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

onlinelibrary.wiley.com

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

#161

Post by baq »

Gibbon1 wrote: post #153
Retric wrote: post #19

Earlier quoted context omitted.

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

Generation of power at the point of consumption is nothing to sneeze at. It’s also efficient use of space. Taxes can work as incentivizing tool instead of or in addition to generating revenue for the government which is precisely what’s going on here.

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

#162

Post by philipkglass »

Manfredo_1 wrote: post #157
philipkglass wrote: post #152

Earlier quoted context omitted.

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 t…

The 75% figure is from solar and wind alone. The balance can come from any combination of nuclear, other renewables, and fossil fuels. It doesn't mean 25% electricity supplied by fossil fuels.

You consider France's electricity sector a decarbonization success story, right? It generates "only" 72% of electricity from nuclear power: https://en.wikipedia.org/wiki/Electricity_sector_in_France

The United States also gets 7% of its electricity from hydro and geothermal:

https://www.eia.gov/tools/faqs/faq.php?id=427&t=3

Plus 19.7% from existing American reactors, though that number is going to drift downward as retirements continue to outpace construction.

I think that the residual fossil demand would be significantly less than 25%. I can't say how much exactly. That needs another study. In the absence of storage, neither nuclear nor geothermal plants are good at supplying peak demands. Hydro can serve a peaking role to some extent even without building new pumped storage but it's constrained by reservoir volumes, minimum downstream flow rates, seasonal snow melt, etc.

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

#163

Post by Manfredo_1 »

philipkglass wrote: post #162
Manfredo_1 wrote: post #157

Earlier quoted context omitted.

> 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 t…

The 75% figure is from solar and wind alone. The balance can come from any combination of nuclear, other renewables, and fossil fuels. It doesn't mean 25% electricity supplied by fossil fuels. You consider France's electricity sector a decarbonization success story, right? It generates "only" 72% of electricity from nuclear power: https://en.wikipedia.org/wiki/Electricity_sector_in_France The United States also gets…

> In the absence of storage, neither nuclear nor geothermal plants are good at supplying peak demands.

This is false. Nuclear and geothermal power can both satisfy peak demand just fine. Nuclear plants do take time to alter the thermal output of the reactor, but they can easily reduce the electric output through overcooling. Same MWt, but lower MWe. Geothermal plants just pump less water into the borehole. Better yet, nuclear plants can direct the excess energy to things like desalination. This is much easier than trying to satisfy peak demand with solar or wind, where peak demand often occurs when the sun isn't visible or when wind speed is substantially higher or lower than demand.

Again, France at its peak generated over 85% of it's electricity from nuclear power. I'm not sure where you're getting this myth that nuclear plants can't satisfy variable demand.

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

#164

Post by philipkglass »

Manfredo_1 wrote: post #163
philipkglass wrote: post #162

Earlier quoted context omitted.

The 75% figure is from solar and wind alone. The balance can come from any combination of nuclear, other renewables, and fossil fuels. It doesn't mean 25% electricity supplied by fossil fuels. You consider France's electricity sector a decarbonization success story, right? It generates "only" 72% of electricity from nuclear power: https://en.wikipedia.org/wiki/Electricity_sector_in_France The United States also gets…

> In the absence of storage, neither nuclear nor geothermal plants are good at supplying peak demands. This is false. Nuclear and geothermal power can both satisfy peak demand just fine. Nuclear plants do take time to alter the thermal output of the reactor, but they can easily reduce the electric output through overcooling. Same MWt, but lower MWe. Geothermal plants just pump less water into the borehole. Better yet…

Nuclear plants can throttle down. But the economics of nuclear power make it prohibitive to satisfy peak demand from nuclear reactors. Even France relies on gas plants and power imports to satisfy its electricity demand peaks, despite being a net electricity exporter over the course of a full year.

The CAISO grid had an average power demand of 25 GW in 2019 but a peak demand of 46 GW (Table 1.1):

http://www.caiso.com/Documents/2019AnnualReportonMarketIssue...

Keeping enough nuclear reactors operating to supply the most demanding hours of the most demanding season would have extraordinarily high marginal costs for the last few terawatt hours.

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

#165

Post by gmueckl »

jameslk wrote: post #22
Grakel wrote: post #2

There'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.

The 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-fail...

One thing that I don't get about this and related stories: if the road surface is damaged as badly as they say, then why are there no pictures of the damage (the one picture showing damaged modules is described as not taken from modules instLled on the road)? Also, I googled several other stories and none of them has hard facts on why it failed, essentially speculating about different reasons.

Something about this story is not quite right, at least the way it was reported in English language media.

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

#166

Post by asquabventured »

dawnerd wrote: post #154
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.

Blossom end rot is caused by calcium deficiency. Easiest solution for this is to just crush up egg shells and put them in and on top of the soil. I save my eggshells in a jar in the fridge for a few months prior to planting. It may be too late for this year but should work wonders for you in the future.

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

#167

Post by Manfredo_1 »

philipkglass wrote: post #164
Manfredo_1 wrote: post #163

Earlier quoted context omitted.

> In the absence of storage, neither nuclear nor geothermal plants are good at supplying peak demands. This is false. Nuclear and geothermal power can both satisfy peak demand just fine. Nuclear plants do take time to alter the thermal output of the reactor, but they can easily reduce the electric output through overcooling. Same MWt, but lower MWe. Geothermal plants just pump less water into the borehole. Better yet…

Nuclear plants can throttle down. But the economics of nuclear power make it prohibitive to satisfy peak demand from nuclear reactors. Even France relies on gas plants and power imports to satisfy its electricity demand peaks, despite being a net electricity exporter over the course of a full year. The CAISO grid had an average power demand of 25 GW in 2019 but a peak demand of 46 GW (Table 1.1): http://www.caiso.com…

This is true not because of any shortcomings of nuclear, but by virtue of the fact that demand is not uniform. The same need to have excess capacity during non peak hours in order to have sufficient capacity during peak hours exists with fossil fuels. If peak demand is 130 GW and trough demand is 100GW you need 130 GW of capacity.

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

#168

Post by recuter »

hutzlibu wrote: post #147
recuter wrote: post #141

Earlier quoted context omitted.

"Dirt grass and a goat get you a LEED point - does the dirt grass and a goat make it work better? No! But you do feel better about yourself! Dirt is not insulation it's just freaking dirt" - https://en.wikipedia.org/wiki/Joseph_Lstiburek ( https://youtu.be/iHBYvqr2_io?t=2224 ) Gotta love greenwashing. A real forward thinker would also start a second startup simultaneously to undo the damage green roofs will cause dow…

I don't really like having to watch some youtube video, to get the counterpoint, all presented in a non friendly way. So do you have some facts, you want to share, why green roofs, a method for example used in scandinavia for a long time, is bad, if done right? Because you quote ... is not a smart one. Because dirt is definitley insulation. And soild is more than dirt btw.

I didn't mean anything in an unfriendly way. The quote is not dumb but it needs a lot of context I suppose that might be missing.. definitely the key point is "if done right".

I can't really condense the video for you, the guy in it does throw in a bunch of jokes from the perspective of a frustrated Canadian building science guy that might put you off but his information is great.

My best attempt at a condensed parable: I once found myself driving around with a very environmentally minded person and she refused to turn the AC on in her car but cranked open the window instead.

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

#169

Post by Armisael16 »

vmception wrote: post #123
pjc50 wrote: post #109

Earlier quoted context omitted.

Very few things have a return that quickly. In an era of 25 year mortgages, a 10 year payback is very reasonable.

Let's make these one of the few things that have a return that quickly.

That’s unlikely to ever happen; if it’s that cheap to produce electricity the utilities will have long since switched over and cut rates.

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

#170

Post by jugg1es »

This 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.
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