You do realize that you can’t grow sugar and rice in Iowa, Nebraska, S. Dakota, Missouri, Ohio, Kansas, Indiana, Illinois, Wisconsin and Minnesota, don’t you? You can grow corn, barley and wheat there, so that’s what they grow.
Similarly, corn doesn’t do as well in S. Florida and Hawaii as sugarcane, or as well as rice in Arkansas, Louisiana and Texas, so that’s what is grown there.
Crop cultivation aside, no food crops are going to cut it as viable large-scale biofuel sources, as they’re not efficient enough.
What’ll make biofuels a real challenge to petroleum is, if and when cellulosic ethanol gets figured out in an economically viable way. That opens up the ability to use just about any plant matter as feedstock- wood, sawdust, grass clippings, old newspapers, etc… In practice, this means people will grow crops of stuff like switchgrass, that are useful on marginal land and which grow fast, and use that as feedstock for the ethanol plants.
Even corn ethanol with modern production is net energy positive, I was someone who frequently pointed out corn ethanol not being net energy positive in the past, but there’s been a consistent stream of publications showing it is since the early 2010s. The status quo does change. Should we be producing corn ethanol? My opinion is no, not at large scale. Half-assed remembered data but I think for example sugar cane what Brazil uses, is 12 times more energy efficient, corn just barely is net energy positive. The only real niche for corn ethanol might be for use in agriculture itself, by large farmers who have excess corn stocks for some reason. I don’t know how realistic a scenario that is.
Biofuels are in some regards an “inefficient” means of capturing solar energy, but it produces a very energy dense fuel that is useful for powering internal combustion engines. Solar panels can’t power ICEs. So that’s really their use case. I think it’s a mistake at this point to go heavy into biofuels but for some countries who aren’t worried as much about the environmental impact it does make sense contextually. I think it’s a mistake to adopt them to such a degree though, Europe is strangely burning more and more biofuels in power plants as part of their “green” initiative but the carbon emissions are bad from these. It makes little sense.
So ok, let’s say the energy return for ethanol is 2. That means that for every unit of ethanol you produce, you had to consume 0.5 units of some kind of fuel which could be ethanol.
That sounds acceptable, except there’s all these other costs. There’s the energy to build the equipment that you’re making the ethanol in. The energy used per human worker - every person you have working exclusively in this industry, you really should subtract the average energy consumption for a worker in that country at their salary level.
This is because ethanol production is labor intensive (lots of tractor trips, lots of complex factory equipment to maintain) and with such a low EROI of 2, all this stuff matters quite a bit.
And then there is the problem of displacement of food crops. The food now has to be produced in less favorable farmland (more energy used).
TLDR, the easiest way to measure all this is to just look at the free market, unsubsidized cost of the resulting ethanol fuel and compare it to that cost for oil produced gasoline. Don’t forget to add the negative externality cost of releasing net CO2 to the gasoline part of the equation.
Anyways, “done right”, this would tell you if ethanol is a viable idea. Of course, there are so many ways to do the math, you can basically work out the numbers to show either answer.
Right. You have to open the little door, unscrew the cap, swipe your credit card, select the grade, stick the nozzle in, and hold the lever up the whole freakin’ time.
From my previous research on this, there is no standard as to what is included in such studies. It varies wildly, and so too do the net energy balance numbers. But there’s also such upstream/downstream energy costs associated with essentially all forms of energy to some degree or another and factoring those in or not is also not consistent across studies.
Like I had mentioned, at one point I was quick to point out that the net energy balance for corn ethanol was negative, because several researchers had persuasively made this claim. But the weight of studies since then has said corn ethanol is net energy positive, albeit very slightly. Depending on what you factor in it’s as low as something like 1.06 and as high as 1.5 (energy out for energy in.) Some of the older studies were right in their day, but efficiency gains were certainly realized.
For other biofuels the net energy balance isn’t even really close, it’s like 12:1 for sugar cane (which is what Brazil uses), and >30:1 for some types of cellulosic ethanol.
What’s notable is a lot of debate about the energy balance for corn ethanol was popular in the 2000s but you don’t see as much coming out about it now. I think the reason is that there is a growing realization that it actually doesn’t matter–burning biofuels doesn’t do much at all to help with our carbon emission problem. If you’re working with genuine national energy scarcity issues like Brazil was when it invested so heavily in sugarcane then again, it may be worthwhile. But for countries trying to grapple head on with climate change it makes very little sense to meaningfully continue to build out another carbon-emitting energy industry when we already have oil, coal, and natural gas we burn a ton of, we need to be moving more toward alternatives to those fossil fuels not burning biofuels which are functionally very the same. The big advantage of biofuels if there was no concern at all about carbon is they’re truly renewable, there’s not a “peak sugarcane” in the future, but it’s just not good in this era with what we know about climate to be pursuing them.
Hyde : the problem is that if the EROI is 7:1 or 10:1, neglecting the energy cost to smelt the steel in the oil refinery is ok, you can just do a Fermi estimate and figure that it’s insignificant.
It’s when the EROI is barely positive at all that these factors dominate. Like, if ethanol were 2:1 and oil were 10:1, and the “labor” factor is proportional to the “1” part of the equation, not the return, it’s quite obvious that if you include those factors, ethanol is either net negative or marginal.
I’m not sure what you mean by labor–but like I mentioned there are a range of energy balance figures for corn ethanol and in the newer studies even the lower range (which incorporate a wide range of what goes into raising the corn and turning it into ethanol) have it slightly energy positive.
It’s also useful to not say things like “if ethanol were 2:1”, ethanol is a finished product, it doesn’t have a net energy balance in and of itself because the inputs versus the outputs varies dramatically from one crop to the next, corn and sugarcane derived ethanol are the same at the end but get there with different efficiencies. As I mentioned corn ethanol is as low as 1.04 or so, while sugarcane ethanol is 12:1, and cellulosic ethanol can be > 30:1.
I think it’s useful to remember marginal ethanol is really corn ethanol and arguably maybe biodiesel, but sugarcane or other common crops used to make ethanol really can’t be energy negative by any reasonable measure.
I have been working for a bio-based fuel/chemical/material start up for 7 years. When we have to compete against a material that is as cheaply obtained as petroleum (and now natural gas), it is impossible to compete. Look at the economics of Shell, BP, etc. (particularly the cost of their raw materials compared to their products) and compare them to any other company and your jaw will hit the floor. They effectively get nearly free access to a shared resource for the planet (it’s not like Shell put the plant matter down there originally), and then are able to sell it at huge markups and still be cheaper than anything from any other source.
This is the key. Once (if?) this gets figured out, ethanol will be a permanent part of the energy picture. It’s really a great solution - you take garbage and turn it into a renewable fuel.
I have a lot of sympathy for this argument, but there is also an argument that cheap fossil fuels have been an amazingly important benefit to humankind. The cheap, ubiquitous availability of gasoline and diesel had led to improved lives for billions of people. People who would have starved or led dreary, deprived lives now flourish across the globe.
Maintaining our global standard of living while carefully weaning ourselves off of fossil fuel will be a daunting challenge.