Explainer: the duck curve
The energy sector is infamously jargon-heavy, and even with a handy glossary of terms at your fingertips it can often be a tough slog reading about developments and issues in the energy industry. One rather abstract term cropping up more frequently is the ‘duck curve’ – but what is a duck curve? And what does it have to do with energy? Duck tales – the history on the ‘duck curve’ In 2013, the California Independent System Operator (CAISO) – the organisation that oversees California’s electricity generation and transmission network, much the same as AEMO oversees Australia’s NEM – published a now-famous chart (PDF)* that showed the energy demand over time on a spring day, and how that was anticipated to change in the future. The 2013 chart produced by the California Independent System Operator (CAISO) predicts electricity demand over time on a typical spring day in California As we’ve marked up below, as small-scale solar generation increases through the day, demand for electricity from the network drops as there is excess energy from rooftop solar. Then, once the sun begins to set and people return home in the evening, network demand begins to peak. See that duck curve now? Grid demand falls in the day, and then rises again in the evening The line of the chart – particularly the increasingly pronounced shape of the predictions as the years go on – was noted to resemble the outline of a duck. Hence, this phenomenon was dubbed ‘the duck curve (PDF)’** – and the name stuck. Quack It’s important to note that the way we consume energy hasn’t changed dramatically over the years - on the whole, people still leave the house to work or study during the day (with correlating declines in demand) and then they spend their evenings in (with a correlating increase in demand), which is then followed by a decrease in demand, as everyone heads off to bed The duck curve is overlaid on this pattern of consumption and was predicted based on increasing levels of rooftop solar. Those predictions have been borne out over time, particularly in sunny markets with a high level of rooftop solar adoption, like California – and Australia. An energy mix The surge in energy demand in the evening, especially in the sunnier months in Australia, means that both traditional baseload sources of power and intermittent renewable energy, need to be supported by flexible firming energy generation. Response to the increasingly steep duck curve demand profile is the development of technology and generation that can cater to these peaks and troughs, like firming supply and energy storage. Firming capacity is generation that can ramp up and down Firming supply is capacity that is agile and has the ability to ramp up generation quickly. It’s a role filled in today’s energy mix by modern peaking gas power stations like the new Barker Inlet Power Station (BIPS) in South Australia, which can ramp up to full power in timeframes measured in minutes. This means that gas peakers can sit at a low-level (or even offline) during periods of low demand during the day, and then rapidly ramp up to meet peak demand in the evening. Energy storage can take excess supply in the day, and save it for use when it’s needed most in the evening. Energy storage, like batteries and pumped hydro also have an important role in the context of the duck curve. An enormous amount of energy is produced by renewable generation – primarily rooftop-solar, in this case – every day. But if that energy is not immediately used or stored, it is lost, and this is where energy storage can help by storing that excess energy and dispatching it when it’s needed most. And like firming power stations, energy storage has the flexibility to ramp up quickly to meet changing demand but unlike firming power stations, that ramp up is measured in milliseconds, not minutes. Both pumped hydro and batteries are incredibly effective at frequency response – with the ability to smooth out the peaks in supply by storing excess energy, or otherwise responding to peaks in demand with flexible generation - in turn making the network more reliable and effectively lengthening out the duck’s neck and flattening the demand curve. Steps we’re taking For these reasons, we’re investing in flexible generation and energy storage, to best meet the needs of the current and future energy market. AGL is making broad investment in firming capacity across Australia for a more reliable supply into the future. In total, AGL has about $1.9b of new energy supply projects completed or in construction, with a further $2b in the pipeline. Of these projects, close to 1,000 MW of supply will provide some of the firming support that the National Electricity Market needs. 1 California Independent System Operator 2013, California ISO Demand Response and Energy Efficiency Roadmap: Maximizing Preferred Resources, December 2013, accessed 27 February 2020, https://www.caiso.com/documents/dr-eeroadmap.pdf 2 California Independent System Operator 2016, What the duck curve tells us about managing a green grid, accessed 27 February 2020, https://www.caiso.com/Documents/FlexibleResourcesHelpRenewables_FastFacts.pdfWelcome to the Neighbourhood!
The Neighbourhood is a dedicated online forum where you can share, discuss and learn about all things energy. We created the online community in an effort to make finding information and solutions easier – by people just like you. We want you to feel at all times that your thoughts and opinions matter and are respected, which is why we have some simple ‘house rules’ to be followed by all of our community members. House rules Keep private information private – we want you to stay safe online. Our team of moderators and community managers will never ask for your private information in public. Respect the community – we encourage debate and engaging discussion between our community members, but the moment it gets personal or offensive, we’ll step in. We encourage our community members to report any abuse to the Neighbourhoot team. Contribute to the community – ensure you search the community before asking a specific question as it may have already been answered. Make sure your discussion remains relevant to the topic being discussed and give thanks when you have a good experience! You can also reward people with Kudos. When we’re likely to step in – we endeavour to leave all content and posts as they were published, however in an effort to foster a friendly and appropriate online environment for these contributions to be made and viewed, our team may modify posts that fit the following criteria: Offensive, abusive, misleading, deceptive or otherwise inappropriate posts – this includes copyrighted material. Off topic or duplicate (multi-posting) / spam content. Links to external or unauthorised pages that are considered inappropriate. In an effort to protect privacy. In any other situation where our team deem it necessary. Moderation overview All comments or posts submitted via the Neighbourhood website are reviewed by a moderator. Moderators will ensure that user comments are relevant and appropriate, and may take any steps they deem necessary to ensure content meets our guidelines. Our team also reserve the right to limit access to the community by temporarily or permanently banning a user from it. Don’t worry – we value all manner of feedback and discussion, and as long as you follow the house rules, your posts will be published ‘as is’. We aim to review all content within 48 hours. Your use of the Neighbourhood website Your use of the Neighbourhood website is also governed by the Neighbourhood Terms of Use and AGL Energy’s Privacy Policy. In addition to these, all AGL Energy employees participating in the Neighbourhood should be aware of and agree to be bound by AGL Energy’s Social Media Policy. Ask the NeighbourhoodAGL responds to the Queensland Emergency Consultation
Queensland is supporting Australia’s energy transition through its nation-leading uptake of rooftop solar PV, which is both an impressive feat and one that has the potential to create challenges for Queensland’s energy system by exacerbating declining minimum demand conditions. Energy Queensland is proposing to introduce a mechanism that can curtail the output of inverters such as rooftop solar PV systems in emergency situations to help balance the supply and demand of electricity and keep the system operating safely. The backstop mechanism is intended to disconnect some customers’ distributed (or consumer) energy resources (CER) to arrest a system blackout in emergency minimum system load events. This will involve installing a generation signalling device (GSD) that can activate the demand response capability DRM0 in inverters connected to the Queensland electricity grid. The requirement to install a GSD will not apply retrospectively to existing systems, however, it is proposed that from November 2022, a GSD will be required for all customer connections or alterations of existing inverter energy systems where: The new connection has an aggregate installed nameplate capacity of 10kVA or above; There is a non-warranty replacement of an inverter, and the aggregate installed capacity is 10kVA; Inverter energy system capacity is added to an existing system which results in the total capacity being 10KVa or above. The new inverter will be required to have a GSD fitted. In the near future, AGL believes that dynamic operating envelopes for solar PV will be one of the leading solutions to declining minimum demand conditions caused by the rapid proliferation of CER assets in Queensland. Until Queensland’s backend infrastructure can enable dynamic operating envelopes, it is important that the interim backstop mechanism includes appropriate safeguards to maintain consumer confidence in the future role of CER in the NEM while minimising the impact on investment certainty, consumer uptake, and the value of CER assets. In our submission we discuss a number of opportunities to improve outcomes for customers affected by the introduction of the backstop mechanism, including by: Incorporating the policy intention that the emergency backstop mechanism be used only as a measure of last resort into the regulatory framework. Explicitly excluding battery storage assets from the backstop mechanism and requirement to install a GSD. Introducing a requirement for DNSPs to notify impacted customers of the curtailment of their solar. Waiving any demand charge reset accumulated by customers during the curtailment period. Revising the implementation timeframe from November 2022 to 1 January 2023. You can read the full submission here.Macarthur Wind Farm
The 420 MW Macarthur Wind Farm can generate enough clean, green energy to power the equivalent of approximately 167,000 average Australian homes. Generating electricity from Macarthur Wind Farm displaces electricity that may otherwise need to be sourced from the grid at a higher emissions intensity. Location Macarthur Wind Farm sits about 16 km east of Macarthur, between Hamilton and Warnambool in south western Victoria. Spanning about 5,500 hectares of freehold agricultural land, it crosses three properties that are predominately used for sheep and cattle grazing. Development and maintenance AGL engaged Leighton Contractors and Vestas to construct Macarthur Wind Farm. It took about 2.5 years to build, and has been fully operational since late January 2013. Vestas continues to play an important role in ongoing operations. As the world's largest manufacturer of wind turbines, Vestas brings state-of-the-art technology, quality and reliability to the project – ensuring its long-term success. During development and construction, the total number of jobs (including flow-on employment) was estimated at 875 from the region, 2,490 from Victoria and 2,782 from the rest of Australia. A permanent site team – responsible for ongoing maintenance and operations – includes 18 local residents from south west Victoria. AGL Macarthur Wind Farm Bushfire Mitigation Plan 2020-2021 (PDF), opens in a new window News In October 2019, AGL welcomed the sale of a 50% interest in the 420 MW Macarthur Wind Farm joint venture to AMP Capital. AGL continues to operate and maintain the wind farm on behalf of Palisade and Atmos Renewables and AMP Capital, and retains the rights to all Renewable Energy Certificates and electricity output until 2038, opens in a new window. Community complaints and enquiries Ask our Community Forum The AGL Community Engagement Forum is a place to ask questions, provide feedback, or discuss anything about AGL’s operational sites and the communities in which we operate. Join the conversation, opens in a new window AGL understands that we don’t always get it right, and we want to be informed when we don’t. If you would like to provide any feedback, good or bad, or simply ask some questions, please feel free to get in touch via the following channels:Broken Hill Solar Plant
On an annual basis, the Broken Hill Solar Plant will produce enough electricity to meet the needs of approximately 19,000 average Australian homes. Broken Hill Solar Plant was one of two large-scale solar photovoltaic (PV) power plants delivered by AGL in 2015, jointly funded by the Australian Renewable Energy Agency (ARENA) and the NSW Government. The 53 MW solar plant is expected to generate approximately 126,000 megawatt hours (MWh) of clean, renewable electricity each year. It will reduce greenhouse gas (GHG) emissions by over 103,710 tonnes of CO2 equivalent per annum, assuming a rate of 0.84 tonnes per MWh of electricity. Particulate and heavy metal emissions will also be reduced. Location Broken Hill has one of the highest levels of solar radiation in NSW, making it an ideal location for a solar plant. Plus, with a large local population and several industrial sites nearby, there is significant demand for electrical power in the region. The site sits about 5 km southwest of the Broken Hill township, adjacent to Willyama Common. An existing substation is nearby, enabling relatively efficient connection into the electrical grid. The solar plant occupies approximately 140 hectares of Crown Land bounded by the Barrier Highway to the north and the Peterborough-Broken Hill rail line to the south, and administered by the NSW Department Primary Industries, Lands and Water. Broken Hill Solar Plant map (PDF), opens in a new window Tilt Renewables On behalf of Tilt Renewables (formerly Powering Australian Renewables Fund (PARF)), AGL announced in November 2016 that it had reached financial close on selling its 102 MW Nyngan and 53 MW Broken Hill solar plants into the fund. The AU$257 million sale, with approximately nil profit on sale, includes AGL writing a long term offtake agreement with the two solar plants. Media release: Powering Australian Renewables Fund achieves first major milestone, opens in a new window Project delivery AGL was responsible for the development and management of Broken Hill Solar Plant. Construction began in mid-July 2014 and was completed at the end of 2015. The plant was officially opened in January 2016. First Solar provided AGL with engineering, procurement and construction (EPC) services and is also maintaining the plant for its first five years of commercial operation. The electricity produced by the project will be sold under a power purchase agreement to AGL Hydro Partnership, a partnership between wholly owned subsidiaries of AGL. How does the solar plant work? First Solar's advanced cadmium telluride (CdTe) thin film photovoltaic (PV) modules convert sunlight into electricity, which is then fed into the electrical grid. This process generates electricity with no air emissions, no waste production and no water use. Generation Generation from the Broken Hill Solar Plant commenced on 15 September 2015. Full generation (53 MW) was achieved in October 2015. The following information is provided for calendar year 2016 (PDF), opens in a new window and calendar year 2017 (XLS), opens in a new window: actual generation from the solar plant during the AEMO trading interval actual regional reference price for each trading interval link to Green Energy Markets showing the LGC market prices. The Broken Hill Solar Plant is connected to the National Electricity Market, opens in a new window (NEM) which is managed by the Australian Energy Market Operator, opens in a new window (AEMO). For a glossary of terms associated with the NEM and mentioned in our report please refer to the AEMO website, opens in a new window. The solar plant revenue is also subject to the Marginal Loss Factors (MLF) which are published, opens in a new window each financial year by AEMO. Report: Broken Hill Generation (PDF), opens in a new window News Broken Hill solar plant viewing platform poses a $10,000 challenge, opens in a new window Tilt Renewables (formerly Powering Australian Renewables Fund) achieve first major milestone, opens in a new window AGL’s Broken Hill solar plant open to the community, opens in a new window AGL’s Nyngan and Broken Hill solar plants officially opened, opens in a new window Half of the modules installed at AGL's Broken Hill Solar Plant, opens in a new window First modules installed at AGL's Broken Hill Solar Plant, opens in a new window Local projects share in $25,000 AGL Broken Hill Solar Plant Construction Community Fund, opens in a new window AGL on track to deliver Australia's largest solar plants, opens in a new window Community complaints and enquiries Mail AGL Community Complaints & Enquiries, Locked Bag 14120 MCMC, Melbourne VIC 8001
