Various scenarios have been put forward showing that 100% renewable energy is achievable. Some of them even claim that we can move completely away from fossil fuels in only couple of decades. A world entirely without fossils might be desirable, but is it achievable?
The current feasibility of 100% renewable energy is easily tested by asking a simple question. Can you build a wind turbine without fossil fuels? If the machines that will deliver 100% renewable energy cannot be made without fossil fuels, then quite obviously we cannot get 100% renewable energy.
This is what a typical wind turbine looks like:
What is it made of? Lots of steel, concrete and advanced plastic. Material requirements of a modern wind turbine have been reviewed by the United States Geological Survey. On average 1 MW of wind capacity requires 103 tonnes of stainless steel, 402 tonnes of concrete, 6.8 tonnes of fiberglass, 3 tonnes of copper and 20 tonnes of cast iron. The elegant blades are made of fiberglass, the skyscraper sized tower of steel, and the base of concrete.
These requirements can be placed in context by considering how much we would need if we were to rapidly transition to 100% wind electricity over a 20 year period. Average global electricity demand is approximately 2.6 TW, therefore we need a total of around 10 TW of wind capacity to provide this electricity. So we would need about 50 million tonnes of steel, 200 million tonnes of concrete and 1.5 million tonnes of copper each year. These numbers sound high, but current global production of these materials is more than an order of magnitude higher than these requirements.
Fossil fuel requirements of cement and steel production
For the sake of brevity I will only consider whether this steel can be produced without fossil fuels, and whether the concrete can be made without the production of carbon dioxide. However I will note at the outset that the requirement for fiberglass means that a wind turbine cannot currently be made without the extraction of oil and natural gas, because fiberglass is without exception produced from petrochemicals.
Let’s begin with steel. How do we make most of our steel globally?
There are two methods: recycle old steel, or make steel from iron ore. The vast majority of steel is made using the latter method for the simple reason that there is nowhere near enough old steel lying around to be re-melted to meet global demand.
Here then is a quick summary of how we make steel. First we take iron ore out of the ground, leaving a landscape looking like this:
This is done using powerful machines that need high energy density fuels, i.e. diesel:
And the machines that do all of this work are almost made entirely of steel:
After mining, the iron ore will need to be transported to a steel mill. If the iron ore comes from Australia or Brazil then it most likely will have to be put on a large bulk carrier and transported to another country.
What powers these ships? A diesel engine. And they are big:
Simple engineering realities mean that shipping requires high energy dense fuels, universally diesel. Because of wind and solar energy’s intrinsic low power density putting solar panels, or perhaps a kite, on to one of these ships will not come close to meeting their energy requirements. We are likely stuck with diesel engines for generations.
We then convert this iron ore into steel. How is this done? There are only two widely used methods. The blast furnace or direct reduction routes, and these processes are fundamentally dependent on the provision of large amounts of coal or natural gas.
A modern blast furnace
The blast furnace route is used for the majority of steel production globally. Here coal is key. Iron ore is unusable, largely because it is mostly iron oxide. This must be purified by removing the oxygen, and we do this by reacting the iron ore with carbon monoxide produced using coke:
Fe2O3 + 3CO → 2Fe + 3CO2
Production of carbon dioxide therefore is not simply a result of the energy requirements of steel production, but of the chemical requirements of iron ore smelting.
This steel can then be used to produce the tower for a wind turbine, but as you can see, each major step of the production chain for what we call primary steel is dependent on fossil fuels.
By weight cement is the most widely used material globally. We now produce over 3.5 billion tonnes of the stuff each year, with the majority of it being produced and consumed in China. And one of the most important uses of cement is in concrete production.
Cement only makes up between 10 and 20% of concrete’s mass, depending on the specific concrete. However from an embodied energy and emissions point of view it makes up more than 80%. So, if we want to make emissions-free concrete we really need to figure out how to make emissions-free cement.
We make cement in a cement kiln, using a kiln fuel such as coal, natural gas, or quite often used tires. Provision of heat in cement production is an obvious source of greenhouse gases, and providing this heat with low carbon sources will face multiple challenges.
A modern cement kiln
These challenges may or may not be overcome, but here is a more challenging one. Approximately 50% of emissions from cement production come not from energy provision, but from chemical reactions in its production.
The key chemical reaction in cement production is the conversion of calcium carbonate (limestone) into calcium oxide (lime). The removal of carbon from calcium carbonate inevitably leads to the emission of carbon dioxide:
CaCO3 → CaO + CO2
These chemical realities will make total de-carbonisation of cement production extremely difficult.
Total cement production currently represents about 5% of global carbon dioxide emissions, to go with the almost 7% from iron and steel production. Not loose change.
In conclusion we obviously cannot build wind turbines on a large scale without fossil fuels.
Now, none of this is to argue against wind turbines, it is simply arguing against over-promising what can be achieved. It also should be pointed out that we cannot build a nuclear power plant, or any piece of large infrastrtucture for that matter, without concrete or steel. A future entirely without fossil fuels may be desirable, but currently it is not achievable. Expectations must be set accordingly.
Recommended Reading
Sustainable Materials With Both Eyes Open – Allwood and Cullen
Making the Modern World: Materials and Dematerialization – Vaclav Smil
This article is factually correct, I have been making the same argument to people for years. I would add to it that the big trucks and cranes required to transport and install the turbines also carry the same dynamics of being manufactured from steel and run on fossil fuels.An analagous argument can be made for solar panels which use plastic polymers in the coatings, significant mineral resources and energy intensive manufacturing. Fortunately there are ways to at least improve the emissions profile on these processes. Maritime shipping is beginning the transition to LNG fuels which produce far less carbon emissions and nearly eliminate criteria pollutants compared to dirty bunker fuels that are far dirtier and carbon laden than on-road diesel. LNG is cheaper in today’s market and much better for the environment and public health. Trucking and big mining operations are also looking at LNG for cost reasons, but they are not being forced to change due to emissions requirements the way that maritime shipping is.Portland cement can be replaced by coal fly ash which reduces the embodied energy of cement, GHG emissions and contributes to cleaning up the world’s largest solid waste problem.Ford is now making the F-150, the world’s most popular pickup truck, out of aluminum. Curious to know what the emissions profile is for aluminum manufacturing versus steel and if more use of aluminum would help in this regard.
Companies are setting up plants to make aluminum and poly-silicon in Iceland to tap the geothermal energy. A price on carbon would drive more of that sort of investment.
I could also imagine putting nuclear power on large ships — recycled oil tankers maybe — to serve as floating factories that take advantage of low-cost clean power.
Remember the original Alien movie where the space ship was processing ore en route to Earth? You could have a nuclear powered ship pick up ore in Australia or Brazil and deliver refined metal to Asia.
An additional thought as to followup from my previous post:While the author of the above article is correct about not being able to use wind or solar to power today’s modern marvel cargo ships – we potentially COULD use nuclear power to drive them, which would significantly reduce global carbon emissions. That is something I really think we should look into doing. The US Navy has been safely and cleanly running naval reactors for 60 years.There are concepts for how to make much cleaner and safer reactors than the HEU light water reactors in todays naval use. I realize that the same designs the Navy uses are probably not suitable for civilian commercial reactors, because they do use HEU UOX or MOX fuel pellets. But, there is a concept called “Triso” or “Pebble Bed” nuclear fuel. Triso fuel are graphite ‘billiard balls’ that have embedded in the graphite, many small ‘particles’ of fissile fuel, and the fuel particles are coated with a layer of silicon carbide (which is extremely durable even at high temperatures and pressures) and Pyrolitic Graphite (to prevent flamability).Triso pebbles would be an especially attractive way to achieve commercial marine reactors – there is, essentially, nothing that can go wrong with them – they won’t ever release radioactive fuel material, and if the fuel pebbles got somehow spilled onto the ocean floor, they’d essentially just be ‘hot rocks’ – they wouldn’t leak radiation into the ocean, just heat.
There are, I believe, technical possibilities to create both cement and steel without fossil fuels, using carbon-free sources of electricity (nuclear, solar, wind, hydro, geothermal).This article mentions that when baking limestone in a kiln to produce lime, it releases CO2. Is there not an opportunity there to create co-located steel and concrete production facilities, and use the output of CO2 from the cement kiln, turn it into CO (I believe if you heat CO2 up hot enough, it will denature into CO? Or perhaps there might be catalysts that can achieve that result), and use that ‘waste’ product from the cement, to reduce the iron ore to steel?Also, this article neglects to mention that cement release carbon when cement mix is made at the factory, BUT THEN the cement, when you turn it into concrete, and it sets, part of the “setting” process is absorbing atmospheric CO2 and reversing the chemical reaction that released CO2 at the factory. So, isn’t cement “carbon neutral”? I was under the impression that it was?So, it seems to me that there might be possibilities to use clean electricity (or nuclear heat) as a source of process heat, and find the carbon needed for various process from the waste of other industrial processes.Another potential source of CO is ‘syngas’ which can be created from municipal trash in a plasma-arc gasification reactor.
JeffFrom a technical point of view this might be do-able, but I find it hard to see how such things can work any time soon. Public perceptions of the risks of nuclear energy are what they are. Do you really imagine the residents of cities near container ports will be happy with nuclear powered container ships passing them by? And inevitably there will be accidents involving these ships. Without a large scale change in public views on risk there is no realistic prospect of large scale nuclear powered shipping. This is likely to take decades.
That is why I mentioned Triso fuel. I’m trying to educate the public about pebble bed reactors/Triso – I think they are the answer to marine propulsion. They are foolproof, really. If they fall out of the ship somehow, they are essentially just ‘hot rocks’ on the bottom of the river, or bay, or ocean. Recovery crews can go scoop them up with suitable equipment, and no radioactivity will be released. People need to hear about that. So, I try to comment about that where suitable, so that I can help the public become educated about this revolutionary advance in nuclear power.
Great article. I have done the same for wind and other “renewables” with diagrams and pictures: MACHINES MAKING MACHINES written in 2011 Solar and wind capturing devices are not alternative energy sources. They are extensions of the fossil fuel supply. There is an illusion of looking at the trees and not the forest in the “Renewable” energy world. Not seeing the systems, machineries, fossil fuel uses and environmental degradation that create the devices to capture the sun, wind and biofuels allows myopia and false claims.Energy Return on Energy Invested (ERoEI) is only a part of the equation. There is a massive infrastructure of mining, processing, manufacturing, fabricating, installation, transportation and the associated environmental assaults. Each of these processes and machines may only add a miniscule amount of energy to the final component of solar or wind devices. There would be no devices with out this infrastructure.The complete essay with diagrams and pictures here: http://sunweber.blogspot.com/2011/12/machines-making-machines-making.html
This analysis does not consider the fossil energy to overhaul and/or recycle a wind turbines materials. I would assume that if wind turbines can be designed for easier parts replacement in a complete overhaul this would be somewhat labor intensive but maybe far less fossil energy intensive. A recycle of all the metal components would obviously be done – but probably not the blades because they are composites -although who knows. If blade recycle becomes a problem using some of the newest monocrystalline aluminum could work. The concrete footing if designed properly should have a very long if not indefinite fatigue life depending on the climate and possibly some other minor factors and even the steel tower if designed properly could have a very long fatigue life. A new study I just read from actual long term data sets wind turbine life at 25 years with some drop off of production and getting better. So the second,third or forth time around should use significantly less fossil fuels.
PS to below post: I suspect that the majority of metals in a nuclear power plant can not be recycled because of embedded radiation. I have no idea what it would take to recycle all of the materials or if it’s practical to overhaul a nuclear plant at end of life.
I’m pretty sure the reactor vessel is a small fraction of the steel in a nuclear plant. I would think re-bar and all of the high pressure steam plumbing would be the majority.On the net steel used though, this 2005 paper from the University of California at Berkeley found that nuclear power plants use an order of magnitude less steel than wind farms for the same average power output. The nukes also last about 3x as long. Either way, the Earth has inexhaustible iron resources, and it is clearly possible to refine iron ore with electricity or hydrogen, neither of which is so energy intensive to destroy the EROI of wind or nuclear. So there’s no way that steel shortages will keep us from power future society with wind or nuclear power.
I didn’t realize that steel and concrete production create almost 12% of the excess CO2 problem. Thanks. It will take proper CCS and lots of clean energy in order to almost completely transition from FF’s (and, advanced materials to take their place). It will also require the wisest use of the fossil store in order to prevent depletion scenarios. Thus, we need to build the least expensive non fossil option with the highest EROEI. Some say wind requires too much material inputs, however, I believe it still requires less energy to make than current solar PV.What does seem trivial is the use of hydrocarbons for non combustionables such as all our plastic stuff because that is a small amount compared to all the gas we use and coal burned on our behalf. Therefore, we should be able to rely on hydrocarbons for a much longer time if we develop the best energy sources a little sooner.I don’t believe hydrogen will be of much use because it is just another energy carrier unless it can be made “cheaper than it is inefficient”. Closed cycle nuclear’s high process heat could make it (or liquid fuels) at a greater efficiency than electricity (I believe, because the steam cycle is omitted) but those fuels will undoubtedly be less efficient in their end use than pure electricity. At least, it is possible to come up with such fuel should concrete and steel not be made properly with electricity alone.
I used to think that biofuels would never amount to much but perhaps they can at least be able to power the equipment needed for industrial transport. Could they be an easier path than nuclear produced fuels in a world where (largely nuclear) electric is used for “everything else”?
Robert, the economics behind the preferential use of coal and fossil gas in steel and concrete production instead of hydrogen (or ammonia or even biomass and bio-methanol), are similar to the situation with other direct heating applications as well as transportation. Hydrogen works just as well as coal and gas for industrial heat (and chemical reduction of iron ore, see Sustainable Materials, p.139), the only problem is that it currently costs much more. So all you are really saying is that you do not believe in the “hydrogen economy”. Fine. But to justify this position, shouldn’t you make an argument that it’s ok to keep using fossil fuels (at least for these high-priority applications) until they are depleted? And why should high priority applications be restricted to iron and concrete? Transportation gets just as big an advantage from the special properties of fossil fuel (in other words, with half of all fossil fuel use coming from “high priority” applications, we’ll never reduce fossil fuel use enough to offset the growing energy needs of the developing countries).
NathanThe debate about the hydrogen economy is probably too much to get into here.On “high priority.” Things like steel making suffer from higher levels of carbon leakage than transport. You cannot offshore a daily commute to China, but you can do this with materials production. Also there are very significant differences in the efficiency of transport and steel making. US steel making is ultra efficient, while the US transport system is, or at least should be, a national joke. There is huge potential within transport, but making steel is much more difficult. No innovation is needed for people to go from driving 22 mpg vehicles to 50 mpg vehicles. There is no readily available option to halve emissions from steel making.
Just a quibbleBOS steel coming primarily from blast fruances and thus raw ore accounts for ~70% of the worlds production. Scrap is used in BOS steel accounting for 25% of each melt. EAF steel coming mainly from scrap accounts for ~30%. So there is a substantial amount of recycling going on though obviously it is the minor route. Recycling rates estimates ar below.http://www.unep.org/resourcepanel/Portals/24102/PDFs/Metals_Recycling_Rates_110412-1.pdfThe world steel has a blurb pdf on wind.http://www.worldsteel.org/dms/internetDocumentList/case-studies/Wind-energy-case-study/document/Wind%20energy%20case%20study.pdf
Robert, all of your attacks on wind energy were comprehensively rebutted in this literature review of every peer-reviewed publication on the lifecycle CO2 emissions of every energy source. The result? Wind energy’s lifecycle impact is a fraction of all fossil-fired energy sources, and significantly lower than almost all non-emitting resources, including nuclear power.http://www.nrel.gov/analysis/sustain_lca_results.htmlMichael Goggin,American Wind Energy Association
I don’t see why the post should be seen as an attack on wind energy. The NREL life cycle assessments may show wind’s carbon impact as a fraction of non-renewable generators, but that doesn’t take away from Pobert’s point that a lot of steel and concrete goes into conventional turbine design. Shouldn’t the wind industry be more open to re-design to reduce its impact still further – particularly offshore, where the impact is so much greater?
MichaelHow am I attacking wind energy here? As I said explictly at the end of the piece:”Now, none of this is to argue against wind turbines, it is simply arguing against over-promising what can be achieved.”At no point did I compare the emissions of wind power with anything, which implies that you have not actually read the piece before accusing me of attacking wind energy. I am providing analysis here, not advocacy. Please don’t attack me for not providing a simple bullet pointed message that would insult the intelligence of my readers.And can you actually point to a single factual error in the piece instead of providing readers with a link to a report?I should remind you that you once personally thanked me for a piece I wrote “defending” wind energy (I still have the email). Sadly, your behaviour here just suggests you are a crude propagandist, but perhaps you can prove me wrong.
If an efficient process is developed to use the waste heat to produce synthetic or biofuels, then fuels from nuclear could be cheap. But it would need to be located next to a 1GW plant and would increase the total footprint significantly – no doubt next to a rail line would be the only practical location.It would compete with industrial solar thermal especially if the process is designed to use heat from an intermittent source.
Conventional nuclear’s highly pressurized water does not get hot enough to split water, but the closed cycle in a molten salt or metals mix can. This saves the 2/3rds wasted into the conversion for electricity (in the steam cycle). Molten fuels closed cycle is inherently safer and far more efficienct, thus the only problem for widespread deployment (such as by railroads) is public opposition and BAU.Biofuels could be used (but it would require extensive amounts of land just) to power heavy equipment. In the case for operating strategic equipment, the very low EROEI could be justified.It may be cheaper to employ CCS and coal liquification to continue with the steel and concrete structures once natural gas and oil become depleted, but then again, I have no idea which of these options would be the least expensive in the long run, because the unlimited power from closed cycle nuclear (such as LFTR or PRISM) is plagued with fear, biofuels are limited to just barely being able to power themselves (low eroei) and a rather large percentage of coal would have to be used to liquify itself and another rather large percent for CCS.Already existing renewable capacity will probably not be enough to provide for the basic needs (of everyone) let alone to do all of the above.
Michael,Here is a report by high level Professors, Doctors, Engineers in Germany recommending the EEG be abandoned as it has been a failure.http://www.e-fi.de/fileadmin/Gutachten/EFI_Report_2013.pdfHere is a photo presenting their report to a smiling Merkel.http://www.e-fi.de/index.php?id=1&L=1Gee, I have been saying that for at least 5 years, including in several articles on TEC. Robert,Your article is 100% neutral. It presents a revelation of reality. One needs to be an energy systems engineer, preferably with some decades of experience, to understand the complete picture.It would require tens of billions of gallons of biofuels PER DAY to replace diesel fuel. The same is true for aviation fuel.
WillemWhat does biofuels have to do with the subject of the post? And German professors handing a report to Merkel about the EEG?Willem, I’ve explained to you many times how you going off topic like this is disrepectful. In this case it is completely rude. All you are doing is shoving something in Michael Goggin’s face, instead of engaging in discussion about the subject of the post. Who benefits from this type of behaviour?In future please be more considerate.
Robert,In a 100% RE world, biofuels would be replacing diesel fuel to mine the ores, to make the metals, to make the concrete, to make the wind turbines, etc. I think my comment is applicable.Michael made a mindless, inconsiderate, comment on your very good article, and I responded with the just released EEG critique, which already is creating quite a stir in Germany, etc.
Edward,”Portland cement can be replaced by coal fly ash which reduces the embodied energy of cement, GHG emissions and contributes to cleaning up the world’s largest solid waste problem.”The article is about 100% RE. Where would flyash come from?
Jeff,What CAN be done is not done, because it is not economical to do so.Making CO out of CO2? In a 100% RE world, how much RE would that take?
WillemI really do not see how you responding to Michael’s comment by linking to this EEG critique makes any sense whatsoever. This post is about our inability to make wind turbines without fossil fuels. The EEG in Germany is completely and utterly irrelevant. Please make an effort to stay on topic. I am beginning to lose track of the number of times I have pleaded with you to do this, but perhaps you might listen this time.
Jeff,First one needs to start by placing a number of standard Navy reactors on a large, offshore, floating platform off the New Jersey shore, and have the energy transmitted via HVDC lines to the onshore East Coast high voltage grid. After that concept is proven, build more such platforms.Then develop your design ONSHORE, and after it has been proven, place a number of them on platforms.
Wind Smith,And that 1 GW plant would be what kind of plant?What would be the features of such a process?
Robert,The world uses tens of billions of gallons of diesel and aviation fuel EACH DAY.How many millions of square miles of land and ocean would that take?
Willem,Not to degrade this thread but coal fly ash is the biggest source of solid waste in the world. I don’t think we will have any trouble finding any. I am not advocating 100% RE anyway, coal is not going away whether we like it or not which I think was the point of the article.
Robert,”The EEG in Germany is completely and utterly irrelevant.” Your article shows, it would be extremely challenging just to make wind turbines with 100% RE. We are not even considering all the other goods and services. Is not Germany aiming to go to a very high percentage of RE? The EEG law is completely and utterly relevant, because it is a big part of that effort. You and the professors, and many others, are on the same wavelength; very high percentages of RE are not feasible, even in Norway which gets 98% of its electrical energy from hydro, the rest, about 67%, from fossils.The German professors, et al, wrote a report that basically says the EEG law is an expensive experiment, that they show, with numbers, is ineffective.It will take politicians, et al, some time to adjust to that.Another item, not mentioned in the article, is the balancing of variable wind and solar energy by the OTHER generators, mostly fossil fueled; without that balancing, such energy could not be fed into the grid.With 100% RE (no more fossil fuels), the electrical RE would have to be SELF-BALANCING over large geographical areas, the cost of which to be determined at some future date. The self-balancing is possible, especially for countries, such as Denmark, it having nearby hydro plants, but for most of the rest of the world, this would be a significant and costly challenge.
Edward,At 80 – 90% RE, as appears to be the goal of RE promoters, there will be very little flyash, but some other means likely will be found to take its place.
An evaluation of material and energy inputs required for ANY source is not an attack! Wind has a purpose but it’s not capable of powering full blown planetary civilizations… as long as they require massive sums of concrete and steel. All the renewables and nuclear have advantages which must be worked together if we are to beat the excess CO2 thing.
If much of the diesel engines can be replaced with electric, less land could be used (or so I thought). That’s probably how most transpo will have to go.Billions of gallons every day ! Yea, I was under estimating the amount of necessary industrial fuel, especially after considering global growth.
Michael,Thanks for the link on the lifecycle CO2 emissions. Perhaps it is relevant to the post as a stand-in for life-cycle fossil fuel consumption.However, regarding this claim, “Wind energy’s lifecycle impact is a fraction of all fossil-fired energy sources, and significantly lower than almost all non-emitting resources, including nuclear power.”I think you have relied on the generic summary data, rather than selecting the data which was more appropriate to this post, from within the underlying journal paper for nuclear, which said this:”While small relative to coal, the difference between nuclear power life cycle GHG emissions constructed in an electric system dominated by nuclear (or renewables) and a system dominated by coal can be fairly large (in the range of 4 to 22 g CO2 -eq/kWh compared to 30 to 110 g CO2-eq/kWh, respectively). “Since this post discusses a world without fossil fuel, the appropriate analysis should not assume the nuclear cycle uses uranium which has been processed using coal and gas fired electricity, via gaseous diffusion enrichments plants as was assumed in some of the CO2 estimates; (diffusion plants would never be built today, and are being replaced with centrifuges). Further, uranium enrichment is a form of self-consumption, such as pumping water or blowing cooling air in a CSP plant. So in this case, nuclear power would have a similar or better life cycle emissions as wind power (a range of 3.0 to 45 g CO2eq/kWh is given in the corresponding wind power report).Additionally (and even more relevant to this thread), this 2005 paper from the University of California at Berkeley finds that nuclear power plants use an order of magnitude less steel than wind farms of the same average output.
I believe its relavent because (after searching) it makes concrete stronger, thus less fossil fuels required to build a wind turbine (or any other concrete structure). Some even compare it to “Roman concrete” (which still exists today)!
We need to get off fossil use quickly not immediately. So fossil transportation, ag and mining fuels will need to be used for the foreseeable future. However we can eliminate the low hanging Co2 emissions such as coal much sooner because we have practical if more expensive alternatives such as renewables and nuclear. The next step is to convert as many cars and light trucks to EV’s as possible. Consumer reports just named Tesla Model S its “best overall” car of 2014 and the following notes Tesla’s potential for storage to balance variable sources of power generation. With the planning of Tesla’s mega battery factory it may became very competitive. ” Morgan Stanley calculates that the roughly 40,000 units of Tesla cars on U.S. roads contain 3.3 GW of storage capacity. equal to 0.3 percent of U.S. electrical production capacity and 14 percent of total U.S. grid storage including pumped hydro. By 2028, the firm estimates Tesla’s 3.9 million units in North America will have an energy storage capacity of 237 GW (and 384 GW globally), equal to 22 percent of today’s U.S. production capacity and nearly 10 times larger than the entirety of U.S. grid storage that exists today.”
According to the EIA (EIA_eth), in 2012, the US produced 13 bilion gallons of ethanol, and (EIA_diesel) about 1 billion gallons of biodiesel. Using 42 gallons per barrel, and assuming ethanol has 67% of the energy in oil, this corresponds to 0.23 billion barrel of oil equiv. Our total oil consumption was 6.8 billion barrels, so biofuel was 3.4%.The oil consumption was about half gasoline (e.g. cars), and half diesel (e.g. heavy trucks, ships, trains, and airplanes). So just replacing the gasoline with batteries only gets us to 7% biofuel.Note that fermenting corn starch is about the worst way to make biofuel. If we choose a cellulosic biofuel method, such as gasifying the biomass, then making Fischer-Tropsch diesel, methanol, or bio-methane we could probably get triple the fuel yield per acre (and we could use a variety of non-food biomass feedstocks). That gets use to about 10% of the current oil use, which is just about equal to the fuel use for aviation. So we could replace all oil, if all land vehicles used batteries, hydrogen, or ammonia, and only aviation used biofuel.If we used sustainable hydrogen (from renewable or nuclear power) to make fuel from the CO2 produced in the biomass gasifier, we would triple the biofuel output again. This would bring us to 30% of current US oil use; which would be adequate with some combination of efficiency improvements, electrification, or hydrogen/ammonia substitution.Keep in mind that the US is sparsely populated compared to Europe and Japan, hence our per capita biofuel production can be higher.
Robert,I like your articles. You write clearly and are generally well-informed on the issues you write about. You appear to value objectivity and facts, and don’t appear to have any particular ax to grind. However, I don’t think this is one of your better efforts. If I were your editor I’d have bounced it back to you with notes and a general comment that “you can do better!”. I’m not your editor, of course, but here are some notes anyway. You get off to a strong start, citing specific figures from the USGS on the material requirements of wind turbines. “Oh, good!” I think, “Looks like he’s going to be quantitative”. But then a statement that is at best misleading, in the context of the article’s theme: “However I will note at the outset that the requirement for fiberglass means that a wind turbine cannot currently be made without the extraction of oil and natural gas, because fiberglass is without exception produced from petrochemicals.“Blaaattt! The resins used to make fiberglass are made from feedstocks that are currently derived from oil and natural gas, but only because those are the cheapest sources. Any so-called “petrochemical” can be synthesized, starting from CO2, water, and electricity. The electricity and water produce hydrogen, and hydrogen and CO2 can be reacted to make synthesis gas — a mix of hydrogen and carbon monoxide. From synthesis gas, you can get to just about any organic chemical your heart desires. And in fact, a good fraction of the petrochemicals that are produced do already start from synthesis gas. It’s just that the synthesis gas they start with is made by partial combustion and steam reforming of natural gas. That’s cheaper and easier than making it from CO2 and hydrogen. But the complexity of the many steps needed to make most petrochemicals and the energy losses incurred along the way mean that the front end cost of the synthesis gas is a relatively minor factor in the end product cost. What that boils down to is that plastics and petrochemicals are about the last reasons anyone should be invoking for why we can’t do without oil and natural gas. The petrochemical industry would weather the transition to an all-renewable economy with barely a hiccup. Now, when it comes to the diesel fuel needed to run all that heavy mining equipment, or the bunker oil (not diesel) used to fuel most large tanker ships, matters are more complicated. Diesel fuel, like any other petrochemical, can be made starting from synthesis gas. There are several well-known pathways for doing so. But even at $100 to $150 per barrel, diesel is a lot cheaper than epoxy resin or the latest petroleum-based pesticide. So the cost of feedstock is a more significant issue. But it’s still “only” a matter of economics, not a fundamental technical issue.If one could show that the energy produced by a wind turbine, over its lifetime, is insufficient to produce the synthetic fuels needed to produce the steel, concrete, and other resources that go into building it, then one would indeed have made a case that wind turbines can’t be made without fossil fuels. But you haven’t shown that. You quickly exit the world of quantified values, and descend into the usual murk of “large”, “very large”, and “enormous”. Useless!In fact, while I’m not especially an advocate for wind power as an adequate solution for our energy needs, I have to side with its advocates on this issue. The best EROEI studies do seem to establish that wind turbines are a sound energy investment. I’m not suffiently familiar with the details of those studies to know if they accounted for the higher energy cost of synthetic fuels over fossil fuels, but even if they didn’t, I doubt that the additional costs would be enough to tip the balance. There’s even one issue on which the favorable EROEI studies are overly conservative: the lifetime of the wind turbine. I believe that most studies assume 20 years. That’s both too high and too low, in my opinion. Too high, because current generation wind turbines with mechanical gearboxes may wear out sooner than that. But too low, in that the overwheming bulk of the “energy in” is for the tower. With very modest maintenance, there’s no reason that a tower couldn’t last for centuries. The wind turbines themselves can be removed and remanufactured for very low energy input. It’s not yet done, AFAIK, but that’s because the turbinnes are mostly too new to need that treatment.You wrap up by writing, “Now, none of this is to argue against wind turbines, it is simply arguing against over-promising what can be achieved. <..>” Now, there you have a point I can certainly endorse. I just wish you had been a bit more rigorous in building a case for it.
RogerThe key point you seem to be making is that I should have considered fuel synthesis. Other people say I should have considered using hydrogen for steel production, or even considred the use of wood as a material for wind turbines.There are no shortage of “solutions” being produced that have little chance of becoming engineering reality any time soon. Fuel synthesis will require us to extract not millions, but billions of tonnes of carbon dioxide from the atmosphere. I view as essentially a science fiction concept for the next few decades, so it is hardly worth discussing in the context of an article about what is currently achievable. For example we now consume over 700 billion tonnes of coking coal in steel production. Replacing this alone with synthetic gas would require the extraction of well in excess of a billion tonnes of carbon dioxide being extracted from the atmosphere. I just don’t see how this can be treated as a serious current option, but one that will require generations of engineers to get to work.
RogerWith all due respect you critize the article in a certain way and then proceed down the exact same path”Any so-called “petrochemical” can be synthesized, starting from CO2, water, and electricity.”In theory this is correct. In practice though we have very few example. A prime example is various isotopes of butanol which can be produced via fermentation pathways but have yet to displace the petrochem derived cousins. What Robert is highlighting is the incredible difficulty of getting of various forms of fossil fuels while we have a multitude of studies saying that 100% renewables is possible that do not even consider the basics of what is written here. (Oh and ethylene would be the chemical that I would bench mark the petrochemical industry on. https://www.irena.org/DocumentDownloads/Publications/IRENA-ETSAP%20Tech%20Brief%20I13%20Production_of_Bio-ethylene.pdf )
Roger,Good comments.As you are familiar with at least part of the front end of “making wind turbines with wind turbines”, why not give it a try based on some estimating. At least, it would develop a methodology for further refinement.The EROEI for wind turbines, commonly quoted, usually leaves out the investments in balancing, storage, grids and “capacity adequacy”. Add to that the higher cost, non-fossil fuel ways, of making wind turbine system materials, and the A to Z “wind turbine” EROEI becomes meager indeed.BTW, in the end, the A to Z EROEI of wind turbines, and all other items, is what matters regarding viability.For example, the corn-to ethanol program would immediately fail the EROEI test; marginal now, with only RE, the EROEI would be significantly negative!!
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http://theenergycollective.com/willem-post/287061/us-corn-ethanol-program
Robert,World coal consumption is about 8 billion ton/yr
Thanks WillemThat should have been 700 million, not billion.
You and your commentors make wonderful points. I could go on for hours on this, but will suffer you less.First, there is a great 140 year history to modern steel and Minnesota. “Taconite” has a wikipedia page. Development of consistent feedstock (taconite pellets) was worked on for many decades with great urgency by skilled scientists. And high grade “iron ore” is created using huge electro magnets. There is high quality steel and there is melted dirt. In short, no you can’t make those turbine structures without far more energy than even considered in this article.Second, if you want to elevate a wind turbine in the Great Plains you might want to build a barn under it with all that construction material. Old barns had huge vertical axis ventillation turbines to cool the hay loft and livestock. A barn roof is quite an airfoil giving more energy to less turbine. I’ve been trying to figure out how they built that stuff for 40 years.Third, I’m very impressed with wood laminates. And fourth, rock makes concrete go further; but good luck finding labor.We can’t abandon wind energy. But we have a right to question the current wind direction.
Wind Smith,At present, the hydro plants of Norway and Sweden act as a balancing and storage utility for Denmark. The more wind energy Denmark generates, the more it needs that “battery”. Denmark pays for this by delivering energy at low grid prices and absorbing it at high grid prices. The exact $ amount appears to be a state secret; it has been estimated at well over 1 billion euros some years ago. As much of the additional Danish wind energy will be offshore, that 1 billion likely will double or triple. Danish households have the highest electric rates in Europe; 30.45 eurocent/kWh in December 2013.
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http://www.eurotrib.com/story/2013/7/2/174936/9080http://www.energypriceindex.com/wp-content/uploads/2013/12/HEPI_Press_Release_December-2013.pdfIn 2002, Denmark had so little winds that during 54 days no wind energy was produced, but the wind turbines were consuming energy, a.k.a., parasitic energy, just the same. There likely were an additional 50 or so days with minimal energy production.http://en.wikipedia.org/wiki/Wind_power_grid_integrationLuckily, Denmark’s OTHER coal, gas, nuclear, generators, and the hydro plants of Norway and Sweden provided the shortfall, but with Denmark’s current annual wind energy percent on the grid, this would be a significantly greater effort. At that time, the lack of wind was noticed only in Denmark, as other nations had much less wind turbines, which would not be the case going forward. Something to think about for planning purposes.Without RE, Germany has the most reliable grid in the world. If, instead of exporting it,Germany had to keep its variable wind and solar energy within its borders, there would be chaos, as Germany has failed to make the investments, tens of billions of euros, in grid infrastructure to match its rapid RE build-outs.In the future, there will be balancing/storage utilities, which, for a fee, will take your variable, intermittent RE and balance and store it. The “cleaner” the RE you present to them, the lower the fee. That means RE generators will incorporate their own balancing and storage BEFORE feeding their RE into the grid. There will be an economic balance.EVs in a neighborhood with solar panels could play a role, but a small one, because cycling EV lithium-ion batteries shortens their useful service lives. Better to use standard lead-acid batteries, as weight is not an issue and they are much less expensive.With distributed generation, there will be distributed balancing and storage, and at each balancing and storage node, there will be (2) 100% systems or (3) 50% systems to maintain current grid stability and reliability.In Germany, there are days on end “the sun does not shine and the wind does not blow”. The energy storage system would need the capacity, MW, to deliver the energy, MWh, for at least a week, or longer to serve demand. Such economically-viable, utility-scale storage has not yet been invented, and would take decades to deploy, in meaningful capacities, AFTER it’s invention.Remember, all this must be put in place to “branch out” to the steady state condition of having “wind turbines making wind turbines, or solar panels making solar panels”.France has a much better idea than Germany: 80% nuclear and 20% RE, mostly hydro, solar, wind and bio. Ultimately that will be a much less costly energy system than Germany’s, an international competitive advantage.
Well, the question how to replace “fossil fuels” / carbon emissions from non-energy related industry processes is a very exiting one. It’s a pitty that you went from “Is it possible?” to “Lets look how we do things today”. Your title should be called: “We don’t build wind turbines without fossil fuels today”————Here’s the fun you missed by not exploring things:Cement without carbon dioxide emissions: (feasable)http://phys.org/news/2012-04-solar-thermal-cement-carbon-dioxide.htmlOrMulti MW wind turbines can also be build using modern wodden towers: (Reality)http://www.timbertower.de/en/
The key point that I meant to make was essentially the same as that made by Thomas Gerke — that there is a disconnect between the article’s title, “Can You Make a Wind Turbine Without Fossil Fuels”, the article’s content, and the sentence just before the final paragraph, “In conclusion we obviously cannot build wind turbines on a large scale without fossil fuels.” As Thomas says, “you went from “Is it possible?” to “Lets look how we do things today”. You’ve made it clear that we currently use a lot of fossil fuel to make wind turbines. No argument about about that. But to go from there to concluding that “we obviously cannot build wind turbines on a large scale without fossil fuels” is leap unjustified by anything you’ve written in the article. To buy that conclusion, we’d have to accept the premise that the way we do things today is the only way they can possibly be done. Still speaking as your friendly hypothetical editor, there are two ways you could go to fix the article. One is to change the title and rewrite the offending “In conclusion” sentence. Take it in the direction of “these are the issues we will have to resolve before we can completely eliminate depencence on fossil fuels”. I think that’s pretty much what you intended anyway, and it’s perfectly valid.The other way you could go would be to stick by your “not possible” guns and make a serious attempt to prove that case. That would be an extremely significant accomplishment, if you could pull it off. But you’d need to quantify all the inputs, accounting for the possibilities of fuel synthesis, hydrogen-based reduction of iron ore, and alternatives to conventional concrete. You’d neet to show that the energy economics just don’t work. That might be difficult, as I suspect it’s not true. Regarding fuel synthesis, you need to be careful with that “science fiction” label. Some serious studies comissioned DOE / NREL concluded that electricity at 3 cents / kWhr could produce synthetic gasoline and diesel competetive with oil at $50 / barrel. The studies I recall reading were maybe five years back, and they may have underestimated the costs. But they were based on off-the-shelf equipment and well-known processes. I don’t think they would have been all that far off the mark. In any case, the issues are economic, not technical. Your statement that it will require “generations of engineers” to get it to work is over the top.
Well you’re right that I didn’t quantify the things I was writing about — but I wasn’t claiming to prove anything. Just describing a pathway that would have to be ruled out (shown unworkable) before claiming that building wind turbines without fossil fuels is impossible.You’re also right that ethelyne is more often the favored feedstock for synthesis of petrochemicals. But there’s not always enough available in natural gas to supply the chemical plant. In that case, I believe the usual practice is to reform methane into synthesis gas and from that, produce ethylene.
Wooden structures a football field high and wide plus enormous pressures lasting as long as steel towers and composite blades… call me a pessimest. I look forward to whatever comes after steel.
When I searched, I see mostly “bio” which means like “all” the forests or whatever at the large scales needed to replace diesel. Excuse my exaggeration (???) but I’m sure the biofuels approach might not suffice unless just for select industrial activities (such as wind turbines?).I hear that closed cycle nuclear has high enough temps to make clean liquid fuels, so I found this (here at TEC) from a google search.http://theenergycollective.com/barrybrook/172766/zero-emissions-fuel-transportationIt’s not necessary to get the excess carbon from the air as it can be taken from the ocean (and probably more urgent to do so). Here’s another link about nuclear ammonia.http://theenergycollective.com/barrybrook/66539/nuclear-ammonia-sustainable-nuclear-renaissance-s-killer-app