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Do Australian wind turbines all blow at the same time?

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How correlated is the wind output from the various states?

At the moment, South Australia supplies over 40 per cent of the wind powered electricity in the National Electricity Market with Victoria next in line. As we move to higher renewable penetration, the question arises as to how correlated the wind powered electricity in NSW, Victoria and Tasmania will be with that of South Australia?

If it’s very correlated, then the issues that are evident in South Australia will become NEM-wide issues. On the other hand, if the correlation is low, then as we diversify the wind fueled electricity by geography we will tend to get a less intermittent wind supply from a NEM-wide perspective.

Figure 1 below shows some modest reduction in the standard deviation of wind over the past 14 months from a NEM-wide perspective, compared to that of any individual state. However, the reduction isn’t as large as it might be because South Australia is a large share of the total.

Looking at Fig 3 shows that NSW and Tasmania are much less correlated with South Australia and as the wind output in those two states grows, its probable the overall NEM-wide volatility will fall.

The new wind farms in the north of NSW will probably further help with that diversification.

Even so, at this stage we still think that “demand driven” renewable energy, as opposed to “availability driven” renewable energy, would be a great help. At the moment the main options for this are CSP, lithium-ion battery storage, pumped hydro storage and – less realistically – geothermal.

Of those technologies, it’s lithium-ion battery storage that plays the best with the other technology trends of microgrids and disruptive consumer-led competition. Still, lithium’s got a lot of work to do, as we will see in the next article.

 

Figure 1: Average wind output and standard deviation last 14 months, half hourly data

Figure 1: Average wind output and standard deviation last 14 months, half hourly data

Wind can supply 80% of the NEM electricity needs

As previously noted, the academic consensus is that, in Australia, the lowest-cost way to a 100 per cent renewable market has wind supplying about 80 per cent of the energy.

Those studies are based on using 2010 electricity demand (half-hourly basis) plus wind speed and other weather related data from that year, together with a set of cost and technical parameters for renewable energy sources. We quote, again, from recent literature on the technical viability and economics of a 100 per cent renewable NEM grid:

How can we achieve lower cost 100% renewable systems?

UNSW’s modelling suggests that achieving 100% renewable portfolios at the lower end of the projected cost range will likely require the following measures:

  •  Enable significant wind generation – The lowest cost portfolios consistently include significant quantities of wind generation (supplying up to 80% of energy). Portfolios with lower proportions of wind are feasible, but generally more expensive. “

Source: 100% renewable literaure review UNSW

We don’t think that’s the last word to be said on the subject and we think the falling cost of lithium-ion battery technology may change some of the parameters. Still, right now, wind is fully in the mix.

Wind currently produces about 10.4TWh of electricity in the NEM – close enough to 6 per cent of total electricity demand. Of that, about 41 per cent comes from South Australia and 31 per cent from Victoria.

A map of the wind resource in Australia suggests that QLD is unlikely to be a major supplier of wind fueled electricity in Australia. The map below is more than 10 years old and more is known today, but still, in the end, there is just a limited wind resource close to the load in QLD.

Just by looking at the map it wouldn’t be hard to imaging that there will be some correlation between wind farms built in South Australia and those built in Victoria and Tasmania.

Figure 2 Wind resource in Australia, 2007 view

Figure 2 Wind resource in Australia, 2007 view

One thing to note is that wind turbines built today are designed to take much more advantage of lower wind speeds. And although it doesn’t look, on the above map, as if there are many spots to build wind farms in QLD, there are bound to be a few.

Cross correlations are high but still show benefits

The table below shows that NSW’s correlation with South Australia is just 34 per cent over the past 14 months. And that’s even allowing for all NSW wind to be in the Goulburn/ACT region. Building wind farms further north would likely reduce that further. On the other hand, and unsurprisingly, the correlation between South Australia and Victoria is 65 per cent. The correlation between Tasmania and South Australia is just 10 per cent.

Figure 3: correlations between wind output across the NEM

Figure 3: correlations between wind output across the NEM

 

These numbers suggest that building out wind farms in NSW and Tasmania would likely have the most impact on reducing the volatility in NEM-wide output.

Wind farm developers more interested in impact of wind on pool prices

As has been well documented, when the wind blows in South Australia the pool electricity price falls. The increase in supply drives down the price.

However in NSW wind is, at present, a very small part of the generation mix. So for the time being a greater amount of wind will only have a small impact on the pool prices in that region.

NSW is presently the largest source of load, followed by Queensland.

As time goes on, though, and as decarbonisation/falling cost of wind makes it, along with PV, the lowest-cost technology, then wind will face an NEM-wide issue of lower prices when the wind blows.

This is the same problem that PV faces. Once we move beyond a certain point for PV it tends to drive prices down in the middle of the day, having a negative impact on profitability.

These are just two instances of the economic disadvantage of “availability driven” rather than “demand driven” supply. Please be clear, this is not being critical of renewables, just drawing attention to the economics. It’s much better for prices when supply reacts to demand.

Two ways to go

In the literature, there are three answers to the problem of matching up demand with renewables supply.

One answer is overbuilding the renewable energy source, in this case wind. This results in a lot of load shedding. That is, the wind turbines are spinning but the power goes to waste. This is presently regarded as the low capital cost solution. The way the market works today, though, it will produce very poor price outcomes for producers at high wind penetration rates. In fact we think it may not be possible to build an 80-100 per cent renewable supply using a “gross pool” in the way we do now within the NEM. That’s even before we get to the problems around REC prices.

The second answer is to store the renewable energy and turn it from an “availability driven” source to a demand-driven source.

Mostly its concentrating solar power [CSP], geothermal and pumped hydro storage that have represented the focus of demand-driven renewable supply. Now, though, we think lithium-ion phosphate has some possibilities of becoming the main partner of wind and PV.  We will return to this in a later article.

The third answer is to adjust demand to match supply. Some household demand can be adjusted quite easily. However, we think that won’t really do it for the broader industrial complex.

Our world view of 100% renewables, or more correctly a fully decarbonised power system, will enable electricity to be supplied to the same degree of reliability and availability as the system today. We want renewables running aluminium smelters, and server farms.

David Leitch is principal of ITK. He was  formerly a Utility Analyst for leading investment banks over the past 30 years. The views expressed are his own. Please note our new section, Energy Markets, which will include analysis from Leitch on the energy markets and broader energy issues. And also note our live generation widget, and the APVI solar contribution.  

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  • David Osmond

    Hi David, a better wind map of the wind can be found at the following link. It indicates quite a few more locations in QLD than your older map.
    http://www.finance.wa.gov.au/cms/uploadedFiles/Public_Utilities_Office/Energy_in_WA/Renewable_energy/mean-wind-speed-2008.pdf

    • Peter F

      Even that is not the complete story, wind turbines are now regularly being built with hub heights of 100m and occasionally up to 140m. At 100m average wind speeds are typically 0.5m/s higher which means that the output is increased by more than 20% and to address Leith’s point below, the time where they are not generating is shorter

      • Leith Elder

        I agree, all of this helps. Little Crookwell windfarm has had a capacity factor of around 22% for the 20 years I have been following it; the more recent Cullarin Gap over 40%. The basic problem remains though, the size and speed of slow moving continental highs that can stretch from Sydney to Perth, bringing with them persistent low windspeeds and high positive correlations. Perhaps surprisingly, even Cullarin Gap is positively correlated with Cathedral Rocks eg +14% for March 2016. For the same month Cullarin Gap had +33% correlation with Woolnorth. A necessary though not sufficient condition for windfarms to fully support each other are negative correlations. Lots of them.

        • Peter F

          Leith We seem to be in furious agreement, you can’t have just wind or even just wind and solar and hydro. If we could double the hydro on the system and have the wind and solar as widely spaced as possible then it is theoretically possible to have a 100% renewable grid but I for one would be keeping 6-12GW of gas, biomass or geothermal available just in case.
          However we can’t double the hydro so we have to build storage. Not as much as many people think but still in the $20-30b range
          It is not just a question of the % of capacity it is the % of actual generation. At the end of the worst day, if thermal plants produced 35% of the power used but only 5-8% over the year that would be a pretty good target to aim for and then we need much less storage.
          The investment to eliminate that last 5-8% would be far better spent on energy efficiency in heating applications and electrifying transport

          • Alastair Leith

            The argument that the last 5-10% of a 100% RE grid needs to also weigh the fact of exponential growth in PV behind the meter. Wholesale pricing for power at peak PV generation periods will not necessarily impact deployment of PV even at high penetrations if there is no grid reform and retailers still charge high tariffs when power is very cheap on the grid.

            PV is projected to be selling at a near zero module cost by 2030 (tonyseba.com), 2036 (Ray Kurzweil), 2040 (my own extrapolation of historical price curve assuming no ‘laws of physics’ limitations on tech breakthroughs increasing efficiencies and decreasing material inputs and fabrication energy). It’s very conceivable at this point that PV will be applied to most exterior cladding materials at near zero cost to offer point of sale competitiveness by manufacturers.

            At this point of ubiquitous near zero cost energy in all but the poorest day time weather and of course night, (for night when wind tends to peak demand management would seem like a good place to start) it’s all about storage, turkey dam PHES, SolarCST, better HV interlinks and for the ‘becalmed national grid’ weeks of the year that will sometimes occur some kind of power2gas conversion and storage seems much more likely to me than biofuels that are highly inefficient at conversion sunlight to energy and compete with food land and habitat.

            BZE managed to model a 100% grid using wind and solarCST alone, even if it was overly conservative on PV and other storage medium given the ‘off the shelf’ principles they applied. AEMO have said 100% is doable for not much more cost than maintaining a largely FF grid. I’m sure by the time we get to 70% RE pentration on the grid a heck of a lot more modelling and costs projections data will be available to inform decisions makers when grid reform gets tackled. To me grid reform is the biggest missing piece of the puzzle, we know we can build wind, PV and solarCST hybrid plants and PHES, creating a market which allows everyone a ‘fair’ ROI (hence ready investment) and eliminates market collision and gaming by utilities would seem to be a much bigger challenge because of the political capture in this nation’s government. Community power and networks seems to have played a big role in Germany and the Bolder, Colorado community seem to have over powered old king coal there.

          • Jens Stubbe

            Australia could and certainly should go 100% renewable not just for electricity.

            The simple solution is to over provision with renewables and establish industries that are able to accept only to get electricity when the grid management allows it.

            One such industry could be producing Synfuel for transportation.

            This does not require subsidies for renewables because renewables are dropping fast in cost.

            In 2014 the average 20 year wind PPA in USA was 2,3 US cent per kWh inclusive PTC unsubsidized without PTC that is 3,5 US cent per kWh.

            Since then Vestas has dropped their average selling price per MW wind turbine by 17% while also scaling to larger more efficient turbines.

            If this trend keeps up the 2021 average 20 year wind PPA in USA will go below 2 US cent per kWh unsubsidized.

            The biggest turbines now are 8MW and come with up to 180 meter rotor diameter, which in good offshore locations secures 70% capacity factor.

            Australia has wind resources enough to produce more electricity than the entire world consumes and more than enough space for solar that can do the same trick.

          • Peter F

            Jens & Leith
            I am not against 100% renewables and I agree costs are coming down all the time and the increasing capacity factor of wind turbines will make a huge difference to the amount of storage required, although less to the peak power backup. Thermal storage is a huge opportunity. In Switzerland my friend heats his 1780 built farmhouse with an air source heat pump coupled to a 2000 L tank heated to only 30-35C and that feeds his hydronic system. Total power consumption for a three story house through a Swiss winter about 5-7kW.hr per day and storage for 3 or 4 days.
            My point is, once we achieve even 40-50% renewable powered grid we would get more bang for our buck both in GHG and economic terms by increasing building and transport efficiency, electric buses, taxis and delivery vehicles etc.
            From about 5 years time, as you both imply, if the market rules are modernised, power will start to look after itself. Solar with behind the meter storage and merchant built wind and solar farms will start to drive inflexible FF out of the market. The new windlab project in Queensland is just the start and at the rate battery and solar prices are falling it would not surprise me if over the next few year most of the existing wind farms will be retrofitted with similar technology but even more storage.

            We all want the same thing, a carbon negative economy. I want to get there by the quickest and cheapest route possible because the more cost effective we make it, the easier it is to sell

          • Jens Stubbe

            Peter F

            The problem is that electricity is fast becoming “too cheap to store” meaning is makes much more sense to curtail or to discount. In the Nordpool area the average wholesale cost is around US $0,02/kWh and the cheapest storage is factors higher, which means storage only makes sense behind the meter for those fortunate to have space for PV.

            ITC and PTC are goners in USA as per 2021 but this does not mean that the plethora of direct and indirect subsidies for Fracking gas, Shale oil, nuclear and coal will go away. And neither will the nasty corruption that prevent renewables from market access. Renewables have to do it the hard way and outcompete fossils and nuclear on an unleveled playing field. As luck will have it the wind industry and the solar industry is capable to do so.

            The coal value chain in USA is basically worthless on the brink of bankruptcy or actually bankrupt and the same is true for Fracking gas and Shale oil. Even the big oil companies like Statoil and BP are now no longer profitable.

            Pushing fossils the last inch over the brink just requires cheaper Synfuel and biofuels and both are coming strong. Synfuels driven by discounted surplus renewable electricity and remarkable scientific research breakthroughs and biofuels similarly by scientific breakthrough in both reverse photosynthesis, Hydro Thermal Liquefaction and Gen. 2 enzymes for biofuels.

          • Leith Elder

            Jens,

            By all means let us have 100% renewables (for my 8 grandkid’s sakes if nothing else) but we have to temper our expectations and our enthusiasm – Engineering is the art of the possible (and Investment the art of the profitable ;-).

            “The capacity factor does not show strong consistent variation across hours, days or months, and share of renewable energy is limited as Jenkins and Trembath describe. There is little evidence of a synergy between wind and solar in the Australian grid, supporting my earlier conclusion that a combination of wind and solar can displace less fossil energy than wind alone. If we really wanted to push towards maximum renewable energy, we would build wind and not solar, and variable renewables share could grow to about 33%.”

            – John Morgan, Chief Scientist at Pooled Energy. Adjunct Professor, RMIT.

            Source: https://bravenewclimate.com/2015/11/08/the-capacity-factor-of-wind/

          • Jens Stubbe

            Leith Elder

            You got to read the entire article more carefully because what he does is to prove mathematically how correlated wind is in Australia and based upon this he comes up with a rule of thump indicating that wind penetration can be the average capacity factor + and added anti-correlation middling benefit.

            The 33% is based on the current fleet of Australian wind power – and actually not even that because he faulty calculated wind projects installed but actually not grid connected yet in his calculation. This may seem innocent but the average growth for windpower capacity world wide is 17% so if this is the case for Australia too up to 17% of the newest most efficient turbines are only on one side of his equation.

            Anyway if wind power keep the momentum wind power will produce as much electric power as the entire globe did in 2014 by 2031.

            Since 2008 there have not been a single year where the cost reduction has been below 6%.

            The new Adwen 8MW turbine been erected at the moment has a 180 meter rotor as opposed to the hitherto largest rotor found on Vestas 8MW 164 meter. This is about 20% more swept area and 16% more annual electricity production. Still the blades weighs the same as the blades for Vestas 164.

            Siemens has upgraded their originally 6MW turbine to first 7MW and now recently to 8MW.

            Both Vestas and Siemens are designing facilities for +20MW turbines and the harbour in Esbjerg is being designed around that format.

    • David leitch

      Thanks David. I note even that map is 2008. I am sure Windlab for one have a better understanding today. In fact I think they have a proposal for a large wind farm in Qld.

    • MikeH

      The limitation of this correlation analysis is that it is based on the available wind farm generation data, not wind resource data. Not a criticism just an observation.

      If you look at the location of wind farms in South Australia, most are more or less all on the same North South axis despite the fact that the prevailing wind comes from the West. Presumably that was about ready access to the existing grid between Northern Power Station and Adelaide.

      http://energy.anero.id.au/wind-energy

      So I would imagine there is still scope for new wind farms further to the West.

  • Leith Elder

    More to the point, they all stop blowing at the same time.

    • Clayton Drury

      I think you will find that the point of this article is that the wind turbines across Australia don’t all stop blowing at the same time.

      • Leith Elder

        Check your facts. They do. Too often and for too long. See http://energy.anero.id.au/

      • Leith Elder
        • Stephen Gloor

          6 year and older data being used. As the field has moved very rapidly since 2010 I think this paper, not peer reviewed BTW, is a bit out of date.

          Also the paper is using data from Victoria and SA primarily which is shown here to be well correlated so there is no real surprise.

          What is your point?

        • MikeH

          I was surprised at some of the hyperbolic language (e.g. the widespread use of the adjective “catastrophic”) being used in a peer reviewed academic paper.

          Then I noticed it had been published in the notorious “Energy & Environment Journal”.

          http://www.sourcewatch.org/index.php/Energy_and_Environment

        • MikeH

          The author of that paper was named in Parliament as a member of the IPA anti-wind front group Landscape Guardians

          “Paul Miskelly, who represents both the Australian Landscape Guardians and the Taralga Landscape Guardians, worked for the Australian Nuclear Science and Technology Organisation, ANSTO, for 32 years and gives talks on nuclear power. Climate scepticism is the stock in trade of the Landscape Guardians. Randall Bell, president of the Victorian Landscape Guardians, said in the Melbourne Age on 3 July 2010 that claims the earth is warming are scientifically unreliable and that the idea of man-made climate change is headed for the Y2K dustbin.”

          https://independentaustralia.net/politics/politics-display/anti-windfarm-astroturfers-exposed-in-parliament,3963

          • Leith Elder

            Mike

            Mate! Paul is a personal friend. He did work for ANSTO and is currently a tour guide at Lucas Heights. He was past president of the Taralga Landscape Guardians and appeared before the Land and Environment Court opposing the Taralga wind farm because it affected his vineyard. He also made submissions to the Senate enquiry on their behalf in 2007. Besides that he is also an Electrical Engineer with a masters degree.

            Now that is out of the way, how about somebody actually reading the paper and evaluating it on its factual content rather than slagging off the author. Surely we are above argumentum ad hominem on this site.

            PS The paper has since been peer reviewed.

  • Andy Saunders

    Hope you give Redflow a chance…

  • Peter F

    Energy efficiency, demand response and EV charging are underestimated sources of electrical demand management.

    If Australia was as energy efficient as the average of Spain, Italy,
    France and Germany, peak demand on the NEM would be less than 30GW.

    In the Nordpool there is 2GW of demand response in a 24GW average power grid. This is practically all industrial demand. With ripple control or internet control of water heating, air-conditioning, pool pumps, dishwashers etc. peak domestic demand can easily be reduced by 15-20% or more so in total we could reduce peaks by probably another 3-5GW. The difference here is that demand is not being reduced just shifted.

    The average electric vehicle needs to be charged every 2-3 days for 4-6 hours so again that load can be moved anywhere up to 48 hours without affecting the drivers. If, in 15 years, 30% of the light vehicle fleet is electric, it will only consume about 60% of Australia’s current wind output, but electric vehicles also make domestic and commercial solar more attractive. In effect, probably less than half their power demand would come from the grid and most of that, off peak. So electric vehicles will have little or no effect on peak demand and if V2G becomes viable they may actually reduce peak demand

    Batteries are being introduced to the grid to reduce investment and peak losses and peak supply charges in businesses. This is already happening and is there to smooth out demand, not supply but it can also manage supply variations. With no change in policy there could easily be 1-2GW of distributed storage available.

    Thus Grid peak could be reduced to around 25-27GW. We currently have 10GW of gas and 8GW of hydro and once wind and solar are evenly distributed across the grid, peak on hot summer afternoons will always be able to include around 4-6GW of wind/solar/CSP. So with a reserve margin of 10% we only need about 4-6GW of pumped hydro/Grid batteries

    • solarguy

      As it stands currently, we have a bus that has travelled 1000km on a single charge, albeit at a low average speed of about 56kmh. This shows what is possible in the future. We may eventually have heavy road freight that is electrified, which may have a range of 800 -1000km between charges.
      Imagine then, these vehicles needing to be fully charged in about an hour. The current draw could be very high for a high number of these vehicles.
      My point is there will need to be a lot RE generating capacity and or storage, as the energy is currently supplied by oil.

      • Peter F

        I agree heavy vehicles are a problem but electric buses are growing rapidly and some of the freight task can be transferred to rail. In the meantime trucks are becoming more efficient so it is possible to imagine that In 15 years, on road diesel use could be halved, but a combination of more public transport and electrified private vehicles can make a huge dent in urban passenger energy use

    • Totally agree. Batteries will be very useful as part of the solution but we risk thinking they are the magic bullet and ignoring demand reduction and the Low hanging fruit in energy efficiency.

  • Brunel

    A more important question is: Does it ever rain in WA and SA and Vic and NSW at the same time?

    If not, we could have huge solar power stations in 4 states and be assured that at least 2 states are making enough electrons to power all 4 states.

    • David leitch

      Yes, but only at lunchtime.

    • Alastair Leith

      BZE managed to model a 100% RE scenario in 2010 against 30 min interval weather data and 5min demand using wind, solarCST, and many new interconnects and upgrades to existing transmission lines, including an EW interconnect across the desert.

      • Brunel

        What desert.

        The thing with UHVDC is the losses are only 10% per 3000 km. AC loses a lot more and requires more land to build and probably more metal/copper to build than UHVDC.

  • trackdaze

    A broader footprint will help.

    There is another option for demand driven renewable energy.

    How about a wind & solar utility scale installation that also produces & stores hydrogen. Should the wind not blow nor the sun not shine it can burn some to generate electricity.

    At other times it can sell hydrogen to the heavy haulage sector or the odd (in so many ways) toyota mirai that some govt dept has been directed to buy.

    You know it makes sense. Still if it doesnt its worth doing only for the fact that it ticks off murdoks, boltz & bernardees.

  • juxx0r

    the more we build, the flatter the production profile