21 ms·

Growing crops under solar panels

152 points by lxm 4y ago

eulenteufel 4y ago
The website blocked my IP from reading the article because it found my uMatrix suspicious. Just tell me to disable it or deny access to the site. No need to lock out people who like to decide where their computer connects to. That is a bit petty.
throwuwu 4y ago
I’m no farmer but wouldn’t putting a whole bunch of stuff in a field make it difficult to drive a tractor through it? Like have you seen the size of modern tractors? These panels will need to be 20ft in the air with support posts really far apart to accommodate seed drills and sprayers and other equipment that the tractor pulls behind it.
- nhumrich 4y ago
  Yes, I think a single picture of a farm setup this way would have increased the value of this article quite a bit.
  - yazaddaruvala 4y ago
    This[0] is a berry farm I was just at. As you can see it’s already covered to protect from extra sun. No tractor could fit anyways. This[1] is one version of agrovoltaics. The solar panels act like window blinds. They can be configured to follow the sun but also can be configured to “provide optimal shade/cooling throughout the day”. [0] https://images.app.goo.gl/mSbtJjtSQRukBQqK6 https://images.app.goo.gl/mSbtJjtSQRukBQqK6 [1] https://images.app.goo.gl/9kakPW8uRHLGp3yJA https://images.app.goo.gl/9kakPW8uRHLGp3yJA
    - hutzlibu 4y ago
      "This[0] is a berry farm I was just at. As you can see it’s already covered to protect from extra sun." Erm, I can see a greenhouse. I think they are made to increase temperature for the plants and not to protect from extra sun. Strawberries like sun and would not benefit from shade, unless we are talking about very intense sunlight and not much water. Most plants usually want as much sun as they can get, so long as the temperature stays in their desired range and enough water is avaiable. So in dry places with lots of sun, acrovoltaics can make some sense, or for plants that like indeed shade, like tomatoes. But it is really not a magic bullet for growing corn and harvesting electricity at the same time. Sheeps grazing under solar panels seems like a working solution that does not need too much effort around it.
      - otherme123 4y ago
        A lot of plants doesn't like and cannot survive the sun at central hours unless you water them like crazy. Basically you are watering to avoid dehydration, but not producing, like drinking in the desert. A lot of plants evolved to thrive near/under trees. Greenhouses can tame the sunlight, and usually they are painted in white in regions of too much sun (https://m.youtube.com/watch?v=Rl6tMOU84tk https://m.youtube.com/watch?v=Rl6tMOU84tk). Also, greenhouses are hot but very humid, so the plants doesn't dehydrate as fast. I could imagine an scheme that instead of watering (costs money) you shade the crops with panels (earns money) during the worst of the day.
        wil421 4y ago
        I live in the hot and humid Deep South and my strawberries do not mind the sun. There’s a local berry patch that has lots of different berries, including strawberries, and no shades in sight. What’s in OPs image is a greenhouse. The sides can be closed if low temperatures are coming in at night.
      - yencabulator 4y ago
        The examples given in the article are mushrooms and broccoli. Obviously the primary and first use cases would be things that want some shade (in the local environment).
- tstrimple 4y ago
  Most of the examples I’ve seen are small scale hand pick farming. But there is nothing about 20’ spans that are outside our technical abilities today. This seems like a rather small obstacle to overcome. Of course this still says nothing about the economic feasibility or impacts. Thinking more about it, you wouldn’t even need 20’ spans. You’d have articulating struts coming off of a central point between the rows. Panels can be adjusted out of the way of equipment when it needs to pass through if it is interfering.
- fencepost 4y ago
  To some extent that falls into the category of "fiddly details." Solar panels are probably not the best choice for use alongside bulk harvested crops like corn, wheat, soybeans and even potatoes, but an awful lot of "produce" crops are harvested by hand. The reason I say "fiddly details" is because questions like "what's the best spacing between rows of panels" and "do I plant under the panels or just between rows" can be decided as people look into available equipment, land prices, crop variation and flexibility, etc.
  - Arnt 4y ago
    I don't know about "growing crops", but a farm outside the city where I live has sheep grazing under/around solar panels.
  - rektide 4y ago
    Heck yes. It's absurd now but... imagine those crop-water-er things, with a central pivot (ed: "central-pivot-irrigation"). What if instead of just a line of watering, that rotated around, it was a vast overhead rotating circle? Like 80% by area solar panels overhanigng. But also, one radian with all the farm stuff: watering, tiller, planter, harvester? An polar-plotter of tools, with solar panels taking up most everywhere else.
    - catmanjan 4y ago
      I’m actually experimenting with building one of those- the problem is the forces involved compared to the irrigator which is basically just suspending water pipes over the ground
      - dylan604 4y ago
        maybe i'm misremembering, but I was under them impression that the water pressure drove the platform. was i totally wrong on this? i ask, as i would never have guessed adding the weight of solar panels to that would be viable without possibly using some of the generated power to drive a motor.
- deleted 4y ago
  [deleted]
- detourdog 4y ago
  I can tell you are no farmer. No tractor is needed in a field maintained by grazing. If tbe panels are mounted high enough sunlight will be cast on the ground for a period each day.
  - mminer237 4y ago
    I am a farmer, and this doesn't make sense. Grazing fields aren't really growing crops. Even if this is just crops that are picked by hand (it mentions broccoli), they typically still have huge machines follow the laborers for them to deposit them in: https://www.youtube.com/watch?v=bKyxMKO2kyU https://www.youtube.com/watch?v=bKyxMKO2kyU I can't see any good way to harvest a field with solar panels that isn't so inefficiently laid out that it would be better to have two separate fields.
    - lovemenot 4y ago
      I am not a farmer, but am interested in watching the development of agricultural tech. >> I can't see any good way to harvest a field with solar panels that isn't so inefficiently laid out that it would be better to have two separate fields. Would there be scope for smaller autonomous machines? Presumably, there should be some crop configurations that could benefit, but we don't yet have all the results of experiments currently running. Here in Japan, farms are typically much smaller, so there's perhaps greater scope for agrivoltaics than in industrial scale farms in USA.
      - detourdog 4y ago
        Yes a Beowolf cluster could definitely harvest crops.
    - schiffern 4y ago
      >Grazing fields aren't really growing crops. Right, they grow food for animals, which walk around the field and graze on it autonomously. Hey, I wonder if that's why they're called that... :) I'm not really sure what the point is in making this observation. Just a "farmer vs rancher" thing, or something deeper? >I can't see any good way to harvest a field with solar panels See above.
- defrost 4y ago
  Picture of sheep grazing under panels in Australia: Solar farm trial shows improved fleece on merino sheep grazed under panels https://www.abc.net.au/news/rural/2022-05-30/solar-farm-grazing-sheep-agriculture-renewable-energy-review/101097364 https://www.abc.net.au/news/rural/2022-05-30/solar-farm-graz... Note the room to drive between panel rows and for "boom mowers" to spread out behind a medium tractor and reach under the panels. There are also many types of vehicles used in agriculture from two storey high broad acre heavy duty combine harvesting monsters to small narrow self propelled engines that run through tree trunks in orchard with various attachments to mow (sprung mowing rings), shake trees (to make fruit fall), spray leaves, trench (for irrigation, drainage, etc). Also, see: "Agri-bots" - a revolution not yet complete in small driverless autonomous helpers to run 24/7 weeding, spraying, picking berries, using solar, etc.
  - schiffern 4y ago
    >improved fleece on merino sheep grazed under panels Makes sense. I'm not sure the exact care instructions, but I'm pretty sure "store this garment outside unshielded in the baking sun and pouring rain for many months" isn't the official recommendation for wool. If available, sheep (and other animals) will seek cover during heavy rains and periods of high heat stress. This protects both the sheep and the wool, and both factors improve quality. I wouldn't be surprised if the diet improves as well, due to healthier grass, higher plant biodiversity, and higher abundance of (tasty and nutritious) insects. Paradoxically, primary productivity will often increase with added shade, because photosynthesis shuts down at even mildly elevated leaf temperatures (~85 °F). Those vast impressive corn fields will often overheat and shut down around 10 AM, and don't start photosynthesizing again until 4 PM. In ye olden days farmers would plant a widely-spaced grid of "farmer's trees."[0] These are a category of trees (eg black locust) which 1) provided shade and windbreak, 2) coexist with crops right up to their trunk, 3) have deep tap roots bringing up minerals and water, 4) drops fertilizing mulch, and 5) produces nutritious animal fodder (pods) which self-dry and store on the tree itself. Clever farmers! For mechanized farms you can choose a planting pattern and varieties that permit machinery to drive right past the tree without losing much area on "gores." Typical density was about 20-30 trees per hectare, so it also stores a bit of carbon. Personally I prefer trees, but ultimately we need both types of systems. [0] https://www.youtube.com/watch?t=25&v=uvQpIHBSPBE https://www.youtube.com/watch?t=25&v=uvQpIHBSPBE
- photochemsyn 4y ago
  Vertical bifacial panels are one approach that doesn't interfere with tractors and equipment, and still have comparable generation (with twice as many panels, so more expensive): https://www.pv-magazine.com/2023/01/24/vertical-pv-for-clean-energy-and-crop-production/ https://www.pv-magazine.com/2023/01/24/vertical-pv-for-clean... > "For conventional ground-mounted systems, the scientists considered a tilt angle of 20 degrees and an average estimated energy yield 1,020 Wh/W. For the bifacial vertical west-east oriented systems, they assumed a bifaciality factor of 90% and an annual energy yield of 999 Wh/W, while for vertical systems with a north-south orientation the annual energy yield was indicated at 926 Wh/W."
  - pfdietz 4y ago
    Vertical orientation can also make sense if you're trying to bias the PV to produce more in winter, when the output might be more valuable.
- Schroedingersat 4y ago
  The crops that are best suited to giant tractors also tend to be less suited to agrivoltaics. They also include energy crops, so you can go from producing no food on land with unprofitable crops that take subsidies to growing food on the land at a profit and producing energy. The land taken up by energy crops exceeds the land needed by solar by over an order of magnitude.
- lost_tourist 4y ago
  there's no reason to put solar panels on fertile land, there is plenty of land that can be used in other places.
  - pbhjpbhj 4y ago
    Solar panels are already being put on fertile land (in UK), so if that land can get dual-use and not waste it's potential for food provision then that seems more optimal. That said, these threads always confirm in me a belief that we need to cut human population replacement to save the planet and our own species.
debacle 4y ago
This idea is being pushed hard right now. I see it everywhere. You can't grow most crops under solar panels. And the crops you can grow will probably have a lower yield. This is an idea that's meant to push replacing farmland with solar arrays. I don't necessarily think that's a bad idea for low yield soils, but in my area they are trying to replace high-yield soils (former orchards, vineyards, market gardens) with solar arrays. It doesn't make sense. What would make sense is arrays that are semi-portable that can be used for re-establishing topsoil. With the right crops, good topsoil can be reestablished in as little as 5-10 years.
- jandrese 4y ago
  I think the idea is to use this on the handful of crops that prefer the shade. Think small artisanal alfalfa farms with minimal mechanization. But all in all I agree that it adds considerable complication for little gain. At least in the US we are in zero danger of installing so many solar panels that there is not enough acres left for food. That kind of concern is orders of magnitude away from reality. Especially if you start displacing corn-for-ethanol acres with solar panels used to charge electric vehicles. In that case you actually increase the available acreage for food crops because the solar panels are so much more efficient than corn ethanol.
  - fencepost 4y ago
    Not just alfalfa, but crops where what's eaten is the stems, leaves and other parts of the plant more than the fruits/seeds. Leafy greens, some root vegetables both starchy and wet, asparagus, some brassicas, etc. Not nearly as broad a list as full sun, but I'm also sure there are a lot of things being grown in southern California now that needed a lot of breeding to deal with as much sun as they get there.
- yazaddaruvala 4y ago
  I just added this comment below: https://news.ycombinator.com/item?id=35101717 https://news.ycombinator.com/item?id=35101717 A lot of farming NEEDs sun protection for better yields. Currently farms that don’t have sun protection over compensate by over watering (also could reduce yields). Not to say every farm should have solar panels but it’s very likely a double digit percentage of farm land would benefit from agrovoltaics.
Jiro 4y ago
Outside of weird edge cases (like mushrooms), how does this work when the plants use the sunlight and so do the solar panels?
- martyvis 4y ago
  There are plenty of places in the garden around my home that either are always shaded or are only in full sun for a few hours a day. Yet there isn't one spot (except under my house) where nothing grows. Suitable spacing, height and angle of panels (which could adjust during the day) and choice of crop all would come into the mix of what would work.
- kragen 4y ago
  for staff-of-life crops like potatoes and grains, it's a bad idea, but an awful lot of common crops like lettuce benefit from having less than full sun
- justsomehnguy 4y ago
  https://youtu.be/xs9hfF3UPQY?t=16 https://youtu.be/xs9hfF3UPQY?t=16
crooked-v 4y ago
I really don't get why people keep coming up with all these elaborate plans to mix solar panels with other stuff that's in active use, instead of just putting fields of them out in non-endangered desert elevated enough off the ground that they won't actively interfere with local animals.
- pornel 4y ago
  Long-distance energy transmission may be technically or politically harder, or just someone else's problem. If you're a farmer and already own the land, that's what you can do. A combination of the two land uses might be more profitable or less financially volatile than either one alone.
- thethethethe 4y ago
  Why would we destroy pristine desert, which is rapidly disappearing, when we could cover land that has already been disturbed, like parking lots, building roofs, and farmland? Deserts are important ecosystems regardless of their immediate utility to industrial society
  - downrightmike 4y ago
    It plain makes more sense to generate the power as close to use as possible
    - onethought 4y ago
      It doesn’t make that much sense. We can transmit power pretty long distances these days. I don’t understand “don’t disturb the desert” - why? It’s not just useless to us… it’s useless to most living things.
      - eru 4y ago
        > We can transmit power pretty long distances these days. Engineering feasibility is not the same as economic viability.
sourcecodeplz 4y ago
Just plant that type of grass the herbivores really like and let the cows, sheep and goats roam. We can't only eat plants we need cheese too.
- ed25519FUUU 4y ago
  This is the only solution that makes sense everywhere where land is not a million dollars an acre (places not California).
  - ta1243 4y ago
    Arable land in England is about $10k an acre. Until the council grants permission to build housing on it, then it jumps to between $500k and $2m an acre because housing is in such short supply.
    - kwhitefoot 4y ago
      This is partly because the UK is addicted to cheap food and has no interest in food security. The big supermarkets can push the price they pay for produce so low that farmers can't make a living so there is little demand for farmland.
- fnordfnordfnord 4y ago
  Yes this, and car parking lots
  - SteveGerencser 4y ago
    And over the top of every aqueduct, storm channel, and man made 'river' designed to deliver water to large urban areas. Generates power and helps reduce that annoying evaporation.
    - hannasm 4y ago
      It would be cool to see photovoltaic's manufactured into shade spheres like these things: https://youtu.be/mEmwJzQjwyw https://youtu.be/mEmwJzQjwyw Maybe they could combat algae blooms at the same time too
f0ld 4y ago
They’re talking about transparent solar panels right? HN has been very weird lately. Was this article topic suggested by chatGPT?
- orbital-decay 4y ago
  No, it's for the areas with excessive insolation - the idea is to use solar panels to create some shadow, reducing the exposure to sunlight for crops and wildlife, which benefits both.
  - dzhiurgis 4y ago
    Which means bifacial panels would suit even better
    - Schroedingersat 4y ago
      Bifacial panels are the default now. They're just better.
tengbretson 4y ago
There are solar farms being installed on previously very productive farm land near me. Between the thousands of truckloads of gravel and the steel piles being driven into the ground as far as the eye can see, I doubt the land will productively grow food of any kind for a century or more. edit: I apologize if this is difficult to hear.
- ceejayoz 4y ago
  We've plenty of productive farmland. We don't yet have enough renewable energy.
  - tengbretson 4y ago
    It costs you, personally, nothing at all to hold that opinion.
- jcampbell1 4y ago
  We dedicate 39 million acres to corn ethanol so our gas is 10% ethanol. 15 million acres of panels would supply all of the US energy needs including all current petroleum energy. 1 acre of corn produces 11 million kcal. 1 acre of solar panels produces 300 million kcal.
ed25519FUUU 4y ago
This is a very CA-centric research topic. In most of the US heartland theres millions and millions and millions of acres of farmland. There’s no need and limited benefit to mixing PV with agriculture. And the places where it does make sense it makes sense only for running goats around in the PV sites to keep weeds down.
- lovemenot 4y ago
  That's a very USA-centric comment. To the best of my knowledge, the two countries doing most research on agrivoltaics are Japan and China.
  - ed25519FUUU 4y ago
    The countries that develop, build, and sell solar panels? Not surprising.
    - lovemenot 4y ago
      Sure. But also, consider the availability of arable land relative to population. I would argue countries like USA, Canada, Brazil, Australia are the outliers. Most of the world cannot afford to be as dismissive of land use optimisation as some US Midwestern farmers appear to be.
- pigsty 4y ago
  Farming and hot sunlight isn’t something that only exists in california. High population density countries also do farming and using every inch of land is essential. Demand for things sensitive to harsh sunlight (herbs, berries, and so on) or in places with long dry seasons means growing under shaded areas has advantages, and doubly so if you can extract energy while doing so. That’s also not exclusive to california.
gumby 4y ago
I’ve long wondered why solar panels and wind turbines aren’t colocated, as the power transmission infrastructure can be shared. In Germany, power companies are installing turbines in farmers’s fields. Solar is harder (but you could mount it higher — harder to wash though). I’ve seen solar installations in India overgrown with vegetation.
- eru 4y ago
  > I’ve seen solar installations in India overgrown with vegetation. I wonder what the institutional setup behind that is. Whoever gets power from the solar installation has a clear incentive to keep them from being overgrown, so I assume there must be some horrible corrupt principle-agent conflict style stuff going on in the background. (Very typical of India, alas.)
  - gumby 4y ago
    I have always assumed that the situation is that someone (NGO a or government) pays for the installation but nobody pays for or trains on maintenance.
    - eru 4y ago
      Yes. If you had a clear owner, they presumably would have an incentive to pay for the maintenance, or sell to someone who can pay for the maintenance.
- Schroedingersat 4y ago
  In many countries it's hostile legislation to make it worse and increase soft costs. Australia was only recently allowed to include batteries on solar.
  - skissane 4y ago
    > Australia was only recently allowed to include batteries on solar. Source? Tesla Powerwall was introduced into the Australian market in 2015. From what I understand, other residential systems existed before that, but they were uncommon. In 2019, they significantly tightened the safety standards, but the impact on people running approved off-the-shelf systems (such as Tesla's) is modest (tighter rules on installation locations may cause issues for some people, especially smaller properties–although those rules only apply to new installs, existing installs are grandfathered), most of the added burden is on those rare people who have bespoke systems.
NathanielBaking 4y ago
Transparent solar cells. https://www.nature.com/articles/s41598-022-15352-x https://www.nature.com/articles/s41598-022-15352-x I think this is far more interesting than Fast Company speculation.
adipginting 4y ago
This could work well for small scale farm lands owned by small families as these farm lands use more manual labors than tractors. The farm lands I am talking about are like the ones in the highlands in South East Asia.
aaron695 4y ago
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locallost 4y ago
There are interesting things in the article, but I think it was never about available land use, but just another knee jerk argument against solar panels. Example: Disneyland Europe will generate over 30 GWh per year from just covering a part of its parking lot. And if France makes it mandatory to cover all "substantial" parking lots it will generate as much electricity from just that as 10 nuclear power plants [1]. And that's France. Countries like the US have a lot more space, especially parking lots. There's enough space for solar panels. [1] https://www.washingtonpost.com/climate-solutions/2023/02/06/france-solar-parking-lots/ https://www.washingtonpost.com/climate-solutions/2023/02/06/...
- vel0city 4y ago
  As someone in Texas I'd really love is more parking lots had even partial covered parking with solar above. Please. It gets dang hot out here, I'd love the shade.
  - dylan604 4y ago
    shoot, around my parts of Texas, when you stand in the shade of a tree, the tree looks at you and says, "trust me, it's not any cooler here"
    - cyberax 4y ago
      You have trees?!?
      - dylan604 4y ago
        well, they are Mesquite bushes, but it's got leaves, grows from the ground, produces wood, and makes a bit of shade, therefore...tree.
    - Fatnino 4y ago
      Shade under a solar panel is cooler than normal shade because the panel is siphoning energy away from the location
ggm 4y ago
People pay rent for land use. Solar panel income on marginally productive land which actually increased yield of different crops with reduced sunburn, bolting and watering costs combined with revenue in rent, might be better economics than high yield, high water, high till, high fertiliser crops.
openpaycard 4y ago
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weinzierl 4y ago
Elon Musk once said: "So, there's quite a big keep-out zone, and when you factor the keep-out zone into account, the solar panels put on that area would typically generate more power than that nuclear power plant." I always wondered if that is really true?

152 points by lxm 4y ago

The website blocked my IP from reading the article because it found my uMatrix suspicious. Just tell me to disable it or deny access to the site. No need to lock out people who like to decide where their computer connects to. That is a bit petty.

throwuwu 4y ago

I’m no farmer but wouldn’t putting a whole bunch of stuff in a field make it difficult to drive a tractor through it? Like have you seen the size of modern tractors? These panels will need to be 20ft in the air with support posts really far apart to accommodate seed drills and sprayers and other equipment that the tractor pulls behind it.

nhumrich 4y ago
Yes, I think a single picture of a farm setup this way would have increased the value of this article quite a bit.
- yazaddaruvala 4y ago
  This[0] is a berry farm I was just at. As you can see it’s already covered to protect from extra sun. No tractor could fit anyways. This[1] is one version of agrovoltaics. The solar panels act like window blinds. They can be configured to follow the sun but also can be configured to “provide optimal shade/cooling throughout the day”. [0] https://images.app.goo.gl/mSbtJjtSQRukBQqK6 https://images.app.goo.gl/mSbtJjtSQRukBQqK6 [1] https://images.app.goo.gl/9kakPW8uRHLGp3yJA https://images.app.goo.gl/9kakPW8uRHLGp3yJA
  - hutzlibu 4y ago
    "This[0] is a berry farm I was just at. As you can see it’s already covered to protect from extra sun." Erm, I can see a greenhouse. I think they are made to increase temperature for the plants and not to protect from extra sun. Strawberries like sun and would not benefit from shade, unless we are talking about very intense sunlight and not much water. Most plants usually want as much sun as they can get, so long as the temperature stays in their desired range and enough water is avaiable. So in dry places with lots of sun, acrovoltaics can make some sense, or for plants that like indeed shade, like tomatoes. But it is really not a magic bullet for growing corn and harvesting electricity at the same time. Sheeps grazing under solar panels seems like a working solution that does not need too much effort around it.
    - otherme123 4y ago
      A lot of plants doesn't like and cannot survive the sun at central hours unless you water them like crazy. Basically you are watering to avoid dehydration, but not producing, like drinking in the desert. A lot of plants evolved to thrive near/under trees. Greenhouses can tame the sunlight, and usually they are painted in white in regions of too much sun (https://m.youtube.com/watch?v=Rl6tMOU84tk https://m.youtube.com/watch?v=Rl6tMOU84tk). Also, greenhouses are hot but very humid, so the plants doesn't dehydrate as fast. I could imagine an scheme that instead of watering (costs money) you shade the crops with panels (earns money) during the worst of the day.
      - wil421 4y ago
        I live in the hot and humid Deep South and my strawberries do not mind the sun. There’s a local berry patch that has lots of different berries, including strawberries, and no shades in sight. What’s in OPs image is a greenhouse. The sides can be closed if low temperatures are coming in at night.
    - yencabulator 4y ago
      The examples given in the article are mushrooms and broccoli. Obviously the primary and first use cases would be things that want some shade (in the local environment).
tstrimple 4y ago
Most of the examples I’ve seen are small scale hand pick farming. But there is nothing about 20’ spans that are outside our technical abilities today. This seems like a rather small obstacle to overcome. Of course this still says nothing about the economic feasibility or impacts. Thinking more about it, you wouldn’t even need 20’ spans. You’d have articulating struts coming off of a central point between the rows. Panels can be adjusted out of the way of equipment when it needs to pass through if it is interfering.
fencepost 4y ago
To some extent that falls into the category of "fiddly details." Solar panels are probably not the best choice for use alongside bulk harvested crops like corn, wheat, soybeans and even potatoes, but an awful lot of "produce" crops are harvested by hand. The reason I say "fiddly details" is because questions like "what's the best spacing between rows of panels" and "do I plant under the panels or just between rows" can be decided as people look into available equipment, land prices, crop variation and flexibility, etc.
- Arnt 4y ago
  I don't know about "growing crops", but a farm outside the city where I live has sheep grazing under/around solar panels.
- rektide 4y ago
  Heck yes. It's absurd now but... imagine those crop-water-er things, with a central pivot (ed: "central-pivot-irrigation"). What if instead of just a line of watering, that rotated around, it was a vast overhead rotating circle? Like 80% by area solar panels overhanigng. But also, one radian with all the farm stuff: watering, tiller, planter, harvester? An polar-plotter of tools, with solar panels taking up most everywhere else.
  - catmanjan 4y ago
    I’m actually experimenting with building one of those- the problem is the forces involved compared to the irrigator which is basically just suspending water pipes over the ground
    - dylan604 4y ago
      maybe i'm misremembering, but I was under them impression that the water pressure drove the platform. was i totally wrong on this? i ask, as i would never have guessed adding the weight of solar panels to that would be viable without possibly using some of the generated power to drive a motor.
deleted 4y ago
[deleted]
detourdog 4y ago
I can tell you are no farmer. No tractor is needed in a field maintained by grazing. If tbe panels are mounted high enough sunlight will be cast on the ground for a period each day.
- mminer237 4y ago
  I am a farmer, and this doesn't make sense. Grazing fields aren't really growing crops. Even if this is just crops that are picked by hand (it mentions broccoli), they typically still have huge machines follow the laborers for them to deposit them in: https://www.youtube.com/watch?v=bKyxMKO2kyU https://www.youtube.com/watch?v=bKyxMKO2kyU I can't see any good way to harvest a field with solar panels that isn't so inefficiently laid out that it would be better to have two separate fields.
  - lovemenot 4y ago
    I am not a farmer, but am interested in watching the development of agricultural tech. >> I can't see any good way to harvest a field with solar panels that isn't so inefficiently laid out that it would be better to have two separate fields. Would there be scope for smaller autonomous machines? Presumably, there should be some crop configurations that could benefit, but we don't yet have all the results of experiments currently running. Here in Japan, farms are typically much smaller, so there's perhaps greater scope for agrivoltaics than in industrial scale farms in USA.
    - detourdog 4y ago
      Yes a Beowolf cluster could definitely harvest crops.
  - schiffern 4y ago
    >Grazing fields aren't really growing crops. Right, they grow food for animals, which walk around the field and graze on it autonomously. Hey, I wonder if that's why they're called that... :) I'm not really sure what the point is in making this observation. Just a "farmer vs rancher" thing, or something deeper? >I can't see any good way to harvest a field with solar panels See above.
defrost 4y ago
Picture of sheep grazing under panels in Australia: Solar farm trial shows improved fleece on merino sheep grazed under panels https://www.abc.net.au/news/rural/2022-05-30/solar-farm-grazing-sheep-agriculture-renewable-energy-review/101097364 https://www.abc.net.au/news/rural/2022-05-30/solar-farm-graz... Note the room to drive between panel rows and for "boom mowers" to spread out behind a medium tractor and reach under the panels. There are also many types of vehicles used in agriculture from two storey high broad acre heavy duty combine harvesting monsters to small narrow self propelled engines that run through tree trunks in orchard with various attachments to mow (sprung mowing rings), shake trees (to make fruit fall), spray leaves, trench (for irrigation, drainage, etc). Also, see: "Agri-bots" - a revolution not yet complete in small driverless autonomous helpers to run 24/7 weeding, spraying, picking berries, using solar, etc.
- schiffern 4y ago
  >improved fleece on merino sheep grazed under panels Makes sense. I'm not sure the exact care instructions, but I'm pretty sure "store this garment outside unshielded in the baking sun and pouring rain for many months" isn't the official recommendation for wool. If available, sheep (and other animals) will seek cover during heavy rains and periods of high heat stress. This protects both the sheep and the wool, and both factors improve quality. I wouldn't be surprised if the diet improves as well, due to healthier grass, higher plant biodiversity, and higher abundance of (tasty and nutritious) insects. Paradoxically, primary productivity will often increase with added shade, because photosynthesis shuts down at even mildly elevated leaf temperatures (~85 °F). Those vast impressive corn fields will often overheat and shut down around 10 AM, and don't start photosynthesizing again until 4 PM. In ye olden days farmers would plant a widely-spaced grid of "farmer's trees."[0] These are a category of trees (eg black locust) which 1) provided shade and windbreak, 2) coexist with crops right up to their trunk, 3) have deep tap roots bringing up minerals and water, 4) drops fertilizing mulch, and 5) produces nutritious animal fodder (pods) which self-dry and store on the tree itself. Clever farmers! For mechanized farms you can choose a planting pattern and varieties that permit machinery to drive right past the tree without losing much area on "gores." Typical density was about 20-30 trees per hectare, so it also stores a bit of carbon. Personally I prefer trees, but ultimately we need both types of systems. [0] https://www.youtube.com/watch?t=25&v=uvQpIHBSPBE https://www.youtube.com/watch?t=25&v=uvQpIHBSPBE
photochemsyn 4y ago
Vertical bifacial panels are one approach that doesn't interfere with tractors and equipment, and still have comparable generation (with twice as many panels, so more expensive): https://www.pv-magazine.com/2023/01/24/vertical-pv-for-clean-energy-and-crop-production/ https://www.pv-magazine.com/2023/01/24/vertical-pv-for-clean... > "For conventional ground-mounted systems, the scientists considered a tilt angle of 20 degrees and an average estimated energy yield 1,020 Wh/W. For the bifacial vertical west-east oriented systems, they assumed a bifaciality factor of 90% and an annual energy yield of 999 Wh/W, while for vertical systems with a north-south orientation the annual energy yield was indicated at 926 Wh/W."
- pfdietz 4y ago
  Vertical orientation can also make sense if you're trying to bias the PV to produce more in winter, when the output might be more valuable.
Schroedingersat 4y ago
The crops that are best suited to giant tractors also tend to be less suited to agrivoltaics. They also include energy crops, so you can go from producing no food on land with unprofitable crops that take subsidies to growing food on the land at a profit and producing energy. The land taken up by energy crops exceeds the land needed by solar by over an order of magnitude.
lost_tourist 4y ago
there's no reason to put solar panels on fertile land, there is plenty of land that can be used in other places.
- pbhjpbhj 4y ago
  Solar panels are already being put on fertile land (in UK), so if that land can get dual-use and not waste it's potential for food provision then that seems more optimal. That said, these threads always confirm in me a belief that we need to cut human population replacement to save the planet and our own species.

debacle 4y ago

This idea is being pushed hard right now. I see it everywhere. You can't grow most crops under solar panels. And the crops you can grow will probably have a lower yield. This is an idea that's meant to push replacing farmland with solar arrays. I don't necessarily think that's a bad idea for low yield soils, but in my area they are trying to replace high-yield soils (former orchards, vineyards, market gardens) with solar arrays. It doesn't make sense. What would make sense is arrays that are semi-portable that can be used for re-establishing topsoil. With the right crops, good topsoil can be reestablished in as little as 5-10 years.

jandrese 4y ago
I think the idea is to use this on the handful of crops that prefer the shade. Think small artisanal alfalfa farms with minimal mechanization. But all in all I agree that it adds considerable complication for little gain. At least in the US we are in zero danger of installing so many solar panels that there is not enough acres left for food. That kind of concern is orders of magnitude away from reality. Especially if you start displacing corn-for-ethanol acres with solar panels used to charge electric vehicles. In that case you actually increase the available acreage for food crops because the solar panels are so much more efficient than corn ethanol.
- fencepost 4y ago
  Not just alfalfa, but crops where what's eaten is the stems, leaves and other parts of the plant more than the fruits/seeds. Leafy greens, some root vegetables both starchy and wet, asparagus, some brassicas, etc. Not nearly as broad a list as full sun, but I'm also sure there are a lot of things being grown in southern California now that needed a lot of breeding to deal with as much sun as they get there.
yazaddaruvala 4y ago
I just added this comment below: https://news.ycombinator.com/item?id=35101717 https://news.ycombinator.com/item?id=35101717 A lot of farming NEEDs sun protection for better yields. Currently farms that don’t have sun protection over compensate by over watering (also could reduce yields). Not to say every farm should have solar panels but it’s very likely a double digit percentage of farm land would benefit from agrovoltaics.

Jiro 4y ago

Outside of weird edge cases (like mushrooms), how does this work when the plants use the sunlight and so do the solar panels?

martyvis 4y ago
There are plenty of places in the garden around my home that either are always shaded or are only in full sun for a few hours a day. Yet there isn't one spot (except under my house) where nothing grows. Suitable spacing, height and angle of panels (which could adjust during the day) and choice of crop all would come into the mix of what would work.
kragen 4y ago
for staff-of-life crops like potatoes and grains, it's a bad idea, but an awful lot of common crops like lettuce benefit from having less than full sun
justsomehnguy 4y ago
https://youtu.be/xs9hfF3UPQY?t=16 https://youtu.be/xs9hfF3UPQY?t=16

crooked-v 4y ago

I really don't get why people keep coming up with all these elaborate plans to mix solar panels with other stuff that's in active use, instead of just putting fields of them out in non-endangered desert elevated enough off the ground that they won't actively interfere with local animals.

pornel 4y ago
Long-distance energy transmission may be technically or politically harder, or just someone else's problem. If you're a farmer and already own the land, that's what you can do. A combination of the two land uses might be more profitable or less financially volatile than either one alone.
thethethethe 4y ago
Why would we destroy pristine desert, which is rapidly disappearing, when we could cover land that has already been disturbed, like parking lots, building roofs, and farmland? Deserts are important ecosystems regardless of their immediate utility to industrial society
- downrightmike 4y ago
  It plain makes more sense to generate the power as close to use as possible
  - onethought 4y ago
    It doesn’t make that much sense. We can transmit power pretty long distances these days. I don’t understand “don’t disturb the desert” - why? It’s not just useless to us… it’s useless to most living things.
    - eru 4y ago
      > We can transmit power pretty long distances these days. Engineering feasibility is not the same as economic viability.

sourcecodeplz 4y ago

Just plant that type of grass the herbivores really like and let the cows, sheep and goats roam. We can't only eat plants we need cheese too.

ed25519FUUU 4y ago
This is the only solution that makes sense everywhere where land is not a million dollars an acre (places not California).
- ta1243 4y ago
  Arable land in England is about $10k an acre. Until the council grants permission to build housing on it, then it jumps to between $500k and $2m an acre because housing is in such short supply.
  - kwhitefoot 4y ago
    This is partly because the UK is addicted to cheap food and has no interest in food security. The big supermarkets can push the price they pay for produce so low that farmers can't make a living so there is little demand for farmland.
fnordfnordfnord 4y ago
Yes this, and car parking lots
- SteveGerencser 4y ago
  And over the top of every aqueduct, storm channel, and man made 'river' designed to deliver water to large urban areas. Generates power and helps reduce that annoying evaporation.
  - hannasm 4y ago
    It would be cool to see photovoltaic's manufactured into shade spheres like these things: https://youtu.be/mEmwJzQjwyw https://youtu.be/mEmwJzQjwyw Maybe they could combat algae blooms at the same time too

f0ld 4y ago

They’re talking about transparent solar panels right? HN has been very weird lately. Was this article topic suggested by chatGPT?

orbital-decay 4y ago
No, it's for the areas with excessive insolation - the idea is to use solar panels to create some shadow, reducing the exposure to sunlight for crops and wildlife, which benefits both.
- dzhiurgis 4y ago
  Which means bifacial panels would suit even better
  - Schroedingersat 4y ago
    Bifacial panels are the default now. They're just better.

tengbretson 4y ago

There are solar farms being installed on previously very productive farm land near me. Between the thousands of truckloads of gravel and the steel piles being driven into the ground as far as the eye can see, I doubt the land will productively grow food of any kind for a century or more. edit: I apologize if this is difficult to hear.

ceejayoz 4y ago
We've plenty of productive farmland. We don't yet have enough renewable energy.
- tengbretson 4y ago
  It costs you, personally, nothing at all to hold that opinion.
jcampbell1 4y ago
We dedicate 39 million acres to corn ethanol so our gas is 10% ethanol. 15 million acres of panels would supply all of the US energy needs including all current petroleum energy. 1 acre of corn produces 11 million kcal. 1 acre of solar panels produces 300 million kcal.

ed25519FUUU 4y ago

This is a very CA-centric research topic. In most of the US heartland theres millions and millions and millions of acres of farmland. There’s no need and limited benefit to mixing PV with agriculture. And the places where it does make sense it makes sense only for running goats around in the PV sites to keep weeds down.

lovemenot 4y ago
That's a very USA-centric comment. To the best of my knowledge, the two countries doing most research on agrivoltaics are Japan and China.
- ed25519FUUU 4y ago
  The countries that develop, build, and sell solar panels? Not surprising.
  - lovemenot 4y ago
    Sure. But also, consider the availability of arable land relative to population. I would argue countries like USA, Canada, Brazil, Australia are the outliers. Most of the world cannot afford to be as dismissive of land use optimisation as some US Midwestern farmers appear to be.
pigsty 4y ago
Farming and hot sunlight isn’t something that only exists in california. High population density countries also do farming and using every inch of land is essential. Demand for things sensitive to harsh sunlight (herbs, berries, and so on) or in places with long dry seasons means growing under shaded areas has advantages, and doubly so if you can extract energy while doing so. That’s also not exclusive to california.

gumby 4y ago

I’ve long wondered why solar panels and wind turbines aren’t colocated, as the power transmission infrastructure can be shared. In Germany, power companies are installing turbines in farmers’s fields. Solar is harder (but you could mount it higher — harder to wash though). I’ve seen solar installations in India overgrown with vegetation.

eru 4y ago
> I’ve seen solar installations in India overgrown with vegetation. I wonder what the institutional setup behind that is. Whoever gets power from the solar installation has a clear incentive to keep them from being overgrown, so I assume there must be some horrible corrupt principle-agent conflict style stuff going on in the background. (Very typical of India, alas.)
- gumby 4y ago
  I have always assumed that the situation is that someone (NGO a or government) pays for the installation but nobody pays for or trains on maintenance.
  - eru 4y ago
    Yes. If you had a clear owner, they presumably would have an incentive to pay for the maintenance, or sell to someone who can pay for the maintenance.
Schroedingersat 4y ago
In many countries it's hostile legislation to make it worse and increase soft costs. Australia was only recently allowed to include batteries on solar.
- skissane 4y ago
  > Australia was only recently allowed to include batteries on solar. Source? Tesla Powerwall was introduced into the Australian market in 2015. From what I understand, other residential systems existed before that, but they were uncommon. In 2019, they significantly tightened the safety standards, but the impact on people running approved off-the-shelf systems (such as Tesla's) is modest (tighter rules on installation locations may cause issues for some people, especially smaller properties–although those rules only apply to new installs, existing installs are grandfathered), most of the added burden is on those rare people who have bespoke systems.

NathanielBaking 4y ago

Transparent solar cells. https://www.nature.com/articles/s41598-022-15352-x https://www.nature.com/articles/s41598-022-15352-x I think this is far more interesting than Fast Company speculation.

adipginting 4y ago

This could work well for small scale farm lands owned by small families as these farm lands use more manual labors than tractors. The farm lands I am talking about are like the ones in the highlands in South East Asia.

aaron695 4y ago

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locallost 4y ago

There are interesting things in the article, but I think it was never about available land use, but just another knee jerk argument against solar panels. Example: Disneyland Europe will generate over 30 GWh per year from just covering a part of its parking lot. And if France makes it mandatory to cover all "substantial" parking lots it will generate as much electricity from just that as 10 nuclear power plants [1]. And that's France. Countries like the US have a lot more space, especially parking lots. There's enough space for solar panels. [1] https://www.washingtonpost.com/climate-solutions/2023/02/06/france-solar-parking-lots/ https://www.washingtonpost.com/climate-solutions/2023/02/06/...

vel0city 4y ago
As someone in Texas I'd really love is more parking lots had even partial covered parking with solar above. Please. It gets dang hot out here, I'd love the shade.
- dylan604 4y ago
  shoot, around my parts of Texas, when you stand in the shade of a tree, the tree looks at you and says, "trust me, it's not any cooler here"
  - cyberax 4y ago
    You have trees?!?
    - dylan604 4y ago
      well, they are Mesquite bushes, but it's got leaves, grows from the ground, produces wood, and makes a bit of shade, therefore...tree.
  - Fatnino 4y ago
    Shade under a solar panel is cooler than normal shade because the panel is siphoning energy away from the location

ggm 4y ago

People pay rent for land use. Solar panel income on marginally productive land which actually increased yield of different crops with reduced sunburn, bolting and watering costs combined with revenue in rent, might be better economics than high yield, high water, high till, high fertiliser crops.

openpaycard 4y ago

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weinzierl 4y ago

Elon Musk once said: "So, there's quite a big keep-out zone, and when you factor the keep-out zone into account, the solar panels put on that area would typically generate more power than that nuclear power plant." I always wondered if that is really true?