[HN Gopher] More energy on less land: The drive to shrink solar'...
___________________________________________________________________
More energy on less land: The drive to shrink solar's footprint
Author : RickJWagner
Score : 69 points
Date : 2022-08-15 11:52 UTC (11 hours ago)
(HTM) web link (e360.yale.edu)
(TXT) w3m dump (e360.yale.edu)
| anonymousiam wrote:
| The article is very light on the technology. (Quad Junction) GaAs
| cells have been produced with >40% conversion efficiency. That's
| more than three times the efficiency of Si or anything else in
| common use. The GaAs cells have thus far only been used for
| space-based applications. Somebody should be working on getting
| production costs down and deploying these things terrestrially.
|
| https://arxiv.org/pdf/1905.08024.pdf
|
| https://boeing.mediaroom.com/2010-11-01-Boeings-Spectrolab-P...
|
| https://www.spectrolab.com/photovoltaics.html
| ncmncm wrote:
| 40% is not, in fact, 3x, or even 2x, current best efficiency of
| Si or CdTe panels.
|
| And, the important efficiency measure is W/$, where GaAs trails
| well back. Perovskites may exceed 40% conversion efficiency,
| and also have good prospects to offer much better W/$. Their
| endurance has grown encouragingly quickly.
| anonymousiam wrote:
| If you looked at the first link I cited, they claim 47%
| efficiency is possible. That is more than 3x the efficiency
| of many Si panels on the market today. Unlike perovskites,
| which to date have only achieved ~25% efficiency, GaAs cells
| have been produced with efficiencies approaching 70% (under
| laser illumination). https://www.ise.fraunhofer.de/en/press-
| media/press-releases/...
|
| W/$ goes down with manufacturing efficiency. Nobody has done
| large scale manufacturing of multi-junction GaAs cells.
| philipkglass wrote:
| _If you looked at the first link I cited, they claim 47%
| efficiency is possible. That is more than 3x the efficiency
| of many Si panels on the market today._
|
| Top-end GaAs technology wouldn't compete with bottom-end
| silicon technology (the below-16% panels that you mention).
| It would compete with top-end silicon technology, which is
| already commercially available at module efficiencies above
| 22%:
|
| https://cdn.energypal.com/panels/spr-x22-370/energypal-
| solar...
|
| Note that the upper cell efficiency limit for _any_ single
| material under incident terrestrial sunlight is about
| 33.5%:
|
| https://www.energy.gov/eere/solar/multijunction-iii-v-
| photov...
|
| GaAs cells reported to operate above this limit are part of
| multi-junction cells and/or incorporate optical
| concentration systems to focus sunlight to higher
| intensities. The experimental record-holder of 47.1% uses a
| multi-junction cell plus optical concentration. Optical
| concentration only works with direct normal illumination;
| light that is scattered through haze or clouds can't be
| focused, so optical concentration systems are a good match
| only for sunny areas that have clear skies year-round.
|
| That said, the National Renewable Energy Laboratory is
| researching ways to make GaAs cells at lower cost:
|
| https://www.nrel.gov/news/video/building-low-cost-high-
| effic...
|
| At low enough cost, GaAs modules could compete directly
| with premium silicon solar modules. They could conceivably
| be lighter as well as more efficient than silicon, since
| thinner layers of GaAs are needed than silicon layers,
| which in turn reduces the required module rigidity,
| thickness, and weight.
| johnday wrote:
| If we are talking about solar installations on land, rather
| than in the built environment, the W/$ also needs to factor
| in the cost of the land itself, which is at a premium in many
| places including across Europe. On that basis there is scope
| for an increased efficiency to lower the cost delta.
| ncmncm wrote:
| You have clearly missed the point that siting solar has no
| need to interfere with other, simultaneous uses of the
| land.
| jefurii wrote:
| Anidolic lighting could be used to provide diffuse light beneath
| solar panels.
| ZetaZero wrote:
| Here in the US, we could power the entire country with solar
| panels by just using 1% of the land now dedicated to agriculture.
| masklinn wrote:
| And the US has plenty of _literal deserts_ to use for that
| anyway.
|
| The issue is really mostly the difficulty of smoothing
| production over consumption. And transmission.
| dublin wrote:
| Your comment shows you really don't know much about solar PV.
| Deserts are _horrible_ for solar, for two major, and a bunch
| of minor reasons:
|
| 1) Heat kills PV efficiency, since, to a first order
| approximation, current is proportional to irradiance (deserts
| good), but voltage is _inversely_ proportional to temperature
| (so deserts very bad). You make _way_ more power on a clear
| winter day in Colorado (assuming no snow on the panels!) than
| you do on an Arizona summer day. If you don 't like this,
| take it up with God, since it's just the way he built the
| universe and the quantum physics of semiconductor junctions.
|
| 2) Dust (and/or salt, if you're anywhere near the ocean) is a
| _huge_ enemy of solar power production (so deserts bad,
| again). Dust or salt spray can easily cost you nearly half of
| your power output. PV panels are scarily susceptible to even
| small shading from leaves or even bird crap on them. I can
| throw a business card on most panels and take out 1 /3 to 2/3
| of that panel's output. If wired in a string, as is typical
| for utility scale PV, the loss of that single can take out
| the power production of that entire string (typically 12-22
| panels worth), since it can no longer reach the inverter bus
| voltage set by the unimpaired strings.
|
| Oh, and cleaning panels is _really_ expensive - it was $0.50
| /panel a decade ago when I was collecting the largest
| database of DC solar panel data in the world - I don't
| imagine it's gotten any cheaper... (One of the big selling
| points of our software was that it could optimize cleaning
| and maintenance timing and intervals. This can actually make
| the difference between breaking even on the array cost or
| not!)
| naniwaduni wrote:
| > I can throw a business card on most panels and take out
| 1/3 to 2/3 of that panel's output. If wired in a string, as
| is typical for utility scale PV, the loss of that single
| can take out the power production of that entire string
| (typically 12-22 panels worth), since it can no longer
| reach the inverter bus voltage set by the unimpaired
| strings.
|
| Wait, how does this shit even work at all, then? Are solar
| farms just perpetually functioning at <50% capacity because
| everything broken all the time?
| extropy wrote:
| This used to be true for cheap panels. Better panels
| would have bypass diodes for every cell (the 10x10 cm
| square) and would only loose the output of the affected
| cell.
| blacksmith_tb wrote:
| You'd like to think there would be some monitoring - on
| my roof at home, I had something smash one of my 20
| panels, right in the middle of the grid (probably a
| bullet falling after someone shot up in the air, but I
| like to pretend it was a meteor...) I didn't notice the
| output was halved for weeks.
| bradstewart wrote:
| A falling bullet broke a solar panel? How big of a
| bullet.... Mine have survived hailstorms without issue.
| alliao wrote:
| i had a hunch this was the case on cleaning, I think around
| my area Auckland, New Zealand not able to clean it yourself
| is the difference... does this mean the maintenance company
| are rent seeking the margin, and if so why aren't panel
| makers do cleaning as well? or is cleaning such a un-
| scalable operation that it's best left to lowest bidders?
| benj111 wrote:
| Water cooling (in a closed loop) could solve point 1.
|
| Bonus if you use that heat to generate more power at night.
| jandrese wrote:
| I've been wondering lately if it wouldn't make sense for
| power companies to offer a battery incentive program to
| homeowners. They'll cover 1/2 the cost of a battery but
| mandate that the system be set to draw from the grid when
| production is high (middle of the day mostly) and be used to
| power the home in the evening when demand is high but
| production is tailing off.
|
| Some companies do Time of Use contracts which do this to a
| degree, but flat incentives (cut a one time check to the
| homeowner) seem much less complicated. The grid gets
| smoothing and the homeowner gets to keep the lights on when
| the power goes out and doesn't have to spend nearly as much
| on the install. The power company doesn't have to manage a
| big bank of batteries somewhere and saves on distribution
| costs. Plus the homeowners technically own the systems so
| when something goes wrong the power company doesn't have to
| roll a truck to fix it.
|
| The only real problem with this scheme is that the battery
| market is already squeezed with so many companies jumping
| into the electric vehicle business and production lagging
| behind demand. However, this is likely to be a short term
| problem, so hopefully in the next couple of years something
| like this will be practical.
| ZeroGravitas wrote:
| Some forward thinking utilities have been doing this for
| years.
|
| https://www.greentechmedia.com/amp/article/from-pilot-to-
| per...
|
| The general term is Virtual Power Plant, where software
| let's a bunch of distributed items act in concert as if
| they were a big powerplant.
| Retric wrote:
| Economies of scale heavily favor grid storage over home
| storage.
|
| The batteries may be identical but installing them,
| monitoring them, doing AC>DC>AC conversions etc become much
| cheaper at scale.
| whichquestion wrote:
| I wonder if it would be a possibility to relay electricity
| across the US with large battery stations from big solar farms,
| or if the loss in transit + the expense of the batteries would
| make something like that intractable.
| bburrito wrote:
| So Cal has Sunrise Power Link which is high voltage
| transmission lines specifically designed to bring in power
| from the solar and wind farms in the desert. The
| proliferation of solar farms in the desert is a clear
| indicator of how that has gone.
| HideousKojima wrote:
| Growing up in San Diego I hilariously remember
| environmentalists protesting the Sunrise Power Link. The
| reason given by my high school classmates who were involved
| in the protesting was that it threatened some desert
| tortoise's habitat or something like that. There were also
| some NIMBY types protesting the transmission lines.
|
| From the gas and oil companies' perspective, with enemies
| like these, who needs friends?
| codereviewed wrote:
| I just don't see how land use is an issue worth worrying about
| right now, climate emergency and all. The federal government owns
| _huge_ swaths of sunny arid desert land in the west. It is
| largely not suitable for crops, livestock, suburbs, etc. We could
| install millions of acres worth of current solar tech out there
| and generate enough power for everyone. The real difficulty lies
| in the infrastructure it would take to get the power to where
| people are.
|
| What we should be focusing on is transmission and distribution,
| those are the really hard problems. We could have all the power
| we want but if our grids can't handle the rapidly increasing
| demand it does nothing for us. And as more people go 100%
| electric for transportation, heating, and cooking the integrity
| of power distribution becomes even more important because we will
| have put all our energy eggs in the electricity basket.
|
| The only place land use seems relevant is for smaller scale off-
| the-grid cases where someone's property is small but they want to
| generate all their own electricity.
| [deleted]
| cronix wrote:
| > The real difficulty lies in the infrastructure it would take
| to get the power to where people are.
|
| I live in Oregon and slightly over 1/2 of the state is federal
| or state owned land which cannot be purchased. Even out in the
| middle of nowhere, there are still massive transmission lines
| carrying electricity from one part of the state to another
| through these areas. This is often in fairly mountainous
| terrain and dense forests. I'm often in awe at how much work
| they have to go through to keep the area immediately around
| these lines clear of trees and vegetation. I explore forest
| roads quite a bit. This is just to point out that we've been
| doing that type of thing for a long time and I don't think
| transmission itself is tremendously difficult. We just lack the
| will.
| einpoklum wrote:
| > just don't see how land use is an issue worth worrying about
| right now
|
| 1. In small(ish), densely-populated countries, land is in short
| supply, regardless of any socio-economic-political
| considerations.
|
| 2. In many countries, land is private, or has been fully
| "divvied up" in some form or another, despite being only
| sparsely used. In these countries, reallocating land is a
| headache - politically, economically and legally.
|
| But I agree that storage, transmission and distribution are
| important things to focus on. Or rather - the important thing
| to focus on is to actually deploy lots of solar instead of
| fossil (which the recent US federal legislation makes even
| harder than before).
| wolfi1 wrote:
| why not use the parking lots and malls and one story buildings?
| jandrese wrote:
| Parking Lot solar makes a huge amount of sense. Not only does
| it create power, but it creates shade for the parked vehicles
| and cuts down on the amount of heat absorbing blacktop visible
| to the sun. The suburbs are absolutely covered in parking lots
| that could be converted. Nobody is going to complain that the
| solar array is despoiling the aesthetics of the suburban
| parking lot either.
|
| Really the only downside is that people will crash their cars
| into the support structures. It is inevitable, and needs to be
| accounted for in the design.
| ssully wrote:
| I am not saying this to be pedantic, but people will 100%
| complain about solar arrays in parking lots. Green energy is
| a politicized and having solar parking lots will be used as a
| political talking point. It already happens with electric
| cars, wind farms, and much more.
| jandrese wrote:
| Well yes, there are always cranks to complain about
| everything. But as long as they are just the usual cranks
| it's not really a problem, especially if you can make them
| look foolish in front of the planning committee by showing
| a "before" picture of the hideous parking lot.
| monkeydust wrote:
| So where are we with practical deployment of perovskite solar
| cells?
| ncmncm wrote:
| Perovskites are lately in the position of needing to prove
| longevity, which takes a long time.
|
| In the meantime, they are quite a lot cheaper to make, so in
| many uses it would not matter so much if they did fail faster.
| In some uses, like aerospace, their lighter weight and better
| areal efficiency are essential, and forgive a lot.
| moffkalast wrote:
| > they are quite a lot cheaper to make, so in many uses it
| would not matter so much if they did fail faster
|
| Hard disagree on that, their current longevity is comparably
| tiny so you'll have lots of overhead in installation costs.
| Not to mention the amounts of toxic lead trash you'll need to
| pay to dispose of, the thing is basically poison after all.
|
| Makes far more sense to invest in multilayer tech even if it
| costs more since it'll last longer by an order of magnitude
| and use far less area to function which is a big benefit for
| vehicles too.
| ncmncm wrote:
| Perovskites do not need to have any lead in them at all.
|
| The thin films amount to very little mass, and in any case
| may be incinerated and the ash used as feedstock.
|
| Longevity is already up to years. In many uses that is
| plenty, especially when you can just roll it out, instead
| of needing to bolt it up.
| moffkalast wrote:
| > Perovskites do not need to have any lead in them at
| all.
|
| Well that's news to me, I thought that was part of the
| core functionality.
| ncmncm wrote:
| Many of the best chemistries have lead, but it is still
| early days. "Perovskite" refers to lattice structure. Tin
| has also been used.
| ZeroGravitas wrote:
| https://pubs.acs.org/doi/full/10.1021/acsenergylett.2c00698
|
| is an overview,
|
| seems like for places where you could use silicon, but are
| limited by space and need high output then thy hybrids from
| Oxford PV seems ready, but I'd guess that's going to be a tiny
| share compared with people who just want it cheap and at scale.
|
| https://www.oxfordpv.com/news/towards-better-understanding-l...
|
| But hopefully that is enough for it to get proved out and
| scaled up.
| monkeydust wrote:
| https://sauletech.com/
|
| Recall seeing a video of their factory printing solar cells.
|
| Looked great but nothing on their site suggests they have a
| product unless anyone knows different?
|
| They are listed on Warsaw stock exchange (and having a
| miserable time of it as the price would suggest).
| fredgrott wrote:
| Something interesting to calculate if you like math and biology.
|
| Why is it that Trees can generate more energy via absorbing light
| than implied by the surface area of leaf coverage of the outer
| branches?
|
| Hint, yes has to do with light spectrums and their behaviors and
| the benefits of chloroplasts using more than one light frequency
| ncmncm wrote:
| Conversion efficiency of most plants, trees included, is around
| 2% or less. A few species, including certain cereal crops, have
| got up to 4%.
| [deleted]
| ZeroGravitas wrote:
| Yale360 seems to cover renewables issues as if the reader already
| has some very weird ideas about them. Probably a sensible and
| sadly necessary approach.
|
| But in reality, land use has never been a problem for Solar. It's
| great that lots of people are working on the issue and improving
| it. Just as lots of people are working on making them cheaper, or
| more environmentally friendly or easier to finance or a thousand
| other metrics.
|
| But none of those were ever fundamental problems with the tech.
| Their own source of data about the 'problem' puts Ground-based PV
| at about the same land use as Coal.
|
| They also missed out 'floatovoltaics' (PV on water) and building
| integrated PV as well as solar PV as a paving solution. Probably
| all of which are likely to be bigger than ground mount PV, given
| the trend to bifacial panels.
| mech987 wrote:
| Is PV at the same land use as coal currently on a per-watt
| basis or on a total land use basis?
| ZeroGravitas wrote:
| They link to this, which has a table at the top:
|
| https://ourworldindata.org/land-use-per-energy-source
|
| I'd assume coal uses much more land in absolute terms, since
| it's what 50% of global electricity vs 3-5% for solar at the
| moment.
| ncmncm wrote:
| Since solar may use up exactly zero acres, its watts per acre
| may be infinite. Wind, also, coexists easily with other uses.
|
| Solar farms are often sited, stupidly, in deserts, not
| because it is a good idea, but because ignorant investors
| think it is a good idea.
| [deleted]
| tbihl wrote:
| >Solar farms are often sited, stupidly, in deserts, not
| because it is a good idea, but because ignorant investors
| think it is a good idea.
|
| Perhaps indulge our ignorance about deserts for a moment?
| ncmncm wrote:
| Deserts are hot and dusty. Efficiency falls quickly as
| temperature rises, and more as dust accumulates. Panels
| degrade exponentially faster as peak temperature
| increases. (Precisely: each fixed increase in temperature
| doubles rate of degradation.)
|
| Siting panels on water and on farmland reduces operating
| temperature. Mounting vertically, in fence-rows, keeps
| off dust, collects more during morning and afternoon
| demand peaks, aids convective cooling, and protects crops
| from harshest afternoon sun.
| naasking wrote:
| "Same land use as coal" isn't necessarily an equivalent metric.
| Solar might be taking up land that could otherwise be used for
| food, for instance.
|
| Better energy density will also help locate solar power closer
| to where it will be used, like on top of buildings in the city
| rather than in a large plant out in the middle of nowhere, thus
| saving on transmission costs.
|
| Finally, IMO photovoltaic pavement is probably going nowhere.
| ncmncm wrote:
| Solar may share land that is _also_ used for food, so _no:
| There is no competition between them_.
|
| In fact, sharing improves efficiency of the panels, cuts
| water loss, and often increases yield.
| naasking wrote:
| May share for some crops yes, but that hasn't traditionally
| been the case has it?
| ncmncm wrote:
| Did _everyone_ always know that solar /crop dual use was
| often purely beneficial for both? No. Did _somebody_
| know? Yes. Does _everyone_ know today? Evidently not.
| naasking wrote:
| > Did everyone always know that solar/crop dual use was
| _often_ purely beneficial for both? (emphasis added)
|
| "Often" != "Always". Therefore you also agree that solar
| still competes for land use with crops.
|
| Furthermore, land that has already been allocated to grid
| scale solar has already been taken away from possible
| crop use. Sometimes it's not arable land, but that isn't
| always the case, therefore solar is still ostensibly
| taking up land that could be used for crops.
|
| Finally, I even disagree that somebody knew that solar
| and farming could use the same land. Someone had an idea
| that maybe they could coexist, then ran an experiment
| that succeeded. They certainly didn't know the outcome
| beforehand.
| ncmncm wrote:
| > _Therefore you also agree that solar still competes for
| land use with crops._
|
| No. It just means that some places are better than
| others.
|
| Since there is overwhelmingly more crop and pasture land
| than could ever be needed to satisfy power needs, solar
| may be placed exactly and only where it does the most
| good.
|
| It has been known for _centuries_ that most plants
| benefit from partial shade. It is an _exceedingly tiny_
| step of logic to go from "shade" to "shade provided by
| solar panels". In the past, providing shade just cost
| money. Now it yields direct revenue, year-round.
| naasking wrote:
| > It has been known for centuries that most plants
| benefit from partial shade.
|
| Again, "most plants" does not necessarily include
| "crops", most of which have been selectively bred over
| millennia while grown under full sun. The step is not
| from "plants do well under shade" to "plants do well
| under solar panels", it's to "crops we've never grown in
| partial shade might actually do better in partial shade
| too".
| defrost wrote:
| Solar might also provide better shade for livestock and
| cropping growth, particularly in future days of greater heat.
|
| > Sheep grazing under solar panels at farms in NSW's Central
| West have produced better wool and more of it in the four
| years since the projects began, according to growers.
|
| > Local graziers have labelled the set-up a "complete win-
| win", with the sheep helping to keep grass and weeds down so
| as not to obscure the panels.
|
| This is not something that works so well with open cut coal
| and down wind from city supplying coal burning power
| stations.
|
| [1] https://www.abc.net.au/news/rural/2022-05-30/solar-farm-
| graz...
| kiba wrote:
| Solar shading would works, probably.
| abainbridge wrote:
| That seems like an excellent point. Why hasn't this already
| been done everywhere that gets sunny?
| ncmncm wrote:
| > _Ground-based solar is land-intensive, however, with utility-
| scale arrays often spanning hundreds of acres. Wind farms have
| their own sprawling land needs._
|
| This is stupid. The article leads with the solution to this non-
| problem. There is no shortage of pasturage to site solar in.
| Likewise, of reservoirs and canals. Both places get net benefit
| from the dual use, even discounting the extra revenue.
| montalbano wrote:
| Do you have some references on this?
|
| I would probably agree if you are referring to USA. But I would
| be skeptical that the same is true in the UK.
| ZeroGravitas wrote:
| https://www.nfuonline.com/updates-and-information/solar-
| farm...
| ncmncm wrote:
| Panels work exactly the same way in the US and the UK.
| Indeed, laws of physics are identical in _all_ countries.
|
| The UK has a large amount of crop and pasture land, and quite
| a lot of reservoirs and canals besides. Most places do.
| BitwiseFool wrote:
| >"Indeed, laws of physics are identical in all countries."
|
| There's no need to be glib, and the GP was obviously
| talking about the availability of land on a much smaller
| and more densely populated nation than the comparatively
| massive and wide open country that is the United States.
| ncmncm wrote:
| Only an entire failure ever to have looked at Google Maps
| "satellite view" would lead anyone to think UK has a
| paucity of crop and pasture land.
|
| It has, in fact, easily many, many times more of both
| than could ever be needed to share with solar and wind.
| [deleted]
| BitwiseFool wrote:
| You also seem to be ignoring cost and land value. Just
| because land _seems_ to be available doesn 't mean it
| actually is. Or that it would be economical to convert
| it. And I also wonder how a solar panel, which blocks
| sunlight, would allow crops/grass to grow underneath it
| at the same time.
|
| It seems like trying to make land do these two sunlight
| dependent things at once is not as efficient as having
| dedicated agricultural fields and dedicated solar farms.
| ncmncm wrote:
| You may concern-troll all you like, but the facts are
| otherwise. Please allow me to suggest you consult some
| actual, you know, facts.
| BitwiseFool wrote:
| >"Please allow me to suggest you consult some actual, you
| know, facts."
|
| You're free to provide them. Call it concern-trolling if
| you'd like, but I definitely sense you've got a "why
| don't we _just_ " mindset, where any potential downside
| is literally a non-issue. You dismiss all concerns and
| then wonder why something isn't being done when the
| solution looks so simple.
|
| >"Since solar may use up exactly zero acres, its watts
| per acre may be infinite."
|
| If it has mass and surface area, it will take up some
| sort of acreage. Solar panels block light, so obviously
| anything needing light to survive is going to struggle
| being underneath them. And, who knew that we could get an
| infinite amount of wattage out of zero acreage, why
| haven't those fools designing our electric grid realized
| this yet?!?
|
| >"But most crops do not, and benefit both from reduced
| heat stress and reduced water loss."
|
| So you've acknowledged that corn and wheat need full
| sunlight, but again, _it doesn 't matter_, because in
| your view solar has no downsides whatsoever. Anything bad
| is actually good!
|
| >"Please do not make up BS problems."
|
| And you say I'm being the troll here.
| ncmncm wrote:
| Corn and wheat do not, in fact, "need" full sunlight.
| They have slightly reduced yield in partial sun. That is
| offset against year-round revenue from power generation,
| a net positive, most places.
|
| You were free to read any of the numerous links provided
| both in TFA and in comments posted here. Instead, you
| trolled.
| cheeko1234 wrote:
| They're quite wrong about 'this being stupid'.
|
| It is true, that the amount of solar needed to power the
| entire US is about 0.5% of the land.
|
| That doesn't mean there's no benefit in increasing the
| efficiency of panels and get dual use of the land. It also
| has the benefit of allowing for solar in more places where
| it's needed for more decentralized power.
| ZeroGravitas wrote:
| On the question of this being stupid or not, I think that a
| sentence saying "Ground-based solar is land-intensive,
| however, with utility-scale arrays often spanning hundreds
| of acres. Wind farms have their own sprawling land needs"
| that links to a source that says:
|
| > Solar energy is one example where the context and type of
| material matter a lot. Solar panels made from cadmium use
| less energy and materials than silicon panels, and
| therefore use less land per unit. It also matters a lot
| whether you mount these panels on rooftops or on the
| ground. Rooftop solar obviously needs much less additional
| land; we're just using space that is already occupied, on
| top of existing buildings. However, they do need some land
| over their life-cycle because they still require mining of
| the materials to make them, as well as the energy (mostly
| electricity) used in refining the silicon. Finally, the
| density and spacing of the panels also makes a difference.
|
| > Wind is the most obvious electricity source that we
| should consider differently when it comes to land use. You
| find it separated from the other sources, at the bottom of
| the chart.3 There are several reasons for this. First,
| offshore wind takes up space, but it's marine, not land
| area. Second, onshore wind is different from other
| electricity sources because you can use the land between
| turbines for other activities, such as farming. This is not
| the case for a coal, gas or nuclear plant. This means the
| land use of wind farms is highly variable. I have
| calculated the land use of 22 of the world's largest wind
| farms [you find my calculations here].
|
| > Take the Roscoe Wind Farm in Texas, which uses 184 m2 per
| MWh. This is a large project, where farmers can generate
| additional income through electricity production while they
| continue their farming operations between the wind
| turbines. The wind farm is almost a secondary land use.
| This contrasts with much more dense wind farms, such as
| Fantanele-Cogealac in Romania, or the Tehachapi Pass in
| California, where energy production is the primary land
| use. These can have a small land footprint of just 8 m2 per
| MWh.
|
| Seems pretty stupid to me. Though if someone get sucked in
| by the headline, reads the article and moves from thinking
| "we don't have enough room for renewables" to "there are
| lots of ways to dual use land with renewables" then maybe
| it's all for the best.
| ncmncm wrote:
| Better efficiency, in dollars per watt, is always good.
|
| Pretending there is some sort of shortage of land to site
| solar in is not a valid reason to court efficiency. There
| are other, legitimate reasons.
| jeffbee wrote:
| Not just pasturage, but other wasteful and dumb land uses. All
| of California's energy needs and much more could be provided by
| a PV plant covering Edwards Air Force Base, with ordinary dirt-
| cheap panels on fixed mountings.
|
| People greatly overestimate the footprint of solar power, and
| underestimate the footprint of oil and gas. Every oil and gas
| well in the nation sits on a 1-5 acre pad that has been scraped
| flat and denuded of all life. The area that has been sacrificed
| for this purpose in west Texas and Wyoming absolutely dwarfs
| the area that we would need to replace that production with PV.
| jacknews wrote:
| It wouldn't be pasture if it were covered in solar panels.
| Isn't that what the article is saying, place solar panels
| sparse enough that you get pasture and panels.
|
| Personally I think they should be put to sea. Along with
| floating farmland. Just make concrete (or seacrete!) pontoons,
| connected together into 1000 km^2 islands. Leave the actual
| land to nature. I concede that is currently scifi though.
| ncmncm wrote:
| Maybe you could take your own remark as a clue that dual-use
| does not "cover" every square centimeter with panels.
|
| When you recognize you have _plenty of land_ that is not
| being used up by placing panels in it, you can understand
| there is no need to try to pack panels as closely together as
| conceivably possible. You can leave room between for
| livestock and grass.
|
| Open ocean has destructive waves. Panels do much better on
| calm reservoirs and ponds.
| BitwiseFool wrote:
| >"There is no shortage of pasturage to site solar in."
|
| I don't believe you are taking into account just how much
| location and transmission distance matters for such projects.
| ncmncm wrote:
| It does not, in fact, matter.
|
| If you have some transmission loss, you just add a few more
| panels.
| BitwiseFool wrote:
| >"It does not, in fact, matter."
|
| What's your basis for this? Real-world power grids don't
| seem to be designed around transmission loss being a non-
| issue so long as they just 'generate more power' at the
| source.
| ZeroGravitas wrote:
| I think most real world grids are (or at least were)
| actually designed like this.
|
| Getting coal from a mine to a power station is a big
| task, so some grids are literally built around the
| locations of the coal. Hydro and nuclear have similar
| location needs.
|
| This has changed more recently with gas and renewables
| where as they get cheaper other factors start to
| dominate, but the grid was not originally set up for that
| kind of distributed load and needed some tweaks to adjust
| I believe.
| ncmncm wrote:
| Power at the source has never been as cheap as solar, and
| has always consumed extra operating expense to generate.
| Solar does not cost more each day it produces; you put up
| more panels and you get more power, day after day.
| ZeroGravitas wrote:
| US government take on this:
|
| https://www.energy.gov/eere/solar/solar-futures-study
|
| > Although land acquisition poses challenges, land
| availability does not constrain solar deployment in the
| scenarios.
|
| > In 2050, ground-based solar technologies require a maximum
| land area equivalent to 0.5% of the contiguous U.S. surface
| area, which could be met in numerous ways including use of
| disturbed or contaminated lands unsuitable for other uses.
| The maximum solar land area required is equivalent to less
| than 10% of potentially suitable disturbed lands, avoiding
| conflicts with high-value lands in current use.
|
| > Various approaches are available to mitigate local impacts
| or even enhance the value of land that hosts solar systems.
| Installing photovoltaic (PV) systems on water bodies, in
| farming or grazing areas, and in ways that enhance pollinator
| habitats are potential ways to enhance solar energy
| production while providing benefits such as lower water
| evaporation rates and higher agricultural yields.
|
| > Expanding rooftop PV could reduce solar land use. Almost
| 200 GW of rooftop PV are deployed in the decarbonization
| scenarios by 2050 (10%-20% of total solar deployment).
| However, the technical potential for U.S. rooftop PV is
| greater than 1,000 GW, and efforts to promote rooftop PV
| could increase deployment beyond the modeled level.
| xt00 wrote:
| At least in the US if you look at all of the long distance
| transmission lines, you could easily find huge areas next to
| the lines that are totally uninhabited to site a new solar
| installation plus the transformers etc to connect up to the
| grid there. The same helicopters they use to service the
| lines could likely be used to blow off the solar panels once
| a month when they get dust on them. Somebody should totally
| do a study of saying "ok here is one major transmission line
| going across Texas from this big power plant.. how much power
| does it deliver, and how large of a solar farm would be
| needed to switch that power over to solar.. " definitely need
| to figure out a widely deployable energy storage method for
| solar energy -- like using existing dam's to pump water back
| up into the reservoir type thing.
| cogman10 wrote:
| There is almost no major city in the continental US where you
| can't find open land and spaces ~30 miles away from the city
| center.
|
| Transmission distance matters when you are talking about
| sending power 1000s miles from the generation location. For
| that, you want something like HVDC. However, for anything
| else, HVAC is good enough.
| greggeter wrote:
| adrianN wrote:
| If Germany switched all the land that is currently used for
| "energy crops" to PV, it could cover a large fraction of its
| primary power demand. I assume it's similar in other countries.
|
| Wind is even a bit more space efficient in Germany. Land use is
| really not a problem for renewables.
| belorn wrote:
| I find the issue of land use for renewables (especially wind)
| to be similar as land use for rail and highways. Technically
| they don't use up a lot of land, but when it is time to
| actually build there tend to be a lot of problems finding land
| that people are willing to sell. Either because of noise, or
| because current utilization of that land would be hindered in
| some way.
|
| Eminent domain is a common tool to solve this, and it is also
| used for mining. It is however not very popular.
| ncmncm wrote:
| They are in fact _nothing_ alike.
|
| Land used for rail and roads is used up. Land used for solar
| may continue being used for whatever else it was doing
| already.
|
| Please do not make up BS problems.
| stevehawk wrote:
| I can grow corn on a field covered in solar panels?
| danhor wrote:
| Popsci Article says maybe:
| https://www.farmprogress.com/corn/will-you-grow-corn-
| under-s...
| jandrese wrote:
| Corn no, alfalfa yes. But you could install wind turbines
| in a cornfield with very little disruption to production.
| Balero wrote:
| You can't always grow corn on fields not covered by solar
| panels as well. Just because they stop one thing, they
| don't stop everything. You can graze sheep and poultry,
| you can transport water, people, vehicles, you can park
| your car, or build a building.
| tstrimple wrote:
| It may even make some crops like grapes perform better.
|
| https://www.reuters.com/business/environment/solar-
| panels-he...
| ncmncm wrote:
| "Covered in"? No. Corn, and also wheat, yield less in
| partial shade.
|
| But most crops do not, and benefit both from reduced heat
| stress and reduced water loss. Livestock, likewise,
| benefit from shelter, and the grass grows not less, same
| reasons.
|
| When you have all of cultivated land available to site
| solar in, you can choose places to put it where it is
| most beneficial.
|
| Farm and pasture are not the only places that benefit
| from shade. Reservoirs and canals lose huge amounts of
| water to evaporation, and need constantly to fight
| biofouling.
|
| Roofs, too, last longer in shade.
| Scoundreller wrote:
| Corn and wheat would be a non-starter since you'd
| partially/entirely lose the scale of mechanically
| planting/tassle/harvesting.
|
| Maybe a specialized tractor could be built to go around
| the panels but really you'd want to grow laborious crops
| that are mostly hand-planted/harvested anyway.
| tstrimple wrote:
| I don't see what this would have to be the case. You
| could install the solar panels elevated with support
| structures wide enough for the harvesters to pass
| between. That being said, like others have mentioned
| these crops in particular do like more sun so other crops
| are likely more suitable. A setup like this (https://s4.r
| eutersmedia.net/resources/r/?m=02&d=20211004&t=2...)
| would be useful for many types of crops.
| montalbano wrote:
| There might be some studies on corn available, although
| it's not explicitly mentioned in the article. From the
| article:
|
| _Researchers are experimenting with which plants do best
| under solar panels and even trying to grow tomatoes and
| potatoes between rows at existing utility-scale farms,
| Macknick says._
| ncmncm wrote:
| Some pepper varieties get 3x yield in partial shade.
| montalbano wrote:
| To add, rail and roads are tricky because they are long and
| _continuous_ pretty much by definition.
|
| Solar and wind can be much more opportunistic in using
| small packets of land.
| adrianN wrote:
| A wind turbine "uses" very little land. The area under the
| turbine can be used for many other things. That doesn't stop
| NIMBYs.
| collegeburner wrote:
| the sight and sound impact of a wind turbine is real though
| newer models are a lot quieter. if i lived out in the
| country where it was quiet i'd be against someone putting
| them up super close as well.
|
| just calling everyone a "NIMBY" is not a valid response to
| criticism of externalities.
| Calvin02 wrote:
| I was curious about the sound impact and found these two
| videos: 1) https://www.youtube.com/watch?v=v-sUDSwsE_w,
| 2) https://www.youtube.com/watch?v=zKgN2G9d0dc.
|
| The first video has pretty sound (pardon the pun)
| methodology.
|
| Findings: Unless you're within 200m of a turbine, the
| background ambient sounds are louder than the sound of
| the turbine.
|
| Do you have evidence to the contrary?
| solardev wrote:
| Anecdotally, having lived in areas where wind farms were
| repeatedly proposed and then rapidly shot down by
| neighbors, the NIMBYism was never about science, much
| less methodology. The kinds of people living in places
| where you'd want to build wind farms (rural ag land,
| mainly) tend to be pretty traditional, conservative,
| anti-government, independent, and basically it's-my-land-
| dammit types. You can show up with presentations and
| videos and visualizations and simulations and offer free
| power and cash incentives and all that, but it usually
| boils down to "No, because I don't like it, and I don't
| like you, and I don't trust people like you". It doesn't
| matter how technically sound a project is if it still
| seems like "here's another bunch of suits trying to sell
| us something that only benefits the city dwellers we hate
| 500 miles away, while telling us they know our land
| better than we do."
|
| Their values and systems of belief/reality-building and
| trust networks are totally different. Successfully
| negotiating that doesn't mean "my numbers are more
| correct" but understanding the different subcultures,
| what's important to them, and being able to respectfully
| and empathetically communicate according to their needs,
| not yours.
| adrianN wrote:
| Well if you want to use cheap carbon free electricity but
| don't want to see turbines that makes you a NIMBY in the
| most literal sense of the word.
| krupan wrote:
| "cheap" and "carbon free"
| throwaway894345 wrote:
| Pretty sure wind is about as cheap and low-carbon as
| energy gets. Hydro might be better, but it's not feasible
| in most locations.
| iosono88 wrote:
| [deleted]
| tbihl wrote:
| Presumably you mean farming? And,more particularly,
| industrial farming since the turbines would probably scare
| animals and endanger birds near it.
|
| Or are there examples of more intensive uses under wind
| turbines?
| lostapathy wrote:
| Crops grow just fine around a wind turbine, regardless of
| farm size. And they don't get scared of it either.
| ncmncm wrote:
| "Industrial" farming? You mean using tractors instead of
| mules?
| tstrimple wrote:
| I'm having a difficult time understanding your arguments.
|
| https://talkbusiness.net/wp-content/uploads/2018/02/Wind-
| Far...
|
| https://static01.nyt.com/images/2016/07/19/world/windfarm
| s-w...
|
| Just what about these turbines makes farming / ranching
| more difficult?
| dv_dt wrote:
| The land doesn't have to be purchased though, there are
| plenty of uses which cooperatively use the land. Parking
| lots, and solar-agriculture. The coop use may even improve
| the hybrid performance - a little less sun and a little
| better shade microclimate for humidity can even be a crop
| yield booster (esp with climate change induced droughts).
| dublin wrote:
| Just putting arrays on commercial rooftops is the most
| cost-effective solution by far. And no you can't really
| grow crops or much of anything but low grass/weeds under
| the panels due to 1) the problems (of shading with tall
| weeds or crops), and 2) the potential for damaging the
| surprisingly fragile wiring.
|
| (And don't get me started on this, but most arrays are
| wired stupidly, ignoring what the telegraph and phone guys
| learned 125 years ago: you want to ground the _positive_
| leg, NOT the negative, so you can use cathodic protection
| via a sacrificial anode to prevent the wires corroding
| away. You would be shocked how many 10-15 year old arrays I
| 've seen that have something rapidly approaching empty
| straws of insulation connecting the panels - the breakeven
| on a solar PV plant is around 20-22 years, so these will
| _never_ break even!)
| detaro wrote:
| Where in the world do you see that problem? Doesn't match
| anything I've encountered about the topic, and I have family
| members deeply involved in the planning and permission
| process for such things.
|
| People generally like making money with their land, and
| _especially for wind_ it often doesn 't impact the economics
| of current land use very much. (And even solar isn't
| necessarily exclusive)
|
| The comparison with rail and highways also isn't very good
| since for those there are much stricter constraints to cover
| a useful and practical route in its entirety.
| DontGiveTwoFlux wrote:
| https://www.sierraclub.org/sierra/2021-4-fall/feature/nimby
| -...
| jandrese wrote:
| Ironically the Sierra Club is one of those organizations
| behind NIMBY type objections to solar and wind
| production. They are an outdoorsman club, not an
| environmental club. Their objective is maximizing the
| amount of untouched wilderness available, and that means
| not being able to see wind turbines from mountaintops.
| detaro wrote:
| That doesn't appear to be about difficulties buying land.
| belorn wrote:
| The average farm in the US is around 2 square kilometers.
| let say a railway road is about 10 meter across, and let
| say it goes through those 2 square kilometers. How much of
| that land is taken up by the railroad? 0.5%, leaving the
| farmer 99.5% to use for everything else. Railroad isn't
| generally that wide and thus don't use up a lot of land.
|
| The biggest problem in those situation isn't that the
| actually land that get used, it is how the farmer get
| impacted by the rail road being there. If they got a lot of
| money for those 0.5% with no negative effect then naturally
| people would have no objection to sell that for huge
| profits.
|
| I can't speak for your family members or the locations
| where they are involved, but I do know how much politics
| there is around where I live. There is a lot of resistance
| to place wind farms on farm fields, and farmers aren't
| exactly lining up to rent out their land (or at least not
| for the price people are willing to pay). Ocean farms are
| often cited as being easier to build because there is less
| resistance from land owners and local government.
|
| One land location that does seem a bit easier for wind
| production are forests in mountain areas which is sparsely
| populated. The draw side is that the consumers isn't
| generally located there, so you get the situation where the
| best and easiest locations to install wind is also the
| worst location to utilize the production.
| ZeroGravitas wrote:
| In the US, just the switch to EVs will reduce the amount of
| land used for energy, since ICE engines need ethanol as a lead
| replacement, which is sourced from corn.
| ncmncm wrote:
| Yes: fully a third of the US corn (maize) crop is wasted on
| fuel. Even more is wasted turning it into poison (fructose)
| for food additives.
| throwaway0a5e wrote:
| This is just falsehood. Ethanol gas is a pure subsidy
| program. It serves no utility other than ensuring fuel
| quality corn gets grown.
|
| Edit: They don't add it to the fuel because they want to.
| They do it because they are mandated to. Anti-knock
| properties are just a tiny silver lining that could be
| obtained through more efficient means were it not for the
| subsidized ethanol.
| ncmncm wrote:
| Not quite.
|
| Yes, Archers Daniels Midland collects a monstrous
| undeserved federal subsidy.
|
| But unleaded gasoline needs _something_ to raise its octane
| rating. MBTE turned out to be a public health and
| ecological disaster. What we use now is ethanol. Probably
| some other alternative would be cheaper and not burn crop
| acreage, but wasting corn has been good politics: corn
| farming states have a preponderance of senators.
| missedthecue wrote:
| What subsidy does ADM get?
| tstrimple wrote:
| Ethanol subsidies.
|
| https://www.masterresource.org/political-capitalism/adm-
| etha...
|
| > Thanks to federal protection of the domestic sugar
| industry, ethanol subsidies, subsidized grain exports,
| and various other programs, ADM has cost the American
| economy billions of dollars since 1980 and has indirectly
| cost Americans tens of billions of dollars in higher
| prices and higher taxes over that same period.
|
| > At least 43 percent of ADM's annual profits are from
| products heavily subsidized or protected by the American
| government. Moreover, every $1 of profits earned by ADM's
| corn sweetener operation costs consumers $10, and every
| $1 of profits earned by its ethanol operation costs
| taxpayers $30....
| missedthecue wrote:
| I know that ag subsidies exist, I'm not getting why you
| or the writer of the article you link assume that ADM
| gets the profit from it.
|
| It seems like a misunderstanding of both ag subsidies as
| they exist today and of ADM's business model
| shortstuffsushi wrote:
| > unleaded gasoline needs something to raise its octane
| rating
|
| Probably naive, what does this mean? There are unleaded
| gases for sale that are ethanol free at some gas stations
| (typically only the premium / highest octane) which are
| often preferred for small motors / high end engines. I
| don't think they mix in lead, is MTBE what is added
| instead in those cases? I haven't heard of MTBE before.
|
| ETA: I've been able to find a number of sites for WI gas
| stations saying "we have ethanol free," but none of them
| mention what is added in its place (if anything).
| ZeroGravitas wrote:
| Some of them do use lead:
|
| https://www.classicfuelsolutions.co.uk/products/classic-
| fuel...
|
| That's a UK supplier but an answer on Quora suggests
| 'race' fuels are sold in the US with lead too. Not legal
| to use on the road though.
|
| > Effective January 1, 1996, leaded gasoline was banned
| by the Clean Air Act for use in new vehicles other than
| aircraft, racing cars, farm equipment, and marine
| engines.
| throwaway0a5e wrote:
| The presence of small amounts of lead in a niche motor
| fuel product in a country that doesn't have a corn
| industry to speak of in ethanol subsidy program is
| irrelevant to the point of dishonest when the subject at
| hand is US corn subsidies.
|
| The only leaded fuel you can buy in the US is aviation
| fuel. You can't buy it at a gas station and the only
| reason it still exists with lead in it is because that is
| necessary for compliance with government rules that
| regulate what fuel can be sold for that specific purpose.
| ZeroGravitas wrote:
| You probably replied before I added the bit that suggests
| in America it's still legal to use leaded fuel in racing
| cars, marine and farming equipment (as well as aviation,
| as you mention). I found several posts from people saying
| that they buy aviation fuel because they don't like
| ethanol for their lawn equipment, and presumably people
| informed enough about the issue to intentionally buy
| leaded avation fuel would know about other options
| available).
|
| You do get alkylate gasoline, maybe that's what is being
| sold:
|
| > The availability of alkylate petrol is limited. The
| actual alkylation process to produce Aspen is a much more
| advanced and expensive process which only a few
| refineries in the world can produce. Even if new ways of
| producing alkylate petrol is developed, regular petrol
| will still be the dominant type of motor fuel in the
| world.
|
| https://www.buyrealgas.com/states.html
|
| I found this website, that lists places that sell ethanol
| free gas, and the number of them that appear to be
| Marinas, combined with the bit above about lead being
| used for marine purpsose makes me think they're just
| using lead.
| ZeroGravitas wrote:
| Replying to myself, looks like you can either live with
| lower octane ratings (like 87 which might work for some
| boats, when some modern cars want 95), or add more
| benzene, toluene, ethyl-benzene and xylene instead of
| ethanol, but it's more expensive. Apparently some of the
| ethanol free options like Rec90, are specifically
| marketed as Recreational, i.e. not for automobiles, as no
| real study has been done on their use for that purpose.
| shortstuffsushi wrote:
| It's funny you linked to buyrealgas - I had been trying
| to avoid them since they seem a bit.. radically anti-
| ethanol ("first of all, we're literally burning our
| food!"). Anyway... never heard of using av gas in a lawn
| mower, that sounds crazy to me. Maybe I'm just hugely
| naive on small motor mechanics, but the difference
| between standard, 10% eth 87 and premium eth free 91
| seems to be about 0, performance wise, and if you end up
| cleaning the engine once every year or two anyway... idk.
| I think I mentioned above, but my frame of reference is
| Wisconsin. Outside of Milwaukee/Waukesha county, most gas
| stations sell eth free premium, and many people here
| actually _do_ make the trip to get it.
| jandrese wrote:
| The problem with ethanol in power equipment is that it
| tends to dissolve rubber seals/tubes. For some reason
| small engine manufacturers were extremely slow to switch
| to ethanol safe rubber and as a result one of the most
| common failure modes is for the carburetor jets to clog
| up with nasty semi-dissolved rubber. It's also just the
| case that people keep their old 80s and 90s lawn mowers
| running because they only put a couple dozen hours of
| runtime on the things each year so they don't tend to die
| except when the ethanol wrecks the fuel system.
| throwaway0a5e wrote:
| >You probably replied before I added the bit that
| suggests in America it's still legal to use unleaded fuel
| in racing cars, marine and farming equipment (as well as
| aviation, as you mention).
|
| Somebody call Congress! Think of the children!
|
| Pretty much nobody does this because on the high end race
| fuels as well as various alcohol fuels are more available
| and better supported by industry and on the low end
| ethanol free premium is substantially cheaper. If lots of
| people did it it wouldn't still be legal. Dumping 100LL
| into your boat or race car just isn't a good value way to
| solve a problem anyone has.
|
| > I found several posts from people saying that they buy
| aviation fuel because they don't like ethanol for their
| lawn equipment, and presumably people informed enough
| about the issue to intentionally buy leaded avation fuel
| would know about other options available).
|
| I hope I'm not the only one appreciating the
| schadenfreude here. It reminds me of when people unscrew
| the spout from their crappy compliant cans. Regardless,
| the overwhelming majority of these people just drag their
| butt to whatever local station has ethanol free premium
| rather than go to the airport because it's a
| faster/easier/cheaper way of accomplishing the same goal.
|
| The current status quo is stupid but the rules are
| written by a bunch of jerks who either a) DGAF about what
| happens beyond the next election cycle or b) DGAF so long
| as they're not responsible and can collect their pension
| so it's no surprise that the things people do to
| compensate are non-optimal.
| enragedcacti wrote:
| You don't necessarily need to add anything depending on
| the engine being used. from my limited understanding most
| small, carbureted engines do perfectly fine on gasoline
| without an anti-knock additive. more intelligent engines
| will usually retard timing with low octane fuel so that
| the engine doesn't knock but you will lose power.
| njarboe wrote:
| "corn farming states have a preponderance of senators"
|
| And the first primary or caucus state of the election
| season is Iowa. The state produces the most corn in the
| Union and by far the most corn per capita. Large corn
| subsidies will likely continue until this fact changes.
| blacksmith_tb wrote:
| Well, they have 2 senators like all the other states...
| perhaps though that's suggesting that they're sparsely
| populated so their senators seem out of proportion to the
| small number of voters they represent (compared to their
| Representatives, who are few compared to populous states
| like CA, NY, TX, GA etc.) The Iowa caucus system
| certainly is an attention-grab, but I don't think it's
| single-handedly responsible for the whole system of ag
| subsidies (which presumably has also been championed by
| other farm states like NE and KS).
| dublin wrote:
| And this is not likely to change as long as Iowa gets
| pandered to in every presidential election cycle.
| ZeroGravitas wrote:
| From Wikipedia:
|
| > Due to the phasing out of MTBE as a gasoline additive and
| mainly due to the mandates established in the Energy Policy
| Act of 2005 and the Energy Independence and Security Act of
| 2007, ethanol blends have increased throughout the United
| States, and by 2009, the ethanol market share in the U.S.
| gasoline supply reached almost 8% by volume
|
| and
|
| > In the U.S. MTBE has been used in gasoline at low levels
| since 1979, replacing tetraethyllead (TEL) as an antiknock
| (octane rating) additive to prevent engine knocking.[15]
| Oxygenates also help gasoline burn more completely,
| reducing tailpipe emissions and dilute or displace gasoline
| components such as aromatics (e.g., benzene). Before the
| introduction of other oxygenates and octane enhancers,
| refiners chose MTBE for its blending characteristics and
| low cost.
|
| It _is_ a farm subsidy program, but it also has an actual
| use. Oil companies went with lead in the first place,
| despite being well aware of the dangers, because ethanol is
| also a competitor to gasoline, being a fuel itself.
| ncmncm wrote:
| General Motors also backed lead heavily, because lead
| additives destroyed engines in only a few years,
| increasing turnover.
| enragedcacti wrote:
| Ethanol is probably the best option we have for anti-
| knock, but corn-based ethanol is worse in pretty much
| every way compared to other sources of ethanol like
| switchgrass. So while ethanol itself has a use, corn-
| based ethanol is pretty much just a farm subsidy at the
| cost of the environment.
| krupan wrote:
| Wait, we are going to replace plants that consume carbon with
| solar panels that do not consume carbon in order to reduce
| carbon in the atmosphere and save us from global warming? Why
| does none of this make sense?
| ncmncm wrote:
| > _Why does none of this make sense?_
|
| Probably because you took the time posting that you might
| otherwise have taken thinking. I suggest trying it the other
| way.
| jrk wrote:
| "Energy crops" are burned as fuel. They aspire to be carbon-
| neutral (and are often still fed a lot of petroleum-based
| fertilizer), not carbon-negative.
| Analemma_ wrote:
| You know all that stored carbon gets released as soon as the
| plants are burned for power, right? As opposed to PV panels
| which can replace fossil fuel consumption.
| cycomanic wrote:
| Completely agree. I think we are seeing two things here:
|
| 1. Lobbying groups for fossils and nuclear trying to find
| disadvantages of renewables. The most bizarre thing I saw a
| while ago was arguing strongly for nuclear largely based on the
| fact that it's more space efficient (saying the importance of
| that outweighs cost), while completely ignoring the fact that
| nuclear plants require extensive nofly zones (note theybare not
| really a problem atm either but would affect how much we can
| build out nuclear).
|
| 2. A strong push for making large scale renewable
| installations. While it is true that large scale solar is more
| efficient than smaller scale, I think the prime motivation is
| that it benefits large operators and investors, not individuals
| or small communities. Hence the lobby efforts.
|
| In reality just putting solar on most existing warehouses and
| parking lots would already cover a significant proportion of
| our electricity use. And others pointed out how solar (and
| wind) can often be used in dual use environments benifiting
| both.
| colordrops wrote:
| Lobbyists in California have made multiple attempts to
| destroy solar, including existing residential installations.
| They failed their first attempt last year and are pushing
| again this year [1]. The proposal is a tax that is so high
| that solar panels will lose you money.
|
| https://solarrights.org/
| api wrote:
| I'm sure California will find some way to screw up anything
| connected with either housing or infrastructure.
| einpoklum wrote:
| It pains me so - yet I have no choice but to upvote your
| answer! T_T
| BostonEnginerd wrote:
| I do think that space efficiency and good availability for
| nuclear are a reasonable argument for that technology. That
| doesn't mean we also shouldn't be putting solar onto every
| flat surface in the country, homes, businesses, parking lots,
| etc.
| ncmncm wrote:
| Each nuke plant in the US uses up a whole square mile.
| Worse though, is that it costs overwhelmingly more to build
| than the solar generating capacity that would displace it.
| Furthermore, you burn enough coal in the time it takes to
| build it as would pay for another matching solar farm.
| throwaway894345 wrote:
| Renewables aren't cost constrained, they're constrained
| by the rate at which we can buy and install the panels,
| turbines, storage, etc. We literally can't build
| renewables fast enough, so not only _can we_ build
| nuclear alongside renewables, but it's the fastest way to
| reduce our emissions while also securing our energy
| supply and diversifying our energy portfolio. It's not
| renewables _versus_ nuclear, it's renewables _and_
| nuclear.
| jandrese wrote:
| It's not like nuclear plants are getting built in a
| fortnight either. In fact the ridiculous lead time on
| getting a nuclear plant generating electricity is one of
| the biggest problems with pitching them as a solution to
| climate change. We have already dithered far too long on
| this, we can't wait 20 years to reduce our carbon output,
| solutions need to be built in the next 5 years or less.
| throwaway894345 wrote:
| Please re-read my above comment--I'm very specifically
| and explicitly _not_ proposing forestalling renewables
| for 20 years while we build nuclear plants! I 'm
| proposing we continue building out renewables _at full
| tilt_ while we also build nuclear plants _at full tilt_.
| akira2501 wrote:
| > it could cover a large fraction of its primary power demand
|
| For a certain number of hours in the day, yes. This always
| strikes me as an odd observation because storage and
| distribution have always been the more important challenges in
| our current implementation.
|
| I'd also caution against any form of "monoculture strategy."
| The lessons from history are pretty clear on this.
| choeger wrote:
| That's at the same time true and misleading. Land usage for
| energy crops will vary year on year (natural crop rotation). On
| top of that, only some crops are really disturbing people
| living close by (e.g. rapeseed stinks when wet). Large-scale PV
| installations really look and feel bad when you live or walk
| right next to them. Wherea a field of wheat, corn, or rapeseed
| somewhat feels natural and even has its beauty, solar panels
| just look ugly up close.
|
| So the question is: Will you find enough locations that don't
| annoy the locals and once you found them will your project
| survive the inevitable intrigues amongst land owners over who
| gets to rent out their land for the lucrative PV installations?
|
| Even though it's more expensive, I think that using rooftops
| and other already occupied spaces first is a more sensible
| route.
| ncmncm wrote:
| And, you can post as much BS you can make up. It is called
| trolling, and is unwelcome here.
| adrianN wrote:
| Personally I don't find PV panels ugly and I bet that the
| biodiversity under the panels is a larger that on endless
| monocultures.
| konschubert wrote:
| I lived by a large PV installation and it neither looked nor
| felt bad.
|
| It's quiet and doesn't smell. It's about as unobtrusive as
| you can imagine a thing to be.
| choeger wrote:
| Could you look over them?
| konschubert wrote:
| I didn't live IN it.
| ericd wrote:
| The thing that would bother me about crops nearby would be if
| they ever sprayed something not-so-great-to-breathe on them
| (which, they generally do). Solar farms seem like perfect
| neighbors, by comparison. I really don't get the whole "solar
| panels are ugly" thing, it feels almost like concern
| trolling, trying to muddy the waters.
|
| Though maybe I'm biased by my feeling that solar panels are
| damn-near magic - you leave them outside, basically neglect
| them, and power just comes spilling out of them.
| choeger wrote:
| I think it's, quite literally, a question of the point of
| view. I know about installations that were (during
| planning) allowed to be 4m tall. If that happens right next
| to your home or any other place you visit frequently, I,
| and many others, find it extremely ugly. If there's a
| distance, say 100m, it's not half as bad. If the
| installation doesn't even block the view (e.g., because of
| elevation), I don't care at all. But given the plans I have
| seen, I prefer a couple of wind energy plants about 1000m
| away.
| ncmncm wrote:
| It is extremely common to put solar panels on residential
| roofs 4m high, often higher. Complaints are rare.
|
| It is extremely _uncommon_ to site dedicated solar farms
| within 100m of residential areas.
| jandrese wrote:
| Solar panels are only like 3-4" above the roof on
| residential installs. Any extra view blocked that wasn't
| already blocked by the house is trivial. In fact solar
| panels are usually not installed all the way to the top
| of the roofline so there is no change in visibility at
| all.
| dublin wrote:
| If you ignore them, then you never know when they stop
| working. Really. The fact that they look the same working
| or not is one of the problems with them, and why you really
| do need monitoring and someone to pay attention to the
| monitoring at least every few days.
|
| I spent six years in the utility-scale solar PV industry.
| You would be shocked to learn how many of the panels are
| not working in any given array. I've seen everything from
| almost 10% of the strings not even being connected to the
| inverters in a utility scale array, to a shocking number of
| rooftop arrays that were producing _nothing_. In my entire
| experience with the company and all its customers, we never
| encountered a single utility-scale array that was fully
| working when we arrived on site to add our monitoring or
| optimization systems, and many of those were brand new!
|
| In one case of a sizable array on the roof of a Texas
| _energy_ provider here in Austin, we discovered the
| inverter had died _years_ before we discovered it! (This
| was field testing of of inverter bus noise effects, and the
| oscilloscope showed nothing but what the wiring picked up
| as antennas!) Turns out no one ever looks at the power
| bills in a power company... :-)
|
| Solar PV actually requires a fair amount of maintenance for
| both prevention and remediation (cleaning and/or replacing
| panels, repairing connections/wiring, combiners, inverters,
| etc.) to ensure they are actually operating, but most
| owners are happier to cover their ears and eyes and sing,
| "La, la, la..."
| ericd wrote:
| Ha! Thanks for the professional perspective! I guess I
| should up my monitoring plans from "glance at the SolArk
| screen every now and then" to maybe something a bit more
| robust/automatic.
| rr888 wrote:
| Sure but solar wont help you get through the cold winter, where
| biofuel will.
| JoeAltmaier wrote:
| Orbital Power Stations!
|
| All the real estate there you could ever want. 9X the solar flux.
| Little or no "night". Direct delivery via lasers to any point in
| the hemisphere.
| dublin wrote:
| Orbital solar is an incredibly stupid idea that just will not
| die. Even Elon Musk has been quite open about it being one of
| the stupidest ideas ever. You only get about 3-4x (NOT 9x) of
| the power you'd get on earth in orbit, and putting things up
| there will _always_ be expensive, even if it 's finally coming
| down from NASA et al's comically high prices.
|
| No matter what kinds of launch cost improvements you predict
| (including, of course, Starship-likes), it will always be
| orders of magnitude cheaper to just build an array here on
| earth that is 3-4x larger than to lob anything into orbit.
|
| The Microwave/Laser power transmission schemes of orbital solar
| are also a _huge_ problem, and in all likelihood would _never_
| make it through any kind of environmental impact study, much
| less an engineering effectiveness /reliability review. (Not to
| mention that, like the famous laser drive in Larry Niven's Man-
| Kzin wars, any laser/maser/microwave array that large is
| inherently a formidable weapon of mass destruction, with no
| modification other than repointing it....)
| ncmncm wrote:
| Or, we could hire children to pedal stationary bicycles
| attached to generators.
|
| Where cost doesn't matter, everything gets easy.
| JoeAltmaier wrote:
| Real estate near major metropolitan centers is not cheap
| either. With modern orbital delivery dropping by orders of
| magnitude, the entire equation changes. Get with the modern
| agenda!
|
| The advantages of orbital are nearly 20X generation per panel
| to start with, even before considering support structures
| (none) and weather-proofing (none). That leaves lots of room
| in the cost equation.
| ncmncm wrote:
| Real estate already generating revenue that may have solar
| added without reducing that revenue is not expensive. It
| has, instead, negative cost.
|
| Solar panels do not need to be "near major metropolitan
| centers". Modern transmission lines move power efficiently,
| silently, and reliably.
|
| It would be impressive for your orbital panels to get out
| 4x as much energy as the light they intercept carries, but
| getting a patent on your perpetual-motion apparatus might
| be difficult.
|
| Maybe do some elementary cost analysis. All the numbers are
| easy to find. Don't forget to figure in conversion loss
| from electric power on orbit to laser light emitted, losses
| scattering in the atmosphere, and conversion again from
| laser light received to electricity on the ground.
|
| You would better loft many-square-km aluminized-mylar
| mirrors to reflect sunlight to solar farms on the ground.
| Keeping them pointing the right direction would be tricky.
| JoeAltmaier wrote:
| That's so far a pipe dream, dual-purpose 'negative cost'.
| Also transmission lines need right-of-way and are not
| free.
|
| Solar flux outside the atmosphere is 9X sea level. Go
| ahead, look it up. Then there's the periodic eclipse
| called 'night' that doubles orbital efficiency again.
| Look that up too.
|
| Conversion losses of 20% seem normal? Both in orbit and
| on the ground. Which halves what you collect, well within
| the budget of 20X reducing it to around 10X.
| ncmncm wrote:
| Solar flux outside the atmosphere is not, in fact, 9x sea
| level. You can cook the numbers by keeping the orbital
| panel square on to the sun, while the ground-mounted
| panel rotates through the day and overnight. But you
| don't get to count nighttime twice.
|
| Conversion losses of only 20% from electric to laser, and
| again from laser to electric again, would be miraculous.
| 20% scattering loss in clear weather would be
| unsurprising. 90% loss, total, would be admirable, not
| counting the original 60%+ loss off the top. So, even
| with 9x, and neglecting huge launch cost you still come
| out behind.
| JoeAltmaier wrote:
| I looked it up.
|
| So about 75% of solar radiation reaches the ground. In
| the continental US, factoring in angle of the sun,
| average weather, night that comes to about 4-5KWh per day
|
| In orbit you would have just 1.37KW X 24 hours (no
| weather, angle issues) which comes to about 33KWh per
| day. So that's 8-9X the collected energy per square meter
| in orbit vs ground level.
|
| These folks
| https://www.allaboutcircuits.com/news/wireless-power-
| transmi... estimate 89% efficiency from orbit to ground.
|
| So we're then at around 30KWh effective.
|
| What am I missing?
| adrianN wrote:
| Electricity can be transmitted quite easily. Many
| powerplants are in fact a good distance away from
| metropolitan centers.
| jandrese wrote:
| The nice thing about solar is that it doesn't have to
| monopolize the land. If you want to convert a suburban
| parking lot to a solar farm you don't have to evict the
| cars, you just have to install them high enough that the
| cars can park underneath.
|
| Orbital power is a total nonstarter if we aren't building
| the panels in orbit. Launch costs will absolutely destroy
| any ROI, even before you get into the transmission losses
| beaming the power back to Earth. SpaceX has completely
| revolutionized the launch industry, getting costs down to
| around $1200/lb. A typical solar panel weighs about 40lbs,
| but aren't optimized for weight. Assuming you can reduce
| this to 20lbs per panel that's still $24,000 per panel not
| counting transmission equipment and the like. The panel
| itself costs maybe $2000 for a very high efficiency model.
| The launch costs dwarf the panel costs, even when
| accounting for the lack of weather in space. It just
| doesn't make sense, especially when you start adding in all
| of the additional costs like building the satellites, the
| ground stations, transmission losses, fuel to keep the
| orbits from decaying, the fact that you won't be able to
| send these to Geo Orbit without incurring crippling
| transmission losses, so you'll need a lot of ground
| stations, etc...
|
| Compared to all of that, the problem of finding parking
| lots in the suburbs seems absolutely trivial.
| acoard wrote:
| Isn't the problem here the wireless/laser delivery? How much
| could you transfer?
|
| Also your design sounds suspiciously like a GDI Ion Canon from
| Command and Conquer[0]. Imagine having dual-use concerns like
| we do with nuclear power.
|
| [0] https://imgur.com/a/T8IDs2h
| JoeAltmaier wrote:
| Solved long ago. Microwave transmitters, target of a couple
| kilometer. No larger than a solar array, but now we've got
| GW. Efficiencies around 90%
___________________________________________________________________
(page generated 2022-08-15 23:01 UTC)