5 ms·

> People have done the math. Land availability is not a bottleneck on this. I'm sorry but people have done the maths and consider land availability to be a maj

by brmgb 6y ago

> People have done the math. Land availability is not a bottleneck on this. I'm sorry but people have done the maths and consider land availability to be a major bottleneck for solar and wind (with the fact that it is intermittent). That's like one of the first point put forward in the Bill Gates'book everyone seems to be talking about nowadays. Offshore capacity means it's harder to estimate the ceiling for wind production but it doesn't seem to be the slam dunk you would like it to be especially when you consider that the world consumption will likely keep rising for decades as population grows and more and more get access to electricity. > If nuclear was the slam dunk you're assuming, China would just do it. China has scaled down its nuclear investment under the dual pressure of significant public opposition after the Fukushima disaster and a need to tighten its investments (China's debt situation is tricky to manage and the CCP absolutely wants to avoid a situation comparable to what happened to Japan in the 90s). China isn't the be all end all regarding energy policies.

kragen 6y ago
I don't understand why people are screaming at each other to do the math, or referring to others who have hypothetically done the math, or accusing each other of lying, or claiming that solar panels are made out of rare earth elements (!!), instead of just doing the math themselves here in the comments. It's almost as if they're more interested in being vicious to one another than in finding out the truth. World marketed energy consumption is 18 terawatts. Terrestrial insolation is 127 petawatts (below the atmosphere. Also my earlier figure here of 41 was incorrect.) Common PV solar panels are 16–24% efficient, so the total PV resource is 20–30 petawatts, 1000–1500 times larger. Utility-scale PV capacity factors (relative to the nominal 1000 W/m² peak insolation) in polar countries like Germany and the Netherlands are around 10%, which is abysmal, but in California they average 29%, and in more equatorial countries with less clouds they're presumably higher (I'd be grateful for more data here but I've only found what look like trustworthy, transparent operational reports containing this data from the US, Germany, and the Netherlands). Let's look at three cases here: a worst case, a best case, and a plausible case. In the worst case, all our solar panels are in terrible places like Germany with a 10% capacity factor, and they're all cheap 16%-efficient panels, and also the world marketed energy consumption doubles to 36 terawatts. In that case they take up 2.3 million square kilometers, a circle of 850 km radius. This is about 13% of the area of Russia or 17% of the area of Siberia. You have: double 18 TW / 10% / (1000 W/m^2) / 16% You want: km^2 * 2250000 / 4.4444444e-07 You have: double 18 TW / 10% / (1000 W/m^2) / 16% You want: circlearea 846284.38 m You have: double 18 TW / 10% / (1000 W/m^2) / 16% You want: 17125191 km^2 * 0.1313854 / 7.611196 In the best case, world marketed energy consumption goes down slightly to 16 terawatts, all the panels are using expensive 24%-efficient monocrystalline solar cells, and they're all located in places like the Atacama, the Gobi, and the Sahara, so there are no clouds, it virtually never rains, and the sun is nearly directly overhead, so their capacity factor is even better than California's. Say, 35%. In that case we only need 190 thousand km², a 246-km-radius circle. This is a little bigger than Tunisia or about 36% of the area of Yemen: You have: 16 TW / 35% / (1000 W/m^2) / 24% You want: km^2 * 190476.19 / 5.25e-06 You have: 16 TW / 35% / (1000 W/m^2) / 24% You want: circlearea 246232.52 m You have: 16 TW / 35% / (1000 W/m^2) / 24% You want: 527968 km^2 * 0.36077223 / 2.771832 For the plausible case, let's figure on a nominal capacity factor of 25% (like Arizona), 20% growth in usage to 22 terawatts, and low-cost 16%-efficient panels, even though PERC is starting to see mass adoption. This is 550 thousand km², a circle of 420 km radius (groovy, mang!), about 80% of the area of Texas: You have: 22 TW / 25% / (1000 W/m^2) / 16% You want: km^2 * 550000 / 1.8181818e-06 You have: 22 TW / 25% / (1000 W/m^2) / 16% You want: circlearea 418414.19 m You have: 22 TW / 25% / (1000 W/m^2) / 16% You want: 695662 km^2 * 0.79061383 / 1.26484 This 18 TW figure isn't just electricity; it includes human energy use in forms like jet fuel, diesel for trucks, bunker fuel, and oil for heating, but not firewood, livestock feed, or human food. And it's world marketed energy consumption, not just the US: that Texas-sized area would be powering Australia, China, Brazil, and Madagascar too. So, no, land availability is not a bottleneck on this. I'd like to challenge you all collectively to step up your epistemological game a bit from the profoundly disappointing "I'm sorry but" level you seem to be stuck at. It's just not that hard. There's a lot of concrete, verifiable information out there, and it's easy to do the calculations. Then if you're wrong you'll change your mind to agree with the people who were right, and if you were right the other people who will wrong will change their minds to agree with you. Either way you won't have anything to fight about. Unless they're just looking for an excuse to be vicious. You should be ashamed of yourselves. You do not become a hacker by attacking people and repeating talking points you don't understand. You become a hacker by figuring things out. Calculemus.
- macspoofing 6y ago
  >or claiming that solar panels are made out of rare earth elements (!!) I responded to so many messages and I tried my best to always refer to 'solar and wind' in tandem (because without wind as a kind of a complement, solar is completely not feasible), and the one message where I got sloppy and referenced only solar panel with a passing reference to 'rare earth minerals' and that's the only aspect that is picked up. OK. Let's move past this. Let's say neither windmills nor solar panels use any rare earth minerals, just for argument's sake. That's not really true, certainly not for windmills, but let's say that it's true ... because that's not the salient point here. Re: your calculations. You forgot that Solar and Wind need to be overprovisioned because they not only need to collect enough energy for right now, but also enough to store to bridge the daily, seasonal and inter-annual intermittency. There are no batteries capable of that, but if there were, you have to add that in there somewhere as well because that road leads to more land-use and more ecosystem stress. >This is 550 thousand km², a circle of 420 km radius (groovy, mang!), about 80% of the area of Texas That is an insane amount of land - I don't understand why so many are so flippant on this point. After all, you're placing high-tech devices in that area. Devices that need maintenance. Devices that break-down. Devices that need to be decommissioned and landfilled and then replaced. If you're covering an area of 550 thousand km² with panels, there is an equivalent volume that you need to dig up somewhere else, ship and process, and of course you then have to landfill, and you have to do that every few decades forever. Right? Are we OK with that? Is the environment OK with that? After all, this is on top of everything thing else we will be doing, like agriculture and transportation. And this is for TODAY. The world is projected to grow to around 10-12 billion. At the same time, per capita energy use will continue to increase. >You should be ashamed of yourselves This kind of emotional appeal is not conducive to good discourse. I made an argument how I see things today. For all the talk about wind and solar being the energy of the future, I don't actually see where solar and wind are actually powering a modern economy. I see a lot hope and handwaving. I see Germany building pipelines to ship natural from Russia and signing multi-decade contracts with that nation while being held up as a model nation. Why not invest in solar and wind deployment instead, especially since Russia is a geopolitical adversary in many ways? I don't understand how the intermittency gap is bridged given that there is no battery technology capable of storing excess generation enough to last a minimum of a a few days, but more likely several weeks. And finally, I see a world that while growing in population to around 10-12 billion, will exponentially increase per capita energy requirements at the same time. I look at all that, I shudder at the amount of solar and wind collectors that will be required to manufacture and deploy and the stress it will put on existing ecosystems. I don't understand why so many pretend this is a solved-problem, especially since we have an energy-dense alternative, with no engineering challenges to solve and with decades of experience.

by brmgb 6y ago

kragen 6y ago

I don't understand why people are screaming at each other to do the math, or referring to others who have hypothetically done the math, or accusing each other of lying, or claiming that solar panels are made out of rare earth elements (!!), instead of just doing the math themselves here in the comments. It's almost as if they're more interested in being vicious to one another than in finding out the truth. World marketed energy consumption is 18 terawatts. Terrestrial insolation is 127 petawatts (below the atmosphere. Also my earlier figure here of 41 was incorrect.) Common PV solar panels are 16–24% efficient, so the total PV resource is 20–30 petawatts, 1000–1500 times larger. Utility-scale PV capacity factors (relative to the nominal 1000 W/m² peak insolation) in polar countries like Germany and the Netherlands are around 10%, which is abysmal, but in California they average 29%, and in more equatorial countries with less clouds they're presumably higher (I'd be grateful for more data here but I've only found what look like trustworthy, transparent operational reports containing this data from the US, Germany, and the Netherlands). Let's look at three cases here: a worst case, a best case, and a plausible case. In the worst case, all our solar panels are in terrible places like Germany with a 10% capacity factor, and they're all cheap 16%-efficient panels, and also the world marketed energy consumption doubles to 36 terawatts. In that case they take up 2.3 million square kilometers, a circle of 850 km radius. This is about 13% of the area of Russia or 17% of the area of Siberia. You have: double 18 TW / 10% / (1000 W/m^2) / 16% You want: km^2 * 2250000 / 4.4444444e-07 You have: double 18 TW / 10% / (1000 W/m^2) / 16% You want: circlearea 846284.38 m You have: double 18 TW / 10% / (1000 W/m^2) / 16% You want: 17125191 km^2 * 0.1313854 / 7.611196 In the best case, world marketed energy consumption goes down slightly to 16 terawatts, all the panels are using expensive 24%-efficient monocrystalline solar cells, and they're all located in places like the Atacama, the Gobi, and the Sahara, so there are no clouds, it virtually never rains, and the sun is nearly directly overhead, so their capacity factor is even better than California's. Say, 35%. In that case we only need 190 thousand km², a 246-km-radius circle. This is a little bigger than Tunisia or about 36% of the area of Yemen: You have: 16 TW / 35% / (1000 W/m^2) / 24% You want: km^2 * 190476.19 / 5.25e-06 You have: 16 TW / 35% / (1000 W/m^2) / 24% You want: circlearea 246232.52 m You have: 16 TW / 35% / (1000 W/m^2) / 24% You want: 527968 km^2 * 0.36077223 / 2.771832 For the plausible case, let's figure on a nominal capacity factor of 25% (like Arizona), 20% growth in usage to 22 terawatts, and low-cost 16%-efficient panels, even though PERC is starting to see mass adoption. This is 550 thousand km², a circle of 420 km radius (groovy, mang!), about 80% of the area of Texas: You have: 22 TW / 25% / (1000 W/m^2) / 16% You want: km^2 * 550000 / 1.8181818e-06 You have: 22 TW / 25% / (1000 W/m^2) / 16% You want: circlearea 418414.19 m You have: 22 TW / 25% / (1000 W/m^2) / 16% You want: 695662 km^2 * 0.79061383 / 1.26484 This 18 TW figure isn't just electricity; it includes human energy use in forms like jet fuel, diesel for trucks, bunker fuel, and oil for heating, but not firewood, livestock feed, or human food. And it's world marketed energy consumption, not just the US: that Texas-sized area would be powering Australia, China, Brazil, and Madagascar too. So, no, land availability is not a bottleneck on this. I'd like to challenge you all collectively to step up your epistemological game a bit from the profoundly disappointing "I'm sorry but" level you seem to be stuck at. It's just not that hard. There's a lot of concrete, verifiable information out there, and it's easy to do the calculations. Then if you're wrong you'll change your mind to agree with the people who were right, and if you were right the other people who will wrong will change their minds to agree with you. Either way you won't have anything to fight about. Unless they're just looking for an excuse to be vicious. You should be ashamed of yourselves. You do not become a hacker by attacking people and repeating talking points you don't understand. You become a hacker by figuring things out. Calculemus.

macspoofing 6y ago
>or claiming that solar panels are made out of rare earth elements (!!) I responded to so many messages and I tried my best to always refer to 'solar and wind' in tandem (because without wind as a kind of a complement, solar is completely not feasible), and the one message where I got sloppy and referenced only solar panel with a passing reference to 'rare earth minerals' and that's the only aspect that is picked up. OK. Let's move past this. Let's say neither windmills nor solar panels use any rare earth minerals, just for argument's sake. That's not really true, certainly not for windmills, but let's say that it's true ... because that's not the salient point here. Re: your calculations. You forgot that Solar and Wind need to be overprovisioned because they not only need to collect enough energy for right now, but also enough to store to bridge the daily, seasonal and inter-annual intermittency. There are no batteries capable of that, but if there were, you have to add that in there somewhere as well because that road leads to more land-use and more ecosystem stress. >This is 550 thousand km², a circle of 420 km radius (groovy, mang!), about 80% of the area of Texas That is an insane amount of land - I don't understand why so many are so flippant on this point. After all, you're placing high-tech devices in that area. Devices that need maintenance. Devices that break-down. Devices that need to be decommissioned and landfilled and then replaced. If you're covering an area of 550 thousand km² with panels, there is an equivalent volume that you need to dig up somewhere else, ship and process, and of course you then have to landfill, and you have to do that every few decades forever. Right? Are we OK with that? Is the environment OK with that? After all, this is on top of everything thing else we will be doing, like agriculture and transportation. And this is for TODAY. The world is projected to grow to around 10-12 billion. At the same time, per capita energy use will continue to increase. >You should be ashamed of yourselves This kind of emotional appeal is not conducive to good discourse. I made an argument how I see things today. For all the talk about wind and solar being the energy of the future, I don't actually see where solar and wind are actually powering a modern economy. I see a lot hope and handwaving. I see Germany building pipelines to ship natural from Russia and signing multi-decade contracts with that nation while being held up as a model nation. Why not invest in solar and wind deployment instead, especially since Russia is a geopolitical adversary in many ways? I don't understand how the intermittency gap is bridged given that there is no battery technology capable of storing excess generation enough to last a minimum of a a few days, but more likely several weeks. And finally, I see a world that while growing in population to around 10-12 billion, will exponentially increase per capita energy requirements at the same time. I look at all that, I shudder at the amount of solar and wind collectors that will be required to manufacture and deploy and the stress it will put on existing ecosystems. I don't understand why so many pretend this is a solved-problem, especially since we have an energy-dense alternative, with no engineering challenges to solve and with decades of experience.