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I don't really understand the advantage of rooftop solar over just putting the same number of solar panels in a field somewhere. Id think it would be a lot che

I don't really understand the advantage of rooftop solar over just putting the same number of solar panels in a field somewhere. Id think it would be a lot cheaper to install the panels in one-place then having to distribute them to a bunch of differently shaped and oriented roof tops, and cheaper to have a few large inverters instead of a bunch of small ones.

ben_w 4y ago
I suspect it's political. Technically, there's also distribution losses (just because we can do HVDC, 5% losses per 1000km, doesn't mean we want to spend the money for it); but I think it's mainly to avoid politicians decrying prime farmland being used for a thing they don't think looks as pretty as sheep grazing on grassy rolling hills.
debesyla 4y ago
Depends on the country - some fields are better used for construction, farming or just being left as a natural habitat. And the roofs can't be used for any of those three things. So... But it depends on the country. Some countries have a whole lot of "low use" fields, like natural or industrial deserts. Others don't.
looping__lui 4y ago
1) you would use up less nature as no new land is repurposed 2) you produce it in close proximity to where its used
rhplus 4y ago
Rooftop solar can help cool roofs/attics by a small amount.
epistasis 4y ago
Electrical transmission and distribution costs dwarf the cost of solar generation, 1x-5x the cost of solar generation, and you have to beef all that up for utility scale solar. Also, the interconnection queues for attaching your project to the grid are getting astronomically long now, and this is one of the biggest impediments to new renewable generation. One of the most valuable assets of a coal generation sites is its connection to the grid; all the rest of facility might have negative value, but the value of the connection can offset all that. Utility scale solar is great, until you consider how to connect it up to load.
- pyrale 4y ago
  I'm honestly surprised about transmission and distribution costs dwarfing other costs. In my country, it's about 30% of power cost, and power generation costs here are pretty cheap, considering they've been amortized for a while now. Are you working in an area with a low consumer density? > Also, the interconnection queues for attaching your project to the grid are getting astronomically long now, and this is one of the biggest impediments to new renewable generation. Yeah, that's unsurprising. Power Grids are not something that adapts fast to topological change.
- simplicio 4y ago
  Those costs are paid either way though, aren't they? At least, it seems that close to 100% of houses with roof-top solar are still grid connected, so I don't really see how they'd achieve any savings related to transmission and distribution.
  - epistasis 4y ago
    With no behind-the-meter solar, the peak for T&D is during midday. With behind-the-meter solar, this peak is capped, and if the local solar is allowed to power the rest of the distribution nod with net metering, then that means less transmission too. T&D must be sized for the peak, so lots of residential solar means a lower peak and lower T&D costs. Of course, this goes agains the utility narrative, because they can't admit that or else their regulators might have to allow such residential net metering. Instead, utilities try to frame the argument that solar customers are taking away from their neighbors or somehow not paying their fair share. But when evaluated as a whole system, using massive distributed solar along with utility scale is far cheaper than building it all utility scale due to the T&D savings.
dpierce9 4y ago
A decent reason to have rooftop solar is that it reduces daytime distribution node demand which reduces wholesale commodity prices and takes pressure of the electricity delivery infrastructure (wires, transformers, etc). These are real costs we all pay in terms of capacity and distribution.
Kon5ole 4y ago
>I don't really understand the advantage of rooftop solar I see many advantages, among them: - You don't have to find new land; roofs are ideal for solar. - No need for a huge project, financing, bureaucracy. Done in weeks. - Costs are low and spread over tons of landowners instead of requiring fundraising and negotiations - You can have literally thousands of workers busy creating solar power at the same time. - You get geographic spread and will be less affected by clouds over your central solar plant. - No single point of failure - Less need for large and expensive long-distance powerlines Rooftop solar puts the power to solve a problem in the hands of the people experiencing the problem and eliminates the need for a megaproject. This has turned out to be really powerful, rooftop solar has grown extremely quickly.
olddustytrail 4y ago
An interesting selection of replies you got. Here's one that I'm sure Americans can appreciate: If the panels are in a field somewhere, an energy company gets the money. If the panels are on my roof, I get the money.
- hamandcheese 4y ago
  The American would of course insist that the energy company has a right to reach into their wallet.
marcosdumay 4y ago
You don't have greedy third parties exploiting monopolies over the electricity you consume. By all means, it should be much cheaper to make large solar farm on some suitable place and buy the electricity from there. The fact that it isn't can't be explained by technical factors.

ben_w 4y ago

I suspect it's political. Technically, there's also distribution losses (just because we can do HVDC, 5% losses per 1000km, doesn't mean we want to spend the money for it); but I think it's mainly to avoid politicians decrying prime farmland being used for a thing they don't think looks as pretty as sheep grazing on grassy rolling hills.

debesyla 4y ago

Depends on the country - some fields are better used for construction, farming or just being left as a natural habitat. And the roofs can't be used for any of those three things. So... But it depends on the country. Some countries have a whole lot of "low use" fields, like natural or industrial deserts. Others don't.

looping__lui 4y ago

1) you would use up less nature as no new land is repurposed 2) you produce it in close proximity to where its used

rhplus 4y ago

Rooftop solar can help cool roofs/attics by a small amount.

epistasis 4y ago

Electrical transmission and distribution costs dwarf the cost of solar generation, 1x-5x the cost of solar generation, and you have to beef all that up for utility scale solar. Also, the interconnection queues for attaching your project to the grid are getting astronomically long now, and this is one of the biggest impediments to new renewable generation. One of the most valuable assets of a coal generation sites is its connection to the grid; all the rest of facility might have negative value, but the value of the connection can offset all that. Utility scale solar is great, until you consider how to connect it up to load.

pyrale 4y ago
I'm honestly surprised about transmission and distribution costs dwarfing other costs. In my country, it's about 30% of power cost, and power generation costs here are pretty cheap, considering they've been amortized for a while now. Are you working in an area with a low consumer density? > Also, the interconnection queues for attaching your project to the grid are getting astronomically long now, and this is one of the biggest impediments to new renewable generation. Yeah, that's unsurprising. Power Grids are not something that adapts fast to topological change.
simplicio 4y ago
Those costs are paid either way though, aren't they? At least, it seems that close to 100% of houses with roof-top solar are still grid connected, so I don't really see how they'd achieve any savings related to transmission and distribution.
- epistasis 4y ago
  With no behind-the-meter solar, the peak for T&D is during midday. With behind-the-meter solar, this peak is capped, and if the local solar is allowed to power the rest of the distribution nod with net metering, then that means less transmission too. T&D must be sized for the peak, so lots of residential solar means a lower peak and lower T&D costs. Of course, this goes agains the utility narrative, because they can't admit that or else their regulators might have to allow such residential net metering. Instead, utilities try to frame the argument that solar customers are taking away from their neighbors or somehow not paying their fair share. But when evaluated as a whole system, using massive distributed solar along with utility scale is far cheaper than building it all utility scale due to the T&D savings.

dpierce9 4y ago

A decent reason to have rooftop solar is that it reduces daytime distribution node demand which reduces wholesale commodity prices and takes pressure of the electricity delivery infrastructure (wires, transformers, etc). These are real costs we all pay in terms of capacity and distribution.

Kon5ole 4y ago

>I don't really understand the advantage of rooftop solar I see many advantages, among them: - You don't have to find new land; roofs are ideal for solar. - No need for a huge project, financing, bureaucracy. Done in weeks. - Costs are low and spread over tons of landowners instead of requiring fundraising and negotiations - You can have literally thousands of workers busy creating solar power at the same time. - You get geographic spread and will be less affected by clouds over your central solar plant. - No single point of failure - Less need for large and expensive long-distance powerlines Rooftop solar puts the power to solve a problem in the hands of the people experiencing the problem and eliminates the need for a megaproject. This has turned out to be really powerful, rooftop solar has grown extremely quickly.

olddustytrail 4y ago

An interesting selection of replies you got. Here's one that I'm sure Americans can appreciate: If the panels are in a field somewhere, an energy company gets the money. If the panels are on my roof, I get the money.

hamandcheese 4y ago
The American would of course insist that the energy company has a right to reach into their wallet.

marcosdumay 4y ago

You don't have greedy third parties exploiting monopolies over the electricity you consume. By all means, it should be much cheaper to make large solar farm on some suitable place and buy the electricity from there. The fact that it isn't can't be explained by technical factors.