Forecasting of Wind and Solar Farm Output in the Australian National Electricity Market: A Review

Accurately forecasting the output of grid connected wind and solar systems is critical to increasing the overall penetration of renewables on the electrical network. This is especially the case in Australia, where there has been a massive increase in solar and wind farms in the last 15 years, as well as in roof top solar, both domestic and commercial. For example, in 2020, 27% of the electricity in Australia was from renewable sources, and in South Australia almost 60% was from wind and solar. In the literature, there has been extensive research reported on solar and wind resource, entailing both point and interval forecasts, but there has been much less focus on the forecasting of output from wind and solar systems. In this review, we canvass both what has been reported and also what gaps remain. In the case of the latter topic, there are numerous aspects that are not well dealt with in the literature. We have added discussion on the value of forecasts, rather than just focusing on forecast skill. Further, we present a section on how to deal with conditionally changing variance, a topic that has little focus in the literature. One other topic may be particularly important in Australia at the moment, but may become more widespread. This is how to deal with the concept of a clear sky output from a solar farm when the field is oversized compared to the inverter capacity, resulting in a plateau for the output.

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Probabilistic Forecasting of Wind and Solar Farm Output

Energies ◽

10.3390/en14165154 ◽

2021 ◽

Vol 14 (16) ◽

pp. 5154

Author(s):

John Boland ◽

Sleiman Farah

Keyword(s):

Electricity Market ◽

Wind Farms ◽

Error Variance ◽

Prediction Intervals ◽

Electrical Network ◽

Probabilistic Forecasting ◽

Short Term ◽

Solar Systems ◽

National Electricity Market ◽

Short Term Forecasting

Accurately forecasting the output of grid connected wind and solar systems is critical to increasing the overall penetration of renewables on the electrical network. This includes not only forecasting the expected level, but also putting error bounds on the forecast. The National Electricity Market (NEM) in Australia operates on a five minute basis. We used statistical forecasting tools to generate forecasts with prediction intervals, trialing them on one wind and one solar farm. In classical time series forecasting, construction of prediction intervals is rudimentary if the error variance is constant—termed homoscedastic. However, if the variance changes—either conditionally as with wind farms, or systematically because of diurnal effects as with solar farms—the task is much more complicated. The tools were trained on segments of historical data and then tested on data not used in the training. Results from the testing set showed good performance using metrics, including Coverage and Interval Score. The methods used can be adapted to various time scales for short term forecasting.

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Wind power in Victoria

Proceedings of the Royal Society of Victoria ◽

10.1071/rs14020 ◽

2014 ◽

Vol 126 (2) ◽

pp. 20

Author(s):

Tom Keddie

Keyword(s):

Electricity Market ◽

Wind Farm ◽

South Australia ◽

South Wales ◽

Generation Capacity ◽

National Electricity Market ◽

Wind Farm Location ◽

Wind Resource ◽

Installed Capacity

In terms of generation capacity, Victoria has about 12,500 MW, out of a National Electricity Market (NEM) total of over 46,000 MW. A bit over half of Victoria’s capacity is made up of the brown coal generators in the Latrobe Valley (Loy Yang, Hazelwood, Yallourn). Gas-fired generation (mainly large open-cycle peaking plants, designed to operate only in times of high demand) and hydro plants (mainly parts of the Snowy scheme) add about 20% each, with wind currently making up the balance of around 9% of installed capacity in Victoria. In terms of wind farm location across the NEM, installed capacity is predominantly located in Victoria and South Australia, and to a lesser extent in Tasmania, with very small amounts in New South Wales and Queensland. This distribution is almost entirely due to the quality of the wind resource across the country.

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Hydro Tasmania – Renewable Energy Drivers, Action and Plans

Energy & Environment ◽

10.1260/095830505774478495 ◽

2005 ◽

Vol 16 (5) ◽

pp. 803-813

Author(s):

Roger Gill ◽

Harry Andrews

Keyword(s):

Renewable Energy ◽

Electricity Market ◽

Wind Farm ◽

Environmental Science ◽

Small Hydropower ◽

Wind Generators ◽

Hydropower Plants ◽

Island State ◽

National Electricity Market ◽

Wind Resource

In Tasmania, the island state of Australia, the generator, Hydro Tasmania, is pushing technical, environmental and business boundaries in its plans to integrate a relatively high proportion (up to 20 percent) of large wind generators into its current complex mix of large and small hydropower plants. Its plans include projects to increase the efficiency of its older hydropower equipment as it prepares to supply much needed peaking capacity to the market in southern Australia via the groundbreaking Basslink undersea cable, which is due for completion in November 2005. Taken as a package these developments are creating a globally significant reference site for renewable energy systems. The paper will describe what is happening, and more importantly what is underpinning the developments, including: the harnessing of Tasmania's world-class wind resource, where recently constructed 1.75 MW wind turbines are achieving capacity factors of over 45 percent – some of the best productivity in the world today; the application of leading environmental science measures to ensure the sustainability of both the new wind farm developments and the transformation of the hydropower system to meet peak capacity demands; the relevance of the existing large hydropower storages that can operate in synergy with the wind resource; the contribution of Australia's renewable energy certificate scheme, which is effectively doubling the value of new renewable energy developments compared with existing generation sources; the application of the latest technology in hydropower turbines, combined with power system expertise from the world's leading manufacturers, to increase the efficiency of older hydropower generators, thereby more effectively harnessing the existing environmental footprint; and the transformation of Hydro Tasmania's business into a significant supplier and trader of premium value peak energy into the sophisticated Australian National Electricity Market.

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Grid-Scale Battery Energy Storage Operation in Australian Electricity Spot and Contingency Reserve Markets

Energies ◽

10.3390/en14238069 ◽

2021 ◽

Vol 14 (23) ◽

pp. 8069

Author(s):

Ekaterina Bayborodina ◽

Michael Negnevitsky ◽

Evan Franklin ◽

Alison Washusen

Keyword(s):

Energy Storage ◽

Power Systems ◽

Electricity Market ◽

South Australia ◽

System Stability ◽

Battery Life ◽

Battery Energy Storage ◽

National Electricity Market ◽

Operating Strategies ◽

Battery Energy

Conventional fossil-fuel-based power systems are undergoing rapid transformation via the replacement of coal-fired generation with wind and solar farms. The stochastic and intermittent nature of such renewable sources demands alternative dispatchable technology capable of meeting system stability and reliability needs. Battery energy storage can play a crucial role in enabling the high uptake of wind and solar generation. However, battery life is very sensitive to the way battery energy storage systems (BESS) are operated. In this paper, we propose a framework to analyse battery operation in the Australian National Electricity Market (NEM) electricity spot and contingency reserve markets. We investigate battery operation in different states of Australia under various operating strategies. By considering battery degradation costs within the operating strategy, BESS can generate revenue from the energy market without significantly compromising battery life. Participating in contingency markets, batteries can substantially increase their revenue with almost no impact on battery health. Finally, when battery systems are introduced into highly volatile markets (such as South Australia) more aggressive cycling of batteries leads to accelerated battery aging, which may be justified by increased revenue. The findings also suggest that with falling replacement costs, the operation of battery energy systems can be adjusted, increasing immediate revenues and moving the battery end-of-life conditions closer.

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Storage and Usage of Energy

Technologies for Electrical Power Conversion, Efficiency, and Distribution ◽

10.4018/978-1-61520-647-6.ch002 ◽

2010 ◽

pp. 10-31

Keyword(s):

Power Supplies ◽

Electrical Network ◽

Network System ◽

Strong Wind ◽

Stored Energy ◽

Renewable Sources ◽

Uninterruptible Power Supplies ◽

Uninterruptible Power ◽

The Moment

A necessity to store energy in purpose to use it later in time arises in different occasions. For example, in uninterruptible power supplies systems examined in Chapter 10, stored energy is required when a drop off of the electrical network system happens. In systems used to obtain energy from renewable sources examined in Chapter 9, the necessity to store energy also arises. This is explained by the fact that energy is not always possible to be consumed at the moment of its generation and of the same quantity. For example, the periods of strong sun lightening or strong wind may not coincide with the periods of maximum consumption.

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