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Photovoltaics are substantially more efficient at turning sunlight into energy than photosynthesis. Rooftops do seem like a good candidate, but they have high

by wffurr 3y ago

Photovoltaics are substantially more efficient at turning sunlight into energy than photosynthesis. Rooftops do seem like a good candidate, but they have high labor costs for installation; not all roofs are built to take extra load; and they don't have the same scale as using acres of flat ground. I agree something seems unsatisfactory about the situation, but the reality of solar energy is getting the installation and supporting infrastructure costs as low as possible for large scale deployment.

decremental 3y ago
[dead]
AnthonyMouse 3y ago
> Photovoltaics are substantially more efficient at turning sunlight into energy than photosynthesis. Humans can't eat electricity though. > Rooftops do seem like a good candidate, but they have high labor costs for installation This seems like the problem to solve. For example, can you make some kind of modular panels simple enough to install for the property owner to do it themselves?
- idiotsecant 3y ago
  Rooftops are terrible places to put solar because they're on roofs. They require support, it increases maintainance costs for both the roof and the solar, and you need to have a bunch of infrustructure coexist with everything else the building is doing. Putting your panels on some dirt somewhere just requires some open dirt, of which we have a lot.
  - AnthonyMouse 3y ago
    Roofs are commonly in direct sunlight and empty. The surface is otherwise-wasted space which isn't good for much else. Open dirt is valuable because you can actually use it for something -- buildings, parks, agriculture, nature, etc. Buildings also tend to be situated near where electricity is used, reducing distribution costs. Especially if the alternative is to use the "open dirt" which is inexpensive, and correspondingly far away from population centers and requiring long-distance transmission. The maintenance cost is the problem to be solved. What you want is the ability for any rando with some basic tools the median homeowner has in their garage to be able to do the whole install in less than an hour, and be able to take them off and put them back on again in a similar amount of time in the event that you have to e.g. replace the roof.
    - idiotsecant 3y ago
      Open dirt is hardly valuable. We barely use any of it. It might be hard to intuit this is you spend most of your life in a city but the vast majority of land is unused, and a great deal of it is not terribly ecologically important. The many multiples of cost that attaching solar to the vanishingly small percentage of land we use is absolutely without question not worth the tradeoff.
      - AnthonyMouse 3y ago
        > Open dirt is hardly valuable. We barely use any of it. We nearly use all of it. The large majority of land in the continental US is used for agriculture and forestry. The land which is actually unused is in places like Nevada (the desert) and Alaska (permafrost). But there isn't really anything like that within a thousand miles of New York City. What is within a thousand miles of New York City is about 80% of the population of the US. > The many multiples of cost that attaching solar to the vanishingly small percentage of land we use is absolutely without question not worth the tradeoff. I see a lot of houses with solar panels on the roof, so evidently plenty of people think you're wrong, and as far as I'm aware they're not generally losing money. Expecting property owners to not do something in their financial interest -- pay money for solar panels, but less than they'd pay to the power company in the alternative -- seems like a weird thing to expect people to do. Large-scale generators are going to have trouble competing with that because they not only have to pay for the land (which may be cheap but it isn't free), they also have to pass through the cost to cover the distribution grid, whereas the homeowner only has to cover the difference in the installation costs between installing them on a roof and installing them on the ground, and then consumes the power themselves. And since this is clearly not only going to happen but already is happening, it makes sense to optimize the cost by making them easier to install.
  - jjav 3y ago
    No, roofs are the optimal place for solar because roofs are almost entirely wasted square footage (with the exception of the occasional antenna or exhaust vent). It is unused space that won't ever be used for anything, so filling all roofs with solar is ideal. As a bonus, they shade the actual roof. Open space ("dirt") is potentially useful for tons of other uses, no point in wasting it on panels that can go on the roof.
    - wffurr 3y ago
      We as a species are surely not short on open space. "Wasting it" in this case means the cheapest possible utility-scale solar energy installations, which is what we need to not just displace all fossil fuel usage but lead to a future of energy abundance rather than shortage.
      - jjav 3y ago
        > We as a species are surely not short on open space. There is a lot of unused open space way out far from cities. Electricity suffers from transmission losses, the more distance the more loss. The ideal place to put that panel is on my roof which is just a few dozen feet from where it's going to be consumed. That'll be a lot more efficient than having it 500 miles away in the desert.
        idiotsecant 3y ago
        A lot? Try a few percent. That's what bad transmission costs. Compare that to the additional costs in actual dollars and cents of multiplying your install costs by the number of installs required to achieve the required mwh. Its not even close.
        AnthonyMouse 3y ago
        Generation is 44% of an electric utility's operating costs: https://www.eia.gov/electricity/annual/html/epa_08_03.html https://www.eia.gov/electricity/annual/html/epa_08_03.html You're confusing the line item called "transmission" with the concept that the electric utility's entire operations expense is in service of operating the power grid and all of that gets included in the price per kWh whenever you buy power through the grid. A property owner who is installing their own solar and consuming the output themselves can avoid the other 56% of those costs. Which is well worth a one-time labor cost.
- EasyMark 3y ago
  In modern life electricity is critical for modern farming methods and food processing so I'm unsure where you're going with that part of your comment.
  - AnthonyMouse 3y ago
    If all you wanted was the electricity for the farm you could put the solar panels on the farmhouse and the barn. Comparing the efficiency of photosynthesis and photovoltaics is meaningless because they don't yield the same product.
    - defrost 3y ago
      Sounds very much like a keyboard farmer comment. In the real world, farm power is required for heavy equipment, battery banks, powering cell phone repeating towers on leased out land and entire paddocks are dedicated to mounting panels. These can be ground panels (saves on mounting) or high mounts (to allow for tilt and track | animals to graze underneath) See, for example: 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...
      - AnthonyMouse 3y ago
        Agriculture has low energy density. <2% of US energy consumption despite being more than half of the land in the continental US.
acyou 3y ago
Sunlight is already energy. Surely you mean something to do with energy conversion? It's upsetting watching millions of acres of fertile land becoming essentially salted with heavy metals. What is really effective at energy conversion is solar to thermal. We're talking 70% efficient, zero heavy metals. If we were to put panels on buildings, it's a crying shame that they are not zero heavy metal, vastly more efficient solar thermal.
- dalyons 3y ago
  What? How is the land getting “salted”? The small trace amounts of metals in the solar panels stay inside the solar panels. They don’t melt into the soil. And you just take the panels away when they reach EOL.
  - acyou 3y ago
    There are certainly not "small trace amounts" of heavy metals in solar panels. If they sit there for 100 years, the heavy metals will not stay put. Have you visited the rust belt? When cars reach EOL, they often don't get "taken away". Difficult to accept that people don't understand that bringing heavy metals up and putting them everywhere will ultimately result in leaching into groundwater and contamination of food and water.
citrin_ru 3y ago
Malls/supermarkets in the US have relatively large parking spaces, why not cover them with solar panels first before taking over agricultural land? It would be more expensive than putting panels in an open field but should not be (much) more expensive than rooftop solar. It would allow to kill two birds with one stone - cars will be heated less under the canopy of solar panels.
- wffurr 3y ago
  Because it's more expensive. Utility-scale solar is looking for the cheapest possible $ per MW. If you want solar car parks, warehouse roofs, etc. there need to be feed-in tariffs to encourage building owners to do it.

by wffurr 3y ago

decremental 3y ago

[dead]

AnthonyMouse 3y ago

> Photovoltaics are substantially more efficient at turning sunlight into energy than photosynthesis. Humans can't eat electricity though. > Rooftops do seem like a good candidate, but they have high labor costs for installation This seems like the problem to solve. For example, can you make some kind of modular panels simple enough to install for the property owner to do it themselves?

idiotsecant 3y ago
Rooftops are terrible places to put solar because they're on roofs. They require support, it increases maintainance costs for both the roof and the solar, and you need to have a bunch of infrustructure coexist with everything else the building is doing. Putting your panels on some dirt somewhere just requires some open dirt, of which we have a lot.
- AnthonyMouse 3y ago
  Roofs are commonly in direct sunlight and empty. The surface is otherwise-wasted space which isn't good for much else. Open dirt is valuable because you can actually use it for something -- buildings, parks, agriculture, nature, etc. Buildings also tend to be situated near where electricity is used, reducing distribution costs. Especially if the alternative is to use the "open dirt" which is inexpensive, and correspondingly far away from population centers and requiring long-distance transmission. The maintenance cost is the problem to be solved. What you want is the ability for any rando with some basic tools the median homeowner has in their garage to be able to do the whole install in less than an hour, and be able to take them off and put them back on again in a similar amount of time in the event that you have to e.g. replace the roof.
  - idiotsecant 3y ago
    Open dirt is hardly valuable. We barely use any of it. It might be hard to intuit this is you spend most of your life in a city but the vast majority of land is unused, and a great deal of it is not terribly ecologically important. The many multiples of cost that attaching solar to the vanishingly small percentage of land we use is absolutely without question not worth the tradeoff.
    - AnthonyMouse 3y ago
      > Open dirt is hardly valuable. We barely use any of it. We nearly use all of it. The large majority of land in the continental US is used for agriculture and forestry. The land which is actually unused is in places like Nevada (the desert) and Alaska (permafrost). But there isn't really anything like that within a thousand miles of New York City. What is within a thousand miles of New York City is about 80% of the population of the US. > The many multiples of cost that attaching solar to the vanishingly small percentage of land we use is absolutely without question not worth the tradeoff. I see a lot of houses with solar panels on the roof, so evidently plenty of people think you're wrong, and as far as I'm aware they're not generally losing money. Expecting property owners to not do something in their financial interest -- pay money for solar panels, but less than they'd pay to the power company in the alternative -- seems like a weird thing to expect people to do. Large-scale generators are going to have trouble competing with that because they not only have to pay for the land (which may be cheap but it isn't free), they also have to pass through the cost to cover the distribution grid, whereas the homeowner only has to cover the difference in the installation costs between installing them on a roof and installing them on the ground, and then consumes the power themselves. And since this is clearly not only going to happen but already is happening, it makes sense to optimize the cost by making them easier to install.
- jjav 3y ago
  No, roofs are the optimal place for solar because roofs are almost entirely wasted square footage (with the exception of the occasional antenna or exhaust vent). It is unused space that won't ever be used for anything, so filling all roofs with solar is ideal. As a bonus, they shade the actual roof. Open space ("dirt") is potentially useful for tons of other uses, no point in wasting it on panels that can go on the roof.
  - wffurr 3y ago
    We as a species are surely not short on open space. "Wasting it" in this case means the cheapest possible utility-scale solar energy installations, which is what we need to not just displace all fossil fuel usage but lead to a future of energy abundance rather than shortage.
    - jjav 3y ago
      > We as a species are surely not short on open space. There is a lot of unused open space way out far from cities. Electricity suffers from transmission losses, the more distance the more loss. The ideal place to put that panel is on my roof which is just a few dozen feet from where it's going to be consumed. That'll be a lot more efficient than having it 500 miles away in the desert.
      - idiotsecant 3y ago
        A lot? Try a few percent. That's what bad transmission costs. Compare that to the additional costs in actual dollars and cents of multiplying your install costs by the number of installs required to achieve the required mwh. Its not even close.
        AnthonyMouse 3y ago
        Generation is 44% of an electric utility's operating costs: https://www.eia.gov/electricity/annual/html/epa_08_03.html https://www.eia.gov/electricity/annual/html/epa_08_03.html You're confusing the line item called "transmission" with the concept that the electric utility's entire operations expense is in service of operating the power grid and all of that gets included in the price per kWh whenever you buy power through the grid. A property owner who is installing their own solar and consuming the output themselves can avoid the other 56% of those costs. Which is well worth a one-time labor cost.
EasyMark 3y ago
In modern life electricity is critical for modern farming methods and food processing so I'm unsure where you're going with that part of your comment.
- AnthonyMouse 3y ago
  If all you wanted was the electricity for the farm you could put the solar panels on the farmhouse and the barn. Comparing the efficiency of photosynthesis and photovoltaics is meaningless because they don't yield the same product.
  - defrost 3y ago
    Sounds very much like a keyboard farmer comment. In the real world, farm power is required for heavy equipment, battery banks, powering cell phone repeating towers on leased out land and entire paddocks are dedicated to mounting panels. These can be ground panels (saves on mounting) or high mounts (to allow for tilt and track | animals to graze underneath) See, for example: 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...
    - AnthonyMouse 3y ago
      Agriculture has low energy density. <2% of US energy consumption despite being more than half of the land in the continental US.

acyou 3y ago

Sunlight is already energy. Surely you mean something to do with energy conversion? It's upsetting watching millions of acres of fertile land becoming essentially salted with heavy metals. What is really effective at energy conversion is solar to thermal. We're talking 70% efficient, zero heavy metals. If we were to put panels on buildings, it's a crying shame that they are not zero heavy metal, vastly more efficient solar thermal.

dalyons 3y ago
What? How is the land getting “salted”? The small trace amounts of metals in the solar panels stay inside the solar panels. They don’t melt into the soil. And you just take the panels away when they reach EOL.
- acyou 3y ago
  There are certainly not "small trace amounts" of heavy metals in solar panels. If they sit there for 100 years, the heavy metals will not stay put. Have you visited the rust belt? When cars reach EOL, they often don't get "taken away". Difficult to accept that people don't understand that bringing heavy metals up and putting them everywhere will ultimately result in leaching into groundwater and contamination of food and water.

citrin_ru 3y ago

Malls/supermarkets in the US have relatively large parking spaces, why not cover them with solar panels first before taking over agricultural land? It would be more expensive than putting panels in an open field but should not be (much) more expensive than rooftop solar. It would allow to kill two birds with one stone - cars will be heated less under the canopy of solar panels.

wffurr 3y ago
Because it's more expensive. Utility-scale solar is looking for the cheapest possible $ per MW. If you want solar car parks, warehouse roofs, etc. there need to be feed-in tariffs to encourage building owners to do it.