Anna Bruce

Cost-Benefit Assessment Framework for PV Mini-Grids

The primary goal of this research is to better understand the cost structures of delivering Renewable Energy (RE) based mini-grid projects. The research has revealed a significant lack of clarity and consistency in the RE mini-grid cost literature, and a lack of appreciation of the impact that delivery mechanisms, service outcomes and other technical aspects have on costs. The RE mini-grid sector is growing and attracting interest from public and private sector investors. However, the ability of investors and other key decision makers to evaluate proposals is limited by this lack of consistency in the presentation of mini-grid project costs, and by insufficient qualifying details provided. With many investors new to the sector, this obscurity results in slow approval processes and high risk premiums, stymying the sector’s further development. It is proposed that a standardised framework for presenting and qualifying costs of RE mini-grids will address this critical issue. The framework would include a standardised set of cost heads, and set of required qualifying information. This paper proposes as an example, a preliminary cost framework for PV based mini-grids. A literature review and case studies are provided to support the proposition of the need for and usefulness of the framework.

Real time generation mapping of distributed PV for network planning and operations

With growing penetrations of distributed photovoltaic (PV) systems in Australian electricity networks, it is increasingly important for network planners and operators to better understand, predict and hence manage the impact of these systems throughout their networks. Time series estimates of distributed PV generation mapped to different Australian geographic regions are now being created from a sample of these distributed PV systems that report their generation in near real time. In this paper a range of potential applications of these spatial PV generation traces are discussed, with a focus on their potential contribution towards transmission network planning and operations. These include estimating the impact of PV on peak demand, load forecasting, situation awareness and dynamic line ratings.

Assessing the representativeness of ‘Live’ distributed PV data for upscaled PV generation estimates

The incorporation of distributed PV generation data into power system planning and operation is becoming increasingly important as penetrations of PV systems on Australian distribution networks continue to grow. However, the availability of such data is currently very limited. The APVI Live PV Map (Live Map) provides near real-time distributed PV generation estimates in 57 different regions across Australia based on some 6000 PV systems reporting their generation online. This data has a wide range of potential applications including, for example, network planning or PV performance assessment. In this paper we investigate the characteristics of the PV systems contributing to the Live Map database, in order to assess its accuracy and suitability for providing total distributed PV generation estimates for power system planning and operational purposes. The study compares the sample of PV systems contributing data to the Live Map database with the total set of PV systems in Australia, according to the Clean Energy Regulators (CERs) database. Representativeness is assessed in terms of PV system location, size, age, and inverter manufacturer. The accuracy of the APVI Live Map PV generation estimates for individual regions is assessed by comparison with a separate database of historical interval metered household PV generation from the Ausgrid network. Finally, an example of the application of distributed PV data to electricity network planning is provided to highlight the potential value of these PV generation estimates.

Review of demand side management modelling for application to renewables integration in Australian power markets

Demand side management (DSM) has considerable potential to reduce power system generation, transmission and distribution costs. However, the integration of DSM into existing restructured electricity markets is not straightforward. Here, major areas of research into DSM will be reviewed, and the elements of most interest identified, particularly in the context of the Australian National Electricity Market (NEM). This paper focuses on research that uses software modelling tools to examine DSM in large power systems. Demand response (DR) in particular is of broad interest for power systems operation and planning. This is partly due to the potential of DR to facilitate the integration of variable renewable energy sources, and also due to the potential complexities that large quantities of responsive demand may introduce into power markets such as the NEM. This paper will review the suitability of approaches to modelling DSM for renewables integration in the NEM.

Analysis and simulation of manufactured screen-printed solar cells

A detailed study has been conducted of the performance of millions of screen-printed solar cells to analyse the various processing parameters and their interdependencies. Algorithms have been developed to quite accurately predict device structure and hence performance as a function of the many manufacturing processing parameters. The processes characterized include the saw-damage removal etch, anisotropic texturing, emitter diffusion, edge junction isolation, AR coating deposition and the screen-printing and firing of the front and rear metal contacts. From the developed algorithms, a simulator has been developed which includes the natural variations in device parameters that occur in a real production environment due to relatively random effects such as thermal gradients within furnaces, slight fluctuations in belt speeds, gas flows, plasma etching power, chemical concentrations, furnace temperature controllers, wafer quality, etc. These can have a significant effect on electrical yields. Even common factors affecting the mechanical yields in production have been programmed into the simulator. Since the virtual production line was primarily developed for the purposes of educating and training engineers, extensive in-line quality control testing has also been incorporated, such as the measurement of: minority carrier lifetimes; substrate resistivity; emitter sheet resistivity; wafer thickness; screen-printing paste thickness and width; AR coating thickness and refractive index; surface reflection; spectral response; I-V characteristics; series resistance; shunt resistance; ideality factor; doping profile; etc.

Materials Engineering Education in Two New Engineering Degree Programs at the Centre for Photovoltaic Engineering

The establishment, in 2000 and 2003, of new degree programs in Photovoltaics and Solar Energy Engineering and Renewable Energy Engineering at the Centre for Photovoltaic Engineering at the University of New South Wales, Sydney was in response to predictions, now being fulfilled, of dramatic global market and employment growth. They were developed by the well established photovoltaics research group at UNSW that has produced many important advances, including two commercially important solar cell technologies. Materials-related education in these programs are mainly focussed on the photovoltaic aspects, including study of the fundamental optical, electronic, phononic and excitonic properties of silicon, crystal structure, semiconductor properties, doping and contacts. Cell manufacturing is taught in detail, including by the use of an interactive virtual production line . Practical projects, taking advantage of a large and active research group, are one of the most important and effective educational tools in both these programs. The Centre also administers postgraduate coursework and research programs.

Impact of Distributed Photovoltaic Systems on Zone Substation Peak Demand

Australia has likely the worlds highest residential photovoltaic (PV) system penetration. In this paper, the impact of distributed PV on peak demand at different distribution network zone substations (ZSs) is assessed by upscaling 15 min PV generation data from 270 distributed PV systems across Sydney, Australia, and comparing it with load data from 138 ZS serving the Sydney region. Gross load (load had there been no PV) was estimated, allowing the impact of current and higher PV penetrations on the value and time of peak at the different ZSs to be assessed. A probabilistic assessment of the impact of PV on ZSs is conducted, based on the availability of PV during the peak demand periods. To better understand the impact of PV on peak demand, K-means clustering is used to group ZSs based on PV generation during peak periods as the clustering features. Mapping of PV availability across percentage of peak times for all ZSs highlights the interannual variability of peak reductions and the potential impact of short-term load shifting. The impact of different penetration levels of distributed PV on the peak demand of the entire distribution network is also assessed by aggregating the ZS loads.

Electricity network revenue under different Australian residential tariff designs and customer interventions

The Australian electricity industry is facing significant challenges, as recent electricity price rises and technological change have lead to changing demand patterns and high penetrations of distributed photovoltaics. Network tariff reform is underway in response to concerns about overinvestment in network infrastructure and cross-subsidies present in existing tariff structures. In this paper, residential demand data is used to model network revenue per household in a variety of future scenarios. Revenue is particularly impacted under flat rate and time of use tariffs by high penetrations of photovoltaics, while energy efficiency has a potentially significant impact under all tariff designs tested.

Planning in the Australian National Electricity Market — Challenges and opportunities

Effective planning is critical to electricity industries due to its role in investment decision-making regarding generation, network and demand-side resources in complex and changing circumstances. This paper expresses the institutional arrangements in Australias National Electricity Market (NEM) in terms of a planning model. Planning was until relatively recently performed centrally. This paper shows what the current arrangements are: in many ways dispersed as part of electricity industry restructuring. It identifies efforts that have been required over time to address some of the resulting challenges. Existing frameworks from the literature are adapted and used to assess planning in the NEM with a focus on the contribution of the Federal Governments Energy White Paper. Our work proposes a number of opportunities to improve the Energy White Paper process to support better planning.

Commencement of world's first Bachelor of Engineering in Photovoltaics and Solar Energy

March 2000 marked the commencement of what is believed to be the worlds first Bachelor of Engineering in Photovoltaics (PV) and Solar Energy. The new program has been implemented at the University of New South Wales. It has particularly strong support from industry, end users, the Australian government and the host institution. The explosive growth in the PV industry is believed responsible for triggering these high levels of support in the educational area. The new degree has been particularly popular. Forty-one students have commenced the program, with most having university acceptance index (UAI) scores well above 90, placing them within the top few percent of students completing high school. This is a clear indicator of the industrys ability to attract the best quality engineers. Details of the new degree program and the emphasis placed on gaining hands-on experience through project work are discussed in detail.