• Energy Research

It has long been known that the use of finely textured transparent conducting oxide layers substantially improves the performance of thin film amorphous silicon (a-Si:H) solar cells. Major efforts to understand the nature of this effect and to fully capture its potential have been made by researchers using advanced modeling techniques. In this work, modeling the oblique angle optical performance and use of an effective medium approximation to simulate microrough interfaces suggests that effective interface grading makes a significant contribution to optical enhancement.

Clustering historical electricity consumption data is very important for creating representative demand profiles for the planning and operation of the power grids. This paper investigates a multi-dimensional framework for data clustering, which takes scattering and separation metrics, as well as the number of clusters into account. A combination of wavelet mutation with the Invasive Weed Optimization (IWO) method for clustering features is proposed. One notable advantage of the IWO method over other metaheuristic optimization algorithms is its ability to dynamically adapt the number of weed colonies during the search process, resulting in improved exploration and exploitation of the search space. The proposed strategy is applied to cluster the electricity consumption data from a large municipal government center in Perth, Western Australia. The suggested method is then evaluated by comparing it with the well-known method in the literature, namely, the k-means technique. After the data clustering, the obtained results are implemented in the design of a multi-microgrid system under two different scenarios of cooperative and noncooperative modes. To evaluate the performance of the proposed method, the proposed method is implemented on the operational planning of a real multi-microgrid distribution system in Western Australia using linear programming to take the advantage of the mathematical-based solvers. After performing some investigations, the cooperative mechanism, where the microgrids have participated in supplying the demand of microgrids was found to yield to greater operational and investment cost minimimzation. In terms of numerical comparison, the total cost in the cooperative model is 6.5% lower than that in a non-cooperative situation.

One of the primary advantages of the internet is its ability to enable flexible, 24-h access to up-to-date information, irrespective of the geographic location of the user. It is thus rapidly becoming an important tool for the dissemination of information on a global scale. In order to take advantage of the increased accessibility available through the internet, the Murdoch University Energy Research Institute has developed an internet-based version of its physical renewable energy remote area power supply (RAPS) demonstration system. In this way, the physical site, which aims to inform the community about the cost, performance and reliability of renewable energy systems by enabling them to visit a practical operating RAPS system, is available to a much larger audience. The internet-based site, WebRAPS, contains a number of features including case studies of the three RAPS systems at the physical site, specifications of the components used in the systems and general information about the renewable energy system technologies. It also displays historical and real-time data from a monitoring system integrated with the largest of the physical RAPS systems. Visitors to the internet site are able to see how the RAPS system is operating, almost as well as if they were present at the physical site itself. This paper demonstrates the features of the WebRAPS site and discusses how it was developed.

Solar photovoltaic (PV) and wind power generation are key contributors to the integration of renewable energy into modern power systems. The intermittent and variable nature of these renewables has a substantial impact on the power system’s reliability. In time-series simulation studies, inaccuracies in solar irradiation and wind speed parameters can lead to unreliable evaluations of system reliability, ultimately resulting in flawed decision making regarding the investment and operation of energy systems. This paper investigates the reliability deviation due to modeling uncertainties in a 100% renewable-based system. This study employs two methods to assess and contrast the reliability of a standalone microgrid (SMG) system in order to achieve this goal: (i) random uncertainty within a selected confidence interval and (ii) splitting the cumulative distribution function (CDF) into five regions of equal probability. In this study, an SMG system is modeled, and loss of load probability (LOLP) is evaluated in both approaches. Six different sensitivity analysis studies, including annual load demand growth, are performed. The results from the simulations demonstrate that the suggested methods can estimate the reliability of a microgrid powered by renewable energy sources, as well as its probability of reaching certain levels of reliability.

Energy storage systems (ESSs) can help to reduce the intermittency and uncertainty of renewable energy supplies in power systems. ESSs are critical components of renewable-rich standalone microgrids (SMGs) to balance power generation and load demand, which is referred to as reliability. To achieve the same level of reliability as conventional power systems for renewable-based SMGs, significant investment in ESSs is required. However, due to the high investment costs of ESSs, the installation of large ESSs will not result in an affordable solution for achieving renewable SMG at the required reliability. As a result, this paper proposes a new sharing concept for ESS, namely energy storage as a service (ESaaS), to be implemented across microgrids as a low-cost alternative for improving reliability. In the proposed ESaaS concept, microgrids can use ESS from an ESS provider as required for different timeframes such as monthly, weekly, or daily, depending on the renewable resources and load profile characteristics. In this paper, the use of ESaaS is investigated over a range of timeframes for a 100 % renewable-based SMG with photovoltaic (PV), wind turbine (WT), and ESS. The SMG reliability is evaluated using Monte Carlo simulation both before and after the ESaaS strategy has been implemented. To evaluate the ESaaS affordability in improving the reliability of an SMG, this paper proposes the criteria of marginal cost of reliability, which indicates the rate of additional investment amount per percentage of reliability improvement. The marginal cost of reliability combines the economic and technical aspects of ESaaS in one simple criterion for effective decision-making among investment strategies such as different timeframes of ESaaS or permanent ESS. The simulation results show the ESaaS based on daily contract results in a lower marginal cost of reliability for the case study. To validate the effectiveness of the proposed ESaaS approach using marginal cost of reliability, the levelized cost of electricity (LCOE) is also calculated for different strategies of reliability improvement. The results confirm that the lowest LCOE is obtained using the strategy that provides the lowest marginal cost of reliability for the case study. In addition, a sensitivity analysis is performed to assess the difference in marginal cost of reliability under various uncertainties associated with the installed capacity of PV and WT, and the cost of utilising the ESaaS.

The Australian Cooperative Research Center for Renewable Energy (ACRE) through its tertiary training projects seeks to help meet the increasing global need for more tertiary trained scientists, engineers and policy makers with the knowledge and skills to develop and implement renewable and energy efficient systems and policies. As part of this objective it is developing a range of undergraduate and postgraduate university courses in renewable energy technology and systems, energy policy, energy efficiency and greenhouse issues which will be available internationally via the World Wide Web. This paper will present the approach and objectives of ACRE in developing its internationally focused, web-based, renewable energy courses. This includes a description of the course structure and examples of the web-based courses developed so far. A discussion of the potential, the practice and the challenges of offering tertiary renewable energy education on the web is given.

If photovoltaic solar cells and modules are to be used as a major source of power generation it is important to have a good knowledge and understanding of their long-term performance under different climatic and operating conditions. A number of studies of the long-term performance of commercially available photovoltaic modules manufactured using different technologies have now been reported in the literature. These have shown clear differences in the seasonal and long term performance and stability of different solar cell techniques. In addition to general module engineering factors that result in a loss of performance in all modules some types of solar cells, such as those made from thin film amorphous silicon (a-Si:H), also suffer specific losses in performance due to fundamental material changes, such as photodegradation or the Staebler-Wronski effect (SWE). A field evaluation of the long term performance of state-of-the-art crystalline and amorphous silicon photovoltaic modules in Australian conditions is currently being undertaken at Murdoch University. The initial results from this monitoring program are reported. This paper also reports on laboratory and field studies being undertaken on the nature of the Staebler-Wronski effect in amorphous silicon solar cells and how the stability of these cells is affected by different operating conditions. Based on a mechanism for the SWE in a-Si:H solar cells developed as a result of our research we propose a number of possible ways to reduce the Staebler-Wronski effect in a-Si:H solar cells. Data on the long-term performance of commercially available photovoltaic modules culled from the literature show differences in the seasonal and long-term operation and stability of various cells. Thin film amorphous silicon cells suffer specific losses in performance due to fundamental material changes, such as photodegradation of the Staebler-Wronski effect (SWE). Initial results from a field evaluation of the long-term performance of crystalline and morphous Si modules in Australian conditions are reported. Avenues for reducing the SWE in amorphous Si cells are proposed, including the use of light trapping to promote uniform illumination of material. (from World Renewable Energy Conf Proceedings, Perth, Australia, Feb 99).

Rising international concern about global warming and the rapid development of the renewable energy industry over recent years has led to a need for multidisciplinary programs in energy studies. We have developed a postgraduate program in energy studies which is based on the principles of ecologically sustainable development. This program combines work in energy technology with energy policy, energy economics and environmental and social issues. The program is offered on campus at Murdoch University and by external study, via the internet, throughout Australia and overseas. It has attracted considerable interest from students seeking to find new opportunities within the renewable energy industry. This paper outlines the philosophy of the energy studies program, its implementation and outcomes.