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Renewable Energy and the Law of Receding Horizons

Schalk Cloete's picture
Research Scientist Independent

My work on the Energy Collective is focused on the great 21st century sustainability challenge: quadrupling the size of the global economy, while reducing CO2 emissions to zero. I seek to...

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  • May 28, 2013
Many people believe that we can realistically build a 100% renewable energy society by 2050, thereby totally getting off fossil fuels in time to avoid the problems related to peak oil and climate change. This is certainly an extremely attractive ideal and, theoretically, it could be accomplished through a sustained exponential growth rate of about 20% p.a. over the next 37 years. As this post will discuss, however, such sustained exponential growth is highly unlikely to materialize.

The reasons behind this assertion can be summarized via the law of receding horizons: the tendency for a goal to just stay on the horizon no matter how hard you struggle towards it. When applied to the sustained exponential renewable energy expansion mentioned above, this simply implies that a significant number of factors will work to make renewable energy deployment progressively more difficult as the total installed capacity increases. This post will briefly discuss these factors.

Declining EROI of energy systems with increasing deployment

As always, humanity will exploit the highest quality resources first according to the lowest-hanging-fruit principle. When looking at the major categories of renewable energy, this implies developing hydro first, followed by wind and finally solar. In addition, for each resource, the regions with greatest potential will generally be exploited first (solar PV in sun-poor Germany is currently a notable exception). Obviously, the climate varies greatly around the globe and so will the Energy Return on Investment (EROI) of the renewable energy systems deployed at any given site.

As an example, the figure above shows how the global wind energy resource quality will decline as the total installed capacity increases. Eventually, the resource quality becomes so low that the EROI drops below 1 and negative net energy is generated (more energy is needed to build, install and ultimately decommission the turbine than will be generated over its operational lifetime). Naturally, this will lead to a situation where new capital investments yield progressively lower returns, decreasing investment attractiveness with time.

Declining EROI of the total energy industry with increasing deployment

As intermittent sources of renewable energy increase their share of electricity production above ~10%, a number of costly alterations and additions will be required in increasing quantities. Energy storage, transformation, long-distance transportation and overcapacity will all subtract from the overall EROI of the energy industry and inflate energy prices. An increased share of intermittent sources that enjoy priority for selling electricity to the grid will also reduce the capacity factors of fossil fuel power plants and increase the necessity for expensive dispatchable power capacity, thereby further increasing costs.

The impact of energy storage through hydrogen is clearly visible in the figure above. In addition, the large capital cost of pumped hydro storage is given in the next figure. Pumped hydro is probably the most economical energy storage mechanism currently available, but it is fairly certain that such prices will be economically unfeasible.

Capital funding issues

The high capital costs of renewable energy compared to fossil fuels is another important factor, especially in a stagnant economy where credit is tight. For fossil-fuel plants, up-front costs are also large, but this is shared with running costs related to fuel purchases and plant operation/maintenance which can contribute roughly between 30% (modern coal) and 70% (natural gas) to the final cost of electricity. In addition to requiring large capital investments, the potential returns on such investments are also rather uncertain because of a strong dependence on unpredictable factors such as government policy, climate change and macro-economic developments. The retroactive feed-in tariff cuts in Southern Europe offer a fitting example.

As an illustration, the 2013 EIA new plant capital costs of various energy technologies and pumped storage for balancing intermittent renewables are given above. In addition, each cost was divided by an optimistic capacity factor (rough estimate): 0.8 for coal and gas, 0.9 for nuclear, 0.25 for onshore wind, 0.4 for offshore wind, 0.25 for solar thermal, 0.2 for solar PV and 0.5*0.75 for pumped hydro with 75% round-trip efficiency.

Sensitivity of renewable energy systems to the energy price

Since renewable energy systems are very energy intensive to produce (have a low EROI), increases in the energy price will significantly increase the capital costs of renewable energy (generation and balancing). As a result of various factors discussed in this post, energy costs will rise with increasing renewable energy deployment, thereby starting a vicious price inflation cycle where increasing energy prices increase the price of renewable energy which again increases energy prices.

Time and monetary cost to revamp other sectors

An exponentially increasing share of renewable energy in the global energy mix will demand a number of very costly changes to other industries. In the absence of a gamechanging technological breakthrough in bioenergy, the bulk of the transportation sector will have to be revamped to run on electricity (battery or hydrogen fuel cell). Other vital industries such as steelmaking and cement will also need to be completely revamped and could see a drop in efficiency (requiring more energy per unit output). If the Exxon prediction shown below is anything to go by, this will be a significant limiting factor. 

Material constraints and waste processing

Renewable energy is not only energy intensive, but also material intensive. Large quantities of steel (which is heavily dependent on coal), plastics (which are made from oil and natural gas) and rare earth minerals (identified in a recent EU study as a potential bottleneck) will be required in the energy transition. If the efficiency of steelmaking reduces (as outlined in the previous paragraph), gas peaks together with oil or rare earths become very expensive due to supply constraints, the capital costs of renewable energy will increase significantly.

A sustained exponential expansion in renewable energy will also create a parallel exponential expansion in e-waste from solar panels, wind turbines and batteries. Processing and recycling this vast stream of potentially toxic solid waste will be very energy intensive, thereby decreasing the full life-cycle EROI of renewable energy sources. Also, if this exponentially increasing e-waste stream cannot be properly handled, significant additional political resistance will be encountered. 

Human capital constraints

Since a renewable energy economy will most probably have a much lower overall EROI than a conventional fossil fuel energy economy, the shift to renewables will also require large shifts in the labour market. A larger portion of the workforce will have to be deployed somewhere along the renewable energy value chain than is currently deployed along the fossil fuel energy value chain. The high-tech nature of renewable energy generation and balancing will also demand a great deal of skilled labour – something which is already in very short supply. Such a large scale exponential shift in the labour market will be practically very challenging and is likely to result in labour shortages, driving up the salaries of people working along the renewable energy value chain and thereby increasing the price of renewable energy.

The negative effects of climate change

Renewable energy systems depend completely on the local climate where they are installed (quantity of sun, wind and precipitation together with the variability/volatility of these weather patterns). Climate change has the potential to substantially reduce the total energy generated by any renewable energy installation through decreases in solar/wind influxes, increasing climactic volatility and complete shifts in weather patterns. Increased cloud cover due to warmer air will reduce solar insolation in certain areas, a reduced temperature gradient between the equator and the poles will reduce global wind speeds, increased climate volatility will enforce greater downtime for wind turbines and reduce the output of bioenergy, and permanent shifts in weather patterns will reduce the performance of renewable energy installations originally cited in ideal locations.

Market forces

Rapid deployment of renewables with the aim of mitigating climate change implicitly implies a significant decrease in the demand for fossil fuels. This creates a severe market-based problem because a decreased fossil fuel demand will cause a parallel decrease in price, making renewables even less competitive against fossil fuels. Just like unsustainable oil demand caused the oil price to quadruple in the 21st century, a drop in demand large enough to make unconventional oil production unnecessary will once again slash the price by a factor of four. An environment of rising renewable energy and falling fossil fuel prices will offer great headwinds to renewable energy deployment, especially if the economy remains weak.

The problem is that direct government subsidies can distort market forces only for so long. The unsustainable fall in solar PV prices will most probably demonstrate this over the coming years. As shown above, the bulk of the large drop in PV module prices in recent years was due to declining margins (where governments kept companies afloat) while technology advancement was responsible for only 7% of the decline.

Social and political resistance to rising energy prices

Currently, renewable energy can only be deployed in an environment of substantial subsidies. Germany is the best example of this approach and generous government subsidies of various kinds have led to a very impressive rate of renewable energy deployment in recent years. However, the share of wind and solar energy (13.2% fof total electricity generation in 2012) is now starting to create substantial problems due to the expensive promises made to investors in renewable energy infrastructure.

Electricity prices are rising rapidly (the growth of the renewable energy surcharge is given above in Euro cents per kWh) and struggling utility companies are forced to replace cleaner gas-fired power plants with cheaper coal (2012 electricity generation saw a 19 TWh increase from coal and a 10.6 TWh decrease from gas). These problems will only get worse as the share of wind and solar is lifted beyond 13.2% of electricity (around 6% of total energy consumption) in the years ahead, especially with the ongoing stagnation of the European economy. The social and political resistance to this self-imposed austerity is already gathering momentum and will be observed with interest in coming years.

Geopolitical implications

Renewable energy advocates often tout the energy independence offered by local implementation of renewable energy as a major selling point, but this is unfortunately false information. David MacKay, a Cambridge University physics professor, gives an excellent talk (based on his free e-book) on how the laws of nature make renewable energy independence impossible for many highly populous developed countries under current consumption patterns. The solution is then simply to build the world’s deserts full of concentrated solar thermal plants (with the necessary energy storage) and transmit the electricity through millions of kilometres of HVDC cable and countless AC/DC substations to the rest of the world.

Apart from the enormous complexity and expense of such an operation, however, this strategy would result in geopolitical implications dwarfing those currently related to oil. The livelihood of entire countries would depend on thousands of kilometres of international cable exposed to political disputes and terrorist activities over the entire distance. The viability of such a plan is highly questionable in the real world, especially one competing over a shrinking resource base. Also, in addition to these problems related to the highly uneven geographic distribution of renewable energy potential, the rare earth minerals crucial in most renewable energy technologies are produced almost exclusively in China, thereby potentially making China the new Saudi Arabia of renewable energy and creating another set of very uncomfortable geopolitical issues. 

Murphy’s Law instead of Moore’s law

Renewable energy optimists often look at the electronics industry and claim that, if only the political will existed, a similar exponential expansion could happen in the renewable energy industry. However, the fact that the electronics industry could scale down several orders of magnitude while the renewable energy industry has to scale up several orders of magnitude, implies that Murphy’s Law is much more likely to occur than Moore’s law. Another well-known energy expert, Vaclav Smil, simply builds his scepticism about a rapid transition away from fossil fuels around the historically proven fact that any large scale industrial makeover usually takes many generations to complete – even when there is a clear economic incentive to do so. The transition away from fossil fuels will be the biggest, most resource intensive, most multifaceted and most expensive undertaking ever attempted by man and will also have to be driven against natural market forces for many years into the future. Therefore, even though this post has already pointed out many potential pitfalls, Murphy’s law is guaranteed to reveal many more as we progress along this unknown path. Murphy’s Law is the reason why large projects include contingency plans and budgets. Standard projections of incessant declines in renewable energy prices involve no contingency whatsoever.

In summary

The twelve headwinds to renewable energy deployment briefly discussed in this post will all escalate significantly (and most probably in a highly non-linear manner) as renewables increase their share in the global energy mix. The only factor working to oppose these escalating headwinds will be innovation: the quest to significantly increase the EROI and decrease the capital costs of renewable energy with time. Betting against human innovation often proves unwise, but the fundamental limitations faced by diffuse and intermittent renewable energy sources may very well prove to be too great a challenge even for human innovation. And if the twelve headwinds herein discussed overwhelm the gains brought by innovation, the penetration rate of renewables will run into a brick wall, much like that which happened to nuclear (below).

Naturally, one has to acknowledge the possibility that a number of incredible technological innovations materialize over the next decade or so, significantly changing this outlook. Betting on some future magic to occur seems quite irresponsible, however, and we should not plan our future on this assumption given the recommendations of climate science and the rising material aspirations of 6 billion (and counting) developing world citizens. Meeting these challenges will require a true technology-neutral approach providing clear incentives to the market to rapidly reduce the CO2 and overall energy intensity of the economy using the full spectrum of available options. Continued technology forcing of wind/solar power is likely to hinder more than it helps in this regard. 

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I K's picture
I K on May 28, 2013

If the aim is to stop co2 increasing you only need to cut fossil fuel burn by about half so you dont need the near impossible task of 100% non FF just 50% non FF is required

That is a reasonably achievable goal. With computer vehicles and 0.5 nuclear reactors per million population* and modest efficency gains you would have a rich world of 10B people using about half whay we do now.

So its not all gloom

* Frace achieved over double this figure so it should be easy

John Miller's picture
John Miller on May 28, 2013

Schalk, another very good post.  The political belief that renewable energy will be “affordable and sustainable” is a large part of the problem as you describe.  While government subsidies are intended to encourage development of more expensive renewables, this strategy has the unfortunately consequence of sometimes supporting inefficient, non-sustainable technologies, facilities and operations; many of which have or will likely go bankrupt shortly after the subsidies stop. 


I recently passed through the California Tehachapi area that contains one of the largest wind farms within the U.S.  Besides being a museum of numerous generations of wind turbine generators I observed something that would be very concerning if I was an owner or operator.  Despite having near ideal wind conditions of 10-20 mph, I noted that about 25% of the turbines were idled/feathered.  Why would so many turbines be out-of-service and not generating power to reduce the need for fossil fuels under ideal wind conditions?  I suspect that the primary reason was equipment reliability related and possibly lack of or delayed maintenance.  This is possibly another (capacity reduction) factor that results from overly generous-potentially wasteful government subsides and/or poor management?  This is another major disadvantage of artificially supporting an industry that is allowed to operate less efficient/profitable than free markets would allow.

I K's picture
I K on May 28, 2013

I have always wondered what is to stop a subsidy farm overstating its generation to collect more subsidies?

John Miller's picture
John Miller on May 29, 2013

Certified (calibrated/verified) electric generation meters normally.  If you are an investor, I would be concerned of the actual generation rates/profit margins over the longer term and how it compared to design/advertised capacity (i.e. actual capacity factor: generation/installed design max. capacity).

Nathan Wilson's picture
Nathan Wilson on May 29, 2013

Nice post, but you left off one additional major barrier to high renewable penetration, specifically, the same one that halted the first nuclear boom.

Version one of the story says that we stopped growing the nuclear industry because it was too expensive and too dangerous.

Version two says that nuclear power is the best hope for humanity, and we only stopped its growth due to opposition from the incumbent fossil fuel industry (which is much more dangerous; and would be more expensive, where it not for onerous nuclear regulations and an societially imposed “risk premium” on nuclear financing, which constitute a negative subsidy).

Regardless of which version of the nuclear story is true, the renewable vision is equally imperiled.  For version one, energy storage (which is dangerous and expensive) will limit renewables.  For version two, any credible fossil fuel substitute will be rejected.

Rick Engebretson's picture
Rick Engebretson on May 29, 2013

The great urban migration after WWII did indeed create generations that don’t see opportunity. And the politics of electing people that sustain a consumptive vs. productive lifestyle is self reinforcing. We see a modern world full of people confined in biological dead zones who produce little of their own needs, yet demand consumption they are presented on high definition TV.

There is good renewable biofuel progress. The (foreign controlled) oil industry is screaming we have too much yeast piss from corn yogurt production. But the air is cleaner with carbohydrate enhanced fossil gasoline. Similarly, coal electric generation is learning to incorporate renewable biomass and broaden their product to waste heat. And we are learning we need to manage forests or they will burn us out.

Most of this knowledge is pre-WWII. I will always feel lucky to have known a generation that had so little, and worked so hard to create so much, and was still of good character.

I K's picture
I K on May 29, 2013

Its an interesting idea that coal killed nuclear because it was too successful. Certainly once an industry is established there will be tremendous VI in keeping it going. Not only from direct coal mines and companies and the many they employ and the unions but also indirect beneficiaries like the railroads that transport the coal to the construction comoanies that rely on the cheap/free byproducts from coal lole the ash.

Bill Woods's picture
Bill Woods on May 29, 2013

Electricity prices are rising rapidly (Euro cents per kWh above) …”

Note that that graph only shows the surcharge for the FiT subsidy. As another graph further down the page shows, total retail prices have grown from about 14 Ecents/kW-h to about 27. A substantial increase, and the renewable surcharge is a big part of it, but not the whole story. 

Nathan Wilson's picture
Nathan Wilson on May 30, 2013

That is a recurring them over at Rod Adams’s website, Atomic Insights

Schalk Cloete's picture
Schalk Cloete on May 30, 2013

Ah, thanks for picking that up, Bill. I corrected the article accordingly. 

Schalk Cloete's picture
Schalk Cloete on May 30, 2013

Ultimately, both versions probably contributed although I honestly cannot say which version was dominant. 

Safety concerns of nuclear vs fossil fuels is much like safety concerns of terrorism vs smoking. If you crunch the numbers, the chances of a non-smoker being killed by a smoker is about 250 times greater than the chances of him being killed by terrorists. But still we seem to be much more concerned about terrorism than about smoking. 

However, do you think that nuclear would still be safe and affordable relative to fossil fuels if it delivered 50% of our energy consumption instead of 5% and fossil fuels only delivered 40% instead of 87%? I doubt it. 

Schalk Cloete's picture
Schalk Cloete on May 30, 2013

I agree with you on the CO2, but it will be a major challenge to first stop our CO2 emissions from increasing and then slicing those CO2 emissions in half within just a few decades (all while the developing world is industrializing). The IEA predicts that all CO2 emissions for the 450 ppm scenario will be locked in by 2017, implying that, if we don’t want to use CCS, we are not allowed to build a single piece of fossil fuel infrastructure after that date. The chances of this happening is zero. In fact, 1200 GW of new coal capacity is currently being planned worldwide (mostly in China and India). 

Nathan Wilson's picture
Nathan Wilson on May 31, 2013

do you think that nuclear would still be safe and affordable relative to fossil fuels if it delivered 50% of our energy consumption...”

The safety advantage cited in McKay’s book is normalized by energy output, so it does not depend on scale.  

Do I think fossil fuels would be safer if we used less (in favor of nuclear)? Yes, because we would presumably replace coal (for pollution) and oil (energy security), more so than natural gas, which is safer.

Do I think nuclear would have less realized safety, due to being distributed into more countries, some with less of a safety-culture than present nuclear countries?  No, if the advanced countries export our modern nuclear technology, it will be safer than the previous generation nuclear technology, even when deployed in less than optimal locations (remember, for example that the pebble bed reactor was developed in part as a “walk away safe reactor” for parts of Africa wherein the plant employees might have to evacuate the plant due to ethnic cleansing).  

Also remember that poor safety culture impacts fossil fuels as well.  China manages to kill off many more miners per unit of coal than we do.  We can expect them to have more nuclear accidents too, but their nuclear accidents will harm far fewer people than the equivalent fossil fuel energy output would have.

On the other hand, if advanced nations choose not to aggressively export nuclear technology with advanced safety technology, the developing nations will be forced to follow our footsteps: they’ll first develop nuclear weapons, then nuclear power as a spin off. They’ll make their own mistakes (repeating many of ours).  They’ll get less safety, and probably pay higher costs (which will mean the age of King Coal lasts even longer).

Do I think uranium scarcity will drive up the cost of nuclear power?  The price of the fuel will go up a little (by around $0.02/kWh at most), but this will be offset by falling plant costs, due to the learning effect.  Note that the Shippingport Light Water Breeder Experiment showed that ordinary reactors can be operated as break-even breeders using the thorium cycle, at somewhat higher costs than the once-thru uranium cycle.  Other reactor types, such as the IFR and LFTR breeders and the DMSR near-breeder promise even lower costs.  Using breeders, the Earth’s uranium and thorium is inexhaustible (after the rich, medium, and low grade ores run out, regular rock at 12 ppm thorium, has plenty of EROI).

Schalk Cloete's picture
Schalk Cloete on Jun 1, 2013

Thanks Nathan, 

Yes, I also think that fossil fuels will become much safer per kWh generated if used in smaller quantities. Also, as IK rightfully said below, we only need to reduce fossil fuel use by about half in order to successfully mitigate climate change. We can therefore still draw a lot of value from fossil fuels if we use them intelligently. 

For nuclear I was more thinking about the expenses that will be necessary to rapidly increase the penetration rate of nuclear in a way that preserves public acceptance. If nuclear is to be increased by one order of magnitude, this could become very costly. 

The breeder idea sounds very promising and, if it can be commercialized at competitive prices would appear to be a very good option. I don’t know much about it though and was wondering if you could help me out by answering a few short questions:

  • When do you think this technology can be commercially deployed? This is another one of those technologies that has been promising wonderful things for decades, but never quite got there. 
  • The EROI of nuclear is not great and, given that breeder reactors will be more complex, the EROI will probably reduce. Could this be an issue?
  • How about costs? Do you have some hard numbers?
  • What are your views on prolifiration risks (on the assumption that such reactors are rolled out on a very large scale)? Will this technology improve the current unfavourable public opinion on nuclear energy?
  • How quickly do you think the technology can be rolled out? Given the complexity and sensitivity of the technology, human resources will probably be the primary factor limiting the rate at which these reactors can be safely deployed. 
Nathan Wilson's picture
Nathan Wilson on Jun 3, 2013

“… expenses that will be necessary to rapidly increase the penetration rate of nuclear in a way that  preserves public acceptance

In the US, I think cost is the biggest driver of public acceptance, i.e. most people who say that don’t like nuclear simply don’t want their power costs to go up; in other words, they don’t like renewables either (of course this does not apply to the very vocal minority).  If and when we decide to make deep cuts in fossil fuel use, the public acceptance of nuclear will be adequate in areas with poor renewable resources (which are the ones that need nuclear the most).  

Deploying  nuclear, wind, and solar in a 10:1:1 ratio (by energy) will create a very large visual presence for renewables, so the public will be satisfied that their utility has a well diversified portfolio, even as they move towards 60% nuclear and 12% renewables.

The other thing that will boost public acceptance (once utilities start trying to sell them to the public) is the fact that the new reactor designs convincingly address the problems that occurred at Fukushima and Three Mile Island; what’s more, the Fukushima melt down was a well understood failure mechanism (loss of AC power), not a mystery or a black swan.

The breeder idea sounds very promising...”

For fast breeders like the IFR, the cost estimates typically said they would be somewhat more expensive than LWRs (light water reactors); I don’t have anything more specific than that.  At the moment, there is no economic justification for them (uranium shortages are clearly many decades away); therefore there is no interest from utilities.  They may gain some traction for waste disposal for LWRs, but I think they are more compelling when used to complement a greater number of thorium reactors.

Liquid fueled thorium breeders (e.g. LFTRs) and near-breeders (e.g. DMSR which uses liquid fuel and breeds U233 from thorium, but the U233 is diluted with U238) actually have the potential to be cheaper than LWRs (but again, no recent rigorous cost estimates are available).  Especially when reprocessing to facilitate waste disposal is desired.  The safety case for these reactors is extremely strong, since the majority of radioisotopes (including the big three: iodine, cesium, and strontium) are chemically bound to the liquid fluoride salt fuel, so they can’t escape, even in the most serious accidents (the ones that can get out in accidents are mostly noble gases like xenon and krypton, plus tritium in some variants, so they can’t bio-accumulate in people, wildlife, or food).  

Both LFTRs and DMSR can be scaled up rapidly, because they don’t require large amounts of new uranium enrichment capability.  Both require an amount of enriched fuel for startup which is equivalent to about a 1-3 year supply for a LWR.  The LFTR requires no additional fuel for life, and the DMSR averages less than a quarter of what an LWR uses.

I think rapid replacement of our energy infrastructure is wildly optimistic.  A coal plant lasts 60 years, so it will take 60 years to replace them all.  The US is in a much better situation than Germany or China in this regard, since we have not built many new coal plants in the last twenty years.  LFTR and DMSRs can be prototyped in 5-10 years, and be in production in twenty, and be at any desired production rate in 30 years.

For EROI, my understanding was that a LWR has about the same 6 month energy payback time as wind power, so the EROI should be very good, averaged over a 60-100 year life (I’ve seen estimates assuming a 30 year life, which strike me as unscrupulous) most of the energy is in the concrete and steel construction materials.  LFTRs and DMSRs have better power density than LWRs (same power from a smaller plant), so the EROI should be better.

On proliferation, I don’t believe the allegations of critics that nuclear power makes weapons proliferation more tempting (i.e. it is a political choice, not a technical one).  In general energy security makes proliferation less tempting.  With that said, some technologies (like uranium enrichment and Purex reprocessing) clearly can be used for weapons; neither is used in the operation of LFTR or IFR.  Even so, there are plausible ways to use IFR for weapons production (with external Purex), so I think it will meet more resistance than DMSR, which may be the most proliferation resistant of all reactors.  The DMSR runs on thorium and low-enriched uranium, has about ¼ of the plutonium production of a LWR; the Pu is of very poor isotopic quality, and there is no practical way to modify the operating cycle to make good Pu.  The fuel cost for a DMSR is very low, so non-fuel cycle nations would have no incentive to develop domestic fuel capabilities; they can easily stockpile a twenty year supply of fuel for energy security.

I highly recommend, Robert Hargrave’s book, Thorium – energy cheaper than coal.  It describes LFTR and DMSR in details, and provides background on other energy technologies for comparison.

Bill Woods's picture
Bill Woods on Jun 3, 2013

“… (the [fission products] that can get out in accidents are mostly noble gases like xenon and krypton, plus tritium in some variants, so they can’t bio-accumulate in people, wildlife, or food).  …”

And they’re volatile in normal operation of the reactor, so they have to be captured and dealt with, but they aren’t accumulating in the reactor. 

Paul O's picture
Paul O on Jun 3, 2013

Will CCS fly in the Third World, (would they accept it), for that matter, would China and even (“green”) Germany agree to do CCS? Can it be done anywhere on the planet regardless of the geology of the area?

In other words, is this not really a losing battle, and we should be doing is looking at technology to Ameliorate the effects of AGW?

I read a recent article that said that the planet is getting greener as a result of increaed CO2 in the atmosphere. If we were to provide arid areas with a modicom of freshh water, could we then mitigate some of the CO2 by growing more plants? All these while we financially help poor countries who want CSS, we acllerate development of MSR and DMSRs, which can be used as a direct future substitute for the Coal Burners now in place.

Schalk Cloete's picture
Schalk Cloete on Jun 3, 2013

CCS will fly under two assumptions: 1) fossil fuels remain our most prominent energy source (still close to 90% of primary energy and this percentage has not changed much since the nuclear boom ended three decades ago) and 2) a consistent carbon tax of more than about $30/ton is implemented together with the outlook that this tax will rise with time.

Regarding the first assumption, there are many alternative energy solutions, but you need only one glance at the projections of the IEA, EIA, BP, Exxon and Shell to realize that we will be a fossil fuel society for many decades into the future. It is therefore likely that this assumption will be true in the vast majority of countries for the foreseeable future. 

The second assumption is more uncertain. CCS has no purpose if climate change is not recognized as a major problem and a strong carbon tax is imposed to make it more economically attractive to capture CO2 than to emit it. Until we see a strong and consistent carbon tax, there will be no CCS.

In their latest energy outlook, the IEA projects average CO2 prices of about $20/ton in 2020 and closer to $40/ton in 2030 under their “New Policies” scenario. This scenario results in long term CO2 concentrations of 660 ppm which many scientists think could have catastrophic long-term consequences. The IEA also discussed a “450 ppm” scenario with much higher CO2 prices of $30-40/ton in 2020 and up to $90/ton in 2030. This is what will be required to play it reasonably safe according to current climate change science. 

When I look at current trends, my feeling is that we will continue doing nothing until climate change really starts to affect the average man on the street. By this time (perhaps somewhere in the next decade), we will suddenly wake up and try to repair the damage of decades of inaction through very high carbon taxes. Under such a scenario, CCS will certainly fly because it will be much more profitable to retrofit our massive fleet of carbon intensive industry than to just keep on emitting CO2. Such a scenario will also put serious pressure on our economy, implying that we will really need to go for the cheapest and most practical solution which, at that time, could still be CCS. 

Regarding the question about location, CCS is limited by the distance to the nearest storage site. Suitable sites are spread throughout the planet, implying that CCS will be feasible more often than not. However, this will affect the economics of CCS and we will obviously start with the most ideal locations and later, when the CO2 price increases, move on to less ideal locations. 

Schalk Cloete's picture
Schalk Cloete on Jun 4, 2013

Thanks for that detailed reply, Nathan. I’ll take some time to go through the links you posted in order to educate myself a little better regarding these technologies. 

I have heard mention of the of 2040-2050 timeframe for the initial deployment of fourth generation nuclear before and your estimates seem to match this timeline. Then, if we assume that nuclear is deployed at a rate similar to the rapid deployment in the 1970’s (around 10% of electricity supply per decade), we might get about 60% of our electricity from nuclear by 2100 – not bad.  

When we finally get a global climate change agreement with a steady global carbon tax this will also promote nuclear. In this case, utilities will have to choose between CCS and nuclear for new plants which could be a pretty interesting choice in itself. Guess we will have to wait and see…

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