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The Fundamental Limitations of Renewable Energy

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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  • Aug 7, 2013
Many people still think that it will not be long before renewable energy such as solar and wind becomes outright cheaper than fossil fuels, thereby leading to a rapid expansion of the thin orange slither in the graph below. This is an ideologically very attractive notion, but, as discussed in this article, it is questionable whether this is in fact physically possible.

Global primary energy by source

So, what does renewable energy have to accomplish before it can compete with fossil fuels in an open market? Well, in short, we will have to overcome the diffuse and intermittent nature of renewable energy more efficiently than we can overcome the declining reserve qualities and unrefined nature of fossil fuels.

In other words, renewables need to overcome the following two challenges in order to displace fossil fuels in a fair market:

  1. Solar panels and wind turbines need to become cheaper than raw fossil fuels. This is the challenge posed by the diffuse nature of renewables.
  2. Storage solutions need to become cheaper than fossil fuel refineries (e.g. power plants). This is the challenge posed by the intermittent nature of renewables.

Point number 1 is the way in which we procure our energy (mining/drilling fossil fuels or deploying solar panels and wind turbines) and point number 2 is the way in which we make this energy useful to society at higher levels of penetration (refining fossil fuels to electricity or smoothing out the intermittent surges of renewable energy). Without point number 1, point number 2 cannot exist and without point number 2, the energy procured in point number 1 cannot sustain a complex society such as ours.

Thus, if renewables are to challenge fossil fuels in an open market, technology must advance to the point where renewables can compete under both these points. This article will examine whether this is in fact possible.

The diffuse nature of renewables

Renewable energy advocates often point to the total energy fluxes of the Earth (below) and proclaim that renewable energy resources are essentially boundless. Yes, it is true: we are surrounded by incredible amounts of diffuse renewable energy (e.g. solar radiation and wind). Unfortunately, however, this energy is useless to us unless it is concentrated into forms such as electricity or fuels.


The reason behind this is called the second law of thermodynamics which states that energy must flow from a concentrated form to a more diffuse form in order to do work. Our entire society was built on the work performed through transforming concentrated fossil energy to diffuse heat and, in order to compete, renewable energy technologies also need to deliver such concentrated energy.

Now there is no question that renewable energy can be sufficiently concentrated by solar panels and wind turbines. The only question is whether this can be done more cost effectively than simply digging already concentrated fossil fuels out of the ground.

This challenge is two-fold. Firstly, energy does not like to be concentrated, hence the fact that the average commercially available solar panel is only about 13% efficient. And secondly, because the energy source is so diffuse, vast areas need to be covered in order to harvest this diffuse energy. The video presentation below gives a very informative discussion on the size of the areas we are talking about here (the video is long, but definitely worth the time).

As a result of this challenge, it was previously calculated that the solar panel price needs to fall to about $0.31/W installed in order to compete with coal at $100/ton. It is therefore clear that installed solar prices still need to fall about one order of magnitude before we can see a sustained market driven displacement of coal by PV.

Is this possible? Well, the most optimistic projection in the OpenEI database sees solar PV levelling off at about $1.44/W installed which is more than quadruple the required level. Perhaps we will be pleasantly surprised by some technological miracle in the medium-term future, but achieving the required prices with current PV technology will unfortunately be completely impossible.

The intermittent nature of renewables

If intermittent renewables like solar and wind are ever to contribute a sizable portion of our global energy mix, a large amount of additional infrastructure will need to be deployed in order to counter the large fluctuations in output varying over timescales ranging from seconds to years.

As an example, the variability of wind generation in Germany for 2012 is shown below. On a countrywide basis, the output varied over more than two orders of magnitude from a minimum of 0.115 GW to a maximum of 24 GW. It is clear that a large amount of extra infrastructure will be needed in order to smooth out this erratic output to something that better resembles the demand profile. Solar PV is of course even worse because it generates no power whatsoever for the majority of the time and delivers most of its energy in the few hours around noon.

German wind output 2012

Again, there can be no doubt that we have a wide range of technically proven solutions to this problem. When just looking at the area of energy storage there are many proven ways to store energy in chemical, kinetic and various potential forms. But again, the challenge is to deploy these solutions at a lower cost than that involved in the refinement of fossil fuels.

A coal power plant is the most expensive kind of fossil fuel refinery. For example, a standard coal-fired power plant must sell electricity for about $0.06/kWh, but coal at $100/ton costs only $0.015/kWh. The remaining $0.045/kWh represents the price of refining coal to electricity and arises primarily from the low efficiency and high capital costs of coal plants.

So, how does energy storage compare? Well, a recent test of lead acid and Li-ion batteries found that these technologies could store energy for about $0.34 and $0.40 per kWh over their respective lifetimes. Hence, we again have to conclude that the most ideal renewable energy storage solution is still about one order of magnitude away from challenging fossil fuels on a level playing field.

The Li-ion battery throughput cost of $0.40/kWh mentioned above was calculated for an initial cost of $600 per kWh of capacity. Most optimistic projections for Li-ion battery costs give longer-term prices at about $200 per kWh of capacity. At these prices, battery storage would be about triple the price of refining coal to electricity. Again, we need a technological miracle.

Final word

So, these are the facts. In order for intermittent renewable energy sources such as solar PV to effectively compete with fossil fuels like coal, both the price of installed solar panels and the price of battery storage will need to reduce by a full order of magnitude. In addition, optimistic long-term projections state that both solar panels and battery storage will reach technological maturity at roughly triple the cost of their fossil fuel counterparts.

Does this mean that it is fundamentally impossible for renewable energy to trump fossil fuels? Well, I would stop short of saying that, but, from this analysis, it appears unlikely that we will see a large scale market driven displacement of fossil fuels by renewable energy in the first half of this century.

Ramez Naam's picture
Ramez Naam on Aug 6, 2013

You write that the most optimistic estimates see installed cost of solar leveling off at $1.44 per Watt.  That’s surprising, as the installed cost at utility scale is already in the neighborhood of $2 per Watt, having dropped from $4 / Watt since 2011.  That trajectory makes a floor of $1.44 look quite unlikely.

See this post, also at The Energy Collective:

The last century of experience tells us that the cost of standardized mass manufactured goods, including deployment, falls towards zero.  There’s very little reason to believe that solar panels, invertors, wind turbines, batteries, or any other piece of renewable technology will be any different. Indeed, as I think we all know, we’ve seen the cost of solar PV (the modules themselves) drop by a factor of 20 over the last 30 years, and Li-ion batteries drop by a similar factor over the last 20 years.  

It’s legitimate to question what the future slope of that curve will be, and to question whether the ‘soft cost’ and balance of system costs can drop at nearly the same rate (now that they dominate the overall cost) but it’s clear that they will to decline.  Rate and timing are the issues (and they are very real issues), not fundamantal limits to the bottom cost.

Rick Engebretson's picture
Rick Engebretson on Aug 6, 2013

Thanks Schalk for the civil presentation. It is worth a civil response. Basically, we need different renewable energy concepts.

First, there is a reason NASA looks for water on Mars to search for life. It is water, specifically the proton, that is ultimately excited by solar energy to store energy in chemicals. Any physicist knows the electon excited state is fleeting. The difficulty storing electron volts derived from silicon crystal conduction bands or magnetic induction has proven many physicists right. In short, we are working with the wrong charged particle.

Second, we don’t know how much biology can do. We do know that watering and fertilizing our garden and lawn makes them grow better. We also know there are many plant forms. And we know much of the Earth is currently too dry and infertile to grow anything. And we know plant growth is a CCS method that has been around longer than us, creating air and coal for us.

Lastly, agriculture was the first notable step of humans out of cave dwelling hunter gatherers. I don’t object to fossil fuel hunter gatherers. But when some boneheads think we grow corn for the waste ethanol, or grow wheat for the straw, it is hard to discuss much.

Nathan Wilson's picture
Nathan Wilson on Aug 7, 2013

I like the graphic above which shows the comparative size of the Earth’s energy resources and current human demand.  It makes a great response to claims that the energy-rich lifestyles enjoyed by those of us in developed countries are somehow unsustainable. Although I would complain that where an enormous nuclear bubble ought to be  (including thorium and uranium for use with breeder reactors), a small “economically recoverable Uranium-235” bubble is placed; like the solar and OTEC resources, these nuclear resources require technology which is pre-commercial but prototyped; see D.MacKay

Nathan Wilson's picture
Nathan Wilson on Aug 7, 2013

I would dispute what appears to be an underlying assumption in this post: that for an energy source to  “compete with fossil fuels in an open market” requires a lower cost than fossil fuels.  I can think of two groups of real-world exceptions to this assumption.

In developed nations, we already pay more than the minimum prices for our energy, in order to improve the emissions of pollutants and improve safety.  We mine coal in a way that reduces the incidence of black lung desease among miners.  Rather than buying coal from the lowest bidder, we pay extra and transport it larger distances in order to get lower sulfur and mercury content.  We buy and install expensive filters to reduce particulate emissions in coal exhaust.  We also pay extra for diesel fuel with low sulfur content and burn gasoline in a way that trades away some fuel efficiency for reduced NOx emissions.

In a small segment of our automobile fleet, we pay extra to get freedom from fuel efficiency regulations.  In the US, manufacturers of gas-guzzeling luxury cars must sell more economy cars (or buy credits from those who do, or add extra-cost flex-fuel compatibility) in order to meet the Corporate Average Fuel Economy regulations.

So clearly, we’ll pay extra for cleaner energy, furthermore I’ve seen estimates of the external cost of fossil fuel use that suggest that we would save money by switching to a cleaner electricity source like nuclear.

Nathan Wilson's picture
Nathan Wilson on Aug 7, 2013

Regarding the renewable energy resource giants, sun and wind, I agree that they are unlikely to be viable in conjunction with batteries any time soon.  However, when they are used with demand-response fuel synthesis making transportation fuel, the intermittency problem is largely solved (here I refer to desert CSP with thermal storage and heartland plains wind, not “cloudy-town rooftop PV” or local wind).  When the energy going to fuel synthesis is of comparable size to the electric demand, the dispatchable load is large enough that very little syn-fuel must be converted back to electricity.

As far as cost goes (i.e. an independent check of Jim Bairds calculations above), note that one gallon of gasoline has 34.4 kWh of energy (same for 1kg of H2).  Using the US DOE’s EIA data for the cost of wind energy, $0.086/kWh, and assuming 60% conversion efficiency, and guessing a 50% cost increase due to added capital cost, we get $7.40/gge (gallon_of_gas_equivalent).  This is competitive with gasoline today, assuming an H2 or ammonia fuel cell vehicle with 2x the energy efficiency of a gasoline ICE (affordable implementations of which are admittedly futuristic), and is in the ball-park for ammonia-fueled ICE cars (affordable today, with 20% better energy efficiency than gasoline ICE). 

This is not to say that the renewable solution would be cheaper than fossil fuels or nuclear but only that abandoning our energy-rich lifestyle is unnecessary.

Kevon Martis's picture
Kevon Martis on Aug 7, 2013

But the only way to argue that the renewable transition is not going to happen is to to have blind folds on and pretend the world and technology will stay as they were yesterday.”

How certain are you that renewables are the only sector that will advance technologically and that they are in fact the next evolutionary step from thermal generation?

Is this simply an article of faith?


Kevon Martis's picture
Kevon Martis on Aug 7, 2013

“The last century of experience tells us that the cost of standardized mass manufactured goods, including deployment, falls towards zero.  There’s very little reason to believe that solar panels, invertors, wind turbines, batteries, or any other piece of renewable technology will be any different.”

But not advanced nuclear, thorium. CCGT or coal with CCS?

That is odd, isn’t it? Only the renewable sector will advance?

I am confused.

Schalk Cloete's picture
Schalk Cloete on Aug 7, 2013

Thanks for the comment, Ramez.

Yes, projections of technological learning curves into the future is always a rather subjective exercise which will have significant impacts on opinions about our energy future. You and I have different subjective interpretations around this point and therefore see different energy futures. 

Here are a few of the elements impacting my view:

  • The wind turbine learning curve seems to have already stopped some years ago. The fundamental limit here is that the diffuse nature of wind requires very large amounts of concrete and other building materials per Watt which have reached technological maturity long ago. 
  • My view is that the economies of scale for solar PV has mostly been had at this point and that it would look a lot less impressive if various kinds of government support was backed out and solar PV companies actually had to make a profit like normal businesses. 
  • Soft costs are now the major component of PV and these are dropping much more slowly. Again, the fundamental limit is the diffuse nature of renewables which demand that vast areas be covered with material, energy and labour intensive PV panels. Perhaps one day solar panels will just be a cheap and highly durable piece of plastic that you can install yourself at home, but, if this is possible, I think it is still many decades away. 
  • I think that, in the real world, the intermittency issue will be much more costly to overcome than most people expect. Material and energy intesive storage technologies face very real fundamental limits. 
  • I worry about the ability of our economies to maintain the growth rates required to advance renewable energy technology if energy prices continue to rise. Here, the fundamental limit is the percentage of our GDP that can be dedicated to energy before the economy starts contracting. 

It would be interesting to exchange some more detailed views with you on these points if you have the time. 

Ramez Naam's picture
Ramez Naam on Aug 7, 2013


I’d be delighted to discuss in more detail.  My email address is easy to find on my website.

I agree with you on the wind turbine learning curve, though somewhat more optimistic (with admitted uncertainties) on the other issues.



Ramez Naam's picture
Ramez Naam on Aug 7, 2013

It is in a sense odd that the cost of nuclear power plants has been rising rather than falling.  One explanation for this (which I favor) is that nuclear power plants, at least within the United States, are not standardized mass manufactured goods.  Were they built in a more standardized assembly-line manner, we should see economies of scale drive their cost down.  I have some hope for small modular reactors in this regard, though their costs have yet to be demonstrated.

Similarly, all reasonable cost assessments of CCS use a model that shows a high cost per ton for CCS initially, which then drops over time as CCS matures – in line with our experience over time.

With coal and CCS, a counteracting wrinkle is an upward price pressure caused by exhaustion of the best coal seams and CCS locations, which can work counter to the downward price pressure of mass production.



Schalk Cloete's picture
Schalk Cloete on Aug 7, 2013

Please consider the following counter-arguments:

1. Your calculations assume that you can sell electricity back to the grid at residential prices and that you do not carry any of the costs related to intermittency. In an open market, any PV owners who are still connected to the grid for the sake of a secure 24/7 electricity supply would sell any excess electricity back to the grid at current wholesale prices which would suddenly make the deal appear much less attractive.

As long as PV only makes a marginal contribution to the local electricity supply, ignoring the intermittency is fine, but later on (when penetration levels increase to 10% and above), intermittency will begin to invoke substantial added costs (see my previous article). For example, if no storage is implemented, solar PV will start to supply more than 100% of the total electricity demand around noon on some hot days if the total penetration level of PV is such that it contributes 10% of total yearly electricity. In this case, there will be a large over-supply of electricity around noon on these days, leading to very low (or even negative) prices. This will mean that PV owners generate most of their electricity when the price is close to zero and buy more expensive grid power when the sun is not shining. To counter this, PV owners will of course have to buy batteries for about $4/W of installed PV with a lifetime of 10 years. 

2. I agree, but many renewable energy proponents claim that we can easily transition to a 100% renewable energy society using technology that is available today. I think this claim is very false indeed. If you look in the article, I do say that we might see future technological miracles, but that achieving the dreams of renewable energy activists with currently available technology will not be possible. 

However, developing, commercializing and scaling up a brand new technology to the point of 100 GW of installation per year will take many years (even decades), hence my statement that we will probably not see a clear market-driven displacement of fossil energy by renewables in the first half of this century. 


Schalk Cloete's picture
Schalk Cloete on Aug 7, 2013

I agree that we are willing to pay for clean energy to a certain extent, but I have two main concerns with using this argument to argue for a global market-driven deployment of renewables:

1. Every year of slow/stagnant developed world growth that goes by further strengthens the theory that energy prices in developed nations are already at the level where they substantially suppress economic growth. Debt is still increasing, populations are still aging, employment rates are still falling and inequality is still rising despite years of extraordinary monetary policy from the Feds. Therefore, I just don’t think we can afford to make our energy any more expensive than it is today. 

2. Over coming decades, the problem is not really the rich world with its willingness to pay for clean air, but the developing world that wants to have all the energy intensive material possessions of the rich world and place very little value on clean air. The air quality in many Chinese cities is horrendous, but coal-fired electricity costs $0.03/kWh and this allows them to achieve enormous growth rates. This Chinese growth apitite is far from satisfied and India and Africa would like nothing more than to do the same.

That being said, I agree with you that nuclear is a good and proven technology which provides low-carbon electricity at reasonable prices. It should definitely see substantial expansion over coming years. 

Schalk Cloete's picture
Schalk Cloete on Aug 7, 2013

Yes, transport fuel synthesis during intermittent peaks would be a good way to counter the intermittency issue. However, as you said, one would need a reliable supply of solar and wind so that supply is not disrupted by seasonal or weather-related longer term dips. 

However, H2 from electrolysis remains triple the price of H2 from reforming. And this is for a constant production rate. If production continuously has to be ramped up and down to only function at intermittent production peaks, this price would multiply. 

In addition, the most important thing that one would need to make this work is tens of millions of hydrogen vehicles and extended hydrogen distribution networks. This will certainly not happen within the timeframes envisioned by most renewable energy advocates or within the timeframes dictated by climate science. 

Edward Kerr's picture
Edward Kerr on Aug 7, 2013


I see several major holes in your analysis. It’s based on some ideas that need to be examined. First that any transition away from fossil fuels MUST be free market competetive and that we, as a species, have the option to continue altering the atmosphere in the reckless manner that we have been to date. You have omitted some major exigent factors that cannot be ignored. Coal (and other carbon based fuels) have inpacts on health, climate and the environment that we pay for in taxes. insurance premiums and possibly in the near future our very lives. Were those costs reflected in our electric bills or at the pump your numbers would simply not “crunch”.

Bottom line: Fossil fuels will run out soon (in geologic terms) and their continued use will lead to a Permian type extinction event. Consequently we MUST develop a carbon neutral energy production paradigm regardless of perceived “variability” or profit/market concerns. Retooling energy, while we still have the necessary resources, will be the only way to avoid the economic catastrophe of declining coal and oil and the spectre of human extinction. Before you poo poo that do a bit more research.


Edward Kerr

Schalk Cloete's picture
Schalk Cloete on Aug 7, 2013

Just to clarify: I fully recognize the urgency of climate change action and I fully support a revenue-neutral carbon tax. My point is just that, if government got out of the energy business and instead only imposed the carbon tax necessary to get the free market to reduce the carbon intensity of our economies in the most cost-effective way, this would happen chiefly through CCS and nuclear instead of through expensive and impractical renewables. My fear is that the expense and practical challenges of renewables will abate only token amounts of CO2 at a very high cost and thereby greatly hamper the ability of our economies to deploy the large-scale solutions necessary for effective climate change mitigation.

For my views on fossil fuel externalities other than CO2, please see the discussion I had with jan Freed and Lewis Perelman below this article.

The articles I publish on TEC come from a very large amount of research into the intricate connections between our environment, our economy and our society. It is a systems-based perspective that many analysts lack and leads to some conclusions that might not be so popular from the current environmentalist paradigm.

Yes, if you look at it from an environmental point of view only, you can easily make statements like we MUST develop a carbon-neutral paradigm regardless of any other factors. However, if you acknowledge that our advanced debt-based economies demand very high quality energy resources (at least an EROI of 10:1) and that solar PV with only 4 hours of storage only returns an EROI of 2:1, you will realize that the renewable energy technology currently being deployed simply cannot sustain our economies. Also, if you understand societal effects such as our aging populations, increasing inequality created by the extraordinary monetary policy currently being implemented and the growing material aspirations of the developing world, the problems with the technological forcing of expensive and impractical renewables become clear.

Our society will have to undergo major socio-economic changes in the first half of this century. This transition will be wrought with challenges and we certainly don’t need to make it any harder on ourselves by insisting on abating CO2 in the most expensive way possible. We still have lots of fossil fuels (which can be used in conjunction with CCS) and even more nuclear fuels. I simply propose that we deploy these cost-effective and practical technologies to cut CO2 in the fastest and most cost-effective manner while we progress through this very challenging time in our history. Sure, renewable energy RD&D should continue at full speed, but we should not force the deployment of these technologies before they are can actually sustain our economies. 

Edward Kerr's picture
Edward Kerr on Aug 7, 2013


Perhaps, based on your reply, we are not so far apart on the many issues that coincide with fossil fuels and climate. (I’ll read the article you referred me too when I have a bit more time) We are truly in a dilemma and I’m beginning to fear that all of the competing factions will prevent a solution.

When you say nuclear I trust that you are referring to Thorium reactors.

Thanks for the trply and clairification.



Schalk Cloete's picture
Schalk Cloete on Aug 7, 2013

No problem, Ed. I was thinking that this article might step on a few green toes and that it might be necessary to clearly explain that I am no climate change denier.

You make a good point about the competing factions. A very worrying feature of our interconnected sustainability crisis is its immense complexity. This great complexity creates a situation where groups with totally opposite viewpoints can build legitimate-sounding arguments and gather large amounts of support for causes which attempt to move in completely opposite directions. Just some examples I can think of now:

  • Climate change and peak everything (deniers vs. alarmists).
  • The correct response to climate change and peak everything (business as usual vs. total makeover)
  • The correct medium-term decarbonization strategy (100% renewables vs. CCS & nuclear)
  • The nature of the economic crisis (insufficient regulation vs. excessive interference)
  • The correct response to the economic crisis (stimulus vs. austerity)
  • Correct response to the entitlements Ponzi scheme (continued borrowing and printing vs. harsh reforms)
  • Conflict over the large burden of public debt and unfunded liabilities (young vs. old)
  • The correct response to inequality (capitalistic wealth creation vs. socialistic wealth redistribution)

I’m sure there are many more, but the point is just that I cannot really see this amount of clashing opinions leading to anything other than perpetual political stalemate and inaction. It certainly is a very worrying factor. 

Edward Kerr's picture
Edward Kerr on Aug 7, 2013


Lack of political will is, as you note, the core of not only our climate/energy problem, but most of our concurrent problems as well. It’s particularly disturbing to me as I have grandchildren and the situation is more dire than most can conceive.

I’m still in the camp that calls for renewables vs CCS and nuclear. Yes, there are inconveniences to renewables but with a revamped grid technologies like CSP/molten salt, wind, other solar, tidal, hydro (though it is already a mature technology) and algal oil, I believe that we could have a carbon neutral energy paradigm. One can also hope for some zero point energy but I’m not holding my breath there. Sadly, as you point out, the divisions amoung us will likely prevent any meaningful change in time to avert the obvious consequences.



Mario Montero's picture
Mario Montero on Aug 7, 2013

Why compete in an open market ?

In fact, markets are the big obstacles renewables face.  Markets were designed for predictable energy, coal, nuclear, gas.  But they don’t know what to do with renewables which have seasonal, daily and even hourly variations (in the case of wind and solar).

Go look at the case of any country without an electricity market.  Say Costa Rica, with 92% penetration of renewables.



Roger Brown's picture
Roger Brown on Aug 7, 2013

My point is just that, if government got out of the energy business and instead only imposed the carbon tax necessary to get the free market to reduce the carbon intensity of our economies in the most cost-effective way, this would happen chiefly through CCS and nuclear instead of through expensive and impractical renewables. 

Why CCS and nuclear? Whichever one is cheaper would win the day in a free market. If it happens to be CCS then we would have to wait for rising coal prices to determine the successor technology. I sure hope that all the CO2 stays where we put it.


However, the hope that an economic system governed by ‘free markets’ (i.e. private credit markets and the unbounded competitive accumulation of consumption rights) will be able to effectively limit CO2 emissions and keep private credit markets from collapsing seems relatively remote. The system of private credit markets is already groaning under its debt load. A carbon tax large enough to make a significant impact on CO2 emissions would probably cause a financial collapse. If we really want to address ecological limits then we need to address limits to economic growth. We need to agree upon a standard of consumption by a social/political discussion that is completely independent of the desire of rich people to preserve and increase the value of their financial holdings and is strongly dependent on intelligent analysis of the earth’s resource base, both mineral and biological. Once a standard of consumption is agreed upon we can use competitive methods to produce the goods and services required to meet that standard as efficiently as possible. But so-called ‘free markets’ and unbridled consumerism as they now exist are not going to get us where we need to go.

Nathan Wilson's picture
Nathan Wilson on Aug 8, 2013

Yes, I agree that carbon-free syn-fuel made from sun or wind would be much more expensive than a product made in the US from fossil fuel with CCS (nuclear would be in the middle for initial levelized cost, but as is usual for nuclear, would deliver low average cost over the plant life).  I have no aversion to ammonia made from fossil fuel; the important thing for me is the clear path to sustainability.  

It seems likely that in China and other developing countries with low labor costs and large oil imports, things could be different (note that China makes nuclear plants for $2/W, and likely has cheap wind too).

An affordable hydrogen fuel cell car is the holy grail we strive toward many decades in the future (the DOE’s equivalent of a Mars program).  Ammonia fuel cars work today (see Korean NH3 proto), and are about the same complextity/cost as gasoline powered cars.  We could easily be building them by the tens of millions/year, 10 years from now, if we choose to do so.

Note also that ammonia fuel is a great way to smooth seasonal supply/demand mismatch in energy supply.  With refrigeration, ammonia can be stored at normal atmospheric pressure.  This means that warehouse-sized insulated tanks are feasible.


Here’s a good intro to ammonia fuel:  NH3 – The Other Hydrogen

Here is a presentation on ammonia safety.  

Nathan Wilson's picture
Nathan Wilson on Aug 8, 2013

The IEA does not have data for Costa Rica.  

What are they using?  Hydro? Biomass?  Those are dispatchable, and small energy resources.  They tell us nothing about the variable, larger resources of wind and solar.

We know how to handle these variable renewables in a non-fossil energy portofolio, but we ignore the obvious solution because we know it makes solar and wind very expensive.  The only solution today to the variability (other than continuing to burn fossil fuel to supply the majority of load) is fuel synthesis.

Obviously, a breakthrough in energy storage could occur any time, but that’s where we are today.

Nathan Wilson's picture
Nathan Wilson on Aug 8, 2013

We have four technologies for reducing CO2 emissions: efficiency, renewables, nuclear, and CC&S.

Deep reduction in CO2 will be extremely difficult, so it is absolutely crazy how many so-called environment groups want to limit our options to only two.

Nuclear and CC&S are the cheapest ways to limit emissions, withholding them hurt the poor (who still need energy), and greatly increase our odds of failure (note that nuclear+hydro is the only solution which is scalable and proven via past experience).


Schalk Cloete's picture
Schalk Cloete on Aug 8, 2013

There is no fixed price for CCS or nuclear. Depending on the circumstances, either one can be the most cost effective option. Their costs are very similar though and we will have to leave it to the free market to decide which one is best for any specific location/application. 

Free market capitalism is not a perfect system – no system is. However, there can be no doubt that it is the system through which we can get things done in the most cost-effective way. However, with all the money printing and interest rate manipulation from the feds and all the government favours available to special interest groups, our current system is far from a free market. 

What you say about consumption makes sense, but how are you going to implement that? To me, a revenue neutral carbon tax is the most effective method. It will make carbon intensive products more expensive and low-carbon products cheaper, thereby sending the price signals that the free market needs to mitigate climate change in the most effective way. 

Schalk Cloete's picture
Schalk Cloete on Aug 8, 2013

This is why I so badly want the government to stop picking winners and losers, just impose a revenue-neutral carbon tax and allow the free market to work. In this case, we would not be having this conversation because CO2 abatement will automatically proceed by whichever method is the most cost-effective. As long as low-carbon energy is driven primarily by politics, however, things will proceed in a very slow and very expensive manner. 

Schalk Cloete's picture
Schalk Cloete on Aug 8, 2013

Thanks Nathan. I have been following your advocacy of NH3 over H2 for some time and I agree with you that it appears to have many attractive advantages. However, I think this pungent and poisonous gas will face the same problems as CCS and nuclear in that it lacks the ideological clean / zero-impact ideal of renewables + hydrogen. 

As an engineer I definitely hear you, but, when looking around at what drives the low-carbon energy market today, I can see many potential problems with public acceptance. 

Schalk Cloete's picture
Schalk Cloete on Aug 8, 2013

Yes, nuclear is a bit more expensive than conventional fossil fuels (see the OpenEI database for example). However, when a carbon price is instated, nuclear will become competitive with fossil fuel plants equipped with CCS, thereby making it a much safer investment. 

Regarding the coal industry sponsoring CCS, the problem is that no amount of research can give CCS a negative price. In other words; fossil fuel plants with CCS can never become cheaper than standard fossil fuel plants. It is therefore not in the interests of the private sector to invest in CCS before a steady carbon tax is on the cards.

Given the uncertainty surrounding the timing and nature of carbon taxes, it is no wonder that CCS is not being deployed. However, the moment that it clearly becomes more economical to capture CO2 than to emit it, we will see rapid CCS deployment.  


Schalk Cloete's picture
Schalk Cloete on Aug 8, 2013

I think there are two important points that you are missing here:

1.The electricity price is determined by the demand for dispatchable power, not the total demand.

2. The demand peak usually occurs in the late afternoon / early evening, not at noon.  

Regarding point 1, electricity markets are very adept at using higher prices to bring additional supply online in periods of high demand. However, this implicitly applies only to dispatchable power sources (thermal power stations and hydro). Obviously, solar and wind have to sell their power whenever it is generated and can therefore not respond to such price signals (in the absence of storage). 

A good example is given on the right hand side of the figure on this page. This graph gives the German power supply breakdown for a typical summer week when Germany will have 70 GW of solar installed. 70 GW is almost excatly double that which Germany has at the moment and will therefore cover about 10% of its total yearly electricity supply. 

As you can see on the figure, the mid-day solar surge reduces the demand for dispatchable power to almost nothing on sunny days. Now since the potential dispatchable supply will be much greater than the demand for this dispatchable supply during these times, the prevailing electricity price will be very low. And since solar power owners cannot choose when to sell their power, they will have to sell most of it at these very low prices. In the meantime, utilities will have to charge higher prices during times of high dispatchable electricity demand (when the sun is not shining) in order to remain profitable. Thus, solar PV owners will have to sell low and buy high.  

Regarding point 2, it is commonly known that electricity demand typically peaks in the afternoon/evening. This even happens on very hot days when lots of airconditioning is used because this is the time when building structures with a high heat capacity reach their maximum temperatures and when people get home and try to cool these hot structures down with their aircons. 

The problem with solar caused by this point is the very rapid ramping required as solar supply falls at the same time as demand rises during the afternoon. The latest example of this is California’s “duck graph“. The rapid ramping of dispatchable sources required by the duck’s neck will probably require some degree of energy storage already at fairly low solar PV penetrations. 

Finally, my mention of the 100 GW per year target was aimed at the totally new technologies that I think will be required to really challenge fossil fuels (e.g. organic PV). I will be very surprized if the standard first generation PV technology being deployed today ever starts displacing meaningful amounts of fossil fuels without any subsidies. 

Alain Verbeke's picture
Alain Verbeke on Aug 9, 2013

” Firstly, energy does not like to be concentrated, hence the fact that the average commercially available solar panel is only about 13% efficient. And secondly, because the energy source is so diffuse, vast areas need to be covered in order to harvest this diffuse energy. As a result of this challenge, it was previously calculated that the solar panel price needs to fall to about $0.31/W installed in order to compete with coal at $100/ton. “

This bureaucrat is again proving that he does not know what is going on in the real world. My PV panels on my home roof (installed in 2010) achieve 15% energy conversion efficiency (Bisol), and recent cheap SunPower PV panels commercially mass produced in 100% automated production lines  (made in the  USA) are above 18% efficiency.

The vast area’s are already being covered. Many big flat plant and office building roofs are being carpeted with solar PV panels, to send the electricity production down to the users on the floor, were it is immediately consumed, instead of piped in from far away, requiring an expensive grid extension.

i do not care about the price of coal. My fossil fuel and nuke power plant electricity bill before installing solar PV panels was above euro 20 cents per consumed kWh, in Belgium. Taxes, high grid maintenance and expansion costs, import duties on fossil fuels (Belgium imports 100% of it’s fossil fuels), make it an expensive proposition. Today, my electricity bill = zero, since my PV panels are put on my home’s roof.

I recently was contacted by Tractebel, a Belgian engineering corporation. They needed a dude to help install a onshore 30MW windturbine park in desertic sun rich Mauritania, near the sea 20 km form the capital Nouakchott. Cheaper than importing coal or building a nuke plant, given that the sea wind regime was very predictable and constant, and electricity consumption in that country is too small to allow a big centralised PP to be built.

Fossil fuels power plants are getting more expensive by the day, and renewables PP are getting cheaper by the day. I built a 250 000 ton per year biodiesel manufacturing plant in 2008, who uses as feedstock waste animal fat and waste cooking oil that cannot be dumped in landfills anymore, and the biuodiesel is then used to power car engines (6% biodiesel mixed in 94% petrol diesel) or is used to be burned in caterpillar piston genset coupled to an alternator connected to the centralised grid.

Next to this biodiesel plant, someone else built a mammoth biogas production plant, who converted boatloads of agro and home food/vegetable waste into methane and compost, methane being burned in turbine/piston genset rows and the compost being sold to flower and gardening wholesale customers, while getting rid of a massive amount of vegetable city waste that cannot anymore be dumped in a landfill.  

fossil fuels rose in the 20th century, matured and now the same is happening with renewables in the 21st century. I hope we will continue on this road, and I hope we will continue to search for even more cheaper ways of recycling wastes into energy and even more cheaper ways to produce clean energy. The will is there, you only have to look how horribly poisoned China is with it’s 70% of electricity coming from coal PP, and only have to remind yourself of the smog clogged London city movies of Dickensian origin to remind yourself of the benefits of coal home heating…..

No need to reply. I have unchecked the notify box, since I am not interested in debating you, I already have made my personal choices, using my own savings money in the process….

Michael Keller's picture
Michael Keller on Aug 9, 2013

The thesis that a carbon-tax is “needed” rests on a soft foundation that is becoming ever more rotten – i.e. man-caused-global-warming-catastrophe. The models have been unable to replicate the +15 year “pause” in global temperatures, which means there is something going on not properly accounted for by the climate models. The panic to “do something” is misplaced and unnecessary.

Rather than place forlorn hopes on the government White Knight of “taxing carbon” saving the day, reduce costs. If renewable energy cannot compete, then it belongs on the scrap-heap of economically dumb ideas.

Also, the cost of power generation is not static. Economic forces are at play and that means productions cost are pushed ever downwward by more cost efective and efficient machines as well as advances in producing fuels (e.g. “fracking” and shale gas).

Alain Verbeke's picture
Alain Verbeke on Aug 9, 2013

” Also, the cost of power generation is not static. Economic forces are at play and that means productions cost are pushed ever downwward by more cost efective and efficient machines as well as advances in producing fuels (e.g. “fracking” and shale gas). “

That is if you happen to sit on large deposits of fossil fuel resources that are easily extractable….  Where I live, in tiny Bellgium, the only fuel resource we still have are sea wind sun wood and city and agro wastes, unless we import fossil fuels ….

Randy Voges's picture
Randy Voges on Aug 9, 2013

Looks like Schalk hit a nerve.

Jonathan Cole's picture
Jonathan Cole on Aug 9, 2013

This smug reliance on phony economic principles is the reason we have a problem. If the true costs of the myriad of unintended chemistry and emissions from fossil fuel extraction, processing and combustion were part of the the price of energy from such resources, renewables would handily win the economic competition. And that applies to nuclear energy as well.

In business school you learn that economic/business systems must accurately account for their true costs. This includes all costs to all stakeholders. If you rob someone of their health or life in order to make a profit because you fudged the books in cost-accounting, that is not only mismanagement, it is actually a criminal act, malfeasance, misfeasance or nonfeasance as defined:

Malfeasance is a comprehensive term used in both civil and Criminal Law to describe any act that is wrongful. It is not a distinct crime or tort, but may be used generally to describe any act that is criminal or that is wrongful and gives rise to, or somehow contributes to, the injury of another person.

Malfeasance is an affirmative act that is illegal or wrongful. In tort law it is distinct from misfeasance, which is an act that is not illegal but is improperly performed. It is also distinct from Nonfeasance, which is a failure to act that results in injury.

The distinctions between malfeasance, misfeasance, and nonfeasance have little effect on tort law. Whether a claim of injury is for one or the other, the plaintiff must prove that the defendant owed a duty of care, that the duty was breached in some way, and that the breach caused injury to the plaintiff.

One exception is that under the law of Strict Liability, the plaintiff need not show the absence of due care. The law of strict liability usually is applied to Product Liability cases, where a manufacturer can be held liable for harm done by a product that was harmful when it was placed on the market. In such cases the plaintiff need not show any actual malfeasance on the part of the manufacturer. A mistake is enough to create liability because the law implies that for the sake of public safety, a manufacturer warrants a product’s safety when it offers the product for sale.

Mark my words, one day soon this debt will have to be paid by all those involved, including those engineers/scientists who have been working on the payroll of these criminal enterprises.

In any case, you are clearly not very knowledgable about battery storage, costs and durability. We are already developing an integrated PV/with battery backup module that we call SunPax that uses 20 year, high specific energy batteries already in mass production by a major manufacturer. You just don’t know what you are talking about.

In less than 10 years, following long-term historical manufacturing trend in the solid state electronics industry, such products as SunPax will be producing dispatchible and uninterruptible solar energy for as little as $0.08/kWh to the owner. If the Utilities are smart, they will be the owners. If not they will go the way of the dinosaur.

Mike Barnard's picture
Mike Barnard on Aug 9, 2013

Mr. Cloete, who works with carbon capture processes, would have us believe that carbon capture and sequestration, which outside of limited value in enhanced oil recovery has no direct economic value,  is more viable than renewables. Amusing.

As others have pointed out, he’s using old data and ignoring negative externalities in his perspectives on the value of renewable energy. It’s so easily debunked, it’s not worth getting into more.

His second point is fascinatingly incorrect however. Energy storage’s heyday was in the 1950’s in California, when huge amounts of it was built. Why? Nuclear plant proliferation. All of those nuke plants couldn’t be turned down at night, so it was cheaper to build hydro storage and pump water into them at night to balance peaks during the daytime. Sensible, realistic, and ignored by Mr. Cloete.

What’s happening now? Well, 45 jurisdictions around the world are now getting 60% plus from renewables. Some are hitting 70%. A lot of that is hydro, but a remarkable amount is from wind and solar. Texas regularly exceeds 25% of demand from it’s wind energy alone.  

If Mr. Cloete’s argument were in any way correct, then all of these jurisdictions must have enormous amounts of storage implemented, correct? So, do they? No, they don’t. These jurisdictions use passive storage in the form of unused hydro, grid interconnection and unburnt fossil fuels to achieve these remarkably high levels of renewables.  

Mr. Cloete is correct that getting to 100% everywhere will require storage. But it will be balanced against just building more easily curtailed renewables capacity, more grid-interconnectedness and smarter demand management as an economic choice, and it won’t be necessary in nearly the degree that anti-renewables folks seem to believe. Odd how they refuse to look at what’s happening in the real world.


For the record, I encourage continued work and investement in CCS. It’s part of the toolkit for solving the mess we’ve gotten ourselves in. But claiming it’s a silver bullet is just silly, and attacking renewables to promote it is sillier.



Schalk Cloete's picture
Schalk Cloete on Aug 9, 2013

Some points for your consideration:

1. It cannot be disputed that dispatchable electricity from fossil fuels + CCS will be much cheaper than dispatchable electricity from intermittent renewables + storage. 

2. For my views on fossil fuel externalities other than CO2, please see the discussion I had with jan Freed and Lewis Perelman below this article.

3. I have no problem with hydro (although many greens do). This article is about intermittent sources of wind and solar which currently supply about 1.5% of total world energy. Due to this small contribution, it will be some time before the intermittency issue begins to cause real practical problems. 

4. Please see my previous article where I discuss the increasing costs of intermittency with increasing levels of penetration. You will see that I accept that intermittent sources can be accommodated by more ramping of fossil fuel plants and more extensive distribution networks when the penetration level is below 20% (although this does come with a price tag). 

Nathan Wilson's picture
Nathan Wilson on Aug 9, 2013

“… looking around at what drives the low-carbon energy market today…”

Alas, it seems that most renewable enthusiasts today would rather gamble on a future breakthrough in biofuel or batteries than accept a stinky bird-in-the-hand like NH3. But who can see tomorrow?

Schalk Cloete's picture
Schalk Cloete on Aug 9, 2013

For my views on fossil fuel externalities other than CO2, please see the discussion I had with jan Freed and Lewis Perelman below this article.

If solar/wind plus storage ever produces reliable dispatchable power at $0.08/kWh, I would happily advocate this solution. Also, I would be happy to retract my words if the close to one order of magnitude price drop that this requires can be achieved in one decade as you claim. Currently, however, I think this is highly unlikely. 

I should also clarify that I am not anti-renewables, I am just opposed to the technological forcing of economically unviable currently available renewable energy technologies. My reason for this is that such technological forcing results in a very high price per ton of CO2 avoided, thereby abating only token amounts of CO2 while hurting the ability of the economy to fund more cost effective CO2 abatement measures. 

Mike Barnard's picture
Mike Barnard on Aug 9, 2013

My apologies, but your point 1 is a bald and false assertion without support. I appreciate that you have an opinion and are entitled to it, but ignoring the presented argument in favour of a bald and unsupported assertion is not a useful debating approach.

Jonathan Cole's picture
Jonathan Cole on Aug 9, 2013

You really do not seem to get it. CO2 is the tip of the iceberg. You are so focused on your narrow specialty that you do not seem to be aware that the chemistry of combustion is about to destroy the planet’s capacity to provide us with a hospitable living environment. This can only happen because the phony economics of fossil fuels lets people like you act as if they are actually cheap, when, in fact they are unbelievably expensive and not just in the present but ten thousand years into the future. Its not just CO2, it’s the wholesale chemical pollution of the atmosphere, land and water.

As a thought experiment why don’t you try to calculate the costs of remediation for every oil spill, pollution-related death, warfare to protect fossil fuels, and then add to that the climate effects like wild-fires, heat-waves, floods, mega-tornados, enormous hurricanes and massive wearther volatility. But we are not finished yet, because we have not included the acidification of the oceans and the destruction of the planetary ecology, which are probably pinpricks compared to the losses that will result frrom from rising sea levels.

The only way to save the planet from these inevitable  costs is to stop burning stuff and to do that as quickly as possible. That means solar energy with storage and it means energy efficiency and zero waste strategies. The only way that this can happen is if we force the fossil-fuel profiteers to actually pay the true costs of their enterprise and not shove it under the rug in the name of phony profits. There needs to be a huge carbon tax, starting modestly and increasing year by year untiil the economic proposition for phony fossil fuel profits is strangled. Without that, we are entering into a period of rapid extinctions which will inevitably include much of the human race. And I am not talking about 100 years from now. This has already started and it will get worse.

Schalk Cloete's picture
Schalk Cloete on Aug 9, 2013

You will find many sources in the scientific literature putting the costs of first generation CCS at about $40/ton of CO2 avoided. Second generation technologies can do this for $30/ton even for retrofits (this review article is a good place to start). This would equate to an increase of $0.03/kWh over conventional coal power. 

In contrast, as outlined in the article, current Li-ion batteries will add $0.40/kWh to the price of the electricity they store (and this is under ideal constant cycling which would definitely not be achievable in the real world). 

Thus, CCS is about one order of magnitude cheaper than battery storage. 

Jonathan Cole's picture
Jonathan Cole on Aug 9, 2013

Boy, are you behind the times. Lithium Titanate cells already in mass-production from a major Japanese manufacturer have a wholesale cost of less than $0.12/kWh today. And the price is expected to fall. The batteries operate from -30 C. to +55 C., retain 85% of their capacity after 6000 cycles and a properly sized battery coupled with PV according to local capacity factor, can provide deep cycle storage for 20 + years in low to medium power applications – such as household electricity or building integrated applications. By integrateding all components at the PV module level, including power electronics, battery cells and IT modules, these units can be paralleled to any size up to MW arrays. If one module stops working, it informs the operator and all the rest continue working. This bundling of all components at the module level, reduces material costs and allows for UL and other certifications reducing permitting requirements while allowing for very rapid, low-cost  and versatile installation  procedures. This is the future of electrical energy. Why? because it can be done and it requires no huge investments in centralized technologies with no track record.

I have been living on PV with battery storage for thirty years. I have never had a power outage. My amortized costs of batteries has been $10-$15 per month. But I had to add water to my batteries, a bit of a pain in the neck. The new batteries require zero-maintenance. They have 4x the specific energy of the FLA batteries that at ~ $0.13/kWh  have been the only affordable solution until now.


Schalk Cloete's picture
Schalk Cloete on Aug 9, 2013

Thanks Jonathan, can you link me to the independent test that found the cost of $0.12/kWh? I would be very interested to take a look at that data. 

When do you think this technology will be widely available? Currently, PV owners who want a grid-tied battery backup system still have to buy about $4 of batteries with a 10 year warranty for every Watt of PV installed.

Schalk Cloete's picture
Schalk Cloete on Aug 9, 2013

Most of the negative effects you mentioned are related to CO2, including the ocean acidification and the sea-level rises. I agree with the urgency of these long-term problems and the need for a scientifically-derived revenue-neutral carbon tax to properly price in these longer-term negative externalities of fossil fuel combustion.

The other effects (e.g. bad air quality and mining-related deaths) are immediate negative externalities which are directly experienced by consumers, thereby enabling them to price this into their consumption and voting decisions. For example, the incredible 3-decade-long coal-boom in China has had substantial immediate negative externalities (e.g. the horrible air quality in some Chinese cities), but, according to the 2012 World Bank “World Development Indicators” report, has reduced the percentage of Chinese living on less than $1.25/day from 84% in 1981 to only 13.1% in 2008. This is an incredible immediate positive externality which has thusfar outweighed the negative externalities in the minds of the Chinese people. 

Joris van Dorp's picture
Joris van Dorp on Aug 9, 2013


I fully agree with the elements in your assessment and your conclusions, and have done so for about a decade. The high cost of intermittent renewable energies make them unsuitable for a global roll-out in a free market context. If they were only a little bit more expensive than fossil options, there would be no problem. But they are far more expensive, as you have explained, and they will likely remain so.

So I am very happy with your article, the professional and transparent way in which you formulate your arguments and the civilitity with which you engage the nay-sayers and doubters. You are an example to all of us who are in some way engaged in the business of solving grand (wicked) problems such as anthropogenic global warming.

I do have one question about CCS which I would like your opinion about, since I gather you are an expert on it as well.

Having also studied the feasiblity of CCS within the context of eliminating the anthropogenic global warming problem I ended up concluding that while the cost of CC at the power plant was going to be affordable sooner or later – given some incentive – the cost of then taking the carbon and securing it in suitable geological strata was going to be far harder than the proponents of CCS would have it. While there are many suitable geologies, not all coal power plants are located near such geologies. So ultimately, there will need to be a CO2 transport infrastructure that perhaps approaches the footprint (and costs) of the existing infrastructure for natural gas. That infrastructure will need to carry the co2 to places with suitable geological conditions. Futhermore, since such infrastructure will be financed completely on the condition of permanent subsidies (i.e. a carbon tax), owners of such infrastructure are constantly at risk from politicians suddenly phasing out such subsidies and thereby leaving the owners of the infrastructure stranded, which adds significat risk premiums to such projects that hardly exist for the natural gas infrastucture and further increase the overall costs of CCS.

So my question is: is your ultimate cost estimate for CCS of 0,03 $/kWh (for coal PP’s, I assume) including the off-site costs for CO2 transport and storage aspect?

Thank you,


Mario Montero's picture
Mario Montero on Aug 9, 2013

They say a picture is worth a thousand words.  Here’s Aug 8, 2013 dispatch.

(I couldn’t paste the graph here, but there’s a link to it)


You can see, Geothermal (yellow) at the base, wind (white), hydro PPA’s (blue, mostly run-of-the-river plants), ICE run of the river plants (lighter blue), Arenal Complex (light blue, multi year reservoir), fuels generation (red, diesel, bunker or gas), and exchange with neighbor systems (black).

On a yearly basis Costa Rica’s generation goes something like this (data for 2012):

Hydropower           77%

Geothermal           14%

Fuels Generation    8,2%

Wind                   5,2%

Biomass                1%

Solar  …           0,03%

That sums up to 91,8% renewable energy, with a very very low carbon footprint of about 80 tonCO2eq/GWh.

Fuel synthesis ???


Mario Montero's picture
Mario Montero on Aug 9, 2013

Ah, forgot the most important piece.  Costa Rica does not have an electricity market.

Schalk Cloete's picture
Schalk Cloete on Aug 9, 2013

Thanks Joris,

Yes, these are big and emotional issues and people often bring this emotion into their discussions (especially their online discussions). I have simply learned that getting emotional in these kinds of debates will just entrench beliefs on both sides and close down any possibility to objectively interpret the available data. 

About your CCS question, I completely agree with you about the risk from government policy. CCS can never work without a carbon tax and, as long as the framework for this tax remains highly uncertain, CCS investments will be too risky and we will see no meaningful deployment. 

If climate science is correct, however, the threat of climate change should become increasingly irrefutable and urgent over coming decades, making a sufficiently high and steadily rising CO2 price fairly certain. For example, the IEA in their 2012 World Energy Outlook projects that CO2 prices will have to steadily rise over the next two decades to over $100/ton in 2035 if we were to aim for long-term atmospheric CO2 concentrations of 450 ppm. Given that the world will almost certainly still derive the bulk of its energy from fossil fuels by that time, the market fundamentals for CCS would be very strong under this scenario. 

Under the most likely “New Policies” scenario, however, CO2 prices only rise to about $40/ton by 2035, thereby presenting a less clear-cut business case. However, this scenario results in a 660 ppm long term CO2 concentration which may very well trigger various positive climate feedbacks. 

My speciality is CO2 capture, so I am not a first hand expert in transport and storage. However, I know that the total CCS cost breakdown is typically about 70% capture, 10% transport and 20% storage (although this would vary substantially from one cite to another). CO2 transport and storage will benefit from very mature gas pipeline and well technology and is therefore generally considered to be the least technically and economically challenging aspects of CCS.

About the proximity of CO2 sources to suitable sites, some studies have been done to find that this will not limit CCS any time soon. For example, this article examines possibilities in the two biggest polluters (China and the US). In both coutries, up to 400 Mton of CO2 per year can be transported and stored profitably (through enhanced oil recovery), while costs remain very low up to a point between 2500 and 3000 Mton per year. This implies that about 6% of the total emissions of these countries can be transported and stored profitably and an additional 33% can be stored at very low costs. This amounts to about 80% of the CO2 emissions from large stationary sources in these countries. 

Personally, I am therefore not very worried about the transport and storage aspect and focussing primarily on bringing the costs of CO2 capture down. For second generation technologies, this cost promises to be about $30/ton for retrofits and as low as $10/ton for new plants based on Chemical Looping Combustion technology. There are also a number of industries which deliver more concetrated process streams making CO2 capture cheaper. 

But yes, this is all just theory until we see that long-awaited carbon tax…

Jonathan Cole's picture
Jonathan Cole on Aug 9, 2013

I cannot link you to any data. I have signed an NDA which includes pricing.

However, most of the info is public. 2.3 VDC cell , 20 AH, 6000 cycle, to 85% of capacity.

As to your figures for grid-tied battery back-up systems, that is a complete misinterpretation of reality. Nearly all battery backup systems are tremendously expensive because they duplicate the main power system. Only when grid power is down, do they come online and then only for critical loads. They usually use the most expensive AGM batteries (which also wear out the quickest) and since they are only in use a small percentage of the time their actual cost per kWh is astronomical. Only when PV with battery storage is the MAIN system and the grid is the backup does battery storage make good sense. For example, I put three such systems in the field powering 2 person households. 2000 Wp PV, 9.6 kWh battery (nominal) derated 50% to maximize battery life. All costs were:

  • Electronic parts including  PV – $8791.68
  • Electrical parts – $2047.23
  • Batteries – $2083.62
  • Rack and component housing – $1119.97
  • Design, Construction and installation – $5786.12

So you see that the batteries equal roughly 1/5 of the cost of the system in order to provide uninterruptible solar generated electricity 24/7/365. In the rare event that the sky is so dark for a prolonged period that the solar PV is insufficient, the grid automatically comes on and powers the whole system for a short time while also charging the batteries – no shift to critical loads only. In practice this means that the Solar PV provides 98-99% of the electrical energy used annually. No power is fed to the grid, the grid only acts as backup.

Now granted that these systems are small, with the owner investing in the most efifcient appliances that can be purchased at a reasonable price. All modern amenities including refrigerator, dishwasher, microwave, washer/dryer,  power tools, big screen TVs, stereos, computers etc.are powered by this system.

So the idea that batteries are so expensive is really a myth. In such a system as described above, the batteries only store about 1/4 or less of the energy generated. Its mostly needed for night-time use. The next day the batteries get charged again by the PV array which also provides ~95% of the energy used during the day.. In my system, the biggest problem is what to do with surpluses. However there are more and more electrical tools and appliances available and ultimately I will also have an EV.

The reason for the mythical super-high battery cost is that it totally depends on the system design. Most system designers are insufficiently experienced with batteries and therefore generally use too many batteries, because they are using faulty formulae for determing what battery size to use.

So you do the math. 12 VDC, 800 AH battery = 9.6 kWh (nominal it is actually more since the battery’s voltage operates between 12.1 and 12.6 (rest state).Then derate that by 50% to prolong battery life and you get ~4.8 kWh. Operated in the correct charging regime (40% -90% SOC) yields a 90% efficent battery according to Sandia Labs. So 4.8 kWh x .9 = 4.32 kWh per cycle. Operated in the efficient charge regime also maximizes cycle life, .The mid-range L-16 solar batteries (which are used in the above-described system) operated this way using shallow cycling can expect  ~3000 cycles over ten years. that comes out to ~$016/ kWh. The more expansive 20 yearFLA  batteries sized properly for the system and operated this way can yield $0.13/kWh stored.

The new lithium titanate batteries from Toshiba do not need to be derated and require zero maintenance. I trust Toshiba’s specifications because the Japanese are rigorous in product development and they have too much to lose to lie about their products. These batteries are in mass production since the beginning of this year.



Pieter Siegers's picture
Pieter Siegers on Aug 9, 2013

Hi Schalk, I think your intent on trying to answer the main questions that we’re all trying to find answers to falls short on a couple of important points:

1. The fact that fossil fuel prices go up, and renewables prices go down; these lines are not linear

2. Technological breakthroughs are already happening (batteries & other energy storage systems, concentrated solar CSP, among others)

3. The fossil fuels are actually much more expensive if you weigh in factors like increased severe weather events like flooding and hurricains, and of course deep pollution which is very if not impossible to reverse

I’d strongly suggest you to update yourself on technologies and facts and rewrite this article. You will see that if you do your home work well you will find that renewables actually outpace other energy technologies, and there must be a reason for it.

The one reason is we need to stop as soon as possible burning fossil fuels and replace them with renewables, where possible non-intermittent and for the rest using intermittent backed up by energy storage systems.

We really need to leave the fossil fuels where they are, in the ground. What we need are advocates that believe we can do it, not visions that stick with the old beliefs.

Renewable energies do not have the resource limitations and extraction problems that fossil fuels do have. Renewables are the way to go if we want a sustainable future, and well who doesn’t want a future like that?


Jonathan Cole's picture
Jonathan Cole on Aug 9, 2013

You have got to be joking!! Since when did the Chinese people have the opportunity to price anything into their voting decisions. What voting decisions? Chinese are imprisoned for criticizing the government.

Why don’t you take a  look at this article that just came out today.

To summarize: Aug. 8, 2013 — Particulate air pollution from incomplete combustion is affecting climate over East Asia more than carbon dioxide and cause premature deaths of over half a million annually in China alone, yet its sources have been poorly understood.

I wonder how those half a million dead people would vote, if they could.

As I said, CO2 is just the tip of the iceberg. So far it is not killing many people directly. But burning carbon fuels regardless of their source is already killing millions of people world-wide. CCS while perhaps being a part of the solution if it can be cost-effectively implemented should not be used as a cover for the much larger problems of poisoning our life-support system for profits. Continuing on this path is total insanity. We need to move to benign energy technologies. We need to change our economic model from one that gives an advantage to churning massive amounts of virgin materials to give a flash-in-the-pan economic advantage to a few rich people, to one that gives economic advantage to extremely durable goods that recognize the vast store of energy in processed materials and reward enterprises that make profits by creating real value. Our speculative, short-term hustling after money at any cost, will be the death of us and our descendents. It is not necessary to organize society and economies this way.

Some ideas for how we need to change can be read at:






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If you have an experience or insight to share or have learned something from a conference or seminar, your peers and colleagues on Energy Central want to hear about it. It's also easy to share a link to an article you've liked or an industry resource that you think would be helpful.

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