171–180 of 228 posts
Earlier quoted context omitted.
If it's a poor location for photovoltaics, it's exactly as a poor for photosynthesis
In most places photosynthesis is limited by (1) the availability of water and (2) the availability of bio-available Nitrogen. Sunlight is less limiting by far.
https://en.wikipedia.org/wiki/Gulf_Stream
The Gulf Stream has more energy than all the world’s rivers combined.
https://www.ebsco.com/research-starters/power-and-energy/oce...
Denmark is a poor location for solar. They are pretty far north and don't have a lot of sunny days that are good for solar generation. When they do, those peaks drive energy prices negative. From the article: Over the next 10 years, the official expectation is a very large rise in the amount of solar produced. But that kind of clashes with the reality on the ground – they can’t make money
I don't understand why energy production must be profitable.
If energy production in Denmark would not by profitable, the Government of Denmark could nationalize the energy production, or push households to install more solar and sell the energy at predefined price to the grid, or increase taxes to pay out subsidies to make energy production profitable again for private investors. Or combine all this approaches.
Earlier quoted context omitted.
> Are you saying it's cloudy for four months straight? No. But it's cloudy most of the time for four month straight (in average there's only 200 hours of sun between November and February in Copenhagen. Yes, you read it right, that's not even 2 hours per day in average!). > A detailed chart would be nice but a good starting point to imagine is 60-70 days that average 50% solar power and the rest of the year is full s…
> That's an insane assumption! [...] load factor No no no no, that line has nothing to do with load factor. I'm talking about half the kilowatts for the house coming from solar, and half coming from the grid. > Just check the live data There's no way those panels are optimally angled and out of shade if they're making that little. Are those panels installed in rows on the ground? Rows that are pretty close to each ot…
Assuming consumption isn't correlated with sun hours, these are equivalent unless you over-panel. With a load factor of 5%, you need to over-panel 10x to achieve 50% of your energy supply (in fact it's more complex than this and you'll need even more of that but that's an OK simplifying assumption).
> There's no way those panels are optimally angled and out of shade if they're making that little
Those are commercial solar farms, optimally angled under the constraint that the cost must be reasonable.
> A thought experiment: You have one big solar panel mounted very high, with a multi-axis aiming system that points it directly at the sun.
Do you have an idea of how much it would cost?! With Materials + installation + maintenance, such a mechanism would dwarf the price of the panels. There's a reason we don't deploy those at scale in practice …
> Do you think the amount of power you can make is going to be that far off a linear relationship with the number of hours of daylight?
In a country where 80% of the winter is cloudy, it's going to be very far, yes. The 10% power happening right now is because it's cloudy (light clouds, no rain, but still). It peaked at 40% in recent days with proper sun, but it happened only a handful of times in the entire winter.
Earlier quoted context omitted.
New England is Spain in terms of latitude. Americans tend to forget how far north Europe is compared to the US.
We have solar in Finland as well, like everyone else. Yes, it's useless in winter. Yes, the expansion has slowed down, because there is no storage and limited export options. The Nordic power market is a mess, and it's not because solar doesn't work in winter but because the grid needs massive investments on all levels and nobody wants to be left holding the bill for it. Electrification? Sure, I'll buy an EV when the…
Data from 2025.
Nuclear 32 TWh, Wind 22 TWh, Hydro 12 TWh, Solar 1 TWh.
Earlier quoted context omitted.
Does it still work out if you take into account the insurance premiums for a cargo ship stacked with batteries? Can't imagine the fire hazard is pretty.
Wait until you hear what other stuff gets shipped
How does that work out in cost per kWh? Profitable operation anywhere close?
Crisis relief (as suggested by jmward01 here) may be another matter, but setting up the ability to do this on scale, and maintaining it, can't be anything like easy economically.
Earlier quoted context omitted.
> That's an insane assumption! [...] load factor No no no no, that line has nothing to do with load factor. I'm talking about half the kilowatts for the house coming from solar, and half coming from the grid. > Just check the live data There's no way those panels are optimally angled and out of shade if they're making that little. Are those panels installed in rows on the ground? Rows that are pretty close to each ot…
> No no no no, that line has nothing to do with load factor. I'm talking about half the kilowatts for the house coming from solar, and half coming from the grid. Assuming consumption isn't correlated with sun hours, these are equivalent unless you over-panel. With a load factor of 5%, you need to over-panel 10x to achieve 50% of your energy supply (in fact it's more complex than this and you'll need even more of that…
I don't think so? If your Nevada desert load factor is 25%, then we're talking about it dropping to 12% or something. Unless I'm not understanding the way you're using those numbers.
> unless you over-panel
Some amount of over-paneling would be perfectly fine here. Not 10x, agreed.
> Those are commercial solar farms, optimally angled under the constraint that the cost must be reasonable.
They're optimized mostly for total power output, which affects things. And they don't have a free house to be mounted on.
They're also not trying very hard to avoid shade. The commercial plant has to buy land for every panel, while a house has much more land than panels. That's a massive difference. When the sun is near the horizon, you want your rows of panels to be very far apart or at different heights. Which means:
A commercial solar plant like one pictured in the article will have each panel shade most of the next row's panel when the sun is very low. To stop this effect, you need to put the rows super far apart, or put them at different heights (like on a roof). This means a home install could have 4x as much light hit each panel in the depths of winter.
> Do you have an idea of how much it would cost?!
It's a thought experiment. Don't worry about the cost of tracking. Because it turns out, a 60 degree angle that completely avoids shade is just as good. The key is avoiding shade. Commercial plants do not avoid shade. Rooftop installs do avoid shade (they won't be quite as tilted, but they'll still have a huge advantage). If you have a nice big yard you can also avoid shade.
> The 10% load factor happening right now is because it's cloudy (light clouds, no rain, but still). It peaked at 40% in recent days with proper sun, but it happened only a handful of times in the entire winter.
I think you didn't go through the full implications of this.
It's mid-april. If it's cloudy this far from the depths of winter, that means needing more panels is much more of a year-round thing. Which means a household array needs to be bigger as a baseline. Which means it can tolerate more losses in the winter.
The thing that would make 90% unreasonable is the difference between winter and non-winter power output. If spring and/or fall also require lots of panels, then 90% gets more realistic because expanding the system saves money for more months of the year.
Earlier quoted context omitted.
We have solar in Finland as well, like everyone else. Yes, it's useless in winter. Yes, the expansion has slowed down, because there is no storage and limited export options. The Nordic power market is a mess, and it's not because solar doesn't work in winter but because the grid needs massive investments on all levels and nobody wants to be left holding the bill for it. Electrification? Sure, I'll buy an EV when the…
Solar power in Finland is really not important. Data from 2025. Nuclear 32 TWh, Wind 22 TWh, Hydro 12 TWh, Solar 1 TWh. https://ourworldindata.org/profile/energy/finland
Obviously solar will be decreasingly useful as you get further to the pole, but the Nordics aren't worse off than Alaska or Canada in that regard, and both do solar to some extent AFAIK.
Earlier quoted context omitted.
> No no no no, that line has nothing to do with load factor. I'm talking about half the kilowatts for the house coming from solar, and half coming from the grid. Assuming consumption isn't correlated with sun hours, these are equivalent unless you over-panel. With a load factor of 5%, you need to over-panel 10x to achieve 50% of your energy supply (in fact it's more complex than this and you'll need even more of that…
> These are equivalent unless you over-panel. I don't think so? If your Nevada desert load factor is 25%, then we're talking about it dropping to 12% or something. Unless I'm not understanding the way you're using those numbers. > unless you over-panel Some amount of over-paneling would be perfectly fine here. Not 10x, agreed. > Those are commercial solar farms, optimally angled under the constraint that the cost mus…
Rooftop solar is more expensive than solar farms. There's nothing free in putting a solar panel on a roof. (Which is a pity because it means that if your country doesn't have a desert, the economically optimal way of installing solar panels is deforestation, but that's the world we live in…).
> Because it turns out, a 60 degree angle that completely avoids shade is just as good
Not at all…
The sun isn't just going up and down you know, it also circles from east to West…
> They're also not trying very hard to avoid shade. […] When the sun is near the horizon, you want your rows of panels to be very far apart or at different heights.
> A commercial solar plant like one pictured in the article will have each panel shade most of the next row's panel when the sun is very low.
I'm sorry but this is utter bullshit. The commercial plants do avoid shade as much as possible because shade destroy efficiency (one cell being shaded criples the output of the entire row…).
They don't care about shade when the sun is low because when the sun is low the incidence angle is terrible in the first place. You want your average panel directed south (or north in the southern hemisphere), when the sun is low, it's going to be completely in the East or completely in the West, and you care about the cosine of your incidence angle, which means the output is going to be near zero even without any shade whatsoever.
> It's mid-april. If it's cloudy this far from the depths of winter, that means needing more panels is much more of a year-round thing.
Of course clouds are a year-round thing, what do you think… But sunny days are still much more frequent in summer.
> Which means a household array needs to be bigger as a baseline
Yes, but that's over-paneling…
> The thing that would make 90% unreasonable is the difference between winter and non-winter power output. If spring and/or fall also require lots of panels, then 90% gets more realistic because expanding the system saves money for more months of the year.
Sigh… Over-paneling 10x isn't going to be more worth it just because in spring and winter you need 5x. That's a nonsensical argument…
I'm sorry but you obviously have no idea about any of these things, I can only invite you to document yourself better at this point, because you're just pilling up crazy takes on top of crazy takes here.
Earlier quoted context omitted.
> These are equivalent unless you over-panel. I don't think so? If your Nevada desert load factor is 25%, then we're talking about it dropping to 12% or something. Unless I'm not understanding the way you're using those numbers. > unless you over-panel Some amount of over-paneling would be perfectly fine here. Not 10x, agreed. > Those are commercial solar farms, optimally angled under the constraint that the cost mus…
> And they don't have a free house to be mounted on. Rooftop solar is more expensive than solar farms. There's nothing free in putting a solar panel on a roof. (Which is a pity because it means that if your country doesn't have a desert, the economically optimal way of installing solar panels is deforestation, but that's the world we live in…). > Because it turns out, a 60 degree angle that completely avoids shade is…
> The sun isn't just going up and down you know it also circles from east to West…
Over a narrow range in winter. You get good coverage from pointing very south and avoiding shade.
> I'm sorry but this is utter bullshit. The commercial plants do avoid shade as much as possible because shade destroy efficiency
They do not avoid it "as much as possible". The panels are shading each other in that very photo, and that photo wasn't taken at the crack of dawn.
It's basic trigonometry. Narrow spacing needs the sun to get pretty high before shading stops. A roof install never shades itself. The difference matters.
> They don't care about shade when the sun is low because when the sun is low the incidence angle is terrible in the first place.
Wrong answer. Those panels are plenty tilted for low incidence sunlight. The ones in front will make plenty of power in the winter. But the ones behind them won't.
The limiter is the price of land. If land was free I guarantee they would spread them out more.
And a home install doesn't have this specific issue.
> Yes, but that's over-paneling…
No it's not! If you need it for most of the year it's not "over"!
> Sigh… Over-paneling 10x isn't going to be more worth it just because in spring and winter you need 5x. That's a nonsensical argument…
If you need 5x or more for half the year, you calculated "x" wrong. Your math is what's nonsense here.