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Semi-transparent solar panels allow concurrent production of crops and power
- Grakel 6y agoThere's no shortage of open area to put solar panels. If we put a (nearly) continuous strip in every highway median, that would be a huge step forward, and still take up practically zero useable space. Even 1% of the federally owned land in the sun belt would generate an enormous amount of power.
- rch 6y agoThis approach would benefit community solar and remote microgrid projects, as well as geographically constrained places like the UK where the study was done.
- vmception 6y agoJust waiting for it to be economical in the nearer term and all of this stuff will magically start appearing. Everyone goes through the motions of thinking about solar solutions to energy, and then they realize how little power they provide and how many they need en masse and then scrap the idea. Once the math adds up for a quicker ROI, the plans will stop getting shelved and will be presented as novel by different people.
- chrisco255 6y agoI think we're already there for regular PV. It's getting to the point where a home system will almost pay for itself in less than 10 years.
- vmception 6y agoI'm thinking 3 months would be ideal
- pjc50 6y agoVery few things have a return that quickly. In an era of 25 year mortgages, a 10 year payback is very reasonable.
- vmception 6y agoLet's make these one of the few things that have a return that quickly.
- Armisael16 6y agoThat’s unlikely to ever happen; if it’s that cheap to produce electricity the utilities will have long since switched over and cut rates.
- hellotomyrars 6y agoIdeal, I guess. Though I don't see how that could ever be possible.
- hirundo 6y ago"if the government were to take over the Sahara Desert, there would be a shortage of sand in five year" -- Milton Friedman (exaggerating, somewhat) Better to put them on home roofs, and arrange for them to be owned by the homeowners, designed so that the occupants are (literally) empowered when the grid is mismanaged, as in California. On highway medians control is more centralized, and they would require more maintenance and cleaning, which would be more disruptive in that location.
- singron 6y agoSolar panels on home roofs aren't necessarily configured to power the house without the grid. Also you would additionally need batteries and related hardware to have a usable source of power at any time, so unless your house is set up for off-grid solar, you still need the grid to be managed well.
- mysterydip 6y agoFound this out in the house we are renting with solar panels installed by landlord. Bright sunny day, someone hits a pole nearby, power goes out. There are two kinds of solar: one that adds to the existing signal from the mains, or one that is self-contained. The second kind is more complicated and therefore expensive. I wasn't aware of the distinction before, but I definitely am now.
- yellow_lead 6y agoAren't there setups that can do both as well? i.e charge battery first and send excess to the grid?
- apcragg 6y agoSure but they are more expensive. You need a rock solid controller with beefy and redundant electronics to make sure you're never going to be connected to the grid when you shouldn't be.
- 6y ago
- ape4 6y agoVehicles often crash into things beside a highway.
- bialpio 6y agoPlanes sometimes fall on people's roofs. Let's not optimize for edge cases here?
- jeffbee 6y agoThis has to be the most ignorant comment ever posted on HN. In a typical year how many aircraft crash into structures? Zero. There are more than fifteen thousand car crashes in the USA every day.
- kube-system 6y agoThe entire reason medians exist is because they are a crash safety device. Consideration for crashes is not an edge case, it’s the entire point of a median.
- evan_ 6y agoThat will surely be taken into consideration from the start, and they will be designed in easily replaceable sections. If a car hits a section maybe it will be disabled but the rest of the cells will be fine and a crew will be dispatched to repair or replace the damaged cells.
- kube-system 6y agoSurely it is cheaper to simply place the panel somewhere else than it is to: 1. Pay for thousands of additional broken panels on a recurring basis 2. Pay people to replace thousands of broken panels 3. Shut down highways for utility work to replace thousands of broken panels 4. Design the panels to meet crash safety design considerations that the structures currently in the median were designed to 5. Add additional electrical safety standards unique to a panel array that designed to withstand car crashes. Really, this is complete silliness.
- altcognito 6y agoThey would also get dirty at a much faster rate because of all the dirt and soot generated by the vehicles going by.
- jameslk 6y agoThe solar panels on roads idea has been tried. Rotting leaves were a big source of its failure. https://www.businessinsider.com/first-solar-road-france-failure-photos-2019-8#it-was-all-smiles-and-high-hopes-in-2016-when-the-worlds-first-solar-panel-road-called-wattway-opened-france-spent-52-million-on-06-miles-of-road-and-30000-square-feet-of-solar-panels-it-was-hailed-as-the-longest-solar-road-in-the-world-1 https://www.businessinsider.com/first-solar-road-france-fail...
- ianai 6y agoDoesn’t matter. Much of the US roads aren’t anywhere near trees - ie the southwest. Huge amount of roads and solar power potential there too. Also, cleaning crews are a thing that have existed in the past and should again.
- jameslk 6y agoReplace leaves with tumbleweeds. Or whatever natural debris we have in the west. The leaves were causing damage to the solar panels. I imagine other types of debris would do the same. But I'd be happy to be wrong. Have you asked why this hasn't already been done yet? Or if it has (besides the example I provided), what was the outcome?
- iancmceachern 6y agoHave you spent much time driving in the empty areas of the west? You can go 100 miles without even seeing a tumbleweed.
- jameslk 6y agoI've been living in the west my whole life and have traveled between Colorado to California through Nevada, Utah, Arizona, etc 7 or 8 times, so yes I've seen an empty western road before. Tumbleweeds was tongue in cheek but there's plenty of dirt, trash and other flying debris that will get baked onto a glassy surface out southwest.
- eloff 6y agoYeah, land is not at a shortage. The best land for solar is also worthless for other things, so it tends to be dirt cheap. There's enough unused space in the Southeast US to power the entire world off of solar. Obviously that wouldn't work for other reasons, but underscores nicely how land isn't the issue at all.
- dehrmann 6y ago> If we put a (nearly) continuous strip in every highway median Is there a shortage of land for solar?
- newyankee 6y agoI was wondering if they can be put up on poles holding train's electric tractive wires and then fed directly to the same wire. The issue i see is dc to ac conversion and lot of variability management.
- amelius 6y agoMaintenance in the middle of the road sucks ...
- aaron695 6y agoI was just thinking farmers had it to easy harvesting their crops. If we take the solar panels off the 1% of roof space they are on and move them far away from the place we use the actual power, we could do this. The attention span of the environmental movement is quite amazing at times.
- newyankee 6y agoI cannot imagine the revolution that solar power will produce if it can fall another 3-5x in the next 10 years. It is already at grid parity. Although my personal hope is for storage, inverters, controllers and other technologies to get cheaper. Especially longer term storage beyond 4 hours.
- toomuchtodo 6y agoI think it’s unlikely you see any fossil generation in the mix in 10 years except in the most remote of locations (with no solar or wind potential). Wind and solar are already around 2 cents/kWh utility scale, and batteries are catching up. No fossil or nuclear generation can compete with that.
- emit_time 6y agoSource? I don't disagree, would just like to share this information with friends :)
- toomuchtodo 6y agoCommenting as a reminder to self to return with a model.
- repsilat 6y agoI'd bet there will be some natural gas generation in the US in non-remote areas in 2030. Maybe not new construction, but gas is cheap, responsive, and already in place. I don't think it'll be completely replaced by batteries and added renewable capacity that quickly, though I'd love to be proven wrong.
- manfredo 6y ago> Batteries are catching up. Are they? The US consumes 11.5TWh of electricity daily. It's estimated that it needs 3 weeks if storage to get to 100% carbon free [1]. By comparison global battery production in 2019 was 300GWh [2]. Even if you factor in the fact that the curve of battery production is rising, it'd take decades to fullfil just the US's storage demands with batteries. There are other storage options like hydroelectricity and pumping air into mineshafts, but those are geographically limited. 1. https://pv-magazine-usa.com/2018/03/01/12-hours-energy-storage-80-percent-wind-solar/ https://pv-magazine-usa.com/2018/03/01/12-hours-energy-stora... 2. https://cleantechnica.com/2019/04/14/global-lithium-ion-battery-planned-capacity-update-9-growth-in-a-single-month-march-charts/amp/ https://cleantechnica.com/2019/04/14/global-lithium-ion-batt...
- xwdv 6y agoAlternatively, dust build up on the solar panels can prevent production of both.
- agumonkey 6y agoautomated panel cleaning is probably solved by now
- Communitivity 6y agoNot just crops and power. I know a guy whose startup is using transparent solar panels in Germany on eco-friendly buildings with grass on roofs, to get power and eco-cooling, as well as Oxygen production - at least that is how he explained it. The concept is called green-roofs. Unfortunately I don't remember his startup's name. A link with details about the concept, minus the use of transparent solar panels: https://buildingradar.com/construction-blog/green-roofs/ https://buildingradar.com/construction-blog/green-roofs/
- agumonkey 6y agoAre there places to read about this field ? journals, websites, discord anything ?
- nitrogen 6y agoDo they grow enough grass to produce enough oxygen for the building?
- BurningFrog 6y agoThe oxygen claim doesn't inspire confidence. Plants don't produce any useful amount of oxygen, and real scientists know that.
- atoav 6y agoA thing that they are good at however, is lowering temperatures in cities (compared to e.g. stone surfaces which store the warmth of the sun) – this alone might be a good reason to look into green roofs, given that we just passed the point of no return for Greenland's ice sheet recently. It takes the same amount of energy to melt 1kg of 0°C ice into 0°C water as it takes to heat 1kg of 0°C water to 80°C.
- gus_massa 6y agoYou probably need to have a irrigation keep the plants alive. Probably spraying the concrete surface has the same effect.
- chrisco255 6y agoSo this technique reduces the sunlight the plants receive by about 57% but only reduces biomass growth by about 30%. It's very interesting. I imagine you could enclose the sides with glass or plastic and make a greenhouse from it. That makes me wonder if the reduction in growth wouldn't be offset by the ability to extend the growing season.
- conscion 6y ago> I imagine you could enclose the sides with glass or plastic and make a greenhouse from it FTA - that's why they tested on basil and spinach. Both crops are commonly grown in greenhouses
- bserge 6y ago> make a greenhouse from it That would be literally Earth-saving in some places. I know people who heat their greenhouses with wood! Wood, from forests, which are quickly dwindling, and yet it's cheaper than natural gas, so people use this country's forests to keep warm during winter just because it's cheaper. From my point of view, that's absolutely insane and this country deserves what it gets. Which is decreased rainfall, increased summer temperatures, landslides, floods (ironically) and crop damage so bad it puts farmers out of business (they're protesting right now). Then they wonder "why, God, why?" like a bunch of headless chickens. We deserve everything we get. Sorry, I had to get this off my chest.
- khawkins 6y agoOnly people who spend most of their life in densely crowded cities could think that the planet has so little space that you'd need to grow crops underneath solar panels for efficiency's sake.
- Causality1 6y agoIndeed. This reminds me of the "let's drive on top of our panels" stupidity. I suppose it could have practical applications in space colonization.
- epistasis 6y agoA lot of farmers are leasing their land to solar developers because it provides guaranteed, stable payments. Though "we" as a whole are not limited by land, individual economic actors are limited by how much land they own. Additionally, interconnection to the grid and node congestion are becoming larger percentages of the cost of solar, since they are roughly constant as the cost of solar plummets. Farms are somewhat ideal for medium size solar installations because they often have significant existing grid connections that are underutilized. Now that we have economical solar tech, the actual implementation of solar installs will be highly dependent on regulations, economic motivations of individual economic agents, the knowledge and intelligence of thistle agents, and combinations with existing infrastructure. (For example, we are seeing batteries being installed in old fossil fuel plants, so that we can reuse those super expensive grid connections.)
- epistasis 6y agoIt's not "need" as much as increasing efficiency and profit. There are at least a few studies now that have shown that multipurpose use for both agriculture and solar will provide greater output than doing only one; for example you may lose 30% of maximum potential solar production and 40% of agricultural output, but it's still not >50% loss for either. These studies were not performed with this type of semi-transparent as in this article, so perhaps the boost could be larger, if the additional cost of the panels is not too high.
- 6y ago
- gdubs 6y agoOur area of Oregon recently banned new solar farms on the grounds that it detracts from the beauty of the landscape – a wine region with lots of tourism. Ironically, that very beauty is threatened by the changing climate, which clean energy could help mitigate.
- foolfoolz 6y agoeh i don’t see anything wrong with this. some areas are beautiful and should remain that way. we have a ton of space in oregon and the us. tons of space that no one is ever going to care about. i think it’s ok for people to protect places that have interest and economic benefits
- gdubs 6y agoI’m not saying there’s anything wrong with trying to protect the character of the region. In fact, the beauty is something that — hopefully — makes visitors appreciate the environment. But when you look at what’s already allowed in farm-use zones, there’s plenty of eye-sore potential. So, my issue is with painting with too wide a brush (and unfairly singling out a use that’s arguably important to preserving the environment over the longer term). They should have the ability to look case-by-case. If someone has an area on their property that’s shielded from public view, why not let them use it for a solar array? Studies have shown that, properly configured, solar arrays can actually improve prairie soils. And like the large array in Hawaii, grazers like sheep can be incorporated into the design. Just seems bonkers to me to outright ban the solar arrays.
- quotemstr 6y agoLet's be real for a second. Climate change isn't going to destroy Oregon's wine-growing regions within our lifetimes. A solar farm will change it within months. You can support or oppose solar farm bans according to your liking, but you should do so on the basis of facts. The two forces aren't even close to equal in magnitude and timing.
- evan_ 6y ago
- mrfusion 6y agoCould we design one to mostly get energy from green light which plants reject anyway?
- dehrmann 6y agoThis was my first thought, but PV panels that capture 25% (I'm guessing) the energy of standard panels are only viable if the cost of land is the limiting factor. The other complicating factor is that large-scale farming requires a decent amount of horizontal and vertical clearance, so the structure for the panels would be substantial, especially if you want to track the sun.
- everybodyknows 6y agoFrom the abstract: >selective utilization of different light wavelengths
- hobofan 6y agoYes, it says it in the abstract, but isn't really given special attention to in the article itself. Looking at the graphic it looks like a fairly normal absorption spectrum for a solar panel without it being specifically tailored to this use-case. It seems like there might still be something won by specifically tailoring it to be complementary to the plant absorption spectrum. On the other hand it might also not be economically viable due to lack of scale and varying requirements for wavelengths between plant species and stages of plant development, which makes some optimizations moot.
- peter_d_sherman 6y agoThis is very interesting! A few related questions come to mind: 1) What happens when two or more semi-transparent solar panels are stacked one behind the other? Is output power then comparable to the highest efficiency solar panel, do you get more, do you get less, and if so, how much less? 2) Polarization of light and solar panels -- what happens if light is polarized by a filter before going to a solar panel? And then, what happens (in terms of overall energy production) when that polarization filter is turned to an angle? And then the same question, applied to both regular solar panels, and these semi-transparent solar panels. 3) While I'm on the topic, has any researcher out there found a way to get even so much as a single millivolt/milliwatt (microvolt/microwatt?) from solar power coupled with a fully transparent surface, like let's say, glass, or some other crystal? I seem to recall some researcher somewhere that showed that very small charge regions occur at boundaries when sunlight hits plain transparent water -- but I do not recall the details...
- csours 6y agoI'm imagining a green-greenhouse which covers all of it's energy usage with these panels. Edit: heck, what about auto-glass?
- quotemstr 6y agoBesides: nuclear power plants take up very little space. I really can't seriously people pushing solar, wind, and so on while they eschew nuclear power (and increasingly hydropower too). Fake environmentalists: "We have an existential crisis! We must change our energy strategy to save humanity!" Engineers: "That's quite a problem. Here's a way to solve it. It's called fission. Here are some power plant designs." Fake environmentalists: "Nooo! Not that plan! This existential problem can be solved using only those technologies that agree with my aesthetics!" It gets old after a while. If carbon-induced anthropogenic climate is a problem --- and I think it is --- then we shouldn't disparage good solutions on weak grounds in favor of solutions with serious problems. We don't need to devote swaths of land to solar and wind if we just build nice compact nuclear power stations.
- guerrilla 6y ago> only those technologies that agree with my aesthetics!" This is an exceptionally bad straw-man [1]. 1. https://en.wikipedia.org/wiki/Nuclear_power_debate https://en.wikipedia.org/wiki/Nuclear_power_debate
- brokencode 6y agoSo you think caring about nuclear waste along with CO2 emissions makes someone a fake environmentalist? Nuclear waste is highly toxic and difficult to store and transport safely. Also, have you ever heard of Chernobyl or Fukushima? Nuclear reactors are great in certain ways, but can be catastrophically bad too. Hydro also can cause a significant environmental impact, flooding natural habitat and interrupting water routes for different animals. Solar and wind aren’t perfect either, but the idea is to try to chose a power source that is as clean as possible.
- codefreakxff 6y agoThe tone of your post (being simultaneously dismissive and insulting to those who have a different view than you) is very trollish. The problem many people have with nuclear power are things like accidents making areas uninhabitable, radiation making people sick, disposal of waste rods is difficult, some materials can be used to make weapons, and the cost to make a safe plant are staggering and leading to cancellation of projects. Renewable sources don’t have these downsides. Are they ugly? Not any uglier than a concrete dome and cooling systems of a nuclear power plant. You can bet wine country does not want a nuclear plant in their valley either. I think it’s perfectly reasonable to zone land usage appropriately.
- adrianmonk 6y agoThere is a LOT of low-hanging fruit when it comes to where to install plain old regular solar. We could probably spend the next 50-100 years installing as many (regular) solar panels as possible and still have plenty of places left to put more of them. Obviously it's not bad to develop these technologies, but I think they'll only be useful in niche applications.
- richardrk 6y ago"Maximizing the generation of electricity is a desirable goal, but might be at the expense of biomass production. For example, for lettuce, the total biomass yield under agrivoltaic installation in Montpellier (France) was 15–30% less than the control conditions (i.e., full‐sun conditions).[28, 29] When growth of tomato was tested in Japan, the yield in an agrivoltaic regime was about 10% lower than for conventional agriculture."
- dghughes 6y agoMy mother ayed tomatoes in the spring when it was still cool. She covered them with clear plastic bags as she always has. But she needed one more bag so she used a blue recycling bag on one of the plants. Blue tinged really it's almost clear. I pointed out to her one of the plants had yellow leaves. It was the plant with the blue bag. Later in the summer the blue bag plant produced fruit just like the other plants. But the bottom of each tomato was disfigured and looked rotten but it was dry to the touch. It's blossom rot due to low calcium. I have to wonder if it was the blue bag or lack of/too much water. All the plants got the same nutrients only this one had the blue bag. It got red light and green light which plants don't need but no blue light. Plants are seemingly very sensitive to sunlight quality. I'm sure the solar panels are clear but even a slight colour blockage may be harmful. It was an interesting result.
- jws 6y agoThe ratio of red and blue light controls various functions of a plant. In the context of aquarium plants, more red light makes them get tall and leggy, more blue light makes them be compact and bushy. https://gpnmag.com/article/effects-of-blue-light-on-plants/ https://gpnmag.com/article/effects-of-blue-light-on-plants/ talks a bit about it in the context of greenhouses and tomatoes, the picture in the middle shows 6 plants grown with wildly different red/blue ratios. If the balance of the light coming through your solar panel was problematic, you could always filter out some of the overabundant light.
- ballenf 6y agoIs that how they know how close to the surface of the water they are?
- carvink 6y agoThat slight colour blockage, or the tint those solar panels have is helpful. There are two reasons. One, plants grow better under red light. Red light has the highest efficiency for photosynthesis in plants, that why LED grow lights are tuned for certain wavelengths. Plants use blue light to know what direction to grow. And for a certain category of tints or dyes that are fluorescent, additional red light. Luminescent solar collectors have an embedded dye with molecules that fluoresce, that give off even more red light. Example: http://www.soliculture.com/lumo-technology/ http://www.soliculture.com/lumo-technology/
- tiku 6y agoI always wondered why you could not just place the panels a bit higher. So that the sun can pass on certain times etc.
- kube-system 6y agoYeah, people are treating this solar panel like a hammer and finding any use-case that looks like a nail. Instead of a entire roof of panels that pass 50% of the light, it’s is more simple to make a roof of half covered in panels that pass 0% of light... like a pergola.
- jugg1es 6y agoThis is fascinating but you have to wonder how it would work with current harvesting techniques. New harvesting machines would have to be invented to work around the support infrastructure for the panels if they were to be deployed at scale.