Abstract

Using first principles calculations we investigate thermomechanical stability of spent nuclear fuels (SNF). Especially, it is rigorously studied how mechanical properties of UO2, such as, bulk, shear and Young’s moduli and Poisson’s ratio vary through alpha-decay of U into Th with generation of He gas. Our results indicate that substitution of U by Th through alpha decay (U1-xThxO2) does not significantly affect the stability of the grain in a fuel matrix. In addition, we study on transport properties of He in and boundaries of the U1-xThxO2 grain. Helium preferentially resides at the grain boundaries through diffusion. Our study can contribute to substantial reduction of environmentally risk and enhancement of our sustainability by safe control of radioactive materials.

Abstract

A simulation tool was developed through MATLAB for comparing Centralized Energy Sharing (CES) and Interconnected Energy Sharing (IES) operating strategies with a standard Stand-Alone Photovoltaic System (SAPV). The tool can be used to investigate the effect of several variables on cost and trading behavior including: initial charge of Energy Storage System (ESS), amount of load variability, starting month, number of stand-alone systems, geographic location, and required reliability.
It was found that the CES strategy improves initial cost by 7% to 10% compared to a standard SAPV in every simulation. The IES case consistently saved money compared to the baseline, just by a very small amount (less than 1%). The number of systems did not have a demonstrable effect, giving the same cost per system whether there were 2 systems or 50 involved in the trading strategies. Geographic locations studied (Indianapolis, Indiana; Phoenix, Arizona; Little Rock, Arkansas; and Erie, Pennsylvania) showed a large variation on the total installed cost with Phoenix being the least expensive and Erie being the most expensive location. Required reliability showed a consistent and predictable effect with cost going down as the requirement relaxed and more hours of outage were allowed.

Abstract

In 2018, the Chinese government takes power sector as the first polit of nationwide carbon emission trading. Faced with the requirement of carbon emission reduction, the design of trading rules and emission allowances is still obscure. Power companies are confused about participation in the trading system and future investment deployment. This paper used agent-based modelling method to simulate the carbon emission trading system implemented in China’s power sector and investigate the impact of the system on the future development of power sector, including the change of electricity supply, carbon emission reduction. Through analyzing transaction status of emission permits and heterogenous behaviors of company agents, the results show that emission trading system can promote a virtuous cycle between the behaviors of emission reduction and invest renewable energy of company agents. Meanwhile, large-size companies show a more diverse investment compared with the small and medium-size companies (SMEs). The investment of the SMEs focuses on PV, hydro and gas-fired power generation, which is related to their historical advancement of technology. The identification of the future pathway and the investigation of the heterogenous behaviors in power sector can both assist the government to design the fully implemented carbon emission trading system.

Abstract

The paper introduces a novel strategy for optimizing waste heat recovery in data centers (DHs). With this strategy, waste heat from a data center is first upgraded to 60-90 oC in a water-to-water heat hump plant and then introduced to local district heating (DH) network to provide heating for nearly buildings. At the same time, the cooling product from the heat pump plant is utilized as a free byproduct (energy company pays electricity for heat pumps) to cool the data center. Both energy company and data center involve in investing heat pumps. This strategy can significantly cut power cost and CO2 emission for energy company and data center (cooling is free). The potential is large for this strategy because, event in summer, heating demand is far more than total IT capacity of data centers in Finland. Furthermore, this strategy is applicable for all kinds of existing data center cooling systems. The paper also describes a real green data center (over 1 MW IT load) implemented by this novel strategy.

Abstract

Geothermal resource of the hydrothermal type is expected to make the full use of the geothermal energy, and more net power is also expected to output for the organic Rankine cycle (ORC) based geo-plant. However, the two aspects often conflict with each other. Moreover, the available temperature range of the geothermal resource has a close relationship with its temperature level. The aim of this paper is to illustrate the corresponding relationship between the temperature level and the available temperature range of the geothermal resource with two different cycle configurations (ORC and Series Double-stage ORC (SDORC)) based on energy, exergy, and entropy analyses, thereby efficiently utilizing the valuable geothermal resource. The results show that the inlet temperature of the heat source has a decisive effect on the system performance. At a fixed inlet temperature of the heat source, there exists an optimal available temperature range to maximize the system performance. Moreover, the cycle configuration is also important for the geothermal power generation. Compared with the ORC, the SDORC can enhance the available temperature range to take the full advantage of geothermal resource. Comprehensively, the SDORC is more competitive than ORC and can be adopted in engineering applications.

Abstract

Building loads and the output of renewable energy in distributed micro-grid system are stochastic, which makes it difficult for traditional methods to describe the system dynamic characteristics. This paper presents a multiple time-varying dynamic model based on modelica non-causal modeling language to realize the coupling of renewable energy generation, energy storage components and controllable loads. Branch and bound method and metaheuristic algorithm are used to optimize the configuration design and operation strategy for four typical scenarios, and the effective penetration of renewable energy (EPRE), a novel evaluating indicator, is proposed to make the optimization model more practical. The results explicitly show that the model and dynamic simulation method are effective.

Abstract

Emissions abatement policies can play a critical role in decarbonising modern power systems, with a scheme’s success often contingent on its initial parameterisation, along with the mechanism by which it is recalibrated – ad hoc adjustments can introduce significant investment risk, potentially stifling the uptake of new technologies. Transparent, practical, and rule-based frameworks are required to clearly exposit operating costs, giving investors greater confidence to pursue the rollout of low-emissions technologies. A Refunded Emissions Payments scheme is one such framework; however, under this mechanism net liabilities faced by individual generators are only known after energy has been delivered. This work considers an alternative formulation of a Refunded Emissions Payment scheme whereby generators have greater certainty with respect to their net liabilities, accomplished by relaxing the requirement of revenue neutrality. Adaptive parameter updating mechanisms are developed to manage fluctuating scheme revenues, with their performance evaluated using an agent-based framework. These mechanisms provide a more nuanced approach to redistributing collected emissions payments, and can assist in accelerating the transition towards lowcarbon power systems.

Abstract

High temperature and high-pressure microfluidics devices were built to screen surfactants for the CO2 foam behavior. The effect of chip geometry, surfactant type, concentration, shear thinning, and gas fractional flow effect on CO2 foam strength was conducted. Oil effect on foam was investigated by an oil fractional flow test. The steady-state foam results from the microfluidic device were used to estimate the STARS foam model parameters. The method we provide here is not only robust for fast surfactant screening and foam fluids transport phenomenon understanding, but also could provide STARS foam parameters for foam simulation purposes for evaluating the potential of the CO2 foam for a specific reservoir at the initial stage of experiment planning.

Abstract

Airborne dust deposition on energy device would cause a lot of problems, such as solar PV panels. Mechanical cleaning using water is still the main method to mitigate dust deposition damage. This paper aims to investigate dust deposition reduction on solar cell covering glass with and without super-hydrophobic coating by experimental measurement. The effects of different tilt angles of PV panels were studied in details. The patterns of dust deposition on different glass samples, deposition density, transmittance reduction and PV efficiency reduction by dust deposition were investigated in the experiments. The deposition density on the coated surface is just 44.4%, 28.6 % or 11.2 % of the bare surface for tilt angle θ=30°, θ=45° or 60°, respectively. Therefore, it can be concluded that super-hydrophobic coating with micro-nano structures can be an effective way to mitigate the dust deposition on solar PV panels.

Abstract

Hydrogen has been identified as central to the decarbonisation of the energy and industrial sectors. Significant efforts in research and development (R&D) are underway to promote hydrogen production, distribution and Autilisation within Australia. Tremendous opportunities also exist to establish a hydrogen (H2) export industry that builds upon Australia world-leading track record as global supplier of liquefied natural gas (LNG). However, many technical challenges exist regarding the most cost-effective methods of exporting H2 from Australia to the large prospective markets in Japan, Korea, China and Europe. Overcoming these challenges efficiently will require Australia to develop systematic and coordinated R&D programs, informed by industry and the experience of other countries that builds upon existing strengths while minimising duplication. The design and use of coordinated research infrastructures that allows for industrial-scale validation of H2 export technologies will be central to this program.
This project hosted few workshops sittings and meetings which brought together global and local experts on H2, natural gas and LNG, representing industry organizations, government agencies, and research institutions, to identify knowledge and capability gaps for H2 export industry. This abstract aims to give comprehensive overview of the current and required R&D activities in Australia to accelerate the H2 export industry, focusing in particular at:
 Presenting driving forces, current efforts and future plans for industrially-focussed H2 research in Australia
 Illustrating the recently established LNG Futures Facility, its capabilities for industrial-scale testing at high-pressures and cryogenic temperatures, and the proposed R&D program
 Presenting an industry-led R&D plan to accelerate the growth of H2 exports from Australia, avoiding duplicating existing research initiatives.