Emissions Nuclear Renewables

The Guardian questions: thorium, shale gas, off-grid renewables, and much more…

The Guardian newspaper’s Environment Facebook page recently put the following to their readers:

Ask the Global Energy Prize‘s expert panel your toughest energy questions and they’ll be back here on Friday with their answers. What should power our cities, homes and industry in the future — renewable energy, nuclear power, or fossil fuels? How significant will shale gas be? And what role will oil play in our energy future? Just post your energy Qs here. 5 experts will answer the 10 best questions: Harry Fair (US), Tom Blees (US), Thorsteinn Sigfusson (Iceland), Barry Brook (Australia) and Klaus Riedle (Germany).

Below are the six questions put to me (Barry Brook) and Tom Blees — and our answers, of course! The original answers were not hyperlinked, but if you are curious about anything we mention here, try searching for the keywords on this website (e.g. type in your browser address bar), or on Google (e.g. type  “ammonia” in your search box).



Q1. Do you agree that Thorium power is a safe, plentiful, and viable energy source that should be investigated as a matter of urgency?

Yes, thorium power is an attractive prospect for the next generation of nuclear reactors, but then surprisingly enough, so is uranium.

For today’s reactors, it takes about 150 tonnes of natural uranium to fuel a 1 gigawatt (GW) power plant for an entire year (the total energy produced is called a gigawatt year, or GWyr).  One GWe of power (the ‘e’ stands for electrical power rather than ‘t’ for thermal power, or heat) is a huge amount. It’s enough to run 65 million desk lamps (assuming they used 15 W compact fluorescent globes), or more practically, to satisfy today’s electricity demand of a typical UK city of more than half a million people. For comparison, to deliver a GWyr of energy using a coal-fired power station, about 4 million tonnes of coal must be burned (the amount can vary depending on the grade of coal).

Most of the nuclear power stations in use today are called ‘thermal reactors’, or ‘light water reactors’ (LWR). They use ordinary (‘light’) water as a coolant, which take heat away from the reactor core. The water also acts as a ‘moderator’, slowing down subatomic particles called neutrons, which shoot out of the atom’s nucleus when a nuclear chain reaction is underway. These neutrons are responsible for causing unstable heavy atomic nuclei to split apart and release energy. Other reactor designs use heavy water (enriched in ‘heavy hydrogen’: deuterium) or graphite (a form of carbon found in pencils) to moderate the neutrons (the latter is used in the UK’s gas-cooled Magnox reactors, for instance), but the effect is similar. These nuclear power plants need, as fuel, a form (isotope) of uranium that has 143 neutrons in its nucleus, called 235U (or ‘uranium 235’). Yet natural uranium contains 0.7% 235U; the other 99.3% is composed of an isotope that has 3 additional neutrons, called 238U (or ‘uranium 238’). As a result, today’s LWRs are able to extract less than 1% of the atomic energy content of uranium. The rest is discarded, unused, either as spent fuel (‘nuclear waste’) or as depleted tails (the leftovers, composed mostly of 238U, after the fuel has been ‘enriched’ to raise the concentration of 235U to 3 – 5%).

However, other sorts of nuclear power plants have been developed called ‘fast spectrum’ reactors (FR) and ‘liquid fluoride thorium reactors’ (LFTR). These are able to not only fission 235U like LWRs, but also readily ‘breed’ other fissionable isotopes from 238U or 232Th. With repeated recycling, this allows them to unlock virtually all of the energy in nuclear fuel. The amazing upshot is that instead of using 150 tonnes of natural uranium to produce a GWyr of electricity, FRs and LFTRs require only 1 tonne.

The key for both types of reactors – uranium and thorium based — is that the nuclear fuel is repeatedly recycled. For thorium, this is crucial because in order to ‘burn’ nuclear fuel, the ‘fertile’ 232Th must be converted, in the reactor, to ‘fissionable’ 233U – which is then consumed to generate the power. Given currently estimated reserves of cheap uranium, there is enough already identified to run the planet at a power level of 10,000 GWe for 4,000 years (which takes us well beyond 2050, to the year 6000AD). Then, consider that there is roughly four times more thorium, and we have 20,000 years of energy, give or take a few millennia. And this is before we start looking for lower-grade ores or uranium in sea water.

Finally, it’s worth noting that uranium FR and thorium LFTR type designs take advantage of a range of ‘passive’ safety systems based on natural physical processes, rather than just depending on active engineered systems or operator actions. In the LFTR design, the coolant is a molten fluoride salt, with the thorium and uranium dissolved within it (a liquid fuel). If the reactor starts to overheat, the molten salt expands in volume. This causes fissile particles to move away from each other, just like dots on the surface of a balloon spread apart as it is inflated. This heat-expansion feedback, in turn, causes the nuclear reaction to slow down, and allows the reactor to cool. It’s a self-regulating form of control.

In the Integral Fast Reactor (IFR) design, the fuel is a metal alloy (of uranium, plutonium and other heavier elements), not a ceramic oxide like in today’s reactors. Metals are superb heat conductors, which mean that if the reactor overheats, the fuel rods expand, like railway tracks on a hot day. As with the LFTR, this causes the reaction to passively slow or shut down, and natural convection in the sodium coolant then takes heat away from the core without needing active pumps. These stunning safety features are not just theory – they have been proven in experiments at US National Research Laboratories.


Q2. Considering ‘energy’ itself is free, enough of it all around us and with cheaper, cleaner, safer, decentralised methods of harnessing it as individuals(going ‘off-grid’) and the growing devastating, global crisis of Fuel Poverty on social-economic conditions:

-Why do you think the energy industry and governments are so keen to continue the current dependency on the infinite extraction of gravely finite fuels, wasteful and polluting means of supplying across great distances from source to customer?

-What are the chances of seeing off-grid autonomous power generation becoming our main energy source? what role could it have in eliminating fuel poverty, climate change and the world economy/markets?

Energy from the sun, which powers all renewable energy sources, is abundant but variable and diffuse. Although solar energy is constantly replenished, the test (and cost) lies in capturing and storing this energy on a large scale. Technically, there are many challenges with economically harnessing renewable energy to provide a reliable power supply. Because solar and wind energy is diffuse, collecting it in large amounts requires wide geographical areas to be exploited and large material inputs for building the installations (concrete, steel, glass and other more exotic materials). For some countries, like Australia, the scale of the installations is not, in itself, a major problem, but it is a severe constraint for small nations with high population density, like the UK. The other issue with capturing industrial-scale amounts of solar and wind energy is that it is variable and intermittent (sometimes delivering a lot of power, sometimes a little, and at other times none at all, meaning that they are not ‘dispatchable’), and it also varies seasonally (this is especially true for rooftop solar energy in winter in countries like the UK).

The most commonly proposed ways to overcome intermittency and unscheduled lulls in local renewable energy generation are: (i) to store energy during productive times and draw on these stores during periods when little or nothing is being generated; (ii) to have a diverse mix of renewable energy systems (including distributed generation – the second part of the question being asked), coordinated by a smart electronic grid management system (so that even if the wind is not blowing in one place, it will be in another, or else the sun will be shining or the waves crashing); and (iii) to have fossil fuel or nuclear power stations on standby, to take up the slack when needed.

The reality is that any of these solutions are uneconomic, and even if we were willing and able to pay for them, the result would be an unacceptably unreliable energy supply system. Energy storage (batteries, chemical conversion to hydrogen or ammonia, pumped hydropower, compressed air), even on a small scale, is currently very expensive, and in order to store the truly massive amounts of energy required to keep a city or country going through long stretches of cloudy winter days (yes, these even occur in the desert) or calm nights with little wind and no sun, we would have to ‘overbuild’ our system many times, to allow for  not only delivering  all of our regular power demand, but also  continuing  to do this whilst  charging up the energy stores when it needs to catch up on those low generation periods. This is the case whether or not the system involves hundreds of very large wind or solar ‘farms’, or millions of rooftop-scale PV panels with grid-connected inverters and on-site lead-acid batteries.

As a result, an overbuilt system of wind and solar would, at times, be delivering five to twenty times our power demand, and at other times, none of it. Modelling of these contingencies has shown that a system which relies on wind and/or solar power, plus large-scale energy storage and a geographically dispersed electricity transmission network to channel power to load centres, would be at least an order of magnitude more expensive than an equivalent nuclear-powered system, and still less reliable.

The answer to the first part of the question is therefore that economic and technical realities currently dictate typical government policies on the use of fossil fuels worldwide. Coal is relatively cheap, gas moderately so, and both are natural forms of stored chemical energy. Society has not yet worked out how to properly price (or implement appropriate penalties) on the damaging externalities these fuels cause to society, so they continue to be sought preferentially. If renewables were cheaper than fossil fuels, or even if they were slightly more expensive but were in the convenient form of stored energy, their uptake would be more likely. Nuclear fission, the other low-carbon, low-impact alternative, has the advantage of using an energy-dense stored fuel, but it carries a social stigma in many countries (centred on ‘radiophobia’) that will be a real challenge to overcome. So currently, fossil fuels win by default.


Q3. My question is about shale gas. It is a natural form of gas which large reserves have recently been found in Lancashire. However, it emits the same levels of greenhouse gases into the environment. Our move from fossil fuels should be for environmental reasons more than a lack of resource. Do you believe we should continue finding new reserves of fossil fuels and try to attenuate the impacts of the emissions, or do we make a move towards a renewable energy future?

Shale gas, derived from fractured sedimentary rocks, is one of the forms of ‘unconventional’ fossil fuels that exist in large quantities. Other unconventional sources include coal-seam gas, deep water offshore oil, tar sands and oil shale. However, these resources are more difficult and costly to extract than conventional oil and gas, requiring substantial energy and chemical inputs and new technologies. Yet, because of the lower quality source material, the extraction efficiency is worse than conventional supplies and faster production-depletion rates are a typical feature. In addition, we are seeing increasingly large local environmental impacts, greater emissions of greenhouse gases, and more public resistance from people concerned about contaminated water supplies and climate change impacts.

Historically, coal, oil and gas have represented a huge store of energy; the accumulated byproduct of millions of years of sunlight harvesting by ancient forests and marine plankton. Most of the cheap and readily available oil and gas, used for transportation, is concentrated in a few, geographically favoured hotspots, such as the Middle East, Russia and parts of South America; coal is found most abundantly in the US, China, India, Australia, Indonesia, Russia and South Africa.

Yet many credible industry analysts are now suggesting that we’re already close to, or have passed, the point of maximum global oil production – at a figure of around 85 million barrels per day – even after accounting for an increasing future use of shale gas and other unconventional fossil fuels. Others, including the International Energy Agency, suggest that with sufficient investment in exploration and improved extraction methods, we may not hit ‘peak’ oil production for a few decades yet. We’ve tapped less of the available natural gas (methane), used mostly for heating and electricity production, but globally, it too has no more than a few more decades of major production left before supplies start to tighten and prices rise significantly, especially if we ‘dash for gas’ as the oil wells run dry.

Most of the world’s coal is buried so deep that we will never access it – even if we were not concerned with the carbon emissions that result from burning coal, we still might only end up using 10 to 20 percent of the estimated 15 trillion tonnes of coal that has been deposited in the Earth’s crust. Why? Because coal is an energy source, and if you need to use more energy to dig it up than you get back from burning it, well, then there’s no point. It just takes too much energy to access the deepest coal seams. A rough estimate is that globally, there may be two centuries of minable coal left, at today’s level of use (less, if we continue to burn more and more each year). Hence to push to stretch our technology to new types of supplies, to keep our seemingly insatiable thirst for fossil fuels quenched.

The development of an 18th century technology that could turn the energy of coal into mechanical work – James Watt’s steam engine – heralded the dawn of the Industrial Age. Our use of fossil fuels – coal, oil and natural gas – has subsequently allowed our modern civilisation to flourish. It is now increasingly apparent, however, that our almost total reliance on these forms of ancient stored sunlight to meet our energy needs has some severe drawbacks (climate change, environmental pollution, regional economic disparities and resource wars), and cannot continue much longer. As the oil runs out, we need to replace it if we are to keep our vehicles going. Oil is both a convenient energy carrier, and an energy source (we ‘mine’ it).  In the future, we’ll have to create our new energy carriers, be they chemical batteries or oil-substitutes like methanol or hydrogen. On a grand scale, that’s going to take a lot of extra electrical energy – and this is likely to come from both nuclear and renewable sources. Although both of these low-carbon alternatives to fossil fuels will be important, I suspect nuclear fission will play the larger role.



Q1.  Do you think nuclear fusion, as opposed to fission, will be the biggest energy development in the future, or do you foresee other technologies as a more realistic alternative to the burning of fossil fuels?

Fusion has been a hoped-for panacea for years despite the old joke among physicists: “Fusion power is only 40 years away…and always will be.” The prominent Russian physicist who was the founder of the ongoing ITER project (the international fusion research effort), Dr. Evgeny Velikhov, intended for fusion to be the answer to providing unlimited clean energy to the entire planet. Though still dedicated to that effort, Dr. Velikhov and many others realize that the urgent and ever-increasing energy needs of humanity warrant utilizing fission systems until such time as fusion comes of age. We simply cannot afford to wait for fusion—or any other as-yet-undeveloped promising technology—to come to the rescue.

Many data-driven and peer-reviewed studies have been carried out to determine the feasibility of providing humankind’s energy needs utilizing various mixes of systems, particularly so-called renewable energy sources such as wind and solar. Most tend to agree that nuclear power will have to play a dominant role in replacing fossil fuels. (Massive, economically viable and extremely effective carbon sequestration technologies to allow continued use of coal have yet to be demonstrated and so cannot yet be considered dependable solutions—even without taking into account the carbon footprint of coal mining itself, for which there is not even talk of a remedy.) Breakthroughs could conceivably happen with geothermal technology or other systems, but for now we have to plan on using proven methods. As for wind and solar systems’ ability to provide the bulk of our energy, adherents of such views have yet to convincingly solve the problems of energy storage, economics (especially in regard to the massive redundancy necessary) and, especially, intermittency and extended down times that are inherent shortcomings of such systems.

Many who have reflexively rejected nuclear power systems of any kind in the past have recognized that those technologies evolve like any other, and that modern nuclear power plants show every indication of being safe, effective, economical and reasonably fast to build. We saw this with the first two GE Advanced Boiling Water Reactors built in Japan in the Nineties. Even those first-of-a-kind plants took just 36 and 39 months to build. We’re seeing it again as China builds the first Westinghouse-designed AP-1000 nuclear reactors, a so-called Generation III+ design that uses modular construction techniques and passive safety systems that greatly enhance their economics. (GE-Hitachi will soon be building their own III+ design, the ESBWR, that will have similar characteristics.)

Many of the same countries that are building nuclear power plants today are concurrently working on fast reactor systems—so-called breeder reactors—as the ultimate step beyond even the most advanced water-moderated reactors. These fourth-generation reactors will produce more fuel than they use by converting abundant non-fissile uranium 238 into fissile plutonium, forever removing the threat of fuel shortages, since their utilization of uranium’s potential energy is so efficient that even extracting uranium from seawater would be economically viable to fuel them hundreds of years hence, when our current inventories of fuel could finally be used up. Nuclear power systems utilizing thorium as their primary fuel are also being researched and may very well prove their viability and economics with pilot plants in the near future. Prototypes were already built in the Fifties that prove the principles are sound. A couple decades hence we might well witness molten salt thorium reactors and metal-fueled fast reactors replacing water-moderated reactors entirely.

What makes nuclear power such a compelling candidate for future energy demand is its energy density. This is the same feature that conversely makes wind, solar, wave and tidal power systems so difficult to scale up to the needed extent, for they rely on extremely dilute energy sources. No matter how efficient solar cells become, there’s still only a limited amount of solar radiation that falls on any square meter of the earth, even under optimal conditions. Energy density is what led to the age of fossil fuels, and energy density millions of times greater—as is possible with advanced nuclear power systems—is the key to bringing the fossil fuel era to a close.


Q2. By what year could the UK decarbonise our electricity supply (i.e. run on 100% renewables)? Would this decarbonisation process be quicker with new nuclear power?

David MacKay, the chief science advisor to Britain’s Department of Energy & Climate Change (DECC), wrote a book prior to his assuming that position called Sustainable Energy – Without The Hot Air. In this book Mackay exhaustively explored the entire range of possible energy mixes available to the UK. Like others who’ve undertaken such challenging projects (though rarely with MacKay’s comprehensiveness), his conclusions could not support the feasibility of 100% renewables being able to power the country.

Germany, being at nearly the same latitude and with similar cloud cover issues, has provided a substantial amount of data to weigh the feasibility of an all-renewable path for the UK. We should be grateful to our German friends for dedicating so much effort (and money) to demonstrating what can be accomplished when a government puts its full effort behind wind and solar power. Rather than rely on glib predictions about these systems’ ability to meet all Britain’s energy needs, we need only look at the German data from the past couple decades to get an idea of the viability of renewables to meet the UK’s energy demands.

That data, alas, is not friendly to those who dream of an all-renewables future. Having committed over 75,000,000,000 Euros to solar subsidies and development, Germany can expect to obtain barely 3% of their electrical needs from the sun, and intermittently at that. Wind power projects are as skittish as they always will be by their very nature, and so have not allowed for the retirement of any fossil-fuel power plants despite the additional and not insubstantial money that’s been poured into them.

If the United Kingdom is to decarbonise its electricity supply, the hard numbers indicate that nuclear power will not only do the job faster but that it will be absolutely necessary. Fortunately, this very week, the nation’s energy policy experts and scientists are being offered an elegant solution to both the plutonium disposition issue and the need for safe, carbon-free and essentially unlimited energy for the future. GE-Hitachi has offered to build the first of its cutting-edge PRISM modular fast reactors in Great Britain. This is the fruit of the most forward-thinking energy R&D project ever undertaken in the USA. It took decades of work from a small army of top-flight scientists and billions of dollars to solve all the thorny issues of nuclear power (safety, proliferation resistance, fuel supply and fabrication, waste, etc.). The PRISM reactor that GE is now offering to the UK is the result of that American effort.

Since the PRISM reactor operates at atmospheric pressure and its modules can be factory produced, once the first one is built to demonstrate its effectiveness (which could likely be accomplished within five years) it would be possible to quickly ramp up production and build as many of these power plants as necessary. Since the UK already has the world’s largest supply of plutonium, that startup fuel could quickly be put to good use providing clean energy for British households and industry.

The UK could certainly completely decarbonize its electricity production well before 2050 using this technology. But the potential goes far beyond just the electricity domain. If sufficient PRISM systems are built to meet peak demand, the fact that they operate just fine at full power 24/7 means that vast amounts of excess energy would be available for other uses, such as heating and the production of liquid fuels, that are now met with fossil fuels. Because the PRISM can be fueled with nuclear waste or depleted uranium, that means that its fuel is essentially free (or even better than free, since people would pay to get rid of it). Since peak demand is roughly three times average electrical demand, that means that Britons would have twice as much excess energy for alternative uses as they require for all their electrical needs.

Decarbonizing must include far more than just the electricity sector. The PRISM system can address the full spectrum of energy needs, and it can do so quickly, safely and economically.

Full disclosure: I have absolutely no financial connection of any kind to General Electric or any other energy company. I do, however, want to repair the damage that the industrialized world has wrought upon the planet, and I firmly believe that the PRISM is the best currently-available technology to do that. It is only because nuclear politics in the USA is so dysfunctional that this opportunity is being proffered to the UK instead of being built within the country of its origin.


Q3. Why is there so much emphasis on fixing the supply side? To reach our targets we need to “simultaneously” reduce the kgCO2/kWh and reduce the total kWh used. Then the benefits will be multiplied and we’ll have a chance to make a real impact on emissions. Why aren’t government talking more about reducing the total demand for energy? Yes, we can do efficiency but it isn’t enough. We need conservation too. Could it be that reducing demand would go directly against their economic goals?

As a resident of California, I’ve been a beneficiary of the most effective energy efficiency policies in the USA. Per capita electricity demand in this state has remained fairly flat for the last three decades, though that statement must be qualified somewhat since some industries have left the state and so reduced the overall electricity demand. Nevertheless, energy efficiency is something that should always be a goal even if we develop virtually unlimited clean energy supplies, since we would still want to save the capital costs of building unnecessary power plants. By the way, you can read about one of the winners of this year’s Global Energy Prize, a man some call the Grandfather of Energy Efficiency, at this website.

But you are right, efficiency is not enough. It isn’t actually an energy source. Talking about conservation and reducing demand for energy is a luxury only allowed those of us in developed nations with already-high per capita energy use. All too often, purported solutions to climate change are trotted out that ignore the fact that the vast majority of people on this planet live in energy poverty. Even if everyone in the USA and the UK stopped using all energy tomorrow, global energy demand would still rise inexorably, for energy availability is inextricably bound to standard of living. This applies to both personal energy use and to the energy used by industries that contribute to high living standards.

If there is to be any egalitarianism and social justice in the world, those living today in poverty must be afforded the opportunity to raise their standard of living to levels enjoyed today in fully industrialized countries. This will be absolutely impossible without a massive increase in global energy supply, all the more so because the world’s population is expected to increase by another 2-3 billion people by mid-century.

But the raw numbers tell only part of the tale. Consider where the fresh water will come from for all those people, not just their personal water use but all the additional water needed to grow the food for such a tide of humanity. The only place where so much fresh water can come from will be from the sea, necessitating desalination projects on a scale hitherto unimagined. Those desalination projects (and the energy needed to move both the water and the salt to their ultimate destinations) will require staggering amounts of energy.

Hence the focus on fixing the supply side. We must consider the entire planet, not just the fortunate nations in which we might live. While ever-better energy efficiency is certainly something to strive for, the policies and technologies to provide virtually unlimited clean energy for the entire planet must be the focus if we are to leave a better and fairer world to our progeny.

By Barry Brook

Barry Brook is an ARC Laureate Fellow and Chair of Environmental Sustainability at the University of Tasmania. He researches global change, ecology and energy.

34 replies on “The Guardian questions: thorium, shale gas, off-grid renewables, and much more…”

The Guardian could have done you the favour of selecting single questions without baggage, to make it easier to provide a clear answer to a clear question. The questions were loaded with popular misconceptions, so I guess you have to choose which part of the question to answer. I like to challenge the innuendo of “fossil” versus “renewable” as being the problem and solution of limited energy supplies …

From Q2: “why … the current dependency on the infinite extraction of gravely finite fuels “

Current thinking has it that mineral resources are limited whereas wind and solar are limitless. The bleak truth is that the opposite is true.

Far from being “gravely finite”, the amount of reduced carbon beneath our feet is vastly more than we could ever turn into carbon waste in the air we breathe. It is our environment that is finite; its capacity to vanish our carbon wastes has already been exceeded. On the other hand, the capability of 10 billion people to collect enough sunshine and air movement to supply our energy needs, including the construction of a vast forest of collectors on land we do not have, is very limited indeed.


The response to the thorium question didn’t appear to address what to do with thorium before LFTRs become commercially available. I say that because I believe it seems likely that Australia will produce more thorium than uranium as a secondary mineral.

The response to the shale gas question seems to hint that natural methane could be a cheaper form of hydrogen carrier and should therefore be conserved. However it doesn’t quite make that point.

The questions aren’t really hard hitting enough to jolt the reader out of complacency. A single succinct question might be ‘won’t gas and wind power see us through for the next few decades?’.


JN, Roger, I agree – but we could only respond to what we were given.

The most obvious immediate use of thorium is as a solid-fuel thoria in heavy water reactors like CANDUs — something the Canadians and others are already contemplating/implementing.


Barry Brook, excellent answers. Barry makes an important point about uranium versus thorium, though he doesn’t state it in so many words: it’s not so much in the choice of actinide, the magic is in the Gen IV reactor types.

Thorium metal in an IFR has many advantages, including less fissile startup needed, higher melting point than uranium metal, better mechanical properties (stronger) than uranium metal, higher chemical stability (only one valence), the option to denature the fissile isotopically (add U238 to the U233), reduced production of transplutonium elements, etc.

But that’s just gravy. The biggest improvement is in the reactor type: passively safe, low pressure operation with non-volatile coolant, sustainable fuel cycle, very high proliferation resistance (low quality plutonium, fissile self sufficiency – no enrichment needed in the long term), greater thermal to electric efficiency, etc.

This is true whether the fertile material is thorium or uranium. One could use existing plutonium waste to startup an IFR with thorium or uranium, or a combination of both, as the breeding material. The opposite is not true: one could not have a sustainable fuel cycle with existing reactors using thorium. Though thorium oxide’s high melting point makes today’s reactors much safer, thorium doesn’t make a reactor passively safe, like arranging for passive decay heat cooling, this is in the reactor design itself. Thorium doesn’t make high pressure reactors operate at low pressure, or increase the thermal to electrical conversion efficiency.

The magic is in Gen IV reactors, in particular the low pressure higher temperature operating ones with passive cooling systems. To be more particular, sodium cooled, lead cooled, fluoride cooled and fluoride fuelled reactors. This is the way forward.


As for California’s shining energy efficiency example, I’ll have more to say on this.

California’s electricity consumption per capita has stayed more or less constant due to expensive energy chasing away industry and attendant jobs, and forcing people into conservation:

Paying two or three times as much for your electricity, and chasing away good jobs to out of state, who here thinks this is a good thing?

Moreover, California’s total electricity use increased because of population growth. Only slightly less increase than the USA average.

By all means, go and use your electricity efficiently. Waste isn’t good. But, don’t fool yourself that this will even stop the growth in electricity use. In a growing world with growing population, growing new technology applications such as computers, electric cars, etc, electricity demand can only go up. The Californians failure to recognize this has resulted in dangerous complacency that has put them in the economic and fossil fuel hole they are in. They’ve lost half of their manufacturing jobs and still ended up using more fossil fuels.

We need more clean electricity sources, reliable, dependable, and affordable. The California case should be a stark warning that snobbish, emotional, innumerate and complacent policies with a blind focus on the demand side, lead to an increase in fossil fuels and a degradation of the economic situation.

Clearly the energy efficiency pushers are proven wrong: if anything we need to focus on the supply side, not the demand side.


And how do the energy efficiency pushers explain this Californian chase away of energy intensive jobs?

They brag about how the productivity per kWh has increased (!)

Amazing propaganda. Chase away energy intensive industries and then claim to have improved on energy use. Duh!

And the manufactured goods, of course, are still used, just imported from out of state, where it doesn’t count as energy consumption (ie it is a hidden energy sink).

Can you believe people are actually falling for this?


We can nitpick, but congratulations you guys on getting such substance in the guardian. You’ve staked out a position beautifully and clearly, with little possibility of confusion (probably because you could not rely on our all important numbers–whose interpretation confuses people in our insufficiently numerate world– and so were relegated to tight paraphrase of what the numbers tell us.)

I’ve been on this list long enough to remember the days when we would fantasize about getting a serious hearing from someone like Monbiot, much less The Guardian, peddler of much scary anti nuclear literature.


From Guardian response:

As a result, an overbuilt system of wind and solar would, at times, be delivering five to twenty times our power demand, and at other times, none of it … [and] would be at least an order of magnitude more expensive than an equivalent nuclear-powered system, and still less reliable.

Just to provide some perspective on a few points. Overbuilding is not typically recommended in any studies I have seen in the range of 5 – 20 times the power demand. Heide, et. al. (2011) has one of the most aggressive papers I have see on this topic (looking at relationship between overbuilding and storage requirements in a modeled system with very high renewable energy production, to 100%, and on a very large scale, 3240 TWh/year). The authors recommend 50% excess generation as a practical target (which brings down storage requirements from 10-12% to 1% of annual consumption, when aggregated on an annual production basis).

When looking at comparative costs, particularly for Gen IV reactors (such as the PRISM reactor design mentioned in the article), one has to do this with respect to projected future costs for advanced reactor designs (and not current low costs for Gen III reactors with once through cycle, non-load following, and very long plant extended lifetimes as we have today). Do we have a credible cost estimate on Gen IV, which would also have to include additional costs for fuel cycle development and plutonium stockpile management? According to this article by MIT researchers (peer reviewed in Energy Economics), we’d be looking at cost projections in the range of 213% – 240% above current costs with Gen IV. Are there better studies out there for this (with same degree of rigor and independence as MIT research), or perhaps more specific cost estimates for the PRISM reactor design (with fuel cycle development costs added in)?

From Guardian response:

If the United Kingdom is to decarbonise its electricity supply, the hard numbers indicate that nuclear power will not only do the job faster but that it will be absolutely necessary.

I’m typically not a big fan of arguments that presuppose 100% renewables or 100% nuclear as a practical technological pathway to the decarbonization of our electricity supply. Most studies along these lines fail (here), or at a minimum are shown to be hugely impractical and inconsistent with modern power systems operation (today or in the reasonable future with projected smart grid alternatives). This is typically what we call a straw man argument (and we should be focused on practical and achievable goals for deep greenhouse gas cuts, and working within the constraints of conventional or foreseeable technology pathways and achievable grid development alternatives). If I am indeed incorrect about this, can someone show me the research on practical and cost effective technology proposals that model a very high nuclear energy content (that does not also rely on some flexible non-nuclear energy resources for integration, balancing, load following, energy storage, and ancillary services). I know that this is theoretically possible (so too is the 100% renewables alternative), but we’re interested in cost effective and practical solutions (which can be scaled up fairly quickly, as the responses to these questions suggest, and meet important long-term, global, and permanent energy decarbonization goals).


EL is making bold statements that are dishonest in light of what he is referencing here.

First, the Heide study. This says the following, using an *actual* quote for a change:

At 50% excess generation the required long-term storage energy capacity and annual balancing energy amount to 1% of the annual consumption.

So you need to increase the cost of wind and solar 50% at that level of penetration, AND install 3.65 days of FULL load power in energy storage. That’s more than half a week of full power storage. In the storage thread we concluded this is not economical. Add to that 50% extra to the solar and wind systems. This is way outside of what is economical.

Second, EL’s “240% above current cost of gen IV” statement should be compared with another *actual* quote of the MIT researchers article referenced:

the sum of the costs for the light
water reactor are slightly lower than the LCOE for the light water
reactor as shown in Table 3—85.41 mill/kWh in Table 5 for all three
conversion ratios as opposed to between 85.86 and 86.91 mill/kWh in
Table 3, depending upon the conversion ratio. However, the sum of
the costs for the fast reactor as shown in Table 5—between 94.52 and
99.84 mill/kWh—are higher than the LCOE for the fast reactor as
shown in Table 3—between 85.86 and 86.91 mill/kWh.

So LWRs are 8.5 to 8.7 cents per kWh and fast reactors between 9.5 and 10 cents per kWh. This hardly supports the bold statement in isolation of “240% above current cost for then IV”. EL is talking about fuel cycle costs not total levelized cost. Fuel cycle cost is only a minor portion of the levelized cost of nuclear power, most of the cost is in the capital.

Perhaps EL could tell us the levelized cost of wind and solar +50% plus half a week of energy storage.


Cyril R. wrote:

First, the Heide study. This says the following, using an *actual* quote for a change:

At 50% excess generation the required long-term storage energy capacity and annual balancing energy amount to 1% of the annual consumption.

This is exactly as I wrote (and as is described in the article): “The authors recommend 50% excess generation as a practical target (which brings down storage requirements from 10-12% to 1% of annual consumption, when aggregated on an annual production basis).”

Cyril R. wrote:

EL is talking about fuel cycle costs not total levelized cost. Fuel cycle cost is only a minor portion of the levelized cost of nuclear power, most of the cost is in the capital.

Are you recommending we exclude the costs of fuel cycle development from nuclear when looking at the cost basis of technology pathways involving IFRs. I don’t understand the logic for doing so (particularly when the fuel costs for a closed fuel cycle are described in the article as being so large)?


Cyril R. wrote:

EL is talking about fuel cycle costs not total levelized cost. Fuel cycle cost is only a minor portion of the levelized cost of nuclear power, most of the cost is in the capital.


Ah ha … I see. You are correct, LCOE for fast reactor cycle is on order of 85.88 million/kWh to 86.91 million/kWh (or slightly higher for the equilibrium model calculation). Thanks for pointing that out.


Cyril R. wrote:

Perhaps EL could tell us the levelized cost of wind and solar +50% plus half a week of energy storage.

That’s fair. Heide 2011 recommends a resource mix of 80% wind and 20% solar as ideal mix for “annual balancing energy” (p. 2522). From EIA/DOE cost estimates, onshore wind has LCOE of $97/MWh, and solar PV $210.7/MWh. Combined 80/20 mix would put this at $119.7/MWh. The same reference source lists advanced nuclear at 113.9/MWh.

To 20% of total energy output no storage would be required to meet this amount (but only 10% wholesale cost of energy on efficiency losses for integration and balancing costs). Above this amount, storage would be needed. You are incorrect on your storage assessment. That’s 1% on an aggregation basis (added up over 365 days), not a single amount that is required to cover wind lulls or seasonal shifts. I provided a back of the envelope costing for a renewable energy mix to 45% in the storage thread (assuming no overproduction and setting storage capacity to 10% of installed capacity). This came to $101 – $152 billion for a system as large as the US (3,906 billion kWh/year). Assuming one full charge and discharge cycle each day, this comes to roughly 7.5 – 11.2% of annual consumption. With no overbuilding, we’d need a full 10% of annual production, with over-building we need a much smaller amount (1% with 50% excess generation). I’ll simply take the full amount at 11.2%. On a kWh basis, averaged over a 20 year operating lifetime, storage amounting to 10% of annual consumption has a capital cost of around 1.7 cents/kWh(LCOE on storage devices is a bit more complicated to calculate, here I am assuming the wholesale cost of energy purchased by storage developers will be less then the energy they sell for regulation, ancillary, and load shifting applications). Where this isn’t the case, this cost obviously has to be added to capital cost for a full LCOE measure (I’m simply assuming it’s 0 for simplicity).

My LCOE result:

– 20% renewable energy with no storage: $119.7/MWh (plus balancing costs at 10% wholesale cost of energy)
– 45% renewable energy with storage: $121.4/MWh (plus balancing costs at 10% wholesale cost of energy, just to make it even more flexible).

I don’t try to get to 100% renewables, because I think nuclear has a role to play, and we need to be practical and reasonable in our approach to resource and capacity planning (given available technology, high standards for grid operability and maintaining low costs, and anticipated future development opportunities). This represents some $7.5/MWh above the advanced nuclear option in the EIA/DOE accounting, or 34.5/MWh above the MIT analysis (with a great deal of development work to be done on advanced reactors). You are free to draw whatever conclusions you wish from these numbers. To me, they represent a reasonable and cost effective pathway to deep GHG reductions using current technologies and a mix of generation resources.


I find it amusing that BNC studies love to use political LCOE estimates from the EIA/DOE

In these studies enormous Wall Street return on equity requirements are always used blow up cost data for capital intense projects like nuclear always it seems built by tiny inefficient private power companies rather than large public companies that finance at less than half the rate. Nuclear costs are always based on first of a kind FOAK costing while.wind/solar always seem to include fine print or unstated subsidies.

Are we all so lazy we can’t look at real numbers from real projects?

The numbers are vastly different.

If you take the $4B/Gw that the FOAK VC Summer project is coming in at and have ultra efficient public power utilities like TVA build it instead, that $4B/Gw is less than 2 cents a kwh financed at 5%. Now add the 2 cents a kwh it costs to run ancient nukes, then subtract a half cent by replacing the current 1950’s antiquated O&M and enrichment technology. and another .2 cents eliminating never to be used decommissioning and waste disposal funds.

3.3 cents a kwh for first of a kind nukes that Westinghouse claims will drop to half the current cost (just like the real Candu costs did) when factory module production gets going – 2.3 cents a kwh for public power.

That’s half the cost of modern coal or natural gas at manipulated current fire sale North American prices.

To get an idea of how much cheaper reactors get after a score or so are built look at Candu’s built around the world to 2007 for $2B/GW.

Why base your pricing on backward US industry models when the more modern industrial structures in China, Japan and South Korea are regularly building nukes at less than $2B/Gw or less than 3 cents a kwh for public power.

Here is a real wind project PGE’s latest wind farm build $15B/Gw (20 cents Kwh at PGE’s discount rate)

Google “pge-to-purchase-operate-246-mw-manzana-wind-project”

Ontario’s feed in tariff pays wind producers $120/Mwh and $190/Mwh for offshore. Cape Wind tariff starts at a total of 24 cents a kwh and grows another ten cents over 10 years and they still can’t get it built after 10 years of lobbying.

Google “Thanet Offshore Wind Farm” to get the actual cost of a recently completed offshore wind farm. $17B/Gw including subsidies and always financed by private investors at 15% return on equity requirements.

Nukes are generally built close to load centers – no need for transmission projects.

A recent study on the other hand had New England’s cost to move its onshore wind to market at $80/Mwh paid for by the public.

Another study estimated the cost of gas backup at another $80/Mwh also paid by the public.Check Willem Post’s work at Energy Collective for more details.

In reality not EIA fantasy land wind costs upwards of 30 cents a kwh, nukes cost 3 cents.

What’s with this 3.5 days of storage. The vast Pacific Northwest had no wind for two weeks in a winter cold snap two years ago. Lucky they still had those Hydro dams half full!!!!

As for storage requirements rather than using recent solar/wind data, use instead exceptional once in a hundred year examples where there is almost no wind or sun continent wide for more than a month even several months. Nuke folks always have to pay to cover once in hundred year events. Why not wind/solar nutters?

Even a month of pumped hydro storage can add a buck a kwh to wind/solar cost.

When discussing wind/solar why is Tambora never mentioned? How much solar wind could we depend on in a year with a repeat of that event? Starvation and freezing in the dark like Fukushima except worldwide – now that’s what I call green!!!! .

The studies need redoing with real data.


EL, we are starting to get somewhere. There are two major issues I have with EL’s numbers though.

First, 80% onshore wind powered Europe. Seriously! Europe can’t even get 10% power from onshore wind because of NIMBY. Offshore resources in Europe are excellent, but it comes at a large cost premium (however offshore wind is more productive than onshore so maybe you’ll do better in reduced overbuild and storage to get to a more reasonable system cost?)

Second, storage costs. You say it is 1.7 cents per kWh levelized cost without backing that up.

There is not enough pumped hydro available. Not enough favorable sites, plus you have serious NIMBY on any site. CAES uses too much natural gas, which isn’t renewable. So you need a different system.

Half a week of storage @ EUR100/kWh (NaS battery with big cost reduction improvement assumed), 14 year float life, 5% interest rate (according to Seth). 1 kWe average flow per European, that means half a week of average storage is 8400 Euros. At an optimistic 50% capacity factor for the storage system, and only $20/kW-year fixed O&M plus 0.1 cent per kWh variable O&M, this gives me 20 cents per kWh for the energy storage system levelized cost.

You can vary the numbers a bit but the conclusion is the same. This amount of storage costs more than advanced nuclear even if wind and solar cost nothing (!).


And I’m being generous in assuming 100% cycle efficiency of the battery (in reality pumped hydro is 70-80% round trip efficiency and batteries are 70-95% depending on battery type). Divide the levelized wind/solar cost by this amount to see how much this adds, eg 10 cents per kWh wind divided by 0.8 becomes 12.5 cents per kWh, adding 2.5 cents per kWh more.


All energy is free in exactly the same sense with exactly the same caveats.

Oil is free, you just have to dig it out of the ground and convert it to useful work.

Uranium is free, you just have to dig it out of the ground and convert it to useful work.

Hydropower is free, you just have to extract power from moving water and make it do useful work.

Wind power is free, you just have to extract it from moving air and make it do useful work.

Solar power is free, you just have to capture sunshine and convert it to useful work.

Geothermal power is free, you just have to extract it from deep underground and make it do useful work.



Reflecting on question two, (assuming unreliables are reliable, why don’t we use them?)…
In his answer, Barry used the word “store”, “storage”, etc ten times, subtly underlining what unreliables need to make them reliable.

Bravo! Grind the axe!

If there ever is a breakthrough in storage technology, it may yet allow small communities to run on unreliables without a backup diesel generator sitting idle in the shed. Hopefully too, without dissolved lead or worse to escape with time. Similarly it may solve the problem of transport fuels.

Remote power users would then have remote power sources. However the big power grids must be supplied with big power sources, and that still needs nuclear.


Pumped hydo: Once again, from the Doty Energy study which I have previously linked several times, we have the costs for new pumped hydro @ {US$/kWh]

LCOE(out) = 0.055 + COE(in)/0.8

It is much more expen$ive than several posting here realize. Worse, there are only a few suitable sites available. Once those are sacrificed for (above ground) pumped hydro, one must go to underground pumped hydro. If a suitable cavern already exists [Reinkohl for example] then the above formula suffices. Otherwise, the fixed costs to be covered go way up to pay off the loan for digging out the cavern.


I forgot to mention that the cost formula is for diurnal cycling with (in) provided from reliable generators. Otherwise meeting the loan costs goes through the roof.


Barry, any chance of the Murdoch press getting on board, and following the Guardian’s example of having a real and meaningful debate about nuclear energy? Today in the Oz, Plimer got another mention, and my reaction was : Oh pleeeaase. Although I do note that the Australian really gets stuck into the solar/wind toy story .


The Australian article hints that PV is an expensive gesture by quoting the Productivity Commission on cost of CO2 avoided
I’m not sure how a German style national feed-in tariff recoups its costs, via taxes perhaps rather than power bills so pensioners get off lightly.

I note elsewhere the solar industry insists that State feed in tariffs and Federal RECs must continue despite the carbon tax advantage. Then in the next breath it says prices are coming down anyway. Trouble is the Australian has painted itself into a corner with climate change denial so it has no mandate to argue for low carbon alternatives to PV.


Cyril R. wrote:

Half a week of storage @ EUR100/kWh (NaS battery with big cost reduction improvement assumed), 14 year float life, 5% interest rate (according to Seth). 1 kWe average flow per European …

Why are you still working with faulty assumptions? You keep trying to run wind and solar like baseload generators, and this is not how energy storage is intended to be used on the intermediate and peak side of the scale (where flexibility is given a premium). We have to try and get this right, or we keep producing faulty results (and cluttering up these threads with comments that have no real world application for energy resource planning or systems operation). And we should be focused on real-world applications for achievable and significant carbon reductions (with careful attention to low costs and systems operability or flexibility).

For a detailed summary of energy storage and it’s applications, I would recommend the following comprehensive accounts: DOE, EPRI, Sandia, NREL, and various professional workshops. As I have stated many times, energy storage is used for frequency regulation, off-peak capture, load leveling (or peak shaving), black start activation, T&D support, micro-grid formation, industrial or commercial building uses, residential, and much more. Replacing all the power on a grid is not among the intended, practical, or cost-effective applications for ESS.

Please revise your calculations to address “real world” and “technically achievable” approaches to energy system planning, resource modeling, and systems operation.

seth wrote:

Nukes are generally built close to load centers – no need for transmission projects.

New Nukes and uprates always have transmission projects, because the energy produced at a single location is so dense (and bottlenecks in distribution are to be avoided). Projected costs for transmission and distribution in general are: transmission at $2200/kW and distribution and $4400/kW (Brattle Group report). According to Global Energy Network Institute (quoting from Wiki): “Long-distance transmission of electricity (thousands of kilometers) is cheap and efficient, with costs of US$0.005–0.02/kWh (compared to annual averaged large producer costs of US$0.01–0.025/kWh, retail rates upwards of US$0.10/kWh, and multiples of retail for instantaneous suppliers at unpredicted highest demand moments).” These may not be the best sources for these things, if you have a better source for T&D cost comparisons (I would love to see them).


David B. Benson wrote:

Once again, from the Doty Energy study which I have previously linked several times, we have the costs for new pumped hydro @ {US$/kWh]

This study is based on the older model of buying energy at retail rates (when costs are low) and selling it back at retail rates (when costs are high). With perfect timing, they calculate the cost benefits of doing so (on MN energy hub prices and 65% round trip efficiency) to be around $48/MWh (p. 3). These rules were recently revised by FERC, allowing storage developers to buy energy at wholesale prices, so you should see the value of stored energy increase on this basis (and also for technologies that have higher round trip efficiencies). Also, on a reserve per-unit capacity basis (or payments for availability), many integrated markets offer payments to storage developers to secure that capacity: “as described above, we found capacity payments to range between $1,000 and $5,000 per MW-month across the five markets” (p. 27). Given these considerations, energy storage cost of $100/kWh are considered very low and attractive from a market perspective, and this appears to be what many developers are shooting for in a very competitive and evolving market design setting.


EL, my numbers are based on a study you referenced yourself!!!!

Also my back of the envelope calculations are always based on real world data of real wind energy production. If you have no wind for days, as happens all the time, then you can burn fossil fuel and emit CO2 plus pollutants, or use enough energy storage so that it isn’t needed.

It really is as simple as that. Energy storage or fossil fuels. Since we need to cut CO2 emissions >90% this is what we must be considering.

You need to start reading the studies you reference. It is against site policy to fire flurries of studies and make statements about it that are not supported by the actual references. The Heide study is a case in point where you completely misread the storage requirement.

Apart from that, EL also is very unspecific about his goals and calculations.

It is you who keeps cluttering up this and other threads.


“…New Nukes and uprates always have transmission projects, because the energy produced at a single location is so dense (”

That’s because there aren’t enough nukes built. After a conversion from fossil to nuke each population grouping of 100K souls will require its own 1 GW nuke.

Ergo – no transmission builds at least of any significance.


As happens frequently (prehaps due to the nature of this form of communication), poster EL misunderstands pumped hydro and confuses that technology with batteries. The recentl FERC ruling assists battery operators (and just possibly flywheel operators), but doesn’t change the nature of the energy market for pumped hydro operators. (1) Pumped hydro operators run entirely on the wholesale market; they buy and sell @ hub prices. So the equation for the LCOE for pumped hydro consists of a term, COE(in)/0.80, which depends upon the wholesale price of energy purchased, ordinarily overnight. (2) Pumped hydro operators, like any other non-subsidized energy producer, must cover capital costss as well as O&M. Unfortunately these costs have increased dramatically, world-wide, since about 1985. Thus the fixed term of US$0.055/kWh.

Of course that fixed term is highly variable, depending upon the project. But at least in the USA it is no longer around US$0.01–0.02 as in days when the first set of pumped hydro facilities were developed.

More generally, I fail to see how to make use of wind energy, being variable, without a dispatchable balancing agent. Attempting to use pumped hydro for that purpose is doomed to economic failure, at least without a dispatchable energy source to recharge the pumped hydro facility.


I’ve read and re-read the Heide et al. study as it took some time to get to the bottom of it.

Click to access imf-thiele-2011-04.pdf

The key numbers provided in tables 1 and 2 are:
Eh – Storage capacity needed to cover for variability. This is provided for both 100% and 60% (each way, 36% round trip) storage efficiency.
Eb – Balancing energy. This is the total amound of engery that must be delivered (from storage or backup generators) over a year to cover for variability.
Qb – Balancing power. This is the amount of power the balancing sources need to deliver. This number is provided for 90%, 99% and 99,9% of the time, i.e. 36,5d, 3,65d or 88h, and 8h45m of average power rationing each year.

There are a couple of issues with the study that I can see:

Firstly, they use Europe (apparently defined as EU, Norway, ex-Yugoslavia and possibly Albania, after checking reference [1]) as a whole for the study. This will to a certain extent smooth variations in wind and solar.
I won’t even speculate about the cost of a fully integrated european grid capable of rapidly responding to changes in available wind and sunlight while keeping losses low.

Secondly, they include data averaged over one day, which I don’t really see the purpose of, other than as an academic exercise. I think even 1h is too low temporal resolution to get an accurate picture.

EL is correct in that only 1% balancing energy is needed with 50% overbuild, BUT (and this is a big one!) only in the daily avarage case. In the more realistic hourly case, 8,7% is needed. The storage amount is not affected much by going to a daily average in the ideal case, from 0,5% to 0,4%. The difference is bigger for lossy storage.


David B. Benson wrote:

As happens frequently (prehaps due to the nature of this form of communication), poster EL misunderstands pumped hydro and confuses that technology with batteries. The recentl FERC ruling assists battery operators (and just possibly flywheel operators), but doesn’t change the nature of the energy market for pumped hydro operators.

You are correct, the new FERC rule applies to frequency regulation (or fast ramping resources) and not other ancillary services (or slow regulation products). This is very helpful to point out. But this does not mean that new rules are not needed on slow regulation products such as pumped hydro, and that these wouldn’t lower costs or provide better market opportunities for pumped hydro storage developers. In fact, pumped hydro storage developers have been advocating for this for some time (here and here): particularly eligibility for investment tax credits, policies to streamline permitting and licensing, qualification for transmission pricing incentives, and even carbon pricing that might disfavor natural gas as a competing capacity resource. Manitoba Hydro pressed FERC on this, and they stated in their ruling: “… we do recognize that there may be value in having a certain level of granularity in defining the ancillary service products. Most of the ancillary services are defined by certain characteristics, and we understand that numerous different ancillary service products could be created based on the characteristics of different suppliers. We understand that the RTOs and ISOs and market monitors will continue examining the ancillary service product definitions and may propose to create new ancillary services as market needs evolve” (p. 76). So perhaps we can expect additional developments on this in the future to benefit all storage developers (if regulators think it is warranted, or wish to move in this direction).

Many thanks for bringing this additional clarity to the issue. And thanks to Speedy as well for taking a closer look (through the briar patch) at the Heide study (which appears to be more confusing in it’s use of terms than anything else it has provided us in our discussions here).


Leave a Reply (Markdown is enabled)

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s