1,673 research outputs found
A non-technical introduction to the ANEMMarket model of the Australian National Electricity Market (NEM)
In this paper, we provide an accessible introduction to our agent-based ANEMMarket simulation model of the Australian National Electricity Market. This model has been purpose built to assess the impacts of emissions trading schemes, carbon taxes and the introduction of significant new suppliers of electricity generated from low or zero carbon emitting generators. We provide an illustrative example that involves the simulation of the impacts of a range of carbon prices on the dispatch of power from different types of generators in different regional locations. From these we compute the resultant carbon reduction effects. However, these remain only illustrative simulations because they do not include a range of operative constraints that exist in reality.
Collinsville solar thermal project: yield forecasting (final report)
Executive Summary
1 Introduction
This report’s primary aim is to provide yield projections for the proposed Linear Fresnel Reflector (LFR) technology plant at Collinsville, Queensland, Australia. However, the techniques developed in this report to overcome inadequate datasets at Collinsville to produce the yield projections are of interest to a wider audience because inadequate datasets for renewable energy projects are commonplace. Our subsequent report called ‘Energy economics and dispatch forecasting’ (Bell, Wild & Foster 2014a) uses the yield projections from this report to produce long-term wholesale market price and dispatch forecasts for the plant.
2 Literature review
The literature review discusses the four drivers for yield for LFR technology:
DNI (Direct Normal Irradiance)
Temperature
Humidity
Pressure
Collinsville lacks complete historical datasets of the four drivers to develop yield projections but its three nearby neighbours possess complete datasets, so could act as proxies for Collinsville. However, analysing the four drivers for Collinsville and its three nearby sites shows that there is considerable difference in their climates. This difference makes them unsuitable to act as proxies for yield calculations. Therefore, the review investigates modelling the four drivers for Collinsville.
We introduce the term “effective” DNI to help clarify and ameliorate concerns over the dust and dew effects on terrestrial DNI measurement and LFR technology.
We also introduce a modified Typical Metrological Year (TMY) technique to overcome technology specific TMYs. We discuss the effect of climate change and the El Niño Southern Oscillation (ENSO) on yield and their implications for a TMY.
2.1 Research questions
Research questions arising from the literature review include:
The overarching research question:
Can modelling the weather with limited datasets produce greater yield predictive power than using the historically more complete datasets from nearby sites?
This overarching question has a number of smaller supporting research questions:
Does BoM adequately adjust its DNI satellite dataset for cloud cover at Collinsville?
Given the dust and dew effects, is using raw satellite data sufficient to model yield?
Does elevation between Collinsville and nearby sites affect yield?
How does the ENSO cycle affect yield?
Given the 2007-12 electricity demand data constraint, will the 2007-13 based TMY provide a “Typical” year over the ENSO cycle?
How does climate change affect yield?
Is the method to use raw satellite DNI data to calculate yield and retrospectively adjusting the calculated yield with an effective to satellite DNI energy per area ratio suitable?
How has climate change affected the ENSO cycle?
A further research question arises in the methodology but is included here for completeness.
What is the expected frequency of oversupply from the Linear Fresnel Novatec Solar Boiler?
3 Methodology
In the methodology section, we discuss the data preparation and the model selection process for the four drivers of yield. We also discuss the development of the technology specific TMY and sensitivity analysis to address the research questions on climate change and elevation.
4 Results and analysis
In the results section we present the selection process for the four driver models. We also present the effective to satellite DNI ratio, the annual variation in gross yield, the selection of TMMs for the TMY based on monthly yield, the sensitivity analysis results on climate change and elevation, and the frequency of gross yield exceeding 30 MW.
5 Discussion
We analyse the results within a wider context, in particular, we make a comparison with the yield calculations for Rockhampton to address the overarching research question. We find that the modelling of weather at Collinsville using incomplete weather data has higher predictive performance that using the complete weather data at Rockhampton but recommend using the BoM’s one-minute solar data to improve the comparative test. Other findings include the requirement to increase the current TMM’s selection period 2007-13 to incorporate more of the ENSO cycle. There is less than 0.3% change in gross yield from the plant in the most likely case of climate change but there is a requirement to determine the effect of climate change on electricity demand and the ensuing change in wholesale electricity prices.
6 Conclusion
In this report, we have addressed the key research questions, produced the yield projections for our subsequent report ‘Energy economics and dispatch forecasting’ (Bell, Wild & Foster 2014a) and made recommendations for further research
Collinsville solar thermal project: energy economics and dispatch forecasting (final report)
The primary aim of this report is to help negotiate a Power Purchase Agreement (PPA) for the proposed hybrid gas-Linear Frensel Reflector (LFR) plant at Collinsville, Queensland, Australia. The report’s wider appeal is the discussion of the current situation in Australian National Electricity Market (NEM) and techniques and methods used to model the NEM’s demand and wholesale spot prices for the lifetime of the proposed plant.
Executive Summary
1 Introduction
This report primarily aims to provide both dispatch and wholesale spot price forecasts for the proposed hybrid gas-solar thermal plant at Collinsville, Queensland, Australia for its lifetime 2017-47. These forecasts are to facilitate Power Purchase Agreement (PPA) negotiations and to evaluate the proposed dispatch profile in Table 3. The solar thermal component of the plant uses Linear Fresnel Reflector (LFR) technology. The proposed profile maintains a 30 MW dispatch during the weekdays by topping up the yield from the LFR by dispatch from the gas generator and imitates a baseload function currently provided by coal generators. This report is the second of two reports and uses the findings of our first report on yield forecasting (Bell, Wild & Foster 2014b).
2 Literature review
The literature review discusses demand and supply forecasts, which we use to forecast wholesale spot prices with the Australian National Electricity Market (ANEM) model.
The review introduces the concept of gross demand to supplement the Australian Electricity Market Operator’s (AEMO) “total demand”. This gross demand concept helps to explain the permanent transformation of the demand in the National Electricity Market (NEM) region and the recent demand over forecasting by the AEMO. We also discuss factors causing the permanent transformation. The review also discusses the implications of the irregular ENSO cycle for demand and its role in over forecasting demand.
Forecasting supply requires assimilating the information in the Electricity Statement of Opportunities (ESO) (AEMO 2013a, 2014c). AEMO expects a reserve surplus across the NEM beyond 2023-24. Compounding this reserve surplus, there is a continuing decline in manufacturing, which is freeing up supply capacity elsewhere in the NEM. The combined effect of export LNG prices and declining total demand are hampering decisions to transform proposed gas generation investment into actual investment and hampering the role for gas as a bridging technology in the NEM. The review also estimates expected lower and upper bounds for domestic gas prices to determine the sensitivity of the NEM’s wholesale spot prices and plant’s revenue to gas prices.
The largest proposed investment in the NEM is from wind generation but the low demand to wind speed correlation induces wholesale spot price volatility. However, McKinsey Global Institute (MGI 2014) and Norris et al. (2014a) expect economically viable energy storage shortly beyond the planning horizon of the ESO in 2023-24. We expect that this viability will not only defer investment in generation and transmission but also accelerate the growth in off-market produced and consumed electricity within the NEM region.
2.1 Research questions
The report has the following overarching research questions:
What is the expected dispatch of the proposed plant’s gas component given the plant’s dispatch profile and expected LFR yield?
What are the wholesale spots prices on the NEM given the plant’s dispatch profile?
The literature review refines the latter research question into five more specific research questions ready for the methodology:
What are the half-hourly wholesale spots prices for the plant’s lifetime without gas as a bridging technology?
Assuming a reference gas price of between 7.19/GJ for base-load gas generation (depending upon nodal location;) and
for peak-load gas generation of between 8.99/GJ; and
given the plant’s dispatch profile
What are the half-hourly wholesale spots prices for the plant’s lifetime with gas as a bridging technology?
Assuming some replacement of coal with gas generation
How sensitive are wholesale spot prices to higher gas prices?
Assuming high gas prices are between 9.71/GJ for base-load gas generation (depending upon nodal location); and
for peak-load gas generation of between 12.14/GJ; and
What is the plant’s revenue for the reference gas prices?
How sensitive is the plant’s revenue to gas as a bridging technology?
How sensitive is the plant’s revenue to the higher gas prices?
What is the levelised cost of energy for the proposed plant?
3 Methodology
In the methodology section, we discuss the following items:
dispatch forecasting for the proposed plant;
supply capacity for the years 2014-47 for the NEM;
demand forecasting using a Typical Meteorological Year (TMY); and
wholesale spot prices calculation using ANEM, supply capacity and total demand
define three scenarios to address the research questions:
reference gas prices;
gas as a bridging technology; and
high gas prices.
The TMY demand matches the solar thermal plant’s TMY yield forecast that we developed in our previous report (Bell, Wild & Foster 2014b). Together, these forecasts help address the research questions.
4 Results
In the results section we will present the findings for each research question, including
the TMY yield for the LFR and the dispatch of the gas generator given the proposed dispatch profile in Table 3;
Average annual wholesale spot prices from 2017 to 2047 for the plant’s node for:
Reference gas prices scenario from 38/MWh
Gas as a bridging technology scenario from 110/MWh
High gas price scenario from 41/MWh
The combined plants revenue without subsidy given the proposed profile:
Reference gas price scenario 52 million
High gas price scenario $47 million
5 Discussion
In the discussion section, we analyse:
reasons for the changes in the average annual spot prices for the three scenarios; and
the frequency that the half-hourly spot price exceeds the Short Run Marginal Cost (SRMC) of the gas generator for the three scenarios for:
day of the week;
month of the year; and
time of the day.
If the wholesale spot price exceeds the SRMC, dispatch from the gas plant contributes towards profits. Otherwise, the dispatch contributes towards a loss. We find that for both reference and high gas price scenarios the proposed profile in Table 3 captures exceedances for the day of the week and the time of the day but causes the plant to run at a loss for several months of the year. Figure 14 shows that the proposed profile captures the exceedance by hour of the day and Figure 16 shows that only operating the gas component Monday to Friday is well justified. However, Figure 15 shows that operating the gas plant in April, May, September and October is contributing toward a loss. Months either side of these four months have a marginal number of exceedances. In the unlikely case of gas as a bridging scenario, extending the proposed profile to include the weekend and operating from 6 am to midnight would contribute to profits.
We offer an alternative strategy to the proposed profile because the proposed profile in the most likely scenarios proves loss making when considering the gas component’s operation throughout the year. The gas-LFR plant imitating the based-load role of a coal generator takes advantage of the strengths of the gas and LFR component, that is, the flexibility of gas to compensate for the LFR’s intermittency, and utilising the LFR’s low SRMC. However, the high SRMC of the gas component in a baseload role loses the flexibility to respond to market conditions and contributes to loss instead of profit and to CO2 production during periods of low demand.
The alternative profile retains the advantages of the proposed profile but allows the gas component freedom to exploit market conditions. Figure 17 introduces the perfect day’s yield profile calculated from the maximum hourly yield from the years 2007-13. The gas generator tops up the actual LFR yield to the perfect day’s yield profile to cover LFR intermittency. The residual capacity of the gas generator is free to meet demand when spot market prices exceed SRMC and price spikes during Value-of-Lost-Load (VOLL) events. The flexibility of the gas component may prove more advantageous as the penetration of intermittent renewable energy increases.
6 Conclusion
We find that the proposed plant is a useful addition to the NEM but the proposed profile is unsuitable because the gas component is loss making for four months of the year and producing CO2 during periods of low demand. We recommend further research using the alternative perfect day’s yield profile.
7 Further Research
We discuss further research compiled from recommendation elsewhere in the report.
8 Appendix A Australian National Electricity Market Model Network
This appendix provides diagrams of the generation and load serving entity nodes and the transmission lines that the ANEM model uses. There are 52 nodes and 68 transmission lines, which make the ANEM model realistic. In comparison, many other models of the NEM are highly aggregated.
9 Appendix B Australian National Electricity Market Model
This appendix describes the ANEM model in detail and provides additional information on the assumptions made about the change in the generation fleet in the NEM during the lifetime of the proposed plant
Collinsville solar thermal project: yield forecasting (draft report)
The final report has been published and is available here.
Executive Summary
1 Introduction
This report’s primary aim is to provide yield projections for the proposed Linear Fresnel Reflector (LFR) technology plant at Collinsville, Queensland, Australia. However, the techniques developed in this report to overcome inadequate datasets at Collinsville to produce the yield projections are of interest to a wider audience because inadequate datasets for renewable energy projects are commonplace. The subsequent report called ‘Energy economics and dispatch forecasting’ (Bell, Wild & Foster 2014a) uses the yield projections from this report to produce long-term wholesale market price and dispatch forecasts for the plant.
2 Literature review
The literature review discusses the four drivers for yield for LFR technology:
DNI (Direct Normal Irradiance)
Temperature
Humidity
Pressure
Collinsville lacks complete historical datasets of the four drivers to develop yield projects but its three nearby neighbours do possess complete datasets, so could act as proxies for Collinsville. However, analysing the four drivers for Collinsville and its three nearby sites shows that there is considerable difference in their climates. This difference makes them unsuitable to act as proxies for yield calculations. Therefore, the review investigates modelling the four drivers for Collinsville.
We introduce the term “effective” DNI to help clarify and ameliorate concerns over the dust and dew effects on terrestrial DNI measurement and LFR technology.
We also introduce a modified TMY technique to overcome technology specific Typical Metrological Year (TMY). We discuss the effect of climate change and the El Nino Southern Oscillation (ENSO) on yield and their implications for a TMY.
2.1 Research questions
Research question arising from the literature review include:
The overarching research question:
Can modelling the weather with limited datasets produce greater yield predictive power than using the historically more complete datasets from nearby sites?
This overarching question has a number of smaller supporting research questions:
Is BoM’s DNI satellite dataset adequately adjusted for cloud cover at Collinsville?
Given the dust and dew effects, is using raw satellite data sufficient to model yield?
Does elevation between Collinsville and nearby sites affect yield?
How does the ENSO affect yield?
Given the 2007-2012 constraint, will the TMY process provide a “Typical” year over the ENSO cycle?
How does climate change affect yield?
A further research question arises in the methodology but is included here for completeness.
What is the expected frequency of oversupply from the Linear Fresnel Novatec Solar Boiler?
3 Methodology
In the methodology section, we discuss the data preparation and the model selection process for the four drivers of yield.
4 Results and analysis
In the results section we present the four driver models selected and the process that was undertaken to arrive at the models.
5 Discussion
We analyse the extent to which the research questions are informed by the results.
6 Conclusion
In this report, we have identified the key research questions and established a methodology to address these questions. The models for the four drivers have been established allowing the calculation of the yield projections for Collinsville
Testing for the Existence of a Generalized Wiener Process- the Case of Stock Prices
In this article, we present two nonparametric trispectrum based tests for testing the hypothesis that an observed time series was generated by what we call a generalized Wiener process (GWP). Assuming the existence of a Weiner process for asset rates of return is critical to the Black-Scholes model and its extension by Merton (BSM). The Hinich trispectrum-based test of linearity and the trispectrum extension of the Hinich-Rothman bispectrum test for time reversibility are used to test the validity of BSM. We apply the tests to a selection of high frequency NYSE and Australian (ASX) stocks.
Are Daily and Weekly Load and Spot Price Dynamics in Australia’s National Electricity Market Governed by Episodic Nonlinearity?
In this article, we use half hourly spot electricity prices and load data for the National Electricity Market (NEM) of Australia for the period from December 1998 to February 2008 to test for episodic nonlinearity in the dynamics governing daily and weekly cycles in load and spot price time series data. We apply the portmanteau correlation, bicorrelation and tricorrelation tests introduced in Hinich (1996) to the time series of half hourly spot prices and load demand from 7/12/1998 to 29/02/2008 using a FORTRAN 95 program. We find the presence of significant third and fourth order (non-linear) serial dependence in the weekly load and spot price data in particular, but to a much more marginal extent, in the daily data.
The Use of Trimming to Improve the Performance of Tests for Nonlinear Serial Dependence with Application to the Australian National Electricity Market
In this article, we build on the results reported in Wild, Hinich and Foster (2008) for the National Electricity Market (NEM) of Australia by testing for episodic nonlinearity in the dynamics governing weekly cycles in spot price time series data. We apply the portmanteau correlation, bicorrelation and tricorrelation tests introduced in Hinich (1996) and the Engle (1982) ARCH LM test to the time series of half hourly spot prices from 7/12/1998 to 29/02/2008. We use trimming to improve the finite sample performance of the various test statistics mentioned above given the presence of significant skewness and leptokurtosis in the source datasets which may adversely affect the convergence properties of the test statistics in finite samples. With trimming, we still find the presence of significant third and fourth order (non-linear) serial dependence in the weekly spot price data, pointing to the presence of ‘deep’ nonlinear structure in this data.
Managerial Incentives and the Valuation of International Joint Venture Formation
Strategic management decisions and actions involving international joint venture formations are significant to many firms and have major economic consequences. Previous empirical evidence on the effects of joint venture formation announcements on shareholder wealth reveals that firm value is more often positively impacted. However, many previous analyses of shareholder wealth from joint venture formations do not fully explore cross-sectional differences in managerial incentives to pursue these international investments. The primary purpose of this study is to exploit these cross-sectional differences using agency theory to explain managerial behavior and subsequent shareholder effects. This study capitalizes on agency theory’s notion that managers are not necessarily motivated solely by the maximization of firm value, but instead are interested in maximizing their own utility. The study’s findings are consistent with agency theoretic hypotheses based on a broad cross-section of international joint ventures. Results demonstrate that shareholder returns to international joint venture formation exhibit considerable variability and, importantly, are at least partially explained by cross-sectional differences in agency incentives. Specifically, returns to shareholders are positively related to the level of managerial ownership and inversely related to the level of free cash flow. Moreover, a positive relation is found between shareholder returns and the joint interaction between leverage and free cash flow. These findings indicate that the effect of international joint venture formation on shareholder value is not uniform and, more importantly is at least partly influenced by managers’ agency incentives
Theoretical Studies of Crystallisation in Hard Sphere Systems
The primary focus of this work is to develop an understanding of crystallisation in hard sphere systems. The thesis is presented in two parts. The first section is an investigation of the liquid/crystal interface at equilibrium using molecular dynamical simulations. The objective is to understand how the interface might bridge between the disordered and ordered states in liquid/crystal environments. Topological measures of structure are used to investigate whether any precursor structures are present in the liquid phase, close to the interface, that would allow transition from disorder to order. This differs from other work where simpler measures of structure, classifying phases into either liquid or crystal, are used. The results indicate that the liquid/crystal interface of a hard sphere system is very narrow and no readily observable structures were found that extended past the width of the equilibrium interface. The second section of the thesis is a theoretical study of growth kinetics in hard sphere systems using density functional theory. The kinetics in a fixed volume are examined with a single conserved order parameter. The work is extended incorporating both conserved particle and non-conserved structure dynamics. The kinetics of growth are examined and it is shown that the small initial crystals are quickly isolated from the higher pressure of the surrounding system through the development of a depletion zone
Market and Economic Modelling of the Intelligent Grid: End of Year Report 2009
The overall goal of Project 2 has been to provide a comprehensive understanding of the impacts of distributed energy (DG) on the Australian Electricity System. The research team at the UQ Energy Economics and Management Group (EEMG) has constructed a variety of sophisticated models to analyse the various impacts of significant increases in DG. These models stress that the spatial configuration of the grid really matters - this has tended to be neglected in economic discussions of the costs of DG relative to conventional, centralized power generation. The modelling also makes it clear that efficient storage systems will often be critical in solving transient stability problems on the grid as we move to the greater provision of renewable DG. We show that DG can help to defer of transmission investments in certain conditions. The existing grid structure was constructed with different priorities in mind and we show that its replacement can come at a prohibitive cost unless the capability of the local grid to accommodate DG is assessed very carefully.Distributed Generation. Energy Economics, Electricity Markets, Renewable Energy
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