Reader Interactions


    • david_fta says

      Snowy 2.0 can outcompete coal? Interesting, considering coal is a fuel that can be used to produce electricity, whereas Snowy 2.0 is a gravity battery that “stores” electricity … so this government can’t even tell the difference between production and storage?

      How much worse could it be if the adults weren’t in charge?

      • Glynn Palmer says

        I think what Paul Broad meant was Snowy 2, as support and balancing for the transition to renewables, is a better financial outcome than building new HELE coal generation.

        Just incidentally, it would also provide a better outcome for reducing carbon emissions.

  1. RobertO says

    Hi All Goes to show how much of a silly debate it is to say that RE can not make the grid 100%. COALition are lost and will not lead Australia on where we could go, on where we should go, or on the idea “It’s where we need to go!”

    • david_fta says

      shh!! The COALition wants to draft legislation forcing AGL to sell Liddell to Alinta.

  2. George Darroch says

    New Zealand could easily have got to 100% renewables. They’ve just had useless governments for the last 18 years. They have amazing wind resources that they could couple with their vast hydro resource (one fifth of which goes into a 5c/kWh contract with an aluminium producer).

    • RobertO says

      Hi George Darroch, Manapouri Power is only for the aluminium at Bluff and it is only 670 MW (630 to 700 depending on lake levels) . A much bigger issue is the transmission pathways in the North Island to allow more Hydro in both (mostly in South) Islands to run more RE grid in the North Island. The South Island has about 70 MW wind and the North Island has about 550 MW wind. Cook Strate has 4 cables HVDC but 1 is spare two are power and one return with earth return also, New wind in the South Island would allow more H2O to be stored but from Wellington northwards there is limited pathways to get to Auckland, and not much power gererated north of Auckland. Yes the governments have been useless but so have the transmission companies. They even stopped maintaining parts of the network (fix only if it breaks) or doing any upgrades on the grounds that micro grids with batteries were coming and you do not need some parts of the networks for that change.

      This is NZ “AEMO equal”

      • George Darroch says

        Interesting. Is there interest in building new transmission in the North Island? I understand that the thermal plants are centred around Auckland.

        • RobertO says

          Hi George Darroch, yes there is a debate going on about what should be built and how it should be paid for. To get from Wellington to Auckland is about 600 km so they are discussing HVDC and HVAC, do you do 1 main link all the way or do you use the hydro stations (6 or 7 are PHES) and interlink some (Huntly was the main PHES recharger point overnight). I believe they do have some plan to reinforce the network northwards, but I believe that a patch fix (and I am also out of date with my information). Yes most are in that area. Huntly (Meri Meri Coal Power station was closed a few years after the pollies ordered the shut down in 1978(or79), be on standby for 8 hr restart, only to suffer a drought on Lake Taupo and the Waikato River, to save money and one of its main jobs was to recharge the PHES stations so they had power outages for about 6 months and a slow recovery about 12 months for the system to recover. Huntly is now gas. Auckland also had co-generation (gas mainly) and some liquid Diesel generators

      • Andrew Roydhouse says

        Well that was SAD.

        Looked at 5.55pm AEST and price across South Island was just below $1,000 /MW and price across North Island was from $1,600 to $1,900!!

        Like the graphics though.

        • RobertO says

          Hi Andrew Roydhouse And look at the spike at 4 pm AEST. It looks like about $22000 / MW in the nothern section of the North Island (6 pm NZ time), it make the rest of the day look flat (click on the names in the centre of the page at the bottom). Usuall it not that high in the spike.

    • MrMauricio says

      they have had large geothermal as well-since the 1960s.This could also be developed much more

      • RobertO says

        Hi MrMauricio, yes we have geothermal but it was redeveloped. Started in 1958 and new sites added in 1989 – 2014. Geothermal very slowly loses it power as it cools the earth down. I was there as a vistor in 1968 and the tour guide stated they systems had lost about 10% of its power over the 10 years.

        • MrMauricio says

          yeah thats true-saw some of it last week at Taupo,a huge set up.Yes there is an effect on surrounding geothermal areas. A lot of wells(hundreds ) have been drilled in the years to maintain operations since-some 3000m deep.Plenty of potential around Pacific Rim countries.

  3. Joe says

    Typo 4th para…”Schleswig-Hostein”… should read Schleswig-Holstein. It is a State in the north of Germany

  4. Mark Diesendorf says

    Achieving 100% renewable electricity is trivial when the system is dominated by hydro with large dams (e.g. Norway, New Zealand, Tasmania). Nevertheless, the rare long drought can be awkward. It is a little more challenging to achieve 100% net VARIABLE renewable energy (e.g. wind and solar PV) when the region of interest has strong transmission interconnections to its neighbours. This has already been achieved in the two North German states mentioned in the article and will soon be achieved by the A.C.T. using some non-local wind and solar farms

    The really interesting challenge is achieving 100% renewable electricity when most of the renewable electricity contribution is variable and interconnections to neighbouring grids are weak (e.g. South Australia) or non-existent (e.g. the NEM). This has not yet been achieved for large-scale systems, although there are no insuperable barriers. In such cases, the system needs contributions from dispatchable renewables (e.g. concentrated solar thermal with thermal storage, gas turbines using renewable fuels, off-river pumped hydro) and/or batteries and/or contracted demand management. Several simulation studies have shown that such systems (e.g. the NEM; USA) can be designed to be reliable even when the vast majority of electricity generation comes from variable renewables. Furthermore, reliability can be achieved without base-load power stations and with a relatively small quantity of storage in the system.

    • Ian says

      Good comments Mark. Hydro plus variable renewables is easy peasy. South Australia and other states situation more interesting.

      In a Wind farms predominant grid you’d need interconnectors over wide areas to smooth out the vagaries of wind. In a solar dominant grid you need installations in dry areas and a combination of storage and demand management to cover the night.

      Pumped hydro is great but it adds to the cost of grid electricity, would this be competitive with behind the meter electricity in the long term? Once through hydro is the ideal because, usually , generation can be throttled back to dispatch for the generation/load mismatches. Smaller semi-grids can shunt excess power to their neighbours or buy power in like a virtual hydro plant. This is where most of the examples in the article are able to achieve such good renewables percentages.

      We should not all wilt and pack our bags when the limits of known renewables percentage is reached, that’s where the challenge and fun begins.

      • RobertO says

        Hi Mark, If PHES is planned (designed correctly) it a no brainer. Waikato River in NZ was built (6 or 7 power stations are PHES) in the 1950 to 1971, it’s 8 dams with 9 power stations and most are 14 MW Francis turbines (combine 4 or more at each dam) that pump up at night time. Often the North Island will feed power southward late night (11 PM ) to early morning (5AM) but small amounts (under about 100 MW) but the South Island will feed northwards usually much larger amounts (700 to 1100 MW) for most of the day.

      • Glynn Palmer says

        Blakers, Lu and Stocks estimated 2016 prices for LCOB at $28-$36; LCOG at $65 = LCOE $93- $101. Future estimates are LCOB $24 – $32; LCOG $50 = LCOE $74 – $82.

        LCOB comprises the capital and operations costs of PHES and HVDC/HVAC, round trip energy losses in PHES systems, resistive losses in HVDC/HVAC systems, and spillage of excess PV and wind energy during sunny and windy periods when storages are full (i.e. the cost of building excess wind and PV). For small penetrations of PV and wind LCOB is approximately zero and LCOE and LCOG are approximately equal. For large penetrations LCOB becomes significant to cover the cost of coping with the variability of PV and wind.

        LCOG is the weighted average cost of generation from each PV farm, windfarm, existing river-based hydro and existing bio power station as measured at its nearest high voltage transmission node (assuming no spillage).

        LCOE is the sum of LCOG and LCOB.

        • TheTransition says

          So the cost of interconnects and storage adds $74-$82 per MWHr to the cost of Wind and PV systems to build a 100 % renewable system? At current prices that’s $120-$140 per MWHr for 100% renewable. That “feels” about right to me.

          • Glynn Palmer says

            The LCOB which is the costs of transmissions and storage is $28 – $36 /MWh. Add generation cost LGOC of $65 you get the LCOE which the generation, storage and transmission cost to get it into the grid. That was based on early 2016 prices.

            The future estimated costs bring the LCOE down to $74 – $82 /MWh.

        • Alastair Leith says

          For those yet to click on the link:
          LOCB: Levelised Cost of Balancing
          LOCG Levelised Cost of annual Generation

    • solarguy says

      100% agree and those renewable fuelled gas turbines should use biogas from sewage. Killing two birds with one stone. Beautiful elegant solution!

      • Mark Diesendorf says

        Biogas at a sewerage farm can be used best to power the sewage farm.

        • solarguy says

          Human waste alone can’t produce enough biogas as our digestive systems are very efficient. However animal waste and green waste added to an efficient digester will give a far bigger yield and there is shit loads of that feedstock as well (pun intended) which can produce high quantities of gas, up to 800m3/per tonne/day. 1m3 of gas= 2kwh of electricity when burnt.

          My idea is to store this gas for reserve generation in regions that are suffering rain depressions when PV and wind generation is low and other forms of storage are low. There could be enough power for several days if designed for that scenario.

          CSIRO has done excellent work in adding 25% more calorific value to gas by reacting it with H2O @ high temps by Solar thermal means.

          Cogeneration from PV and or CST can be used to run the plants.

          • geraldf says

            when I worked with renerwables in spain, the biomass plant in Navarre used the post cooling warm water to also grow additional biomass. unfort they used a thai lillee which is classified as a pest in australia. however that 2mw plant was using feedstock from farmers within a 50km radius, so it was seen as a huge benefit to the community due to farmer contracts. there’s still some hurdles to cross with integrating waste management (sewerage) as a vertical integrated solution

  5. A2er says

    Sadly in Costa Rica a lot of their ‘renewables’ are hydro. They dammed up, and destroyed, a lot of beautiful, natural rivers. Yet, astonishingly, there’s little solar there.
    Every time I got there I hope I’ll be surprised by an upsurge in solar and am disappointed again and again.

  6. Peter F says

    All of those countries are outliers in different ways so they don’t actually help the case much. Germany currently running at 42% YTD is a much more realistic example. Even China will probably make 28% this year.
    An interesting question is how much pumped hydro will be required. SA is probably tracking toward 2.5 GW summer peak in 3-5 years time. With 2 GW of tracking solar, 300 MW of solar thermal solar thermal and another 1 GW of wind sited for afternoon and evening sea breezes SA can probably meet 2.5 GW system peak with only 1,000 MW of alternatives/storage. If the various battery/VPP plants go ahead that will be about 600 MW and then the balance might all come from imports.
    Total renewable generation in SA then would be about 12 TWh which would be net zero. There will be generation peaks and lulls which will need more support but increasing annual generation by a further one GWh with biomass, hydrogen or even more wind and solar would mean that SA was a net exporter with probably less than 5% of annual generation from fossil fuels and possibly no need to invest in large bulk storage facilities

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