°. The output power of both the cleaned and dusty modules was recorded over a 12-month period. The results show that dust accumulation, tilt angle, and rain significantly reduce power. The optimal tilt for maximum average output power varies with the seasonal position of the sun and the amount of dust on the module’s surface. After 183 days of dust accumulation without rain, the power reduction for the dusty modules reached 80.4%, 75.6%, and 60.2% at tilt angles of 0°, 15°, and 25°, respectively. In the rainy period, the highest performance of the dusty modules was observed at a 45° tilt angle, with a power reduction of 5.9%. Conversely, during the dry period and throughout the year, the tilt angle that generated the highest power output was 25°, with power reduction of, respectively, 28.7% and 20.7%. These findings provide valuable insights into the impact of dust and tilt on PV module performance and contribute to the development of predictive models and optimization strategies for solar panel systems in harsh desert conditions. This research highlights the importance of strategic tilt selection to enhance the performance and longevity of PV installations in desert environments.