[HN Gopher] Dedicated biomass is not a good idea
___________________________________________________________________
Dedicated biomass is not a good idea
Author : gk1
Score : 72 points
Date : 2023-01-07 17:47 UTC (5 hours ago)
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| phas0ruk wrote:
| Well the story is pretty different if we are using waste like
| animal manure to create fuel.
| golemotron wrote:
| Based on the chart, nuclear is the clear winner.
| SkeuomorphicBee wrote:
| I don't get it, Brazil has been using biofuels (sugarcane
| ethanol) successfully in large scale since the 70s or 80s. Like a
| third of the car fleet of the country was ethanol fuelled in the
| 90s, and all cars since the 00s are dual fuel "flex" motors. All
| petrol stations have pumps for ethanol and gasoline side by side.
| And Brazil is no micronation, that is a fleet of millions and
| millions and millions of cars. So how can something that has been
| working for so long be unworkable?
| andrewflnr wrote:
| When they're being careful, they state "dedicated biomass for
| electricity production", which is... not something I'm aware of
| anyone doing? Seems more like trying to head off a future bad
| idea than criticizing something that happens today... again,
| when they're being careful with their phrasing.
| fsh wrote:
| Brazil has one of the lowest population densities on earth,
| less than half of the _world average_. Even so, sugar cane
| farming in Brazil is not exactly known for being sustainable.
| If anything, this example proves the author 's point about
| dedicated biomass being unsustainable at large scale.
| choeger wrote:
| Correct me if I am wrong, but did the author make a calculation
| error?
|
| The number of required energy comes in at the order of 10^20 J or
| 90000TWh:
|
| https://www.wolframalpha.com/input?i=300+quadrillion+BTU+in+...
|
| but if I multiply the energy return from biofuels with these
| alleged 1billion hectares of land, I get much, much more energy,
| billions of TWh:
|
| https://www.wolframalpha.com/input?i=582Mwh%2Fm%5E2+*+1billi...
|
| So unless there's a mistake somewhere, only a marginal fraction
| of land would be needed to cover all needs.
|
| So what went wrong here? I think it's the MWh per square meter
| number. 500MWh in PV would be a 500kW solar installation in
| Germany. I am quite sure you cannot fit that into a square meter.
|
| But even if we assume 580MWh per hectare per year, the output
| from 1billion hectares would be 580000TWh. So there's probably
| more wrong in that post.
| fsh wrote:
| Your units are completely off. From the article:
|
| > According to Google, the world's total arable land is about
| 1.38 billion hectares. Using the biomass LUIE figure of 580
| m2/MWh/y, we get a total potential electricity production of
| 23,793 TWh / year.
|
| This is correct:
|
| https://www.wolframalpha.com/input?i=%281.38+billion+hectare...
| snewman wrote:
| [Author here]
|
| The LUIE figure we found for dedicated biomass is 580 m2/MWh/y:
| 580 square meters to generate one megawatt-hour per year. You
| multiplied this by hectares, meaning you multiplied area times
| area. If you want to determine the amount of energy you can
| produce from a given area (e.g. 1 billion hectares), you need
| to divide by 580, not multiply by 580.
| scythe wrote:
| >"24% more carbon-intensive than gasoline" is not a ringing
| endorsement for [ethanol fuel]. The US really ought to stop doing
| this.
|
| Ethanol in the current US gasoline supply, as I understand it, is
| not really an energy source. Rather, the purpose is to increase
| the octane rating. Other octane additives were added in smaller
| amounts (tetraethyl lead, methyl tert-butyl ether) but they
| tended to be persistent pollutants, while 10% ethanol is
| foolproof and non-polluting. But it's bad for food prices: 40% of
| the US corn crop is used for ethanol.
|
| I could be way off, but that's what I heard.
| adastra22 wrote:
| Land value tax fixes this.
| Spooky23 wrote:
| There's no problem LVT won't fix.
| asdff wrote:
| The big one is probably getting individuals to vote to tax
| themselves out of ownership of property they can't afford to
| improve
| nibbleshifter wrote:
| Define "improve".
|
| If I accumulate some land, its becoming a forest. For at
| least as long as my direct descendants live.
| adastra22 wrote:
| And if your land is in a highly desirable location and/or
| contains desirable resources, you end up paying ever
| increasing property tax to keep it that way.
| eternityforest wrote:
| Why can't it just be a progressive tax that starts at 0%
| for the bottom 70% of lot size in your area?
| adastra22 wrote:
| It's all still too low. LVT should be 85% of the assessed
| value of the unimproved land, as a flat tax with no
| brackets and no controls.
| asdff wrote:
| I'm not sure how well that would work or not, but in
| cities with a housing crisis, the issue is not really
| people having acreage, but that they have a single family
| home or some other low usage building on the land at all
| in a place where there is demand for a lot more housing
| than what there is.
| JasonFruit wrote:
| In the US, isn't the main lobbying on behalf of this coming from
| industrial agriculture that has become addicted to the renewable
| fuel standard, which mandates that ethanol be added to gasoline,
| providing welfare for the ethanol industry at the expense of
| petroleum refiners (and eventually the driving public)? A good
| first step to end this idea would be to drop the mandate the same
| way the subsidies and tariffs supporting ethanol production were
| dropped.
| Spooky23 wrote:
| That will require a constitutional change, as the makeup of the
| Senate makes it impossible to make such a reform barring a
| significant economic change.
|
| It's either that or the depletion of aquifers.
| JasonFruit wrote:
| I'm afraid you haven't made clear what constitutional change
| you mean, at least to me. Can you elaborate?
| kfk wrote:
| I am the angel investor of a small startup trying to scale insect
| larvae production. The idea is to use larvae as a more eco
| friendly animal feed. I am still collecting numbers, but I was
| wondering if planting biomass to grow insect protein for humans
| is a good idea or not, it should be multiples better than growing
| crops to feed animals as a source of protein. I am just saying,
| dedicated biomass can mean a lot of different things, no?
| Spooky23 wrote:
| I think it depends on your starting point from a principles
| perspective.
|
| Nerdy people on message boards will adopt extreme positions.
| The argument against meat is that animal fodder is inefficient
| and everything would be better if we just ate soy, peas and
| beans. The same argument would be made against your idea.
|
| I think it's dumb to grow crops to stretch the viability of ICE
| engines in cars. But growing crops to produce upstream value,
| whether that's steak or food for my steak isn't an issue for
| me, and probably isn't a problem for 98% of people once they
| get over the "yuck, bugs".
| adrian_b wrote:
| Chicken protein is quite cheap. Divided by the protein content,
| the price of chicken breast is only 2 to 2.5 times higher than
| that of beans or lentils.
|
| To have any chance on the market, the price per protein content
| of the insect larvae must be at least twice lower than that of
| chicken meat. Therefore it must be about the same as for
| legumes like beans or lentils.
|
| To be able to judge whether investing in such a thing is
| worthwhile, you need a very accurate prediction of the
| production costs, to determine whether it is possible to match
| the legumes in price per protein content.
|
| I would be very wary about the risk that the estimation of the
| future production costs might be exceedingly optimistic.
|
| Currently some cereals are the cheapest source of proteins
| suitable for human consumption, but they cannot provide much
| more than a half of the daily protein intake of a human,
| because they lack lysine, so they must be combined with a more
| expensive source of proteins, like meat, legumes, or perhaps
| insect larvae.
| tinco wrote:
| Chicken protein is not as cheap when farmed sustainably and
| even if farmed sustainably it is rife with problems and
| risks. Where I live "ethical" (less densely farmed) chicken
| is 12 euro/kg and "organic" (sustainably farmed) chicken is
| 24 euro/kg (both thigh fillet) so there's a factor 2 right
| there.
|
| If they could come to be just the same price as "ethical"
| chicken that would be amazing. I think it's been shown that
| there's not much market for meat replacements at a premium
| (like impossible and beyond). But I can't imagine there's not
| an insane market at the parity. I know I would buy insect
| burgers for my family at least once or twice a week if they
| had comparable quality to chicken and similarly priced.
| dsr_ wrote:
| Some people object to eating insects. Some object to eating
| meat.
|
| Nearly nobody has an objection to eating legumes (I am
| ignoring, among other things, people on ultra-low-carb diets,
| specific allergies, and Ashkenazi Jews during Pesach), so an
| improved yield of legumes, or a reduction in water usage, or
| a tolerance for greater temperature extremes, or... would be
| extremely valuable.
| dinkleberg wrote:
| As biomass is the only source of fuel for us biological
| machines, I don't think anyone is questioning it in regards to
| food.
|
| But biomass being converted into electricity is horribly
| inefficient.
| beefield wrote:
| > But biomass being converted into electricity is horribly
| inefficient
|
| Even in CHP?
| dinkleberg wrote:
| The thing you need to consider with biomass is the
| efficiency of photosynthesis, which is incredibly poor. The
| upper limit for most plants is like 2% efficiency, many are
| significantly worse than that. Whereas photovoltaic cells
| are much higher, ranging from 15-20% or even higher. And
| this continues to improve.
|
| And that optimistic 2% efficiency for plants is just the
| energy conversion to grow the actual plants. Then to
| convert it into electricity requires it to go through a
| power plant which often have lower efficiencies of say 30%.
| If it is in a co-generation facility, it may have upwards
| of say 80%. Which sounds nice, but when you multiply those
| efficiencies and end up with in the best case, something
| like 1.6% efficiency which is terrible.
|
| And that is to ignore the other major factor which is that
| burning biomass causes major pollution.
|
| Fossil fuels are just convenient biomass that have been
| given the luxury of hundreds of millions of years to
| compress into dense hydrocarbons which make a convenient
| fuel source. We don't have this luxury when it comes to
| creating new biomass.
|
| The best aspect of biomass is that it is freely available
| to everyone. Anyone can gather sticks to burn.
|
| However, the parts of the world that still heavily rely on
| these methods for heating their homes and are used for
| cooking unfortunately suffer the consequences of breathing
| all of the smoke in over the years.
| ZeroGravitas wrote:
| The phrase "biomass" is misleadingly vague.
|
| The article is aboit dedicated biomass for electricity
| production, which given the cheapness of solar and wind is a
| little like dunking on steam-powered cars. I'm not aware of
| anyone arguing for that as an approach. We did these sums a
| couple of decades ago.
|
| On the other hand, wwste food, sewage, manure, and various
| other things that would become methane are useful to capture
| as it can be GHG negative comparrd woth letting it rot. That
| is also "biomass".
| bjelkeman-again wrote:
| There is a lot of waste in our food supply chain. Use that for
| feeding the insects, instead of taking resource that humans
| could eat. For example the remains from beer brewing is good
| insect feed. There are many other resources that today become
| waste, compost or biogas instead.
|
| I work with creating efficient closed loop food production
| systems.
| kfk wrote:
| For animal feed we will start with that, but I am finding
| hard to imagine that clean organic waste is not being used
| already in some other way? Meaning, probably we need to pay
| for it?
| colechristensen wrote:
| Watch the waning success of plant-based meat substitutes like
| beyond meat. If they're having problems selling passable meat
| simulations, imagine the problems you have convincing people to
| eat bugs.
|
| On top of that, food margins aren't huge and you're aiming for
| the low budget market, not a lot of money to be made there. And
| the optics aren't great, lots of people will find your product
| repulsive and at a low price it will look like you're trying to
| feed bugs to the poor.
|
| If insects as food ever becomes significant, it probably won't
| be the first to market that will succeed but a later breakout
| learning how to be successful after somebody else tries and
| fails several times.
| pfdietz wrote:
| I think the biggest argument against biofuels is that if they
| achieved large scale use, it would encourage people to mine
| biomass from existing forests instead of growing it.
| cbsmith wrote:
| Existing forests aren't good biofuel sources. You'd be better
| off mining the oceans, tbh. Neochloris oleoabundans or even
| industrial rapeseed are just so much more dense sources of
| fuel...
| pfdietz wrote:
| Mining the oceans? How does that work? A forest should be a
| much denser source of carbon, particularly reduced carbon,
| than the ocean.
|
| CO2 fixed per hectare per year should be much higher in
| lignocellulose than in seed oils. And if the forest is
| already there, you don't even have to wait for it to grow.
| The temptation to strip mine forests will be strong.
| cbsmith wrote:
| > Mining the oceans? How does that work? A forest should be
| a much denser source of carbon, particularly reduced
| carbon, than the ocean.
|
| Algae tend to grow in large clumps, and you can very
| efficiently filter for them from water. I don't think it's
| a great strategy, but it's more practical than extracting
| from forests.
|
| > CO2 fixed per hectare per year should be much higher in
| lignocellulose than in seed oils.
|
| Forests are definitely way better for CO2 capture, but
| we're talking about producing fuel here. I'm speaking in
| terms of the net energy produced per hectare, so factoring
| in the energy consumed to extract fuel, industrial rapeseed
| oil beats the forest every day of the week.
| pfdietz wrote:
| I don't know of any algae, anywhere, that are more
| concentrated sources of carbon than existing trees. Even
| if we had to grow both sides, algae are still
| problematic, since separating them from water is
| apparently quite a difficult problem.
|
| Yield of rapeseed in the US in 2020 was 2.16
| tonnes/hectare/year. Yields of lignocellosic biomass (dry
| mass) in the US (miscanthus, eucalypt) is almost an order
| of magnitude higher.
|
| Above ground forest biomass in Guyana: 499
| tonnes/hectare.
| ruined wrote:
| people already do that. it's called "logging" or "slash-and-
| burn"
| pfdietz wrote:
| And now it will be feeding something that's replaced the oil
| industry.
| ruined wrote:
| yes. it's well-known that policy-based demand for biofuels
| is accelerating deforestation in Brazil, for example
|
| https://www.nature.com/articles/d41586-020-00005-8
| shkkmo wrote:
| Yes, to make space to grow crops to make biofuel. Not
| because the forest is being "mined" for it's carbon to
| make biofuel out.
|
| As the article points out, growing crops to make biofuel
| is very space intensive.
| andrewmutz wrote:
| Why does this article focus primarily on the land cost of
| biofuels and ignore other costs?
|
| I am not a fan of biofuels, but the article would be much more
| persuasive if biofuels were 25x more expensive than the
| alternatives, rather than just 25x worse in land usage
| dec0dedab0de wrote:
| There is one aspect of biomass generators I always thought was
| overlooked. The process is very similar to making charcoal.
|
| If we used wood as a fuel source, heated it enough to release
| methane and other violitile gases to power a generator, but not
| enough to release the majority of carbon, that would leave us
| with charcoal.
|
| Instead of trying to extract the remaining energy from the
| charcoal, we could bury it. Which would sequester the carbon, and
| be fertilizer. Growing clovers or legumes would add nitrogen.
|
| I am sure I have something wrong, and maybe a better answer is to
| just not do it with dedicated crops as the article suggests.
| Maybe we could grow corn for food, but cram the stalks into the
| generator and sequester the remaining carbon?
| snewman wrote:
| > Maybe we could grow corn for food, but cram the stalks into
| the generator and sequester the remaining carbon?
|
| This is a thing; it's called "BECCS". You can also sequester
| the carbon without trying to burn it first; see, for instance,
| https://charmindustrial.com/.
| [deleted]
| habitue wrote:
| Seems like an idea worth trying to pencil out on paper to see
| if the numbers are in the right ballpark.
|
| A couple of questions I have:
|
| How much carbon could be captured this way, vs other carbon
| capture methods?
|
| How are cornstalks etc dealt with today by farms? Maybe they're
| already doing something efficient with it
| culi wrote:
| Dedicated biomass is indeed a terrible idea, but the usage of
| what would otherwise be waste products to produce biofuels still
| benefits from this research
| culi wrote:
| On that same note, it's crazy to me how much energy and effort
| we spend on getting rid of what is potentially one of our most
| valuable resources: manure. Specifically humanure
|
| In 18th century Japan for example, landlords often had rights
| to their tenants manure. "Night soil" became especially
| valuable as fertilizer prices grew. There have been fights over
| who is entitled to these biosolids. Even up into the 1980s much
| of Japan used special vacuum trucks to deliver night soil
| collections to treatment facilities
|
| Contrast that with the West where we spend billions of dollars
| on sewage systems that often cause ecological harm
|
| https://daily.jstor.org/a-history-of-human-waste-as-fertiliz...
| pfdietz wrote:
| That would be a great idea in a world without pathogens.
| Consider what would happen if there's a nasty prion that
| survives sewage treatment and then gets absorbed into crops.
| culi wrote:
| Why would this same prion not make its way in our ocean or
| soils with the current sewage system set up? If the
| treatment fails, I don't see why dumping it in the oceans
| is safer. The food chain there is much more complex and
| therefore the prion would be exposed to many more possible
| hosts. In fact, prion biology shows that exposure from fish
| is a much greater concern than foodplants
|
| https://www.sciencedirect.com/science/article/pii/S09254439
| 1...
| pfdietz wrote:
| You're asking why the current sewage system wouldn't be
| safer than the nightsoil system, where raw waste is
| applied directly to cropland. Or why applying processed
| sewage to cropland might be less safe than NOT applying
| the bioprocessed sewage to cropland. I think you can
| understand why the latter there could be safer, by
| increasing the distance between waste and food.
| culi wrote:
| that's not at all how nightsoil works lol
| pfdietz wrote:
| Untreated waste was used directly as fertilizer. Yes, it
| might be untreated sludge from holding tanks, not people
| directly shitting in the fields.
| [deleted]
| jagtstronaut wrote:
| It isn't a concern to use human waste for non-food
| applications, and there are times that it actually is. With
| food or food that our food eats there is the risk of
| communicable disease.
|
| The problem from there is twofold 1. Generally we grow things
| for food and beauty, both of which are kind of ruined by
| human manure. 2. Most needs for manure come from animal farms
| and they usually have an excess of the animal manure and
| don't really need anymore.
| culi wrote:
| I think you underestimate how easy it is to neutralize the
| risks of human manure. In fact it's something you can even
| do in your own backyard. Compost toilets are gaining in
| popularity. Even federal agencies like the NPS are
| exploring implementing them
|
| https://www.nps.gov/articles/composting-toilets.htm
|
| In fact, I'd argue solutions like this would be an overall
| reduction in the risk of spreading communicable diseases.
| Sewers can still transfer diseases like this until the
| waste reaches treatment facilities. Treating it more
| locally reduces the overall amount of time available for
| diseases to grow and spread
|
| > 1. Generally we grow things for food and beauty, both of
| which are kind of ruined by human manure
|
| Cow manure is an excellent compost used all the time that
| you can even buy at a local gardening store. It's mostly a
| silly cultural "yucky" aversion that keeps us from
| utilizing safe, neutralized human manure in the same way
|
| > 2. Most needs for manure come from animal farms and they
| usually have an excess of the animal manure and don't
| really need anymore.
|
| ...cities and towns have an excess of human manure that
| they don't really need anymore too lol
| Spooky23 wrote:
| We do. Sewer districts sell screened solids as fertilizer in
| many places.
| dec0dedab0de wrote:
| A friend of mine works at a company that processes waste
| water. A few years ago he was telling me about how they were
| working on(or already have?) A way to extract nitrogen to
| sell.
| someweirdperson wrote:
| > For each energy source, we pulled out the figure for LUIE
| (land-use intensity of energy), i.e. the amount of land required
| to produce a given amount of electricity.
|
| Turning bio-mass into electricity comes with a lot of losses.
|
| If the desired product is fuel, the numbers for bio-mass are a
| lot better, and the numbers for all other sources that first
| produce electricity are a lot worse, because turning electricity
| into fuel comes with a lot of losses.
| plaidfuji wrote:
| > turning electricity into fuel comes with a lot of losses.
|
| This is true, but when generating fuel, the end goal is usually
| to move a vehicle X miles. Now that electric cars are nominally
| competitive with ICE vehicles, the metric should be something
| more like "land required to drive a truck X miles/year" - and
| assume the best of either electric vehicle efficiency or ICE
| efficiency, not force an arbitrary electrical->chemical
| conversion for the metric's sake. Biofuels probably wouldn't
| look like as much of an outlier as they do here, but I would
| still wager that they're among the least efficient options.
| pfdietz wrote:
| Biofuels would be focused on applications where electrical
| vehicles would suck, such as aircraft.
| adgjlsfhk1 wrote:
| Tran-oceanic shipping and long haul airplanes are the 2
| places where biofuel theoretically has some merit, but it
| still has the problem that it is about 25% worse than just
| using fossil fuels.
| pfdietz wrote:
| That 25% argument was addressed elsewhere in the
| comments.
| concordDance wrote:
| It would be helpful to include a link.
| cbsmith wrote:
| > Biofuels probably wouldn't look like as much of an outlier
| as they do here, but I would still wager that they're among
| the least efficient options.
|
| I wouldn't wager because it's not a simple yes or no type
| question. There's a lot of ambiguities even in the analysis
| behind the graph presented in the article, but when it comes
| to fuels vs. batteries, it gets even more insane. Fuels have
| a weight advantage over batteries that gets magnified as the
| weight and range of the vehicle increases... and there's a
| lot of variance within fuels too. So, while an electric
| bicycle is going to be a no-brainer over a motorcycle for
| pretty much any scenario, it can be quite the opposite for
| something like a commercial truck.
|
| I keep coming back to the economist argument that if we just
| captured the externalities related to climate change, we
| avoid having these discussions and simply look at the price
| of things... but of course, that's the hard part in all these
| discussions.
| enkid wrote:
| But he address the fact that it's actually worse from a carbon
| standpoint than gasoline. That added to the other environmental
| impacts associated with agriculture makes it clear it's still a
| worse choice than straight gasoline. Not only does it not help,
| it actively makes the problem worse.
| pfdietz wrote:
| That was for ethanol from corn. Most of the carbon in the
| corn plants doesn't turn into fuel in that system. Even if
| cellulose could be converted, a great deal would still be
| lost in CO2.
|
| A land-efficient biomass fuel system would convert all the
| carbon in the biomass into fuel. This would require adding
| extra hydrogen, particularly if you want hydrocarbon fuels,
| since the oxygen in the biomass has to be carried off
| somehow. The hydrogen could be sourced from solar or wind by
| electrolysis.
| cbsmith wrote:
| Yeah, and ethanol from corn is arguably one of the worst
| options for biofuels. You're better off with biodiesel
| sources... even soybeans are better, and they're not great.
| colechristensen wrote:
| I am not a huge fan of ethanol fuel but the leftovers from
| fermentation aren't waste, they're sold as cattle feed. So
| the land utilization is split between products and it
| wouldn't necessarily be better if the corn to fuel
| concession was higher.
| enkid wrote:
| Is there a better alternative?
| pfdietz wrote:
| I've been interested in this company's technology for a
| long time: https://www.virent.com/
|
| In any biomass technology with a CO2 waste stream, the
| CO2 can be converted to hydrocarbon fuel by Fischer-
| Tropsch, if you have additional hydrogen.
|
| In the post fossil fuel age, there will be an entire
| biochemical industry that converts biomass to chemicals
| now obtained from fossil fuels. Some of these processes
| will look a lot like things developed for the
| petrochemical industry. All the carbon going into
| landfills now will instead be fed into this industry.
| bob29 wrote:
| Really beating up a strawman. No one's proposing or implementing
| "dedicated" biomass.
|
| Corn ethanol utilizes the starch from corn, and leaves behind
| proteins, fats, minerals, and yeast cells which are used as
| animal feed, where its superior to plain corn.
|
| Likewise woody biomass isn't coming from clear cutting forests,
| its from necessary thinning to keep forests healthy (thats
| otherwise burned in slash piles) and mill waste thats a byproduct
| of lumber production.
| snewman wrote:
| > woody biomass isn't coming from clear cutting forests, its
| from necessary thinning to keep forests healthy
|
| From what I've seen, claims to this effect often turn out to be
| false. For instance, from
| https://billmckibben.substack.com/p/a-little-xmas-cheer-
| for-...:
|
| > ...the world's largest supplier of wood pellets for power
| generation ... has long insisted that it doesn't use big, whole
| trees, but only uses wood waste, "tops, limbs, thinnings,
| and/or low-value smaller trees." It insists it only sources
| wood from areas where trees will be regrown, and that it
| doesn't contribute to deforestation.
|
| > As it turns out, Mongabay reporter Justin Catanoso found a
| management whistleblower who pointed him in the direction of
| clearcuts that the company was making: Catanoso watched as a
| feller-buncher machine grappled down a fifty-acre forest and
| fed the old oaks straight into a chipper, producing tons of
| wood to be turned into pellets. The whistleblower said that was
| par for the course: "We take giant, whole trees. We don't care
| where they come from. The notion of sustainably managed forests
| is nonsense. We can't get wood into the mills fast enough."
|
| > He continued: "The company says that we use mostly waste like
| branches, treetops and debris to make pellets. What a joke. We
| use 100% whole trees in our pellets. We hardly use any waste.
| Pellet density is critical. You get that from whole trees, not
| junk."
| [deleted]
| Hani1337 wrote:
| These numbers were compiled by a mathhead who knows nothing about
| renewable agriculture meets new technologies. To be clear I'm not
| saying growing crops to turn them into biofuels is a good idea,
| but there are plenty opportunities to render the calculations
| based on arable land and energy output irrelevant.
| jasonhansel wrote:
| > each box represents a source of electricity. The higher the
| box, the more land that source uses. [...] If you look carefully,
| you might notice that the vertical axis uses a log scale.
|
| I think this graph wins the hotly contested "most misleading use
| of a log scale" award. Anyone glancing at it quickly would vastly
| underestimate the differences between energy sources.
| lukeasrodgers wrote:
| Based solely on my personal experience, this log scale graph is
| no more misleading than a typical log scale graph. What in your
| mind makes it unusually bad? Do you have examples of better log
| scale graphs?
| jasonhansel wrote:
| First, the use of a log-scale seems to serve no purpose. The
| point is to illustrate that biomass is vastly worse than the
| alternatives; a comparison between those alternatives is
| irrelevant. So the log scale obscures the point rather than
| elucidating it.
|
| But secondly: some log scale graphs have unevenly-spaced
| lines along the Y axis to make the use of a log scale more
| obvious. This is an example of what I mean: https://www.geol.
| lsu.edu/jlorenzo/geophysics/graphing/semilo...
|
| On this graph, though, the lines along the Y-axis are
| _evenly-_ spaced, increasing the confusion.
|
| Thirdly: the use of a log scale should be mentioned in the
| graph's caption, not buried in the text.
| sfink wrote:
| Yeah, I was thinking a linear graph with a scrollbar would
| emphasize the point a lot better, and then add a toggle for the
| log scale so you could actually see the data without scrolling.
| But then you'd need to explain why you're seeing so little and
| that you need to scroll.
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