Comparing Like for Like

Since you’re reading this blog, you’ve almost certainly encountered this claim:

We don’t need nuclear because we can use renewables.

For renewable sources like geothermal and hydroelectric this may apply, since they can provide guaranteed generation around the clock. But the former has been abandoned in Australia and both can meet only a small portion of our future requirement for climate-friendly electricity.

But in truth the claim invariably refers to solar and wind, not all renewables. For a scalable technology like solar power to hypothetically meet such a demand profile, storage is implicitly included, or at least invoked upon inquiry. David Green of Lyon Solar described it well:

If we really want to address the penetration of large-scale renewables – and not just be able to satisfy the market you can connect large-scale batteries onto the grid – you need to be able to demonstrate that power generated from renewables can be dispatched with power from the batteries like base-load power, so it’s not creating problems.

However, the size of Lyon’s projects instead indicate a peak demand role in the power market. The megawatt hour (MWh) capacity of their batteries are too limited to supply constant overnight power (not to mention the unlikely economics of supplying at low overnight prices). So the question still remains, what would that look like, and how would it compare to the modern nuclear energy technology some believe it supercedes?

Simplified capital costs over time

In this thought experiment, we’ll use

By multiplying the number of 50 MW class solar plants to ensure that excess generation above this number equals overnight requirements, an idealised “solar+storage plant” can be modelled. Slightly more than 3 Broken Hill-sized plants would be needed but we’ll assume three for simplicity. Similarly, operational costs are excluded for both technologies.

Thus, we can compare assumed overnight capital costs for a NuScale plant, 60 year design life, and twelve solar+storage plants which would hypothetically match its nameplate capacity. As mentioned in the Finkel Review, the lifespan of lithium ion technology is 10 years so the cost of regular replacement has been factored in, in addition to renewal of the solar panels after 30 years (assumed to be half today’s cost).

When the capabilities of the two technologies are hypothetically levelised in this simplified way, it appears that the specific argument on cost is reversed.

Estimated required land area

The area of Broken Hill solar plant is 140 hectares. Thirty-six such plants will need about 5,000 hectares, only slightly smaller than the area of Sydney Harbour. However they don’t all need to be co-sited.

NuScale’s plant, which is now under formal design and licencing review by the US Nuclear Regulatory Agency, will cover a little over 36 hectares, including its maximum required emergency planning boundary. It can essentially be situated anywhere that would be suitable for an industrial facility, as water is not necessary for operational cooling. Notably, other options may well be available for the 2030 timeframe.

Material requirements levelised by generated energy

The US Department of Energy 2015 Quaternary Technology Review estimated various levelised material requirements for major electricity sources. Additionally, silver and uranium requirements can be authoritatively sourced. Charting these estimates illustrates the difference in amounts of materials needed by solar and nuclear, for the same amount of electricity produced.

This doesn’t include the materials like lithium, graphite and cobalt needed for the batteries, which aren’t a power source. It is assumed that materials needed for iPWR (intergrated pressurised water reactor) type SMRs are sufficiently similar to conventional PWRs.

This thought experiment attempts to match solar energy capability to that of nuclear. It hardly needs to be said that the reverse is a much less valuable exercise. Cyling a collection of SMRs daily between 0% and 100% output (with considerably less in poor weather) makes little sense in many ways, not least of which is the consequence of diminshed emissions abatement in a system still overwhelmingly supplied by coal and gas combustion. The whole benefit of including nuclear energy sources is they represent a drop-in replacement for dispatchable fossil fuel fired generators.

There are also commercial scale examples of battery storage paired with wind farms, such as the facility in Rokkasho, Japan. The particular battery chemistry used – sodium sulphur – was recently evaluated in California with sobering results.

We won’t compare the potential emissions savings since authoritative research puts solar and nuclear both at desirably low factors. However, the extra material intensity of batteries may contribute dramatically to lifecycle emissions, depending largely on their country of manufacture.

Solar plants and battery modules can be installed rapidly. In contrast, a certain first time regulatory cost and lead-time for that nuclear plant is unavoidable. Yet it isn’t necessary to overstate this hurdle. In its submission to the South Autralian Nuclear Fuel Cycle Royal Commission, Engineers Australia observed that ANSTO’s OPAL research reactor is of similar size but greater complexity than an SMR unit, and concluded:

The OPAL development at Lucas Heights provides an excellent management example for an SMR nuclear power station in South Australia. Extensive international guidance is available from the IAEA to assist in establishing a nuclear power program…

Australia already has a competent and very well managed regulatory regime with staff with wide international experience. Many of the ARPANSA staff have extensive experience in operating nuclear power plants both civil and military. There is no fundamental reason why the ARPANS Act 1998 cannot be amended to include the regulation of nuclear power in Australia.

The results illustrated here should not be taken as any reason not to build solar, especially paired with storage so as to shift generation to meet high demand, like Lyon Solar’s projects. The importance of this was underscored in the Finkel Review.

However, excluding nuclear energy, with its specific supply profile that can’t realitically be emulated by a variable source like solar, is probably unjustifiable on grounds of cost, land use, material intensity or regulatory challenges. This isn’t intended to downplay the regulatory and public education headwinds the technology faces, but rather to emphasise how important it is – considering the results here-in – to face them now and seriously begin the process. As the Engineers Australia submission noted:

The utilisation of a mix of all low emissions electricity generation technologies will be essential to achieve long-term greenhouse gas emissions targets.

What can be more serious than achieving targets that are aggressive as possible with everything available?



14 thoughts on “Comparing Like for Like

  1. Batteries are to 2017 what dry rock geothermal was to 2011. In a few years it will be something else. Lyon aren’t giving a levelised cost for their electricity but the Powerwall 2 for home use costs 32c per kwh plus charging. $320 per Mwh could be comparable to future high priced open cycle gas except you can run the latter for a lot longer than 4 hours. What about the fog and frost now over much of eastern Australia?

    The right location for Nuscale is Hazelwood as the barramundi tropical fish must be feeling the cold in the lake by now. Add some more light water SMRs at places like Liddell then bring back the used fuel to SA for reprocessing. That fuel can be burned in a 4th generation or heavy water plant and the leftovers buried up near Woomera.

    • I’ve matched scales with NuScale’s design footprint and GoogleMaps in a handy image here:
      You can take this and paste it on the grounds of nearly any exisiting power station in Australia. The bounday accounts for the required emergency planning zone, discussed here:
      I’m confident that in practice, the power plant poses no more hazard than OPAL at Lucas Heights does.

      • I am not aware of a realistic need for a physical buffer zone around coal fired power stations. My experience is that the power station does not need to be protected from its neighbours, or vice-versa. We called our external lands just that and used them for sundry operational purposes, eg asbestos waste disposal (registered on the title deeds and all above board), pipeline and power routes, ash dams, water storage dams, etc. Any land that was not actively operational tended to be leased for grazing.

        So, the power stations held much more land than was strictly necessary, which was handy when gas turbines, rail sidings, conveyors, new transmission lines, etc, were added over the years. In part, this additional land was left over from earlier ownership of adjacent large tracts of land for coal mining purposes, or simply because they were part of a private property that was purchased before construction of the power station and had no long term purpose relating to power station construction or operations, past or future..

        Take-away message: The actual land holdings may bear only scant resemblance to the strict need.

        Perhaps the same would apply to nuclear power stations, especially since as ANSTO discovered over the decades, those who choose to build on new subdivisions within 1 or 2km of their fence subsequently fought to have the Opal reactor relocated due to their recently-developed concerns.

        Most decisions as to both actual land requirements and any restriction on future development of land beyond the power station fence, it seems to me, will be made by politicians and town planners.

        My preference is for there to be NO buffer zone by that name. There probably should be an “Operational Area” which is sufficient to ensure that exposure to operational risks of those outside it are below agreed specified, measurable guidelines.

  2. This article unpacks a subject that has been glossed over for far too long.

    Thanks for providing us with such a well presented resource.

  3. The capital cost comparison cuts of at 2066. The SMR’s design like extends to 2090. The difference in capital costs is 6 to 7 billion dollars, so the comparison becomes even more stark.

    Offsetting this is the cost of fuel for the SMR’s, via periodic replacement.

    Do you have a handle on what the step height ($$) and frequency (2 years?) for this might be, because they could be substantial. If periodic battery, panel and inverter replacement are included in the PV mix, then so should fuel replacement… but now this is heading toward a full LCOE and the argument about the relevance or otherwise of LCOE to a PV and battery system.

    • Including these costs and others (like inflation, which I neglected to mention I had ignored for simplicity) would be a worthwhile exercise.

      Thank you for the kind words and further discussion.

  4. In addition to capital costs, you might also compare emissions from LCA analyses. One recent study (Majeau-Bettez et al. 2011) found 1.4 kg CO2e per “functional unit” where 1 FU = 50 MJ of charge and discharge. Do the math and it works out to 67.2 T CO2e/GWh. Which means that adding batteries to PV not only triples the cost, it more than triples the CO2 emissions too.

  5. Oscar,

    You have done far more research than me on these comparisons. I have not read the Finkel report thoroughly, However, if, as you say in your blog, that the cost of a NuScale reactor was used as a comparator, then it is another misuse of the numbers. The consultants to the SANFCRC did something similar, except they used the mPower reactor. Both of these reactors are essentially attempts to scale down traditional reactors and they used cost estimates for those that are sky high. mPower has now been abandoned and NuScale has soaked up $400M of the American public’s money on the way to $1bn for no commercialisation – that is, unless POTUS pulls the remaining amount, which is possible.

    I know that it is difficult to make such comparisons when there is little data and precious few assets on the ground in the SMR space.

    My point, however, is that by selecting the most expensive, and in my view, unlikely technology is hardly a way to make a reasonable comparison.

    As did the consultants to the SANFCRC, there has been little attempt to look at the technologies in the SMR space that have been developed and developing – some more advanced chronologically than others. One that has been successfully used is the HTGR which has been known for several decades and which the Chinese (among others) have successfully implemented and are developing larger ones. Others require more development. The HTGR in particular is self limiting and has been demonstrated to be so by the Chinese – so why pursue outdated technology with no guarantee of the inherent self limiting capability of the HTGR?

    Also, with the scarcity of real data, there has no doubt been a tendency to load up the capital of the developing reactors making the basis of the comparison worse.

    Your blog mentions ARPANSA. I have no doubt that there are some well experienced people there and at ANSTO, but it is not only the ARPANS Act that requires to change, the EPBC Act will also need to change. That might be harder with the bunch of Fake Greens (aka Activists) that we have in Australia.

    Bring back Tony Abbott. At least he will push for nuclear subs which maybe will lead to some sense being injected into the power debate with the inclusion of nuclear power into the land based system.

    With all the clever people in ARPANSA and ANSTO I believe that it would still be possible have HTGR SMRs in Australia and nuclear subs by 2025 or soon after. The IAEA INPRO committee and I’m sure the CNSC would love to help. Lets get away from comparisons with US SMRs and the NSC. Both are moribund and unlikely to help much. We might actually find that there are technologies out there that can be deployed more quickly than we think. I know that if I had one to sell you, (actually, give you on a BOO basis), that we could have an HTGR SMR on the ground in about 1 year from your order. Also, It is the Russians in fact who have commissioned a Fast Reactor (in 2016) and as I understand it have “burned” the agreed quantity of nuclear weapon material. The US is still fiddling about trying to work out what to do with theirs (or not).

    Another caveat, however, is that SMRs are more likely to be deployed in remote areas off-grid, such as mine site and remote communities, rather than on the so-called “National” grid, though could be useful on the edge of grid where stability could be a problem.

    One could also look at ANSTO being a competitor, rather than a saviour. They compete in the Grants space for public money with everyone else, so they will depend on their grants being politically acceptable in order to maintain their funding at the level they’ve become accustomed to.

    Thanks for your insightful blogs, keep it up, we need it. There is a mountain of mischievous misinformation out there.

    Irrespective of what the Fake Greens position is, nuclear power is happening around them. China has deployed SMRs and larger systems and I believe we will see SMRs commissioned in Canada in the near term.


    Ross Elliott

    Director Business Development – Australia StarCore Nuclear (Canada)

    M: +61 419 906 861


    • Thanks for your comment, Mr Elliot.

      I acknowledge that a weakness of this article’s analysis centres on the defensibility of the NuScale cost and its actual likelihood of being built and operated by UAMPS in Idaho Falls. A reference plant would be a huge advantage for Australian adoption. But in comparison the hypothetical solar+storage overnight cost numbers are defendable and indeed markedly optimistic, representing bare minimum technical storage capacity for days of ideal weather.

      I’m very keen on high temp gas-cooled designs and I’ve read a bit about yours, including your NFCRC submission. I’d enjoy plugging in the capital costs you forsee for your power plant (and estimates of the first-time cost for Australia to establish its nuclear sector) into my spreadsheet.

  6. I thought Lyon were supposed to build a 4 hour X 100 MW battery charged by PV in the SA Riverland by Xmas. Now we are told the biggest battery will be 129 Mwh adjoining Hornsdale wind farm nearer Pt Augusta.
    Presume that’s 4 hours X 32 MW and the sheep will no longer find grass where the batteries will be located.

    If summer raises SA demand from 1500 to 3100 MW keeping the lights on will cost over $250 per Mwh, be it open cycle gas, diesel or battery.

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