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Semi-transparent solar panels allow concurrent production of crops and power

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Re: Semi-transparent solar panels allow concurrent production of crops and power

#151

Post by hutzlibu »

dTal wrote: post #111
khawkins wrote: post #21

Only 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.

And only someone blind to the ecological damage that agriculture does would regard all that land as free to use by humans, without consequences. Here [0] is a map of the world's remaining wilderness. Notice how it's nearly all desert, with the exception of the Amazon rainforest. And hey, guess what's happening to that? We are short of space. And time. [0] https://images.theconversation.com/files/256144/original/fil..…

Deserts are a perfect place for greenhouses as well as solar panels. Just not both of them combined. That concept might make sense in very densly populated areas, where people want to use the most out of their garden greenhouse. But on industrial scale, I am very sceptical, the efficency should be a lot higher to justify the building costs and increased complexity.

Re: Semi-transparent solar panels allow concurrent production of crops and power

#152

Post by philipkglass »

Manfredo_1 wrote: post #145
philipkglass wrote: post #140

Earlier quoted context omitted.

The paper you cited shows that 1.5x overproduction can get the US to 75% of electricity from solar and wind without building any storage. Every big construction project is cheaper in China than in the US. China can build a solar farm for $0.83/watt [1], half the cost I cited up-thread for an American solar farm. But I don't think that $0.83/watt is a credible construction cost for a solar farm in the US in 2020. Nor…

> The paper you cited shows that 1.5x overproduction can get the US to 75% of electricity from solar and wind without building any storage. Right, without storage you have to scale back the percentage of electricity you get from intermittent sources. Like I said, without storage, renewables do not present a valid option for a carbon free source of energy. I you want a US example of a nuclear plant construction, you c…

75% of all electricity consumption is too low to be a "valid option" for decarbonizing electricity? We have different ideas of what's valid.

If you want a US example of a nuclear plant construction, you can take the Diablo Canyon plant [1]. This is not only built in the US recently, but also in an earthquake prone area and thus needed more robust construction. It cost 13.8 billion in 2018 dollars. ... You're picking an individual plant to inflate the cost of nuclear dramatically.

Diablo Canyon unit 1 construction began in 1968 and unit 2 in 1970 according to the page you linked. That's hardly recent. I was actually trying to be charitable to American nuclear by talking about the new Vogtle units without mentioning the billions spent at V.C. Summer on two incomplete AP1000 reactors that will not enter service at all.

I agree that 1970s era nuclear plants cost less. Part of that was that there was more experience with building them, so the average was lower. Another reason is that when we look at nuclear plants running today and tabulate cost by year of construction, we're cherry picking the projects that went well.

I count 41 American reactors that were cancelled while under construction on this page:

https://en.wikipedia.org/wiki/List_of_cancelled_nuclear_reac...

37 of them started construction in the 1970s. That's a high project failure rate compared to any other generation source.

Re: Semi-transparent solar panels allow concurrent production of crops and power

#153

Post by Gibbon1 »

Retric wrote: post #19
hirundo wrote: post #7

Earlier quoted context omitted.

"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 mainte…

Rooftop photovoltaic is currently more expensive, less efficient, and surprisingly dangerous to install. Solar thermal designs actually benefit from being on rooftops. As to dust, economies of scale make a huge difference. It’s rarely worth it, but using a farm truck to spray water across miles of panels is much more efficient than tens of thousands of homeowners doing the same.

I'm dubious about rooftop solar in suburban/urban areas. I think the gain is mostly from tax write offs and arbitrage. Compare hand installing solar panels on a roof with mechanized installation of a large scale solar array.

Just isn't going to compete with stuff like this.

https://www.youtube.com/watch?v=Xk21aAaJL_s

Re: Semi-transparent solar panels allow concurrent production of crops and power

#154

Post by dawnerd »

dghughes wrote: post #85

My 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. B…

All of my plants this year have gotten blossom rot, pretty much too late to fix too. No tomatoes for me this year.

Re: Semi-transparent solar panels allow concurrent production of crops and power

#155

Post by lifeisstillgood »

BurningFrog wrote: post #112
Communitivity wrote: post #16

Not 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://…

The oxygen claim doesn't inspire confidence. Plants don't produce any useful amount of oxygen, and real scientists know that.

Umm ... You may be confusing net production with actual production (ie plants produce pretty much all the O2 but they then reabsorb it)

I suspect it is also worth differentiating between production as has been going on for millions of years and industrial production - there is really no way to collect or harvest the oxygen made by plants - but that is kinda implied by the GP statement (that they wanted to cool the roof make electricity and Oxygen production (the implication being something useful to a business based on that roof)

So I can see your point.

https://en.m.wikipedia.org/wiki/Oxygen_cycle

Re: Semi-transparent solar panels allow concurrent production of crops and power

#156

Post by andromeduck »

dTal wrote: post #111
khawkins wrote: post #21

Only 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.

And only someone blind to the ecological damage that agriculture does would regard all that land as free to use by humans, without consequences. Here [0] is a map of the world's remaining wilderness. Notice how it's nearly all desert, with the exception of the Amazon rainforest. And hey, guess what's happening to that? We are short of space. And time. [0] https://images.theconversation.com/files/256144/original/fil..…

Nuclear power is a thing.

Re: Semi-transparent solar panels allow concurrent production of crops and power

#157

Post by Manfredo_1 »

philipkglass wrote: post #152
Manfredo_1 wrote: post #145

Earlier quoted context omitted.

> The paper you cited shows that 1.5x overproduction can get the US to 75% of electricity from solar and wind without building any storage. Right, without storage you have to scale back the percentage of electricity you get from intermittent sources. Like I said, without storage, renewables do not present a valid option for a carbon free source of energy. I you want a US example of a nuclear plant construction, you c…

75% of all electricity consumption is too low to be a "valid option" for decarbonizing electricity? We have different ideas of what's valid. If you want a US example of a nuclear plant construction, you can take the Diablo Canyon plant [1]. This is not only built in the US recently, but also in an earthquake prone area and thus needed more robust construction. It cost 13.8 billion in 2018 dollars. ... You're picking…

> 75% of all electricity consumption is too low to be a "valid option" for decarbonizing electricity? We have different ideas of what's valid.

The US already generates ~40% of its electricity from carbon free sources. An increase to 75% represents only about a 60% reduction in fossil fuels from the current status quo. This is absolutely not a solution. We're still advancing climate change. Halving the time it takes to reach a disaster is not even remotely close to the same thing as averting a disaster.

> 37 of them started construction in the 1970s. That's a high project failure rate compared to any other generation source

Yes, because of Three Mile Island. Most of the cancellations were for reactors that started in the 1970s, because the US mostly stopped constructing reactors in the 1970s. You don't have cancellations for projects that began in the 1960s because those projects finished before Three Mile Island. You don't have project cancellations in the 1980s and 1990s because the US largely stopped starting new nuclear projects.

This pattern of cancellations demonstrates the fact that the high failure rate is due to political pressure, not economic unsuitability of nuclear reactors. Serialized production yields costs per kilowatt hour well below your estimates for renewables even without the cost of storage.

And no, if we look at reactors that are no longer in operation we don't see a much higher cost [1] [2] [3] [4] [5].

Serialized nuclear construction is by far the cheapest and most effective way to eliminate carbon emissions from electricity generation. Intermittent sources are cheap until they reach saturation during their time of production. Then costs skyrocket when storage becomes necessary. And even more importantly, nuclear is the only proven way of accomplishing this.

1. https://en.wikipedia.org/wiki/Rancho_Seco_Nuclear_Generating...

2. https://en.wikipedia.org/wiki/Big_Rock_Point_Nuclear_Power_P...

3. https://en.wikipedia.org/wiki/Crystal_River_Nuclear_Plant

4. https://en.wikipedia.org/wiki/Kewaunee_Power_Station

5. https://en.wikipedia.org/wiki/Oyster_Creek_Nuclear_Generatin...

Re: Semi-transparent solar panels allow concurrent production of crops and power

#158

Post by tsimionescu »

hutzlibu wrote: post #148
BurningFrog wrote: post #112

Earlier quoted context omitted.

The oxygen claim doesn't inspire confidence. Plants don't produce any useful amount of oxygen, and real scientists know that.

So what on this earth is producing useful amounts of oxygen then?

Algae in the ocean, mostly.

But also, any growing plants - you could compute for every kg of dry plant matter, how much oxygen is released, as the dry plant matter is almost entirely carbon produced from breaking up CO2.

So unless you're collecting tens or hundreds of kilograms of dead plants from your roof every year, it isn't producing much oxygen.

Re: Semi-transparent solar panels allow concurrent production of crops and power

#159

Post by BurningFrog »

hutzlibu wrote: post #148
BurningFrog wrote: post #112

Earlier quoted context omitted.

The oxygen claim doesn't inspire confidence. Plants don't produce any useful amount of oxygen, and real scientists know that.

So what on this earth is producing useful amounts of oxygen then?

Big picture, oxygen isn't being either produced or consumed. The level is constant.

Individual oxygen atoms alternate between being in CO₂ molecules and O₂ molecules, as plants grab the carbon to build their bodies and return it after death.

But since the total mass of plant life doesn't change much, it all evens out.

Re: Semi-transparent solar panels allow concurrent production of crops and power

#160

Post by vbezhenar »

khawkins wrote: post #21

Only 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.

You need logistics (electricity, roads, water). It costs a lot. It's more efficient to utilize 3D rather than utilizing only 2D.

When we're talking about humans, I'd agree that living in a crowded city is a terrible thing (though some people might like it). But when we're talking about industrial objects, efficiency is important.

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