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Growing crops under solar panels

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Re: Growing crops under solar panels

#91

Post by lost_tourist »

Schroedingersat wrote: post #79
gumby wrote: post #39

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.

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.

I find it hard to believe it was against the law to use batteries to store excess solar power.

Re: Growing crops under solar panels

#92

Post by lost_tourist »

eru wrote: post #62
hahamrfunnyguy wrote: post #22

Earlier quoted context omitted.

True, however I think the point is to put more shade tolerant crops under the panels. A lot of the crops we grow are not grown directly for human consumption. Consider the corn grown for the production of ethanol: why not just harvest the energy directly with solar panels there and grow lettuce or carrots? It would be good to explore other uses for the space as well, like using the panels as shade or cover for livest…

I mostly agree. As an aside, growing maize for ethanol in the US is only really viable because of subsidies and tariffs. Otherwise, Brazilian ethanol would be cheaper.

Ethanol in the USA is a scam that representatives from states that benefit from the subsidies keep alive.

Re: Growing crops under solar panels

#93

Post by eru »

gumby wrote: post #84
eru wrote: post #60

Earlier quoted context omitted.

> 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.)

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.

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.

Re: Growing crops under solar panels

#94

Post by xyzzyz »

locallost wrote: post #69

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]. A…

> 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].

It will not, not even close to that. You are being deceived. This deception is willful, because it is obvious to anyone who has any idea about realities of energy generation. The linked article, however, while not literally lying, omits some obvious facts, the goal of which is to make you believe falsehoods.

The article talks about "installed capacity", and compares installed capacity of photovoltaics vs. nuclear power plants. It is extremely deceptive to make such comparison without taking into account the notion of capacity factor, and the proof of this is that you have successfully been deceived.

The nuclear power plants typically generate north of 90% of their installed capacity, averaged over the entire year. The photovoltaics in Europe, on the other hand, typically generate 10-15% of their installed capacity, averaged over the entire year. This is caused by the unfortunate fact which is that the sun doesn't shine at all for at least half of the year, and for the significant part of the remainder, it is occluded by clouds, or shines at suboptimal angle, preventing the panels from reaching their maximum generating capacity.

This means that 1 GW of installed nuclear power capacity is worth at best something like 6-9 GW of installed photovoltaic capacity. At best, because photovoltaic generation will mostly happen on summer days, resulting in excess supply and so low value of generated energy. In winter, when photovoltaics generate relatively little energy, and the energy demand is high due to heating needs (especially during the night), the value of 1 GW of produced nuclear power will be higher than value of 1 GW of produced photovoltaic in summer.

The result of this is that covering half of all parking lots in France with photovoltaics is effectively worth less than a single nuclear reactor. This is obvious to anyone who pays even minimum attention to the economics of energy production, but the activist-media complex works very hard to deceive the public, leading them to believe that photovoltaics are already cheaper than fossil fuels and nuclear power. They are not, not even close, and this is even ignoring how nuclear power in France subsidizes solar/wind in a deliberate, systemic way.

Re: Growing crops under solar panels

#95

Post by defrost »

lost_tourist wrote: post #91
Schroedingersat wrote: post #79

Earlier quoted context omitted.

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.

I find it hard to believe it was against the law to use batteries to store excess solar power.

I'm guessing the comment was about regulating against sufficient large battery installations in a dense urban setting until standards where in place.

Australia has a high (very high by world standards) % of houses with solar panels on the roof which feed power back to the main grid (in cities and surrounding towns) which minimises the need for battery walls (which will no doubt come soon enough).

In (sub)urban housing in Australia it's against zoning for residential houses to have large tire piles (ie an entire yard of old car tyres with more house high stacks out the back) due to the dangers of dirty fires, ditto having a shipping container of fireworks next your house (and other houses in area), massive fuel tanks, etc.

I dare say large battery walls were also zoned against until plans were in place re: standards, etc.

Australia does have neighbourhoos battery banks here and there, one that serves 200 houses (at mean consumption) can be purchased for ~ $1 million AU (IIRC) - and there's the South Australian battery bank that was the world's largest when it was installed.

Re: Growing crops under solar panels

#96

Post by otherme123 »

hutzlibu wrote: post #64
yazaddaruvala wrote: post #8

Earlier quoted context omitted.

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 [1] https://images.app.goo.gl/9kakPW…

"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…

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). 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.

Re: Growing crops under solar panels

#97

Post by gpvos »

xyzzyz wrote: post #94
locallost wrote: post #69

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]. A…

> 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]. It will not, not even close to that. You are being deceived. This deception is willful, because it is obvious to anyone who has any idea about realities of energy generation. The linked article, however, while not literally lying, omits some obvious facts, the…

What makes you think they didn't already take that into account? There are really an awful lot of parking places.

Also, the panels will give electricity at the same times we are going to want airco due to global warming, so at least it helps to cover that need.

Re: Growing crops under solar panels

#98

Post by kwhitefoot »

ta1243 wrote: post #73
ed25519FUUU wrote: post #38

Earlier quoted context omitted.

This is the only solution that makes sense everywhere where land is not a million dollars an acre (places not California).

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.

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.

Re: Growing crops under solar panels

#99

Post by mikro2nd »

dylan604 wrote: post #87
catmanjan wrote: post #65

Earlier quoted context omitted.

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

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.

Early systems were driven by water pressure. Modern systems have an electric motor for each pair of wheels.

Re: Growing crops under solar panels

#100

Post by mikro2nd »

schiffern wrote: post #55
mminer237 wrote: post #31

Earlier quoted context omitted.

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 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 t…

>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.

Pastures used for grazing are managed intensively using big machines. (Source: I live next door to a large dairy farm. Pastures irrigated with centre-pivot systems.) Pastures get replanted/supplemental sowing every so often, weeds get sprayed with herbicides, fields get mowed to maintain uniform growth after they've been grazed...
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