Seems to be pretty close though. Just running some numbers, typical UK year has 1000kWh/m2 of sunlight. A 21m^2 solar installation costs roughly 5000 pounds, and is around 18% efficient, hence it produces about 3780kWh/year and 56700kWh over a 15 year lifetime. So the total cost over the lifetime is 5000pounds/56700kWh or ~0.088pounds/kWh. Average electricity cost in UK is ~0.11pounds/kWh in 2017. If electricity price rises this seems like not such a bad deal. Am I missing something?
Who cares? If that's what it takes, let's go to Mars!
He wants to cut all sorts of science and research budgets, so he's obviously not in favor of public money being spend on science. In Trump's eyes science is a private enterprise thing, not a government thing.
So why does he want to go to Mars, and specifically why does he want to go during his presidency?
The answer is Ego.
Who cares? If that's what it takes, let's go to Mars!
He wants to be known as the President who got man to another planet. He wants the capital city on some long-in-the-future Mars to be called Trump Town.
He doesn't want to go to look for signs of life, he doesn't want to go to advance science, he doesn't want to go to see if there is any long-term investment strategy.
Who cares? If that's what it takes, let's go to Mars!
He wants to go for the ego-boost.
Who cares? If that's what it takes, let's go to Mars!
Only if you are willfully ignorant of context and history. Where did the "trend" come from?
Mainly from developments outside of coal that lead to cheaper oil and natural gas prices. That's mostly what's replacing coal. Unless we're talking about solar, then the trend started in the 1970's when panels started being manufactured. You can pretty cleanly follow the cost learning curve as supply chains became more developed, efficiency rose, and manufacturing became more streamlined. We really have engineers to thank for all of this and the DOE for some early stage work, but it certainly began far earlier than the Paris accord, which has had no impact on the slope of the solar cost learning curve. Go ahead, check.
These are development decisions made by state governments with decades of emphasis on heavy industry at lowest cost, and to the exclusion of every other priority.
Yes, that's right. They chose the cheapest option and it wasn't coal. Paris accord had nothing to do with it. That's exactly what I said.
The fact that China and India are acting now shows that there is an alternative which is cheaper and brings other benefits, those highlighted in the respective articles.
The fact that they are acting now reflects the shift in the cost of coal vs other energy sources. Again, thank an engineer.
Investigate and you can find direct links discussing the relationship with the Paris, but the basis in real physical improvements is more concrete demonstrating the benefits derived from it.
I can find no such direct links. If you have found them, please post a link. The "basis in real physical improvements" has been due to massive investment in infrastructure by corporations, consumers, and stakeholders. We can thank the NSF and DOE for providing seed funding, but essentially all of the new technology that's improved natural gas and solar tech has been thanks to talented engineers and privately invested funds. Don't get me wrong, this is a good thing. It shows that private citizens are not patient enough to rely on their government to fix every single problem.
Technology doesn't develop by itself, it requires careful cultivation with research funding which was made available due to the same pressures which led to the predecessor in Kyoto and eventually the Paris accord.
Research funding to be dispersed by the government... Yeah. Don't get me wrong, I'm all for government funding of research, but I'm pretty sure that dollars left in the pocket of private investors and companies like First Solar, Tesla, and Sunpower would be more productive than dollars offered up to the government. Also, keep in mind we've offered seed funding to green tech from a time that predates the Paris accord.
One could argue that these cancellations are merely the continuation of a previously existing trend of power moving away from coal. In fact, your China article doesn't mention Paris at all, and the India one specifically says they cancelled the plants before joining the accord. In all likelihood, these cancellations are more due to economic trends. Coal is not cheap anymore. Environmentalists love taking credit for market trends. See for example the solar learning curve, higher efficiency electronics, reductions in packaging waste, improvements in fuel economy for cars, etc etc. Every single one of these trends is first and foremost about improving profits and making a better product for consumers. Capitalism and clever engineers deserve the credit for these trends, not politicians.
The Paris climate accord took decades to achieve, and is valuable as the basis for further international cooperation to encourage industrial development without excessive pollution. In particular notice the cancellation of 104+ coal plants by China and India. 2C maximum as target, once achieve can be renewed with 1.5C, 1C, etc. as technology develops to achieve those goals.
Can we really credit the Paris accord with any of those accomplishments? The shift away from coal seems to be due to an increase in the levelized energy cost of electricity from coal. I suspect those economic forces have more to do with it than the Paris accord. This reminds me of the DOE's sunshot program which promised to lower the cost of solar energy and later took credit when massive investment into manufacturing technology and R&D from the industry drove down the module cost. I'm just saying, it's not safe to assume that correlation between a government program's goals and outcomes imply causation.
Yeah, that's right. The need for about a day's worth of energy storage is real. I told you how much energy that represents and made a valid comparison with our current manufacturing ability to illustrate how traditional batteries alone are probably not enough. I even linked a source backing up my assertions. Here it is again.
Feel free to counter with another source. This thread has gone on too long and I'm not getting suckered into replying any more, not unless you can produce some facts and/or science to back up your argument.
No, you were wrong, that's why you can't put up numbers or articles to back up your argument. My initial back of the envelope assumptions turned out to be rather close to what the models predict we'll need.
That [facts] is of course what I was asking for instead of your deliberately insane fantasy.
I gave you facts, it turns out they support my logical argument and not your baseless opinions.
According to this (http://www.powermag.com/update-whats-that-scrubber-going-to-cost/?pagenum=2) the capital cost of adding a scrubber is around $300/kW. According to this (https://www.eia.gov/outlooks/capitalcost/pdf/updated_capcost.pdf) the capital cost of a coal plant is around $3,000/kW. So the capital cost is ~10% of the overall cost is that right? Why is it so expensive to run?
Christ, no less than Rick Perry himself has admitted the US needs to stay in the Paris Accord. Even the most pro-oil of pro-oil politicians know full well the jig is up. Oil isn't coming back, and as the price falls away it's impact on the economy diminishes. Coal was the first because it's the most expensive and most obviously harmful, but it applies to all the fossil fuels.
What does the Paris Accord actually do to alter warming? Using the IPCC models, following all of the CO2 reductions set forth in the Paris Accord, the warming will be 0.1C less compared to business-as-usual by the year 2100. It's just a feel-good law so we can all pat ourselves on the back and act smug. I'm not saying this because I'm against renewable energy, I'm saying this because I believe we need much more aggressive targets and the Paris Accord is so weak that we may as well not have it. It's probably doing more harm than good if people are able to point to it as some great thing.
In the interest of presenting a more thorough picture, let me point out that modern coal plants are equipped with scrubbers that can remove SO2, mercury, thorium, etc from the smoke. Still, a lot (half?) of our coal power plants are not equipped with scrubbers. Not a coal shill, I just think that you've omitted a rather important factoid from your list.
"Graham says that the CSIRO modelling showed that at very high levels of wind and solar, a maximum of half a day’s average demand was needed for storage."
Looks like my order of magnitude approach was actually pretty close.
If you disagree, please offer something more than accusations of partisanship. I want facts. You keep saying you're an expert, well, present your numbers.
It's a back-of-the-envelope type of calculation dealing with orders of magnitude. The order of magnitude approach to looking at scientific problems is a time-honored tradition, it is in no way ridiculous. Here: https://en.wikipedia.org/wiki/...
Taken to task? How exactly have you taken me to task? You said I made a ridiculous example (I've explained now several times why it's not ridiculous) and have made no effort to back your position. It's getting pretty obvious to me that you either don't know as much about this subject as you claim or don't know how to defend your opinions.
What agenda? Using math to assess technology? Discussing specifics? Failing to see how anything I've seen can be construed as a political agenda.
At this point I'm suspicious that you're pulling my leg, I'm not sure how anyone could get so worked up over a post regarding battery vs hydrogen storage. However, if what I said was factually wrong and you are an expert, go ahead, convince me. Use facts. Use numbers. Put links, I'll read them. I'm not some partisan idiot like you apparently believe I am. So go for it, give me the benefit of your expert knowledge and experience.
A suggestion that batteries (or insert any other "green" technology you with to attack instead) are useless because they cannot single-handedly supply a days worth of electricity for a nation the size of the USA is not ridiculous and not a politically motivated move?
So you are calling me stupid or gullible as well?
WTF is it with this political luddite shit. Something doesn't have to be the "one true energy" that can do everything for it to be useful.
Relax for a minute, I'm afraid you're going to pop a vein. If you'll read my other posts in this topic, I think you'll find that I'm pretty positive with regard to "green" technology. I simply pointed out a potential advantage of hydrogen compared to batteries. I think you're getting offended over nothing.
Also ask a high schooler to tell you about electricity grids and time zones. Distributed generation capacity that can be turned on and off as required are vastly less lossy than any sort of storage, and since you have a grid the size of a continent that peaks are spread so storage isn't so necessary anyway. When New York needs power for an evening peak Texas isn't using a lot.
Instead of pretending you know everything, I suggest you read up on energy storage with regard to attaining high penetration of renewables. In every study I've read, the authors assert that we need much much more storage and that a variety of technologies work better than a single technology. Read my post again, the battery calculations I made were meant to display the scale of the problem and compare it to where we are today. It's pretty obvious that's what the intent was unless you're really trying to put words into my mouth.
Let me stress that I'm not at all offended by you branding me a "luddite" I think it's pretty funny actually. But how about instead of calling me names you go read up on energy storage and argue with facts?
Wow there, take it easy. This wasn't a political post, I'm simply discussing energy storage in the context of generating 100% of electricity from renewable sources and using algebra with order-of-magnitude thinking to show the magnitude of the solution needed. In any case, I'd like to know exactly why you believe my example is "utterly ridiculous."
It's not exactly clear how much storage would be needed to achieve 100% renewable energy. The more storage we have, the less generation capacity we need for cloudy days or low-wind days when each power source produces less energy. Conversely, the more excess capacity we have, the less storage is needed because it power could be transmitted over long distances from places with excess capacity to places with non-ideal weather conditions.
The mass of the atmosphere is 5.15E18 kg, 20% of which is oxygen, or ~1E18 kg. A day's worth of grid storage for the US is ~11TWh. Hydrogen has an energy density of 33.3 kWh/kg. So 11TWh is 3.3E8 kg of hydrogen. Hydrogen is 1/16 the mass of oxygen, so an equivalent mass of oxygen would be 5.29E9kg, however one molecule of hydrogen is produced per 1/2 molecule of oxygen in water splitting, so the mass of oxygen generated would be half that, 2.64E9kg. So to make enough hydrogen to store a day's worth of electricity for the US, we'd have to increase the O2 concentration of our atmosphere by 2.64E9/1E18 = 2.64E-9 (0.000000264%).
I think we'll be OK. Also, keep in mind that cars consume oxygen yet we generally don't die from lack of oxygen when standing by a busy intersection.
Well, we have to solve the storage issue before renewables can take over anyway. Batteries are still a long way from being viable for grid-scale storage. One day's worth of energy in the US (which we would want to store due to the intermittent nature of renewable sources) is around 11TWh. Take for example Tesla's GW battery plant that will make something approaching ~35GWh/year worth of battery storage. At that rate it would take 11TWh/(0.035TWh/year) = 314 years to produce a day's worth of grid storage in batteries. Hydrogen is energy stored in chemical bonds, so hydrogen storage is in some ways an easier problem to solve than making countless batteries.
A couple years ago I'd have agreed with you, but a lot has changed.
Toyota unveiled a (admittedly very expensive) hydrogen-powered car that goes >300 miles on a charge and takes 5 min to refuel. Toyota, the largest auto manufacturer in the world, is probably not doing this as an empty gesture. They've announced they'll almost eliminate ICE cars from their lineup by 2050 and have yet to release an all-electric car (just plugin hybrids). They're working with Shell to provide fueling stations, of which there are >80 in Japan and 25 in CA right now, promising 160 in Japan within a couple years.
Hydrogen can be produced via electrolysis of water or salt water from any source of electricity, including intermittent sources like renewables. The efficiency of electrolysis is very high today, approaching 90%.
Yes, they are a threat. However, I doubt they could get their subs anywhere near America. Those old noisy subs would be detected and destroyed.
They are a threat because they could easily bomb Seol and kill millions with the flick of a switch. They have lots of missiles and dug-in defenses right next to the DMZ, which is also riddled with huge tunnels for transporting armaments and troops. If they attacked Seol it would result in a massive bloodbath, America would step in, China would fight back to keep their buffer state and it could spark WWIII. China doesn't want WWIII, nor does the US. They are working to tone things down (hopefully somehow remove Kim in the process) so that they can keep a buffer state between China and South Korea, a US ally.
For those saying "ignore DRPK" you are ignoring the danger. If the regime gets deliverable nukes they will blackmail all countries surrounding them for money, food, resources and could then actually become a real international power. If you think they won't do it, remember how sane and rational Japan is, yet they justified the attack on Pearl Harbor because we wouldn't sell them fuel or steel.
Slashdot Mirror
Seems to be pretty close though. Just running some numbers, typical UK year has 1000kWh/m2 of sunlight. A 21m^2 solar installation costs roughly 5000 pounds, and is around 18% efficient, hence it produces about 3780kWh/year and 56700kWh over a 15 year lifetime. So the total cost over the lifetime is 5000pounds/56700kWh or ~0.088pounds/kWh. Average electricity cost in UK is ~0.11pounds/kWh in 2017. If electricity price rises this seems like not such a bad deal. Am I missing something?
http://solargis.com/assets/graphic/free-map/GHI/Solargis-United-Kingdom-GHI-solar-resource-map-en.png
http://www.theecoexperts.co.uk/how-much-do-solar-panels-cost-uk
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/604131/QEP_Q416.pdf
I have a suspicion this is Ego vs Science.
Who cares? If that's what it takes, let's go to Mars!
He wants to cut all sorts of science and research budgets, so he's obviously not in favor of public money being spend on science. In Trump's eyes science is a private enterprise thing, not a government thing.
So why does he want to go to Mars, and specifically why does he want to go during his presidency?
The answer is Ego.
Who cares? If that's what it takes, let's go to Mars!
He wants to be known as the President who got man to another planet. He wants the capital city on some long-in-the-future Mars to be called Trump Town.
He doesn't want to go to look for signs of life, he doesn't want to go to advance science, he doesn't want to go to see if there is any long-term investment strategy.
Who cares? If that's what it takes, let's go to Mars!
He wants to go for the ego-boost.
Who cares? If that's what it takes, let's go to Mars!
STOP USING GOOGLE. They're evil, screw 'em. Already switched to their competitors for everything.
Only if you are willfully ignorant of context and history. Where did the "trend" come from?
Mainly from developments outside of coal that lead to cheaper oil and natural gas prices. That's mostly what's replacing coal. Unless we're talking about solar, then the trend started in the 1970's when panels started being manufactured. You can pretty cleanly follow the cost learning curve as supply chains became more developed, efficiency rose, and manufacturing became more streamlined. We really have engineers to thank for all of this and the DOE for some early stage work, but it certainly began far earlier than the Paris accord, which has had no impact on the slope of the solar cost learning curve. Go ahead, check.
These are development decisions made by state governments with decades of emphasis on heavy industry at lowest cost, and to the exclusion of every other priority.
Yes, that's right. They chose the cheapest option and it wasn't coal. Paris accord had nothing to do with it. That's exactly what I said.
The fact that China and India are acting now shows that there is an alternative which is cheaper and brings other benefits, those highlighted in the respective articles.
The fact that they are acting now reflects the shift in the cost of coal vs other energy sources. Again, thank an engineer.
Investigate and you can find direct links discussing the relationship with the Paris, but the basis in real physical improvements is more concrete demonstrating the benefits derived from it.
I can find no such direct links. If you have found them, please post a link. The "basis in real physical improvements" has been due to massive investment in infrastructure by corporations, consumers, and stakeholders. We can thank the NSF and DOE for providing seed funding, but essentially all of the new technology that's improved natural gas and solar tech has been thanks to talented engineers and privately invested funds. Don't get me wrong, this is a good thing. It shows that private citizens are not patient enough to rely on their government to fix every single problem.
Technology doesn't develop by itself, it requires careful cultivation with research funding which was made available due to the same pressures which led to the predecessor in Kyoto and eventually the Paris accord.
Research funding to be dispersed by the government... Yeah. Don't get me wrong, I'm all for government funding of research, but I'm pretty sure that dollars left in the pocket of private investors and companies like First Solar, Tesla, and Sunpower would be more productive than dollars offered up to the government. Also, keep in mind we've offered seed funding to green tech from a time that predates the Paris accord.
One could argue that these cancellations are merely the continuation of a previously existing trend of power moving away from coal. In fact, your China article doesn't mention Paris at all, and the India one specifically says they cancelled the plants before joining the accord. In all likelihood, these cancellations are more due to economic trends. Coal is not cheap anymore. Environmentalists love taking credit for market trends. See for example the solar learning curve, higher efficiency electronics, reductions in packaging waste, improvements in fuel economy for cars, etc etc. Every single one of these trends is first and foremost about improving profits and making a better product for consumers. Capitalism and clever engineers deserve the credit for these trends, not politicians.
http://reneweconomy.com.au/muc...
That's carbon capture, I believe we were talking about sulfur and mercury.
The Paris climate accord took decades to achieve, and is valuable as the basis for further international cooperation to encourage industrial development without excessive pollution. In particular notice the cancellation of 104+ coal plants by China and India. 2C maximum as target, once achieve can be renewed with 1.5C, 1C, etc. as technology develops to achieve those goals.
Can we really credit the Paris accord with any of those accomplishments? The shift away from coal seems to be due to an increase in the levelized energy cost of electricity from coal. I suspect those economic forces have more to do with it than the Paris accord. This reminds me of the DOE's sunshot program which promised to lower the cost of solar energy and later took credit when massive investment into manufacturing technology and R&D from the industry drove down the module cost. I'm just saying, it's not safe to assume that correlation between a government program's goals and outcomes imply causation.
Yeah, that's right. The need for about a day's worth of energy storage is real. I told you how much energy that represents and made a valid comparison with our current manufacturing ability to illustrate how traditional batteries alone are probably not enough. I even linked a source backing up my assertions. Here it is again.
http://reneweconomy.com.au/much-storage-needed-solar-wind-powered-grid-47605/
Feel free to counter with another source. This thread has gone on too long and I'm not getting suckered into replying any more, not unless you can produce some facts and/or science to back up your argument.
No, you were wrong, that's why you can't put up numbers or articles to back up your argument. My initial back of the envelope assumptions turned out to be rather close to what the models predict we'll need.
That [facts] is of course what I was asking for instead of your deliberately insane fantasy.
I gave you facts, it turns out they support my logical argument and not your baseless opinions.
According to this (http://www.powermag.com/update-whats-that-scrubber-going-to-cost/?pagenum=2) the capital cost of adding a scrubber is around $300/kW. According to this (https://www.eia.gov/outlooks/capitalcost/pdf/updated_capcost.pdf) the capital cost of a coal plant is around $3,000/kW. So the capital cost is ~10% of the overall cost is that right? Why is it so expensive to run?
Christ, no less than Rick Perry himself has admitted the US needs to stay in the Paris Accord. Even the most pro-oil of pro-oil politicians know full well the jig is up. Oil isn't coming back, and as the price falls away it's impact on the economy diminishes. Coal was the first because it's the most expensive and most obviously harmful, but it applies to all the fossil fuels.
What does the Paris Accord actually do to alter warming? Using the IPCC models, following all of the CO2 reductions set forth in the Paris Accord, the warming will be 0.1C less compared to business-as-usual by the year 2100. It's just a feel-good law so we can all pat ourselves on the back and act smug. I'm not saying this because I'm against renewable energy, I'm saying this because I believe we need much more aggressive targets and the Paris Accord is so weak that we may as well not have it. It's probably doing more harm than good if people are able to point to it as some great thing.
http://www.cnsnews.com/news/article/barbara-hollingsworth/climatologist-despite-hype-paris-climate-accord-doesnt-really-do
In the interest of presenting a more thorough picture, let me point out that modern coal plants are equipped with scrubbers that can remove SO2, mercury, thorium, etc from the smoke. Still, a lot (half?) of our coal power plants are not equipped with scrubbers. Not a coal shill, I just think that you've omitted a rather important factoid from your list.
Here: http://reneweconomy.com.au/muc...
"Graham says that the CSIRO modelling showed that at very high levels of wind and solar, a maximum of half a day’s average demand was needed for storage."
Looks like my order of magnitude approach was actually pretty close.
If you disagree, please offer something more than accusations of partisanship. I want facts. You keep saying you're an expert, well, present your numbers.
It's a back-of-the-envelope type of calculation dealing with orders of magnitude. The order of magnitude approach to looking at scientific problems is a time-honored tradition, it is in no way ridiculous. Here: https://en.wikipedia.org/wiki/...
Taken to task? How exactly have you taken me to task? You said I made a ridiculous example (I've explained now several times why it's not ridiculous) and have made no effort to back your position. It's getting pretty obvious to me that you either don't know as much about this subject as you claim or don't know how to defend your opinions.
What agenda? Using math to assess technology? Discussing specifics? Failing to see how anything I've seen can be construed as a political agenda.
Sources like the BBC are already very good. Yes, they screw up sometimes, but they fix it and 99% of the time are factually accurate and impartial.
citation needed
We don't really need more than that, what we need is a way to flag up fake news and opinion marketed as news.
Ah, the good ol' truth by popular acceptance approach.
Completely on batteries? I don't think it'll happen for reasons stated above. Still waiting for that expert analysis of yours.
At this point I'm suspicious that you're pulling my leg, I'm not sure how anyone could get so worked up over a post regarding battery vs hydrogen storage. However, if what I said was factually wrong and you are an expert, go ahead, convince me. Use facts. Use numbers. Put links, I'll read them. I'm not some partisan idiot like you apparently believe I am. So go for it, give me the benefit of your expert knowledge and experience.
Salt water works just as well as fresh water.
A suggestion that batteries (or insert any other "green" technology you with to attack instead) are useless because they cannot single-handedly supply a days worth of electricity for a nation the size of the USA is not ridiculous and not a politically motivated move? So you are calling me stupid or gullible as well? WTF is it with this political luddite shit. Something doesn't have to be the "one true energy" that can do everything for it to be useful.
Relax for a minute, I'm afraid you're going to pop a vein. If you'll read my other posts in this topic, I think you'll find that I'm pretty positive with regard to "green" technology. I simply pointed out a potential advantage of hydrogen compared to batteries. I think you're getting offended over nothing.
Also ask a high schooler to tell you about electricity grids and time zones. Distributed generation capacity that can be turned on and off as required are vastly less lossy than any sort of storage, and since you have a grid the size of a continent that peaks are spread so storage isn't so necessary anyway. When New York needs power for an evening peak Texas isn't using a lot.
Instead of pretending you know everything, I suggest you read up on energy storage with regard to attaining high penetration of renewables. In every study I've read, the authors assert that we need much much more storage and that a variety of technologies work better than a single technology. Read my post again, the battery calculations I made were meant to display the scale of the problem and compare it to where we are today. It's pretty obvious that's what the intent was unless you're really trying to put words into my mouth.
Let me stress that I'm not at all offended by you branding me a "luddite" I think it's pretty funny actually. But how about instead of calling me names you go read up on energy storage and argue with facts?
Wow there, take it easy. This wasn't a political post, I'm simply discussing energy storage in the context of generating 100% of electricity from renewable sources and using algebra with order-of-magnitude thinking to show the magnitude of the solution needed. In any case, I'd like to know exactly why you believe my example is "utterly ridiculous."
It's not exactly clear how much storage would be needed to achieve 100% renewable energy. The more storage we have, the less generation capacity we need for cloudy days or low-wind days when each power source produces less energy. Conversely, the more excess capacity we have, the less storage is needed because it power could be transmitted over long distances from places with excess capacity to places with non-ideal weather conditions.
OK, let's do some algebra.
The mass of the atmosphere is 5.15E18 kg, 20% of which is oxygen, or ~1E18 kg. A day's worth of grid storage for the US is ~11TWh. Hydrogen has an energy density of 33.3 kWh/kg. So 11TWh is 3.3E8 kg of hydrogen. Hydrogen is 1/16 the mass of oxygen, so an equivalent mass of oxygen would be 5.29E9kg, however one molecule of hydrogen is produced per 1/2 molecule of oxygen in water splitting, so the mass of oxygen generated would be half that, 2.64E9kg. So to make enough hydrogen to store a day's worth of electricity for the US, we'd have to increase the O2 concentration of our atmosphere by 2.64E9/1E18 = 2.64E-9 (0.000000264%).
I think we'll be OK. Also, keep in mind that cars consume oxygen yet we generally don't die from lack of oxygen when standing by a busy intersection.
Well, we have to solve the storage issue before renewables can take over anyway. Batteries are still a long way from being viable for grid-scale storage. One day's worth of energy in the US (which we would want to store due to the intermittent nature of renewable sources) is around 11TWh. Take for example Tesla's GW battery plant that will make something approaching ~35GWh/year worth of battery storage. At that rate it would take 11TWh/(0.035TWh/year) = 314 years to produce a day's worth of grid storage in batteries. Hydrogen is energy stored in chemical bonds, so hydrogen storage is in some ways an easier problem to solve than making countless batteries.
A couple years ago I'd have agreed with you, but a lot has changed.
Toyota unveiled a (admittedly very expensive) hydrogen-powered car that goes >300 miles on a charge and takes 5 min to refuel. Toyota, the largest auto manufacturer in the world, is probably not doing this as an empty gesture. They've announced they'll almost eliminate ICE cars from their lineup by 2050 and have yet to release an all-electric car (just plugin hybrids). They're working with Shell to provide fueling stations, of which there are >80 in Japan and 25 in CA right now, promising 160 in Japan within a couple years.
source: https://ssl.toyota.com/mirai/f...
source: https://www.bloomberg.com/news...
Hydrogen can be produced via electrolysis of water or salt water from any source of electricity, including intermittent sources like renewables. The efficiency of electrolysis is very high today, approaching 90%.
source: http://www.h2fc-fair.com/hm14/...
It's not a perfect answer, but it's looking a lot less ridiculous than it did a few years ago.
Yes, they are a threat. However, I doubt they could get their subs anywhere near America. Those old noisy subs would be detected and destroyed.
They are a threat because they could easily bomb Seol and kill millions with the flick of a switch. They have lots of missiles and dug-in defenses right next to the DMZ, which is also riddled with huge tunnels for transporting armaments and troops. If they attacked Seol it would result in a massive bloodbath, America would step in, China would fight back to keep their buffer state and it could spark WWIII. China doesn't want WWIII, nor does the US. They are working to tone things down (hopefully somehow remove Kim in the process) so that they can keep a buffer state between China and South Korea, a US ally.
For those saying "ignore DRPK" you are ignoring the danger. If the regime gets deliverable nukes they will blackmail all countries surrounding them for money, food, resources and could then actually become a real international power. If you think they won't do it, remember how sane and rational Japan is, yet they justified the attack on Pearl Harbor because we wouldn't sell them fuel or steel.