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Can Nuclear Power and Renewable Energy Learn to Get Along?

Jesse Jenkins's picture

Jesse is a researcher, consultant, and writer with ten years of experience in the energy sector and expertise in electric power systems, electricity regulation, energy and climate change policy...

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  • Apr 15, 2014

Full Spectrum: Energy Analysis and Commentary with Jesse Jenkins

Nuclear power and variable renewable energy sources like wind and solar power “don’t play well together.”

That’s a commonly accepted nugget of wisdom these days. I heard the argument most recently during an interesting colloquy on Twitter this week with Fresh Energy CEO Michael Noble, reporter Matthias Krause, and author and editor of Renewables International Craig Morris.

If true, the idea that renewables and nuclear don’t mix has important implications. It would mean that if we want to build an ultra-low carbon electricity system to confront climate change, we may face two mutually exclusive paths: one path dominated by nuclear energy (call it the French paradigm) and the other dominated by variable renewables (call it the German paradigm).

(In fact, supporters of the German Energiewende use this argument that large penetrations of renewables are incompatible with nuclear as one of the justifications for the nuclear phase-out underway there now).

The more I think about this, however, the more I’m convinced that the accepted wisdom that renewables and nuclear mix like oil and water is true only up to a point.

In fact, if we want to build an ultra-low carbon system powered by variable renewables, we’re going to have to solve precisely the same technical challenges that will make a hybrid renewables and nuclear power system possible as well.

My thinking is as follows, and I present this as a hypothesis for discussion and with plans to analyze this in more detail in the future (i.e. using power systems modeling)…

I begin with this basic point: In rough terms, once a variable source of renewable energy, such as wind or solar power, reaches an energy penetration level (measured as the share of total energy supply) equal to that source’s average capacity factor, aggregate output from that variable renewable energy source will routinely fluctuate between 0 and 100 percent of total electricity demand.

For example, if the average capacity factor of solar photovoltaics is 10 percent (about what it is in Germany), once solar PV reaches about 10 percent of the system-wide energy mix, solar output will vary from 100 percent of demand when producing at full capacity on a bright mid-summers day and 0 percent when night falls. Wind turbines in the breezy American Midwest have a capacity factor closer to 35-45 percent, so wind would reach a ceiling at about 40 percent of energy share in that region. 

There are two important implications of reaching this point where a renewable energy source’s share equals its capacity factor.

First, without energy storage, high penetrations of renewables don’t leave much room in the power system for nuclear power plants (or any other “baseload” power plant).

While nuclear reactors can technically “ramp” or vary output up and down to follow loads (albeit less flexibly than gas turbines), “cycling” or shutting down entirely and start up again later is too challenging for a nuclear plant to do routinely. Yet at high penetrations of variable renewables, every other plant on the system would have to be capable of routinely cycling on and off.

  • Summary: it’s true then that absent energy storage and flexibility, high penetrations of variable renewable energy sources doesn’t play well with nuclear.

Second, increasing the penetration of renewables beyond the point where energy share equals capacity factor would mean the renewable source would begin to regularly produce more electricity than demanded. Without storage or energy sinks willing to buy up excess power, renewable generators would then have to curtail a growing share of their output and waste any associated revenues.

In practice, this ceiling could actually be reached before renewable energy penetration equals capacity factor, as production would begin to regularly exceed demand on high output/low demand days long before this point.

In addition, if renewables are exposed to wholesale prices (and not subsidized outside the wholesale market, i.e. with feed-in tariffs), the market prices earned by renewables would be negatively correlated with their output. Wholesale prices are lowest precisely when renewable generators are all cranking out power (again, this assumes no energy storage/sinks.) At some point, adding more renewables just wouldn’t be profitable any more. If renewables have to pay for the system balancing services and flexibility needs they contribute to, this economic limit is reached even earlier.

This point where energy share = capacity factor is probably a generous ceiling for renewable energy penetration absent storage then.

If solar capacity factors typically range from 10-20 percent and wind from 25-45 percent, that makes it awfully hard to reach an ultra low carbon energy system powered principally by renewables. Once these sources reach a combined share of maybe 30-40 percent of the energy mix, technical and economic constraints will make it very hard to increase their share further.

  • Summary: absent energy storage and sinks that can make profitable use of excess energy and massive system flexibility to handle variations in renewable output from 0 to 100 percent of load, penetration of variable renewables is effectively constrained below the point where their energy share equals their capacity factor.

If we want to increase renewable penetration beyond these levels and drive truly deep decarbonization of the power system, we therefore need massive amounts of new system flexibility to match demand with varying renewable energy output.

We’d need electric batteries and thermal energy storage to shift output to when its needed, dynamic load shifting and demand response to align demand with output, and ‘energy sinks’ to make productive use of excess output.

But here’s the kicker: if we have the massive amounts of storage and flexibility needed to achieve an ultra-low carbon electricity system dominated by variable renewables, we also have the storage and flexibility needed to make a hybrid nuclear-renewable power system feasible as well.

With that kind of system flexibility, we could store energy and shift loads to avoid having to cycle off and on nuclear plants and limit their ramping only to when it’s the most economical way to provide system flexibility.

  • Here’s my contention then: If you want an ultra-low carbon renewable energy system, you need storage and flexibility. And if you have storage and flexibility, then renewables play just fine with nuclear.

Maybe renewables and nuclear can learn to get along after all. Maybe they won’t offer competing visions for a low-carbon power system in the end.

Let’s discuss…

(A note for comments thread: this post isn’t asking whether you want a nuclear-renewable hybrid power system. It’s asking whether a renewable-hybrid system is technically and economically feasible if we did want one. This is a post about what options we have, not which ones we want to chose. So let’s save those discussions on which you’d choose for another day. Thanks! -Jesse)

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Nathan Wilson's picture
Nathan Wilson on Apr 17, 2014

“… if you have storage and flexibility, then renewables play just fine with nuclear. “

Yes, if we had a hypothetical 100% renewable grid (primarily solar and wind), with LCOE costs matching the current average for US wind power (about 25% less than nuclear according to the EIA, as it is weighted toward the central plains), and assuming use of battery storage which cost about one third of today’s costs (so that it reached about $0.10/kWh), then it is likely that overall costs would be reduced by replacing a big chunk of the renewables with nuclear (especially in areas with poor solar & wnd resources), since storage and curtailment would also be reduced, and less transmission would likely be needed.  

Likewise, for a 100% nuclear grid, it is likely that overall costs would come down if some of the nuclear in the south was replaced with solar (to boost summertime output), and possibly some wind in the north (to boost wintertime output, but this would entail large springtime curtailment).

But to get there from here is a problem that the renewable lobby does not like to discuss.  They admit that a renewable-friendly grid must have flexibility, but flexibility in general is expensive.  Flexibility comes for free with big hydro, but the only other energy source which can truly say this are those with high fuel costs (e.g. Hawaii’s oil-fired grid).  Even natural gas and biomass produce cheaper power in baseload mode than when load-following.  Of course the demand variation will require some flexibility anyway.  But substitute storage for the fossil fuel, and all of a sudden the cost of the extra flexibility needed by supply variation will become very apparent.

This cost of flexibility also applies on the demand side and shows up in the net-metering debate.  Electricity users buy energy and flexibility.  Home solar system owners who use the grid for backup or time-shifting need just as much flexibility as other users, but buy less energy.  An electric car that is charged during the evening peak requires more flexibility from the grid, but one charged at night needs no added flexibility.  So a billing system that gives away the flexibility for free to anyone regardless of how much electricity they buy will strike many as unfair.

With low penetration wind and solar, the external cost of flexibility caused by use of wind and solar is mostly born by fossil fuel fired merchant power producers, who receive no sympathy from the public.  When public utilities complain of the added cost, they are accused of greedily clinging to an obsolete business model (generally by those who demand flexibility for free).

The result is that no large-scale energy storage solution or dispatchable load solution (thus no 100% renewable or renewable+nuclear grids) can be implemented unless and until the cost of the missing flexibility is internalized into the cost of variable renewables.

Great topic/kick-off Jesse.

Nathan Wilson's picture
Nathan Wilson on Apr 16, 2014

Yes, fuel synthesis is a great way to utilize otherwise-curtailed sustainable energy.  But instead of making methane or other hydrocarbons we should make carbon-free ammonia (NH3), to get several benefits:

  • Capturing the needed nitrogen (which is 80% of air) is much cheaper than trying to capture CO2 from the air, sea, or biomass.
  • Like diesel fuel, ammonia can be burned in high compression internal combustion engines (ICEs), which deliver higher energy efficiency than is possible with gasoline engines; ammonia burns cleaner than diesel, with zero-particulate emissions guaranteed.
  • When leaked, ammonia is not a green-house gas (unlike methane), but it is a buoyant gas (unlike methanol and MTBE which can find their way into waterways).
  • Ammonia use would not create another dependence on continued fossil fuel use to assure CO2 availability.
  • Unlike hydrocarbons, ammonia does not release CO2 when burned, so ammonia (which is made today from fossil fuels for a price competitive with gasoline) can be used to allow fossil fuel with CC&S to join sustainable energy in providing non-CO2-emitting energy for transportation, construction, combined heat & power, or electrical peaking applications (so even countries and regions with deeply entrenched fossil fuel industries can achieve deep reductions in CO2 emissions).
  • Ammonia can be economically stored in large above ground (refrigerated) tanks for seasonal energy storage (applicable to all locations, unlike underground methane storage which requires special geology). 


see also:   

Robert Bernal's picture
Robert Bernal on Apr 16, 2014

The remainder of the demand can not be supplied by fossil fuels… in the end.

Schalk Cloete's picture
Schalk Cloete on Apr 16, 2014

Just a note, Jesse. I suspect that, like so many other things, decarbonization would also follow the famous Pareto principle, i.e. 20% of the effort will give about 80% of the result. In other words, getting a low-carbon electricity system (~100 gCO2/kWh) will be a lot easier (and faster) than getting an “ultra low” carbon electricity system (~10 gCO2/kWh). Thus, low carbon solutions that still utilize natural gas turbines like Michael suggested will be able to achieve much faster decarbonization than ultra-low carbon solutions that demand a wide range of technological breakthroughs and an entire revamp of the power sector (and, ultimately, several other sectors).

And this is exactly where the incompatibility of nuclear and wind/solar comes in. I’m sure that you can model some very attractive-sounding numbers for a steady-state nuclear-varRE system if you simply assume the cost of flexibility (storage, transmission, demand response) to be low enough. However, I don’t think this exercise will be of much practical use at present. What we need is a strategy for getting from here to there which accounts for sunk investments and the contingency that non-fossil flexibility remains prohibitively expensive/impractical for decades to come.

It is well established that (in the current absence of super-cheap storage) nuclear makes the integration of moderate amounts of wind/solar significantly more expensive because of its capital intensive nature. This is part of the reason why RE-based decarbonization pathways don’t include nuclear – the gradual integration of increasing amounts of politically popular wind/solar requires the flexibility of a nuclear-free grid. 

In summary, yes, of course a nuclear-varRE grid can be feasible in the distant future under the assumption of super-cheap storage/flexibility. However, building towards such a system now (i.e. aggressively building out both wind/solar and nuclear in the same system or building out wind/solar in a nuclear-heavy capacity mix) will soon become prohibitively expensive because intermittency costs of solar/wind will rise much faster, thereby only further delaying decarbonization efforts. 

Nathan Wilson's picture
Nathan Wilson on Apr 16, 2014

“…nuclear makes the integration of moderate amounts of wind/solar significantly more expensive because of its capital intensive nature. …  thereby only further delaying decarbonization efforts

The first part is true, but the second part is not:  the variability and low capacity factor of wind and solar make their cost rise above around 30-40% penetration.  The inflexibility of nuclear makes its cost rise above 50-70% penetration.  Any linear combination of these two penetrations are also viable.

This means that for a given price-point (above around 10% renewable penetration – where only the very best renewable resources are used), the nuclear-rich grid will have lower carbon emissions than the renewable-rich grid.  This is clear from theory, and France and Germany are proving it in the real world.  The long-life of nuclear plants means that 30-40 years into the transition, the costs will favor nuclear even more, as the cost of re-powering old wind farms will play a growing role.

But as you said, these penetration limits assume that we don’t have a breakthrough in low cost energy storage, and also that we don’t embrace sustainble syn-fuel.  Note that syn-fuel benefits national trade balances and boost energy security (and H2 and ammonia fuel reduce particulate emissions), so it has large benefits beyond the $/gallon and $/ton_avoided_CO2 metrics.

Nathan Wilson's picture
Nathan Wilson on Apr 16, 2014

Solar thermal heating has for years been the most economical form of solar energy, and solar swimming pool heaters have been popular in some locations.  However, sunlight is weakest in winter when heat is needed most.

The district heating concept can be applied to nuclear power as well when the reactors are small and safe enough to be located near energy users, so new SMRs could be enablers of this application.

Conventional (LWR) nuclear plants can produce heat for about one third of the per kWh cost of electricity, and high temperature plants can deliver usable waste-heat while making almost their full electrical output.  This means the nuclear solution for combined heating & power for district heating can displace more fossil fuel when substituted in a solar-dominated system than solar alone.

Schalk Cloete's picture
Schalk Cloete on Apr 16, 2014

Agreed. From a practical decarbonization point of view, it would be much better to have a nuclear-led buildout. You can achieve faster and deeper decarbonization with very little impact on the rest of the power system. This comes out clearly in the work of Lion Hirth we discussed earlier where the optimal share of varRE keeps on decreasing with an increase in CO2 price beyond €30/ton (i.e. as decarbonization is increasingly prioritized, nuclear is increasingly favoured over solar/wind).

But from a political point of view (the one that matters at the moment), it is much better to have a renewables-led buildout. At least something is happening along this decarbonization pathway and nuclear on the grid will stifle this enthusiasm sooner. Yes, renewables lock in fossil-fuel infrastructure, but this could potentially be retroactively addressed through CCS when a high CO2 price is finally impemented a decade or so from now. 

A simultaneous nuclear-varRE buildout is therefore unnecessarily cumbersome from a practical viewpoint and unnecessarily challenging from a political viewpoint. When considering transient decarbonization pathways, nuclear and wind/solar can both play well with fossil/hydro systems but will only impede each other. 

B W's picture
B W on Apr 16, 2014

the trough created by the duck curve could best be solved by an energy sink rather than storage because an energy sink would have greater efficiency. If we can sink the nuclear output in industrial heat applications, desalination, fuel synthesis, or possibly even CO2 sequestration from the open air (as Berkeley research suggests we may be able to) we could maintain a healthy utilization of our nuclear plants in combination with larger capacities of solar. 

The question then becomes: would the variable use as nuclear capacity for energy sink purposes be economically viable (the nuclear plant output would go to the sink according to the PV output, and therefore become variable). I am not sure of the answer to this question, most industrial processes run according to tight schedules and thermal capacities are sizes specifically according to need. Inputting a variable contributor to the energy sink may undermine the economics, but perhaps in cases of desalination such variability wouldn’t be such an issue. 

I think the best solution would be to construct large elevated reservoirs that would double as energy sinks for desalinated water and act at the same time as a form of stored hydro energy capacity.

i have little doubt that principally nuclear and solar can approach the cost of fossil fuels, if we can overcome the fossil lobbyists and excessive litigation.

B W's picture
B W on Apr 16, 2014

thanks for the response Jim, and I think you did great work on the ‘prejudice against nuclear’ articles. 

i agree with your points, although I still see wind and solar serving the needs of conservatives more now because a home owner can earn a healthy return on a subsidized PV system while his poorer neighbors energy bills eventually go up…. a nuclear plant such as vogtle incurs some small immediate increase in the cost of electricity (~6%) but provides a long term benefit to all rate payers regardless of their wealth – that is how I distinguish between socialized/privatized benefits. Leasing land for wind projects is the same ideal, the rich can make money off of RE, they can’t reap any short term returns on nuclear that are comparable. Of course this is a pretty crooked line of logic for supporting RE, but I think it’s the one that many Californians are following whether they realize it or not. 

Anyhow I we’ll know nuclear is the right solution to the problem right now…. But how do we get the other half of the country to realize it. I think we have to concede some space to the solar people, to include them in the solution rather than rebuffing them with negativity. If 5% or more of the electricity in this country is eventually produced by PV it’s not necessarily a bad thing. Let them have it, let them be excited about it, and remain inclusive and diplomatic about discussing the objective realities of keeping the lights on in an industrialized nation.

we have to remain honest but I think friendliness and inclusiveness with the RE crowd could get us much farther than returning the favor in regards to prejudice. Nuclear is in a class of its own, a lot of rich and very powerful entities are fully aware of that, it’s only a matter of time until we turn the corner, but the current LWR designs are probably not the flagship to do it in the US, though there’s no reason they shouldn’t be.

B W's picture
B W on Apr 16, 2014

That’s a very relevant point which I’ve been trying to make as well. The common thought among the masses is that RE and storage go hand in hand, but analytic contrarily indicate that storage makes more economic sense with controllable generation sources, especially nuclear due to its high reliability to operate near full capacity as required.

same principle applies to utilizing transmission networks or Accomodating shifted load.

B W's picture
B W on Apr 16, 2014

How do we avoid throwing large amounts of energy away in a scenario of 60-80% renewables and the rest NG (assuming a large share of these renewables are wind and solar since hydro and geothermal are geographically constrained)?

i don’t think wasting energy can be avoided in such a scenario without energy sinks or storage, and thus such a scenario would be uneconomic compared to alternatives that avoid throwing energy away. 

Bob Meinetz's picture
Bob Meinetz on Apr 16, 2014

Engineeer- Poet, your analysis appears to be sound, but I doubt that grid-scale storage will be economical before the engineering and materials aspects of durable, quick-ramping nuclear are worked out.

Even if storage is comparably-priced, it’s another system and another level of complexity which is best avoided.

Jason Burwen's picture
Jason Burwen on Apr 16, 2014

Interesting BOTE. Although in a world where you’re reliably pairing storage with generation, you’re probably going to see a convergence between peak and off-peak wholesale price signals. So you may not get the amortization you’re expecting.

Joe Schiewe's picture
Joe Schiewe on Apr 16, 2014

If I understand correctly – the key to resolving the problematic fossil fuel waste issues (gases, particulates, solid) is for some kind of non-carbon source to become less expensive and less obtrusive than them so that nations (especially poorer high growth nations: China, India, Malasia, parts of Africa, etc.) would prefer them.  The renewable and nuclear power proponents seem to claim that their preferred future generators will deliver power to the customer profitably in the future at a low cost, be more distributed therefore grid friendly, improved safety & reliability and be even less environmentally intrusive than current designs. If either or both proponents are correct – would this not allow for various needed energy sink profitable enterprises (carbon neutral/non-carbon fuels, desalinazation, industrial process heat, trash materials recycling, all season hydroponic agriculture, etc.) to be viable and thus eliminate the need to curtail either source?  Let’s get behind the R&D efforts to lower power costs, lower grid distribution costs and make power generation less intrusive.  I don’t see power storage becoming efficient or flexible enough any time soon to lower renewable or nuclear energy costs below non-taxed fossil fuels power generation costs.   It is my understanding that the United States and other wealthy countries have reduced energy R&D investments and have instead invested in generation subsidies that has increased our overall costs.  I would prefer my tax dollars going toward renewalble & nuclear (50/50) R&D that provides the opportunity for low power costs, low distribution costs, improved safety and reliability, and less intrusive power sources instead of the current subsidizing the current high cost power that won’t translate into benefiting the high growth poorer countries. 

James Hopf's picture
James Hopf on Apr 16, 2014

B W,

Sorry for my somewhat negative tone, which was in reaction to what I perceived to be the old “nuclear is socialist” argument often used by opponents.

I agree that many renewables subsidies, particularly the residential PV subsidy, primarily benefits rich homeowners while being paid for, in part, by taxes on much lower income people.  I’m not sure however that its a significant reason conservatives support RE subsidies.  I certainly hope not.  Again, you would think that such (heavy) subsidies, for “green energy” no less, would go against conservatives’ principles.

I’ve got no problems with people installing PV on their roofs, or allowing wind farms on their property in order to collect royalties.  If anything, that should be encouraged.  I’m not even necessarily opposed to RE subsidies, although the appropriate level of subsidy is obviously arguable.

I do have a real problem with outright mandates for renewables use (not to mention outright bans on nuclear plant construction).  And I would think that all true conservatives would find such policies objectionale as well.  How is that in any way in line with free market principles, or the principle of less govt. interference?  Talk about govt. picking winners, and intervening (excessivly) in the market!  Those policies literally remove all market competition as a basis for selection.

You would really think that conservatives would embrace cap-and-trade or CO2 tax policies long before they would accept large renewables subsidies or (worse yet) renewables mandates (i.e., portfolio standards).  After all, those are the market-based approaches to the GW problem, which conservatives should undertand means the program that will achieve maximum CO2 reductions at minimum cost. 

Unless, of course, their real agenda to keep us using fossil fuels, and they’re deliberately only supporting the least effective approach (and the approach that is most expensive, which will lead to its political rejection).  How does one explain the fact that the only approach that is going forward (renewables subsidies/mandates) is the most expensive, least effective approach?

B W's picture
B W on Apr 16, 2014

Your last point nails it on the head- why is nuclear seeing such obvious opposition from global banks to governments despite tge fact that it clearly creates long term equity and is the only real scalable solution to the climate problem? Because fossil interests are far more powerful than anything else at this point in time, and the effort is to thwart competitors. 

Nuclear is a direct competitor for fossils, wind and solar are a tool for them to appease the masses while still dominating market share.

i believe this situation to be only temporary, the climate issue will overcome the power of fossil lobbyists.

Bill Hannahan's picture
Bill Hannahan on Apr 16, 2014

It makes no sense to spend 5 to 20 cents for an un reliable un dispatchable kwh in order to save 1/2 cent worth of uranium.

The simplest non breeder MSR can reduce uranium consumption per kwh by a factor of 5 due to improved neutron economics and higher thermodynamic efficiency at high temperature. Extracting uranium from seawater is estimated to cost about three times that of land based mines.

Factory mass production of simple non breeding land and floating MSR’s can get the capitol cost down such that the plants could be profitable even at fairly low capacity factors without land based uranium mining.

Joris van Dorp's picture
Joris van Dorp on Apr 16, 2014

Mr. Nogee, with all due respect, to call for more R&D on nuclear, like you are doing, as opposed to calling for more nuclear deployment or at least RD&D, is a fairly well worn tactic of the crypto-antinukes. It’s a delaying tactic. I understand why Mr. Wilson is doubting your agenda.

Seriously, there is no credible scenario where 60% RE can plausibly compete with 60% fossils or 60% nuclear, let alone 80%. Conversely, France proves today that 80% nuclear *already* competes.

Are you denying this?

Or perhaps do you believe that the French achievement is impossible to repeat for some reason?

Sorry for my distrust, but in the past, people who have expressed serious doubt about the economics of nuclear power have in my experience always turned out to be hard-core antinukes. Can you do more to convince you are not an anti-nuke?


Jesse Jenkins's picture
Jesse Jenkins on Apr 16, 2014

Hey gang: let’s try not to question anyone’s motives here and give people a respectful benefit of the doubt unless given reason otherwise. Joris, this was a pretty respectful comment, and I appreciate that, but I just wanted to caution on this going forward. Thanks,


B W's picture
B W on Apr 17, 2014

Engineer poet, that’s an interesting point because we forget to acknowledge that the storage capacities are also competing in the market….. in a fair market at least

Joe Schiewe's picture
Joe Schiewe on Apr 17, 2014

Am I missing something here?   It seems to me that no amount of being rationale and playing nice between current nuclear and wind/solar with or without storage will solve the problem of “Climate change is a pressing global imperative” unless we can get their high upfront capital costs/kwh and environmental intrusion down substantially.  I just don’t see the poorer high growth nations making the necessary upfront investment sacrifices if they can get the heat for their homes & meals, fuel for their transportation and electricity from fossil fuels, wood and dung for less cost.  If they don’t come along – we are sunk on this global imperative.  At the risk of being considered an anti-nuke (not the case at all) – again I recommend that we get fully behind the R&D for future nuclear & wind/solar low energy cost innovations that can allow these key nations to come along.  I recommend that we get behind this even if we don’t feel that climate change is an issue but just to help these 1 billion impoverished people out.  

Robert Bernal's picture
Robert Bernal on Apr 17, 2014

The best energy source needs to become politically acceptable because it is highly unlikely that any 30% renewables is ever going to be politically acceptable, pricewise. And that doesn’t do good concerning the excess CO2 problem. We need to sequester like “all” the CO2. Is that possible? Wouldn’t it be easier to talk “everybody” into the best high temp nuclear coupled with the same gas turbines that burn NG, but with a max rating of about twice that of the nuclear. For variability, simply add NG for efficient (already hot) “instant” ramping. This should allow for renewables and their massive variability. Perhaps the CO2 from the NG can even be sequestered? Perhaps, synfuel from coal (powered by nuclear) can be applied in the same manner?

Nuclear is intrinsically the safest, most powerful and most abundant source. There is no reason to “let” politics get in the way and cause what may become “energy rationing”.

Nathan Wilson's picture
Nathan Wilson on Apr 17, 2014

“….much better to have a renewables-led buildout.  At least something is happening …”

Hmm, I suppose there might be countries (e.g. in Europe) where this is true.  But Europe is not simply not relevant to future global CO2 emissions.  The thought that countries like the US, China, and India will build an entire grid which is capable of producing electricity for  2¢/kWh (using coal), and then over-lay half of it with a second grid which makes renewable power for 10¢/kWh, then update the first grid to add CC&S for another 2¢/kWh strikes me as unlikely.  I really see the Europeans leading a path that the majority will not follow. (the Europeans themselves may not follow this plan, as it would benefit their fossil fuel companies more to build only enough renewables to replace their nuclear).

I understand that picking a common enemy to blame for the ills of the world is an effective way to unit people.  Unfortunately, the benefits of growing renewables likely won’t offset the harm caused by stifling nuclear.


Engineer- Poet's picture
Engineer- Poet on Apr 17, 2014

Intuition says that you’d have 3 basic price tiers:

  1. Low-demand, when storage is purchasing power from the grid.  Base-load generators would bid their marginal cost.
  2. Mid-demand, when storage is being drained.  Sellers from storage would bid their net cost per kWh (including losses and amortization) more or less, and base-load generators would receive a premium.
  3. High-load, when fuel-burning peaking generators have to be brought on-line.  They’ll bid enough to pay for fuel and amortization on machines that hardly ever get used.

Convergence of prices is likely.  If batteries become cheap, it makes sense for users to buy their own batteries when the day/night differential exceeds their cost.  When night-time rates start to go up, it’s time to build more generation.

Engineer- Poet's picture
Engineer- Poet on Apr 17, 2014

If we do get that quick-ramping nuclear, it will still mean that a lot of excess generating capacity will exist in the off-peak hours.  Its marginal cost will be close to zero, just like wind and PV.  The big deal will be amortizing the extra capital cost.

Excess generating capacity with low marginal cost suggests a big market in interruptible demand.  If that market develops, the demand curve will be levelled again and the nuclear would simply run flat-out.  I’d be in favor of skipping the intermediate stage if we can manage it.

Engineer- Poet's picture
Engineer- Poet on Apr 17, 2014

For some time, “Greens” have been saying that renewables require that nuclear and base-load coal must go away:

Of course, they don’t say why the easily-throttled RE shouldn’t just take a back seat to the carbon-free nuclear power.  For the benefit of the environment, of course.

I wish I had the skills to produce a rebuttal video to that.  The idealized steady wind curve is just begging to be refuted by real data, like the BPA’s two-week hiatus from last January.  That would put the lie to all the pretty claims.

Engineer- Poet's picture
Engineer- Poet on Apr 17, 2014

Of course some people will point to Denmark and say that they are showing you how it can be done without storage, but Denmark is a unique case.

Denmark also has ~3x the per-kWh emissions of France, and around 10x the emissions of Sweden.  Denmark is not clean enough to be our role model; EVs charged by the Danish grid would emit some tens of grams of CO2 per km, while EVs on the French grid would emit around 12 gCO2/km and just 3.5 in Sweden.

(Consarn it, where did my input format options go?)

Jesse Jenkins's picture
Jesse Jenkins on Apr 17, 2014

Thanks for the comment Charles. I’ll add that paper to the resources link above and take a look myself as soon as I get a chance. Cheers,


Jesse Jenkins's picture
Jesse Jenkins on Apr 17, 2014

You’re preaching to the choir with me Joe! 

martin burkle's picture
martin burkle on Apr 17, 2014

Two thoughts:

1. A really good cheap energy storage system works better for a nuclear system than wind/solar because less storage is needed for the nuclear only system. So, if nuclear and storage are available, why have wind and solar at all?

2. Let’s assume a molten salt reactor is developed. What does the reactor do when there is less demand than production? “Produce less heat” is one answer but that is a waste of capital. “Make liquid fuel” is another answer. But a billion dollar MSR might need a billion dollar liquid fuel generator. Eithor the electric generator is under used or the liquid fuel generator is under used. “Store heat for later use” is the most likely economic answer using a secondary molten salt repository.

I vote with the guy that says, “Right now we need more R&D”.


Marcus Pun's picture
Marcus Pun on Apr 17, 2014

I have never thought that it was an either or for nuclear and renewables.  A solid base load is critical to maintaining economical electric power.  

Ultimately this all comes down to storage.  In other posts I have brought up the rather clever use of 3MWH of storage over at Gil Onions in Southern California – storing 5-7 cent/kwh power at night and using it to replace power from the grid that costs up to 30 cents/kwh. Flow battery technology storage is practical, ready to go, but the infrastructure for marketing, production, installation is not there.  That means the prices are high per installation.  Solar had this problem until a  few years ago but anyone who has driven by a Solar City yard or that of any other installer undoubtably has noticed that they are now rather crowded with vehicles at the end of the day where a few were parked only a few years ago.  Perhaps the next government sponsored push should be for local storage in areas where the power, due to storms and other natural disasters, is less than reliable, and to also build out in areas where there is a lot of wind power.


Jesse Jenkins's picture
Jesse Jenkins on Apr 18, 2014

As I’ve told a couple other commenters: please keep the discussion focused on the question at hand. This isn’t the right forum to air your views on nuclear or renewables. The question is can they work together. Not do you want them to work together. 

To keep things off topic, I’m going to prune this part of the thread of off-topic comments. I mean no disrespect to those posting their strong beliefs about nuclear power (one way or the other), but I don’t want this comment thread to devolve into another battle over nuclear. I hope everyone understands. Thanks,


Jesse Jenkins's picture
Jesse Jenkins on Apr 18, 2014

It sounds like you’d like the paper Charles Fosberg references below… 

Nathan Wilson's picture
Nathan Wilson on Apr 18, 2014

All too often, the claim that we need more R&D is used as an excuse for postponing deployment of new technology.  One thing that is a clear lessons from the recent declines in the cost of solar power is that R&D alone is not enough to bring costs down; it takes dozens of GWatts of deployment (which has not really been done for the post-TMI enhanced safety nuclear plants of today).

Another factor that helped solar a lot was the societal commitment, and streamlining of red-tape and permitting processes.  We know that nuclear has great potential for cost reductions (the fuel only contributes 0.5¢/kWh, and the steel and concrete inputs are only a tenth of that used for wind energy).  Safety by design can be cheaper than safety through regulations.

Another message from the clean energy movement that is applicable to developing nations is that with the right technology from the start, there will be no need to make a difficult transition to clean energy.  This is most often part of a promotion for renewable energy, but it is also applicable to the question of nuclear versus coal, and striking the right balance between nuclear and solar.

If developing nations could get loans or vendor financing to develop nuclear plants, the up-front cost would be less of a problem, since they would be built with mostly local labor, steel, and concrete which allow them to produce energy for a cost which is easily competitive with imported fossil fuel (or fuel that would otherwise be exported at world prices).

The whole issue of nuclear and solar playing well together is a non-issue if nuclear and baseload solar (i.e. desert solar with storage) provide all baseload, and other solar is limited to peaking and does the much of the load following via curtailment.  If wind power is introduced, then developing nations must also develop the domestic fossil fuel industry to go with it, and they must develop robust long-distance power transmission to smooth out the power flows.


Nathan Wilson's picture
Nathan Wilson on Apr 19, 2014

Should we over-build electrical generation and add fuel synthesis?  It depends a lot on whether we need the liquid fuel for other purposes.  There will always be some nations that can’t grow enough bio-fuel for their transportation system (maybe most nations).  For these nations to get off fossil fuel, their syn-fuel industries will be roughly 1-2 times the size of their electricity industry.

Such a nation would need very little energy storage, since the syn-fuel plants would constitute enough dispatchable load.  To put down some ball-park numbers, say the baseload power plant costs $6/Watt (plus fuel for nuclear at around 2¢/kWh) and the hydrogen plant costs an extra $1/Watt, including several days of storage.  Then baseload electricity is around 8¢/kWh, and dispatch load at the syn-fuel plants adds 1¢/kWh to the cost of baseload for the idled equipment; this is really cheap peaking power (it does assume that as with today’s costs, per-Watt the chem plant is much cheaper than the nuke, and of course a cheap chem plant is crucial for applicability to low capacity factor off-peak wind and solar). 

Thermal energy storage at nuclear plants or advanced batteries (for a few hours) might also fall to the $1/Watt point, but we would still have to pay depreciation for the storage, even on days we didn’t need it.  When we don’t need the syn-fuel plant to load-shed, it makes product for its fuel customer, so it does not burden the electricity economics (in reality there would likely be a small payment).

I mentioned several days of hydrogen storage, but note that if liquid fuels (e.g. ammonia or DME) are produced, or if the local geology is suited to underground hydrogen storage, then seasonal energy storage is feasible.

Providing syn-fuel for the entire transportation market using plants configured for dispatchable load is such a powerful tool, that nuclear and renewables can almost be mixed freely on such a grid.

Note that the energy prices given (8¢/kWh for baseload electricity, $1/Watt for hydrogen plant) and 70% conversion efficiency suggest a hydrogen cost of $4.60 per gallon of gasoline equivalent.  Conversion to ammonia fuel would add another 5-25%, depending on the technology (this improves storability/transportability and allows simpler ICE cars rather than expensive fuel cell vehicles).  

This cost would not be attractive in the US unless the hydrogen/ammonia car got much better mileage than gasoline cars (20-50% better is likely).  However, it is possible that the very high temperature nuclear plants in development coupled with thermo-chemical hydrogen production could reduce the cost substantially.  Also in China and India nuclear power is only one third of what it costs in the US, so the retail price of ammonia syn-fuel would easily beat imported fuel.


Marcus Pun's picture
Marcus Pun on Apr 18, 2014

“it is highly unlikely that any 30% renewables is ever going to be politically acceptable, pricewise”


You might want to let CAL-ISO in on that bit of information as we already have had some days where renewables, excluding large hydro, went up to 30%. Within 10 years we’ll be seeing major inroads into energy storage to balance out wind and solar and to store baseload from existing n-plants and fossil plants. The technology is already there, the build out is all that is needed.

Robert Bernal's picture
Robert Bernal on Apr 19, 2014

We need cheap storage for solar, wind and nuclear, but especially closed cycle because that means far less n-wastes (and for far less time) for predictable baseload and, with dry cooling, anywhere. Consider molten salts: with CSP and (high temp) nuclear, it is already a given but with wind and PV, up to 3x the build out would be required to make up for the thermal losses back to electricity. I imagine larger molten salt storage and a larger heliostat field for the CSP setup and just read about the possibility of secondary molten salts (without the fissionable fuel or radioactivity) for advanced nuclear, in this post (and in part of the recomended resources).

I’m hoping the Eos battery becomes commonplace at $160/kWh for the windfarms and scalable down for rooftop (because they should have 10,000 cycles!). I admit, when I wrote the above, I was thinking in the $500/kWh range and above for lessor quality battery storage.

Nathan Wilson's picture
Nathan Wilson on Apr 19, 2014

In the spirit of pulling this discussion back on topic, the two energy technologies that Capt D mentioned nearly exactly fit the mold of the other renewables and nuclear compatibility problem.

Tidal power has a varying output, with both a 12 hour cycle (which maybe could be smoothed with advanced batteries) and a 2 week cycle which could only be smoothed with fuel synthesis.  Basically this is another technology which is a difficult fit for any grid that is not fossil fuel or hydro dominated.

The deep-sea hydro thermal plan is the “nuclear energy” of renewables.  (Anyone who thinks small is beautiful will hate this: Marshall Systems wants to hook a pipe into a 50 GWatt hydro thermal vent in 7500 feet of water, hundreds of miles off-shore.  All they need now is a few billion$ for a small prototype.)  Like land-based geothermal, this baseload technology can be combined in any ratio with nuclear and baseload solar thermal, but will need a lot of hydro, storage, or dispatchable fuel synthesis to go beyond around 80% non-fossil.

So basically, neither of these technologies can flourish in a grid that is 40% solar+wind, unless and until we develop and deploy the exact same technologies which are needed to add new nuclear to such a grid.  These technologies also have the additional impediment that they are new and have unproven economics.

Nathan Wilson's picture
Nathan Wilson on Apr 19, 2014

Here is a summary on MIT News of Dr. Forsberg’s 2013 paper discussing hybrid energy systems, and here is a video in which he discusses an advanced nuclear technology which would be well suited to the renewable-rich grid of the future.

Robert Bernal's picture
Robert Bernal on Apr 21, 2014

I consider it the other way. After realizing that it takes an overbuild of renewables to supply a baseload (which is not debunked) I find that the math is more favorable towards some advanced reactor design which uses molten salts as the storage medium (and possibly even molten salt for fuel mix in the reactor itself to prevent any possibility of meltdown as with the MSR or LFTR). Consider the we must transition over to an all electric fleet, except for industrial processes, in order to actually really solve the excess CO2 problem. The industrial processes shall be fueled by liquid fuels made by some kind of high process heat (again, MSR or similar), thereby further transitioning from some 80% to 99.9% non fossil fuels. Or, battery tech will enable heavy equipment as well.

Solar panels for rooftops will be made by nuclear derived electricity, thereby causing them to be 100% carbon free as well (reducing fission products a few percent as well).

Let’s do some math! Assume 10 billion people will want clean water and food, transportation and entertainment (including all the “unseen” industrial processes required for all such infrastructure support). Currently, the world consumes about 500 quads in all primary energy. The USA consumes about 1/4th of that yet is about 1/20th the population, thus, to be fair, the world should be consuming 5x more, or 2,500 quads. Most of that energy is wasted due to thermal losses in the traditional way: 66% in steam generation from nuclear and coal, and 75% from transportation. NG looses about 60%. We will not account for line losses (at this point in the equation). Therefore, we can say that the world would need about 800 quads (equivalent) from renewable sources (in order to power 10 billion happy humans without harm). That is still more than what the world uses now, so we will count on conservation and efficiency to cut this number in half (besides, it wouldn’t hurt the USA to cut some of the waste)! Now, a solar panel will generate about 150 


Now, a solar panel will generate about 150 watts for about 6 hours from a single sq m (in perfect sunlight). That’s about 900 Wh x 365 or 328 kWh/sq m/year (without clouds).

Half of my projected fully electrified global requirements will need 60,000,000,000,000 kWh / 328 or 182,000,000,000 sq meters. At $2/watt installed (x 150 watts per sq m), that’s about $50 trillion… and 182,000 sq km (or about 70,000 sq mi) of land.

Much of this electricity will have to be stored. Let’s say that about half (not 3/4ths) of the energy will need to be used in the 3/4ths of the 24 hour cycle that the sun isn’t shining (I believe this is “about” the right amount since most industriual and commercial processes are concentrated around business hours while the sun is shining). We will assume that battery technology will kick ass and cost just $100/kWh of storage, and that they last the lifetime of the solar setup (there are already reports of utility scale zinc air batteries coming down to just $200/kWh that last for 10,000 cycles!). We will need to store up to two day’s worth of that, or about 165,000,000,000 kWh to make up for any serious weather related issues assuming regional distribution will even out any further such issues (so batteries should cost $16 trillion, globally). Thus cheap solar and batteries should cost about $70 trillion to power half of the projected global population at half of the American standard (efficiency improvements from electric cars, led lighting and better insulation/passive solar siting should enable that).

We can say that the other half will require even more money! Wind has longer and less predictable lulls and costs slightly more per watt to install (than the $2/watt figure I used for solar).

Thus, I come up with about $150 trillion for the complete wind and solar scenario for 10 billion people. This does not account for the 25% loss due to ineffeciency of storage. neither does it count for extra powerlines and extra labor/equipment needed to periodically clean 70,000 square miles of solar panel.

Now, for the mass deployment of high temp nuclear scenario. Since it will be baseload, we can try to calculate how much needed for storage.  But first, let’s say that it is most economical to crank out a bunch of 100MW units instead of 1GW units (and safer, too).120 trillion kWh = 120,000 trillion watts / 100,000,000 (for each unit) / (about) 8,000 hours in the year = 150,000 such units, globally for 10 billion happy humans. At $10/watt, which is the cost of today’s one of a kind, more complicated light water reactors, a whopping $150 trillion.

If mass produced, these units will come down to about $2-5/watt. For comparison, a brand new coal plant costs about $2/watt and with (some) CCS, about $5/watt.

However, much of this electricity will also, need to be stored. Unlike the renewable option, the nuclear is still running during grid variabilty. Thus, we need to divert its power for charging whenever demand is low to be added to demand when high. Again, let’s say that we need to store half of the generated electricity, but for only up to a whole 24 hour cycle (instead of for 48 hours, as with the renewables, it should be less than that, since no full on nuclear power outages should occure for that long at the regional level). That’s about $8 trillion for batteries.

We should throw in another 8 trillion (over 50 years) for the proper disposal of fission products. But we should also assume that they will not cost anymore than $4/watt to make, ship and install because they must be made in the factory just as solar and gas turbines are today.

Thus, the nuclear option is not only more predictable, it is half the costs!

Other considerations are:

  • That solar peaks in the middle of the day, which could reduce the amount of nuke plants and battery storage for nuke plants.
  • That liquid fuels will need to be made (and possibly from thermal which is 3x the energy equivalent of electricity) from nuclear, thus offsetting some storage.
  • That molten salts should instead be used for storage if cheaper than battery.
  • That machine automation required for the solar should also be used for vastly reducing the costs of electric car (and utility scale) batteries.

Clearly, less battery storage is needed with an (almost) all nuclear scenario than with an (almost) all renewable scenario.

Robert Bernal's picture
Robert Bernal on Apr 22, 2014

These companies and governments that withdraw development do not really care about 99% fossil free. If they did, there would be a “war like effort” towards developing the best option. I’m not sure if the highly radioactive MSR is it, but know that it will take a lot more resources to do it with wind and solar than to build reactors and shielding.

In the above figures, I forgot to consider shadow (and access) spacing. NREL has come up with a figure of 7.9 acres per MW and I assume just over 20% capacity for a total of 30 acres per MW at “100% CF”, or 3,000 acres (12 sq km or 4.6 sq miles) per 100MW. Since the nuclear would have about a 90% CF, it still takes about 4 sq miles of solar PV and spacing to equal the output of just one 1/10th GW hardened reactor. In actual resources demands (without spacing) that is still about 1 square miles of solar infrastructure to one such reactor plus the extra amount of storage and powerlines needed.

Robert Bernal's picture
Robert Bernal on Apr 22, 2014

Thanks, I believe that rooftop PV is the best way to supplement electrical needs, that we all should reduce, especially the corporations. When I go to the store and buy anything, chances are it is over packaged with mostly air. If they don’t do it that way, then they lose to the competition. So we need laws. I think this is my “Earth day awareness” talking but what we really need to do is transition to a resource based economy, where things are not designed to break down and where money doesn’t get in the way of our efforts (where machines make and manage “everything” and people somehow get compensated for not being able to work). The technology is headed there anyways!

We still need nuclear to make solar PV, musical instruments, computers, electric cars, fuel for heavy machinery and such but I agree, there is A LOT that the Americans could cut! I am simply born into the “suburban, spend lots of energy on trivial stuff and drive everywhere” type mentality… and can have a hard time figuring out our way out (I can tell you to not buy into all the holiday stuff and to not travel but you could say for me to not buy musical instruments, computers and such). We need to be able to have what we want most. Problem is, if I was rich, I don’t think the solar panels (that I would buy) would make up for all the musical instruments, larger house, electric cars and the extra running around… even though most of it would be to bring attention to climate change solutions awareness. So, in effect, I would be adding more CO2 to the equation even though money buys efficiency. Once in a totally electric powered world, then it doesn’t matter. Then, we all could concentrate on the less serious things such as over packaging.

Earlier, I read about how many people went to movies and meetings about climate change and just made me sick! I commented about how much extra they are causing to the problem by driving there (and I said) “unless the meetings were actually about how to get to 99% clean and abundant electricity”. They were mostly just about picking up trash, reducing plastics, drinking less soda and such (but, at least some of it was about planting trees).

Jesse Jenkins's picture
Jesse Jenkins on Apr 23, 2014

We all know those arguments well here. There have been hundreds of posts at this site hashing out those issues. So please, if you don’t want to have this particular conversation, then don’t. No one is forcing you to.

As I’ve told other commenters, please stay on topic for this discussion thread, or refrain from commenting. The question here is not do you specifically want nuclear or renewables? Your answer is clear. Others disagree. That’s not what were discussing in this specific post. The question is, if a nation decided it wanted both nuclear and renewables, could they work together?

Pieter Siegers's picture
Pieter Siegers on Apr 28, 2014

Hi Jesse, to be honest it is difficult to say whether xRE + yN should be the energy mix formula. I could agree with it if at this moment all fossil fuel plants would be shut off, and nuclear plants could provide for the basepower we currently depend on. That would lower carbon emissions significantly.

I just read the following article, which puts nuclear in the midst of some clean and some dirty energy sources:

Whilst nuclear looks a great option to include in the energy mix at short term, on the longer term we will need to leave nuclear behind, the reasons for that are already being discussed in the same article so here I won’t mention them again.

So basically what the main argument is for nuclear is that it provides baseload power continuesly. In other words, nuclear would provide for an adequate energy backup when RE do not provide enough energy. On the short term, for existing nucelar plants I would be willing to accept that.

I think there are other arguments that come into play when talking about combating climate change, or better said, avoiding it by reducing carbon emissions to levels where it was when the industrial revolution began. We’re talking long term business here.

First one is energy efficiency. There is much energy to save when talking transportation and industrial processes. I have read that this argument is very real and big business.

Second one is a bit far fetched and related to energy grids that could be integrated, passing along any energy that is generated extra to the ones that are in need. With RE, that means that grids that receive lots of sun and / or wind could transport energy to the ones that are without sun or wind. This requires some very intelligent power regulating components and lots of interconnection, but is doable.

Third argument is lowering the carbon footprint at the residential level, by using concepts like passiv house, excelent insulation, solar boilers on the roof for showering washing and cooking, heat pumps, and using LED lighting, just to name a few. Some of them apply very well or even better on industrial level as well.

The argument in your article Jesse that you suppose the energy use per capita should be based on what the Americans use today, I think that Americans should first lower their energy use per capita to be fair. What happens instead is that even when the US saw an increase in the use of RE, there was also an increase in carbon emissions last year…! So something is still very wrong, and I doubt it very much should we take the US strategy as an example. We all know that the fossil industry is a very powerful wall and is insisting on using up all fossil fuel there is to find, driving up the prices as is needed… This is clearly what our planet does not need at all, and we should refuse any attempt they make to continue this madness. The answer is simple. What we need to do is lower fossil fuel demand. How? Use RE and efficiency, develop sustainable energy storage. Lower fossil fuel demand.

As an example of the fossil fuel industry being like a tsunami that apparently can’t be stopped, is that while the whole world saw the Arctic 30 protest, being put in prison for a long time, then sent home by Christmas, and what do we see? The first tanker with Arctic oil has arrived. Where? In Rotterdam, the Netherlands… being Dutch, it is hard to understand why they, being very active with recycling, bicycles, and solar and wind, let this happen… it makes me ashamed, but on the other hand it makes it very clear that commercial power from fossils is so strong, it almost makes you feel like you cannot do nothing. But then, we are all part of the same demand, so lowering it seems to me the only viable option we have to break their power, to finally really see some substantial reduction in carbon emission. As long as the fossil fuel industry is in power, or, in other words, we are providing them with demand, no real changes will be seen on our planet indicating the ship is moving in opposite direction.

So, tell me, knowing this, what will you do?


B W's picture
B W on Apr 28, 2014

Peter, not to discourage your commenting but a lot of people commenting here are very well educated on the global energy problem including Jesse.

energy efficiency is a very cost effective means of carbon abatement, though due to the large rapid growth of energy usage in the developing world, the importance of energy efficiency to mitigating the climate change problem is limited.

the idea of vast interconnected networks of renewables does not work without a storage component, because equatorial sunshine is still only during a part of the day, and wind varies in a less predictable manner. Creating enough output from wind and solar to meet the needs of billions of people throughout the day and night without substantial storage capacity would mean overbuilding peak demand capacity by several factors with intermittent generation sources, and even that may not cover all peaks. It would also necessitate throwing large amounts of energy away. Any scenario with out large capacities of stored energy is essentially an impossibility. Nuclear power seems to have a significant edge on other forms of stored energy in terms of cost and scalability.

Peter, why can we not use nuclear energy long into the future? Work done at Argonne labs in the 80s provided a lot of progress in terms of reducing the waste and proliferation threat of the fuel cycle, and the energy content in spent fuel alone is enough to power a country such as the US for centuries. 

We have to understand fully the developments in all technologies, unfortunately far too many people are completely in the dark about the research advances made in regards to proliferation resistance, waste minimization, and safety of nuclear fuel cycles and reactor designs.

since nuclear doea well as base load and to load follow, and solar can provide a lot of peak output (though the duck curve is still a problem) it seems apparent that nuclear and solar will work well together. I can’t say the same about wind, which at large penetrations would undermine the economics of every other generator on the grid due to ita high variability.

Bas Gresnigt's picture
Bas Gresnigt on May 18, 2014

It is remarkable that the post neglects the free whole sale market with renewable and it effects on nuclear, as that free market is the situation in many countries & states now. So lets take an example.

In the first quarter of this year renewable delivered 27% of Germany’s electricity. During a day in May renewable delivered 75% (wholesale price was negative).  Solar+Wind capacity in Germany is now ~75GW which is more than German peak demand (~70GW).
Taken the German implementation rate of Solar+Wind of ~10GW/a, we will see days in which renewable deliver >100% of all electricity Germany needs before ~2018. Then the number of those days will grow.

What will(is) happen(ing)?
As the variable costs of wind and solar are ~ zero, they will continue to produce until the price is zero. That implies that during an increasing number of days the whole sale electricity price will become <$1/MWh.

As NPP’s costs are substantial higher, they will make increasing losses with the increasing share of renewable. It implies that the high ‘fixed’ costs of NPP’s (interest, depreciation, maintenance, employees, etc) have to be earned during less hours in the year.
Which implies that the needed price during those hours will become higher the less of those hours are available in the year. And those hours will become less and less due to increasing renewable.

As other more flexible methods of electricity generation do not have those high fixed costs (e.g. a remote controlled gas turbine), those will compete NPP’s out of the market even if the gas price is rather high.

With the present German priority system for renewable this will happen even much faster as part of renewable production will enter the market even if the price is negative. Leipzig saw already electricity prices of minus $100/MWh.
Considering present NPP’s cannot regulate down below ~70%, it implies loosing money fast. As Germany’s new coal plants can regulate down towards ~10%, even those will compete nuclear out of the market.

Other effects
Those low whole sale electricity prices make electricity-to-(car)fuel/gas conversion plants economical. So you see much pilot plants in Germany springing up (e.g. the Audi 6MW plant).

About 35 pumped storage plants are installed in Germany, but those make losses as whole sale price nowadays nearly never rise above $50/MWh. One may expect those may start to makee a profit in the 2025-2030 period when the share of renewable becomes >50%.

Robert Bernal's picture
Robert Bernal on Jun 2, 2014

Nuclear and solar will HAVE to get along, or the biosphere will die. We need to power up to FIVE times what the world powers now (can’t forget all the other billions who want to “live”). Efficiency will reduce that by a factor of about 2. Therefore we still need to replace at least 2.5 total global power supplies with nothing but CO2 free energy. Guess where ALL THAT will come from? Nuclear, wind, solar (proper mineral) sequestration of fossil fuels and a tad fro hydro, geothermal and even less than that from wave and tidal. Biofuels needs to be limited for obvious reasons. So we better get our act together and learn how to properly MANAGE ALL of these CO2 free sources… or the biosphere will die. First, it’s the loss of shellfish and icecaps, then subsequent loss of biodiversity and poor ocean circulation causes ocean anoxia, then comes the killer, microbes that “instantly” replicate in anoxic oceans which exhale hydrogen sulfide… nuff said.

Steve Darden's picture
Steve Darden on Feb 19, 2015

Schalk, I appreciate your points in the political context of Northern Europe. 

Personally, I’m much more concerned about how efficiently China and India decarbonize. Let’s simplify by focusing just on China, where demand is growing faster than any feasible low-carbon buildout strategy. China has chosen to build both VRE and nuclear as fast as they can cope with the project management and development of supply chains. As a citizen of planet Earth I want China to continue at maximum speed building low-carbon energy, which is necessarily neither nuclear-led nor VRE-led.

Question: is it not true that the short VRE replacement life will bring a new decision point where China possibly could choose the more economical nuclear-led pathway? This time frame will be roughly 2035 when China passes through “peak coal” and hopefully “peak carbon”.

Steve Darden's picture
Steve Darden on Feb 19, 2015

Providing syn-fuel for the entire transportation market using plants configured for dispatchable load is such a powerful tool, that nuclear and renewables can almost be mixed freely on such a grid.

Nathan, for me, that should be the debate-winning argument. Question: powering the syn-fuel plants by nuclear works economically, and radically reduces the amount of multi-week level storage required for the ultra-low carbon pathway. How could we accomplish the same design based mainly on VRE?

I want to see Lion Hirth and Schalk Cloete tackle the modeling to find the optimal nuclear-VRE contributions in a system that exploits syn-fuel load-shedding to substitute for most of the storage. My guess it will turn out to depend heavily on System LCOE and location particulars.

Grace Adams's picture
Grace Adams on Jun 2, 2015

Yes, we need lots of R&D, especially at the engineering level, getting technology already proven technically feasible down in price enough to be not only economically feasible but cost competitive with fossil fuels, dung, and wood in less developed nations.  Maybe governments and large private philanthropic organizations in already industrialized nations (mostly US and most of EU) could rent land in less developed nations (mostly near equator) for pilot plants for both advanced nuclear power and renewable energy, and for technology that still looks good after a pilot plant several more similar plants for beta testing, then donate the pilot and beta testing plants and some licenses for more plants of the same design, reserving the right to also use the technology in middle income and industrialized nations. Already industrialized nations will have to subsidized both advanced nuclear power plants and renewable energy until they do become cost-competitive with fossil fuels, dung, and wood in less developed nations.  And probably also bail out politically powerful fossil fuel firms by buying much of their otherwise stranded  inventory of fossil fuel reserves at generous prices to prevent them from engaging in a price war against advanced nuclear power and renewable energy.   


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