There is a good overview in today’s Guardian regarding the status of affairs with respect to electricity storage technologies:
The challenge for green energy: how to store excess electricity
So with grid parity now looming, finding ways to store millions of watts of excess electricity for times when the wind doesn’t blow and the sun doesn’t shine is the new Holy Grail. And there are signs that this goal — the day when large-scale energy storage becomes practical and cost-effective — might be within reach, as well. Some technologies that can store sizeable amounts of intermittent power are already deployed. Others, including at least a few with great promise, lie somewhere over the technological horizon.
I have used the “Holy Grail” term several times to describe cost effective storage of electricity. I have also given “energy storage” as an answer when people ask what we should be focusing more attention on. While this article is perhaps overly optimistic, it provides a good overview of what people are working on.
I also read a good article last night on renewable energy in India:
A Growing India Sets Goal to Harness Renewable Energy
Despite the deepening energy crisis, renewable energy, predominantly wind and biomass, make up 3 percent of India’s total electricity production. Solar energy is not even a fraction of that, though India receives abundant sunshine throughout the year.
But India hopes to move from near-zero to 20,000 megawatts of solar electricity by 2020, as part of the National Action Plan on Climate Change. Announced in June 2008, the plan is a structured response to combat global warming and part of a proposal India intends to pitch at a climate change summit in Copenhagen this December.
If there is one thing the world desperately needs, it is for India and China to embrace renewable energy as their economies grow. If they do not, I think their growth is going to encounter fierce economic resistance as their growing energy needs start to put serious pressure on oil prices.
I read that India had made no provision in their budget for this major effort. Waiting with hand out apparently.
During the monsoon season which some parts of the country have once for three months and others have twice a year there is a lot less sun available.
Right now it seems they are in the do nothing mode. I lived there for fifteen years and observed all this type thing in action before.
From the article: "Housed in a giant warehouse, the 1,300-metric ton battery is larger than a football field, and can crank out 40 million watts of power. Still, the Fairbanks battery provides only enough electricity for about 12,000 residents for seven minutes."
Yes, we do seem to keep going over the same ground.
One's expectations for a Gruaniad article are necessarily low — but it is hard to see how a writer can get so excited about the potential for lithium batteries, and not enquire into the world supply of that metal. And while we are in our green dream, let's remember that lithium is an intense poison, with a half life of forever.
As usual, the enthusiasts miss the main point. When better men than they eventually do develop practical large scale energy storage devices (as they will), the immediate effect will be to improve the efficiency of conventional fossil & (especially)nuclear power stations, since they will be able to run at their most efficient steady rate. That in turn will lower the price that the wind factories have to meet to achieve grid parity.
And let's never forget that we already have a word for large scale energy storage devices — they are called "explosives".
The human race has limited time to avoid a catastropic change. Let's not waste it chasing the end of some unphysical, tax-subsidized rainbow.
Can't say I'm impressed with that Guardian article. Overly optimistic is putting it mildly.
"there are signs that this goal — the day when large-scale energy storage becomes practical and cost-effective — might be within reach, as well."
And yet they give no costs per power rating or energy capacity for the battery in Fairbanks, or any flow batteries, or that still terribly expensive platinum-requiring electrolysis system from MIT's Nocera. They imply that getting lithium ion batteries down the the price of lead acid batteries would be a magnificent breakthrough, and yet they don't note that even lead acid batteries are way too expensive for utility scale energy storage. 40 MW in Fairbanks sounds nice, but at only 7 minutes of capacity, it's only good for bridging the time between when a utility generator goes down, and they start up one to take its load. It's not going to bridge the night time for solar plants, or long lulls in the wind.
Try this if you want a better comparison of the electricity storage technologies.
http://www.prod.sandia.gov/cgi-bin/techlib/access-control.pl/2007/074253.pdf
Greentech Media oftens has some interesting info not found elsewhere.
This speaks to the cheapest form of energy storage: Compressed Air
http://www.greentechmedia.com/articles/read/what-is-the-cheapest-energy-storage-of-them-all/
My daughter did an internship in India with an NGO two summers ago. One of the things her group worked on was installing solar panels on the roofs of houses in villages off the grid. Many rural Indian homeowners do that to charge banks of 12v auto batteries they then use for, lights, TV and radio at night.
Why not mini-nuke plants? Just take them off-line when not needed, bring back as needed.
Besides, have you seen how much land solar power and windmills require?
I think the greenest answer is nukes,
KInu: Why the doomsterism about "running out of time."? Seems like we are developing ever longer timelines away from doom.
takchess: "This speaks to the cheapest form of energy storage: Compressed Air"
There is one cheaper method of story energy ~ gravity.
Imagine if you will: Cuckoo clock weights on a very large scale.
For example, suppose every wind turbine had next to it a tall steel tripod with a pulley at the top. When the wind was blowing, an electric motor would winch a many-thousand ton block of concrete to the top of the tripod.
When the wind stopped, the block of concrete would begin to descend, its weight turning the electric motor (now in generator mode) pumping energy into the grid as though the wind were still blowing.
"Try this if you want a better comparison of the electricity storage technologies.
http://www.prod.sandia.gov/cgi-bin/techlib/access-control.pl/2007/074253.pdf"
I'd say Sandia doesn't have much imagination. They didn't even consider gravity storage using the cuckoo clock weight concept in their report.
Sandia's gravity stored-energy solution is pumped hydro, which is the second cheapest after CAES.
Gary Dikkers is a funny guy.
Here's another crazy story I read the other day. I guess a bunch of French engineers are proposing that Savonius "egg-beater" style rotors be installed in existing electrical transmission towers. That way the rotors could be hooked directly into the grid without long transmission lines and losses.
This would cut down on some of the land grabbin by windmills.
Same for solar, Put that stuff on roofs and cut out all that land grabbin', in the Mojave Desert.
John
“Why not mini-nuke plants? Just take them off-line when not needed, bring back as needed.”
Why not big nukes. If the O&M cost of nukes running at 90% CF is $20/MWh, then it would be $40/MWh at 45% CF. France uses nukes in load following along with hydroelectric. So far nukes and hydroelectric still make electricity long after the capital cost are amortized. EDF has announced that they intend to extend the operating period of their nuke plants based on US leadership.
EDF is also calling for a 20% rate hike.
Wendell,
Here's something that corresponds to your daughter's experience in India……….
Some 400 million people in India have no access to grid powered electricity.
———————————-
Solar Power Takes Off in Kenya
Source: East African Standard
"The expense and unreliability of electricity supply is fuelling East African interest in solar energy.
"In rural Kenya, where there is no electricity, solar systems have proven popular with small-scale businesses and farms, where it is used to power water pumps and lighting.
"Solar energy is cheap compared to electricity because, once the necessary equipment has been installed, there is no additional monthly charge.
"Additionally solar systems require little maintenance, owing to the lack of moving parts, and solar energy offers "a stable grid quality output without power fluctuations".
"Private company Solar World East Africa is set to launch "solar kits" that provide enough power for lighting, charging a mobile phone and operating an FM radio. These packs will cost 3,000 Kenyan shillings each (around US$47)."
John
Gary D,
I think the problem with the giant Cuckoo Clock is it is unsubstainable. Imagine the large areas of Bavarian Forests that would have to be stripped to build the thing. Not to mention the NIMBY concerns of the abutters who would have to hear the ear piercing Cuckoo on the hour.
Wendell,
Solar Powered Medical Clinic Will Save Lives in War Torn Iraq
In Iraq, where rolling blackouts and severe electricity restrictions plague the nation, a reliable power supply can mean the difference between life and death. Without it, important medical centers can't provide the necessary treatment to the wounded. So it was a stunning achievement for the American-Iraqi Multinational Force—and a great moment for solar power technology—when an Iraqi-led group designed and installed a photovoltaic cell system on a Baghdad medical clinic.
This has far greater significance than most ordinary solar projects: this solar power will literally help save the lives of Iraqi civilians and Coalition soldiers………
Solar power is an ideal technology for sun-drenched Iraq. Mahdi Johnny, the (Iraqi)electrical engineer who was the advisor for the installation of the project, said,
"In Baghdad we have, on average, 10 hours of sunlight on a daily basis. What we are getting out of these rechargeable batteries is about 72 hours of power for every 10 hours of sun.”
The clinic now operates 24 hours a day, and can now keep vital medications and medical supplies requiring constant refrigeration onsite. And since the clinic serves around 500,000 people in the area, these advances mark a huge step forward in medical services for Iraqis and help further the urban renewal of Baghdad."
for complete article/pictures >>>>
http://www.treehugger.com/files/2009/01/solar-powered-medical-clinic-iraq.php
John
“Some 400 million people in India have no access to grid powered electricity.”
This likely means that they do not have drink water that meets the US standards.
That is more people in than in the US in a country that is one third the size. I lived 7 miles down a dirt road in Appalachian Mountains and had electricity. So much for poverty in America.
Thanks to the leadership of President Bush, western companies are lining up to build nukes in India. The US did build some in India many years ago but we stopped helping after they decided to build nuke weapons. I do not know the history of India well enough to why they built nuke weapons. I suppose Pakistan built nuke weapons because India did. Maybe Iran has a nuke weapons program because Iraq did.
One of the thing that we demonstrated in Iraq is that nuke weapons are obsolete as a tactical weapon. One smart bomb per Russian tank is all that is needed.
I am very cynical about NGO that help nuke weapons counties with solar panels when there is a long list of countries living at peace with their neighbors and could use a few solar panels.
Better managing the electricity they have is also needed. With respect to irrigation, better electricity pricing would couple to sustainable aquifer management, as these are also being depleted.
The Socio-Ecology of Groundwater in India
Power Subsidies: A Reality Check on Subsidizing Power for Irrigation in India
Groundwater:Towards a aquifer management framework
Kit P. ~ "I am very cynical about NGO that help nuke weapons counties with solar panels when there is a long list of countries living at peace with their neighbors and could use a few solar panels."
I doubt much those poor people in rural India far off the grid care much of your cynicism when some NGO helps them electrify their houses.
I also doubt those poor rural people had any input into India's decision to go nuclear.
The truth is that India is the future, and the effort by those NGOs will pay huge dividends — we should be grateful they do it.
Carbon capture and storage (CCS) is regarded as a good transition solution in Europe, eventually the goal must be energy generated
from clean/renewable sources. There are several projects underway right now, heavily sponsored by the EU.
Emerging economies should take their responsability and start investing in CCS as well as renewable energy.
“NGOs will pay huge dividends — we should be grateful they do it.”
No Wendell, you should grateful that that your child had an interesting experience and came home safe.
There is no technical reason that every person in the world can not enjoy my living standard. Clean water and the electricity they need. I can not ensure that all will be rich enough to fly around the world for a group hug. You will have to check with Boeing for the possibility of transcontinental air travel.
How to make a rich person in the US feel green? Install PV on their big house and run around town in pious. How to to keep the poor living in poverty? Give them PV.
"Why the doomsterism about "running out of time."? Seems like we are developing ever longer timelines away from doom."
Hardest thing to predict is the timeline — but there is no disputing that fossil fuels are finite. And there is no disputing that global demand for power will keep increasing as long as our fellow human beings are able to climb out of poverty. Those trends are going to crash into each other at some point. Reasonable people can disagree whether we are there now, or whether it happens in 1-5-10-25 years. But the fossil crunch is going to happen within the lifetime of most people reading this blog.
Let's be optimistic — say we have 25-50 years. How long does it take to build the infrastructure to replace an increasing part of the 90% of growing global energy demand that comes from fossils? A first guess would be 25-50 years.
Read the comments on this blog. So many people are naive and under-educated. And yet the people writing on a blog like this are much more engaged than most.
It is time to quit messing around. Time to get moving on real very large scale non-fossil power sources.
The small 12 to 14 watt solar panels being sold in Kenya and East Africa as well as India are being SOLD to the people by established solar companies.
They are NOT just "donations from non-profit organizations."
The vast majority of these small solar panels are sold for a profit.
Rural people in India and East Africa came to their senses and realized that they would:
PROBABLY NEVER BE A NUCLEAR POWER PLANT installed in their neighborhood within their life-time, and opted for the more realistic source – Solar Power.
John
I sort of wonder why the US army didn't handout solar panels on Baghdad corners instead of trying to fix the Iraqi grid. Cheaper, faster better. Lack of imagination?
Clee ~ "Sandia's gravity stored-energy solution is pumped hydro, which is the second cheapest after CAES."
Pumped hydro is certainly a cost-effective and reliable way to store energy. But, it is limited by topography and the availability of water.
For a wind park located on a bluff 300 ft above the Mississippi River, pumping river water up to a holding tank or reservoir and letting it run back down to power a hydraulic turbine is attractive.
But that option isn't so attractive or feasible out in the flatlands of Iowa, Southwestern Minnesota, or South Dakota.
The falling weight method I proposed is actually simple and technologically sweet for areas where topography or lack of water don't permit hydro pumping.
A tall tripod made of steel I-beams near each wind turbine would allow a heavy weight to be winched to the top when there is surplus electricity at night or when the wind blows steadily, to be released later as the weight descends and turns a generator when the wind stops blowing.
It would also be possible to build a tall (300 – 350 ft) water storage tank near each wind turbine, but such a system would be limited by the hardware and valving needed to control the tremendous head of a column of water that high, and by the fact that water tends to freeze during the winter months in the Midwest and on the High Plains.
takchess jokingly talks about the stress it would put on the Bavarian cuckoo clock industry, and I appreciate his humor, but despite what on the surface may seems rather silly, scaling up the descending weights of a cuckoo clock by a factor of ten-thousand or so, would be an inexpensive and simple way to store energy in wind parks and wind farms.
"…you should grateful that that your child had an interesting experience and came home safe."
Kit P.
I am grateful, she had a wonderful experience.
I should also add that the program she was involved with was primarily about teaching women and teenagers in rural Indian villages how to produce, assemble, and install solar panel kits, and not a program of providing the kits and doing it for them.
The intent was that her NGO would teach people who could then pass their skill on to others.
Blogger robert said…
"I sort of wonder why the US army didn't handout solar panels on Baghdad corners instead of trying to fix the Iraqi grid. Cheaper, faster better. Lack of imagination?"
Answer:
The Grid is too esy to attack. Some Street-lights in Baghdad now solar-powered AND bullet-proofed.
John
PHEV's may turn out to be the cost effective storage solution. Utilities are already researching load-balancing the grid with them. I read an estimated 1.4M will be on the road by 2015. That may be too rosy a forecast,but PHEV's are definately game changers.
There're also renewable options that provide baseload power. My favorite is deep geothermal. Solar satellites are also on the horizon. Each has the potential to power the planet for 50,000 years or so.
I love the 'pie in the sky' type of ideas.
If you calculate the amount of weight necessary for the clock idea you see it is a little impractical.
Using your car battery to back up the grid is great – for the power companies. For the one that has to buy the batteries it is horrible.
As far as how many have or don't have power in India – the vast majority that have power also have extensive power cuts daily. Any industry requiring constant power has their own captive plant as the grid supply is totally unreliable.
I'm sure it'll be mutually beneficial Russ. People won't agree to the load-balancing scheme without some sort of incentive. Battery prices will fall,and fossil fuel prices will rise. That's our near future,like it or not. The new CEO of GM believes cars and light trucks will become more electric as that happens. There are 32 hybrid models to choose from today. That was "pie in the sky" not so long ago.
“rural Indian villages how to produce, assemble, and install solar panel kits,”
That sound really nice, on paper at least. Taking a page from the NGO play book, if the NGO taught them to conserve they would not need expensive solar power plants. [/sarcasm ]
Hey Wendell, why not build transmission lines to area that do not have electricity? Not politically correct enough for the NGOs I suppose. Then the poor women of India could could on a hot plant instead of spending their day scavenging for wood or cow pies to cook on an open fire. Talk about a huge dividend in the quality of life.
Speaking of cow pies, another non-politically correct option is to build crude anaerobic digesters to process animal waste. Biogas is good for cooking and gas lights. Fertilizer is produced and water not contaminated. Huge reduction in ghg too. India is doing lots of this.
Now Wendell, if it looks like I have given this thought; you would be right.
The main task that consume lots of resources of NGOs is collect money from rich women who have too much time time on their hand and have low self esteem. To do this you need pretty pictures. Look at the help wanted section of NGO and see who they need. They hire interns and fund fund raisers. One of the more irritating parts of being associated with renewable energy is watching the folks from NGO. They spend large amounts of cash on their lifestyle. They do not buy their close at yard sales, they buy them at Nordstroms. In any case, ROI for NGO renewable energy is very low.
If you would be so kind as to provide a link to the NGO, I would be happy to provide to send a check if I think they are worthy.
"That sound really nice, on paper at least. Taking a page from the NGO play book, if the NGO taught them to conserve they would not need expensive solar power plants. [/sarcasm ]"
Kit P.
I'm glad you put that sarcasm entry there. The rural people of India (and Africa) already consume far less energy than we do. If they conserved anymore, it would literally be a return to the Stone Age.
"If you would be so kind as to provide a link to the NGO, I would be happy to provide to send a check if I think they are worthy."
Kit P.
Here you go: Barefoot College — Solar Programs
No one in that program buys their clothes at Nordstrom's. If you want to contribute, there is a box on the left side of the page for doing that.
“it would literally be a return to the Stone Age.”
Well then maybe you daughter should conserve by staying home and help at the local soup kitchen. Then you could send the check to the NGO.
Wendell, you first post about NGO. Then you made wild claims.
The best way to store energy in India is fuel rods for nuke plants. A big coal pile next to a coal plant works too.
Secretary of State Clinton is India making a fool of herself and the US. Before that it was China. Many Americans can just not seem to get the message about AGW. India and China are going to follow a path of development.
"Then you made wild claims."
What wild claims would those be?
"…finding ways to store millions of watts of excess electricity for times when the wind doesn't blow and the sun doesn't shine is the new Holy Grail."
How do you store a watt of electricity? That's like saying I want the tank in my car to store two gallons per hour of gasoline. Meaningless. If you want your alternative energy article taken seriously, at least get the units right.
Also, it is not the NEW Holy Grail. People have been searching for better ways to store electric energy for over a century. All of the low-hanging fruit has been picked. If compressed air or giant cuckoo clock weights made any sense, we would be using them already. New technologies will be expensive incremental advances.
Here is a link to US Secretary of State Hillary Clinton visit to India.
http://www.google.com/hostednews/afp/article/ALeqM5jRH6s5a6ZntZB_tSTQ0UYVfN5cww
“In talks with Clinton on Sunday, Environment Minister Jairam Ramesh hit out at the pressure placed on emerging nations to accept legally binding reduction targets, and insisted that India was "simply in no position" to do so.”
But HC is in denial
"We believe we can work through our differences," Clinton said at Monday's briefing.
On nuclear power: “Clinton said the new administration was first of all committed to a landmark but controversial agreement on civil nuclear cooperation sealed last year under Bush.”
Imagine if you will: Cuckoo clock weights on a very large scale.
This idea has been imagined a few times on theoildrum. If you run the numbers, it stores very little energy and would never repay the cost of construction. It makes more sense to just feed the electricity to the grid and then somewhere else entirely have a large central storage which would be more efficient.
As for energy storage = bombs, that doesn't seem to be a problem for petro products. Despite accidents like Buncefield, very large "bombs" are commonly placed in populated areas.
There's some streets in Chicago and elsewhere that could use bulletproof lights. When a gang decides to make a block their drug market, first thing they do is shoot out all the streetlights.
Maury – I didn't say electric cars were a pie in the sky idea. I like them. I said the idea of using your car batteries to store energy for the gird was dumb.
Everything about batteries is cycles – whether you use the power for your car to go a kilometer or to feed the grid is the same – cycling the battery.
In 15 years in India the only conservation I saw was done by stealing power from the grid and making one's power bill go down. Tapping into the electric grid or anything else not closely guarded is a national pastime.
Wendell
This is a good news, good news thing.
First, I love being wrong. You can learn a lot with better information.
Here are some things I learned about Barefoot College.
“The College serves a population of over 125,000 people both in immediate as well as distant areas.”
The first thing I really like is the ‘transparency profile’ that discuses
“Administration Expenditure 6.23% and Highest Cost Employee and Lowest Cost Employee”
They are also documenting results and doing some of the other things besides solar such as:
“-DRINKING WATER – Installation of 1735 hand pumps
-Waste leave have been used in the biomass plants to produce gas for lighting
-40 Bio gas constructions in 10 villages of…
So Barefoot College is certainly worth of a donation. This NGO in India puts many US organizations to shame.
RR this is me being nice to Wendell so please indulge my next post.
Russ said:
"In 15 years in India the only conservation I saw was done by stealing power from the grid and making one's power bill go down. Tapping into the electric grid or anything else not closely guarded is a national pastime."
————————–
You must know the situation having lived there. An article I read recently said that some 40% of the power from the grid in India is stolen.
India seems like a strange place. They have cell phones but rotten roads. They have the atomic bomb but half the country is without electricity.
Sounds to me like they need to drop some of their "high tech" emphasis and start working on their infrastructure
Your comments….?
John
Wendell
Second, I love being right too. Remember all those harsh things I said about the folks at US NGOs? So Wendell did you click on your link?
So while trying to figure out how to send money directly to Barefoot College without send it to NYC I did discover that one of my charities is in the highest rating category for India.
I do understand why so many waco environmentalist who live big cities think the earth is being destroyed by coal plants. Cities folks are ignorant of the natural balance. Their vision of the world is obtained from journalists who live in big cities.
So Wendall, can you provide me a disclosure of the salaries of for those in NYC that you want me to send money too? Do any of those folks have any technical expertise to provide oversight of how the money is being spent?
The consumer/taxpayer always ends up footing the bill Russ. Building a smart grid will be much more cost efficient than other schemes in the long run. Sure,cycling a battery wears it out. But,consumers will do it anyway,because they'll pay less by buying their electricity during off-peak hours,and selling it during peak hours. These guys are making it happen.
http://www.gridpoint.com/
DOE case studies of energy storage: http://www.eere.energy.gov/de/cs_energy_storage.html
The pumped hydro case can provide full power (1080 MW) for ten hours.
The compressed air case provides 110 MW, and is an adjunct to a natural gas fired turbine plant.
Are some of the scaling issues starting to sink in?
Another DOE report on energy storage.
And energy storage has to be added into the total system costs.
Maury, just how does this use case work out? I charge up my PHEV at night, drive it to work in the morning, plug it into the smart grid where? And when I want to drive home, how much of the power is left? It's a 25 minute drive to/from work, and I do most of my shopping before I go home.
And color me skeptical on the estimate of ~1.4M PHEV's, at least until they can get the cost of the battery packs down. Until the price can come down a lot, PHEV's are a just a status symbol.
LarryD, there will be thousands of electric cars sitting in garages fully charged at any one time. They'll be charged during off-peak hours,and the owners will allow utilities to draw X amount of power during peak hours. Draw 50% of power from a few 1000 PHEV's,and you might be able to balance the grid during peak demand,instead of cranking up another coal plant. Even if you're working during peak hours,you might want to sign up for the plan,because then your car would only be charged during off-peak hours….no matter when you plug it in. Utilities spend billions taking power plants on and offline to deal with peak demand. Even without solar or wind power,electric cars can help utilities save big money.
"So Wendall, can you provide me a disclosure of the salaries of for those in NYC that you want me to send money too?"
Kit P.
I wouldn't deal with those people in NYC either — my daughter didn't. You are perceptive in the way of NGOs, but Barefoot College is doing some good work for rural Indians. The director's name is Bunker Roy. Go direct to the following address:
The Director
The Barefoot College
Village Tilonia, via Madanganj, District Ajmer
Rajasthan 305816, INDIA
ph+91 (0)1463- 288204,
FAX +91 (0)1463-288206
bunker@del2.vsnl.net.in barefoot@sancharnet.in
PHEVs don't actually have to feed electricity back into the grid, they can help simply by being a dispatchable load. If the wind dies for a few hours don't fire up NG peakers, just stop charging
PHEVs. In this scenario wind no longer needs backup or storage for six 9s reliability, just reasonable predictability. No big deal if PHEVs don't get full charges a couple days per year, they have gasoline engines to fall back on.
Another dispatchable load is Ice A/C (e.g. IceBear), which can easily be designed to run the compressor whenever excess wind/solar power is avaialble instead of following a fixed overnight icemaking schedule. A/C is a major source of peaking load in hot climates so Ice A/C also helps a lot with peak-shaving in general.
You can adapt the Ice A/C concept to refrigerators and freezers. Dispatchable loads are vastly cheaper than dedicated storage using flow batteries and such. There is also a place for cheap energy storage such as CAES and pumped hydro. BTW, pumped hydro doesn't always need mountains, it can also work in flatland areas with large underground resevoirs.
Best of all is Vanadium Redox Battery
"BTW, pumped hydro doesn't always need mountains, it can also work in flatland areas with large underground reservoirs."
Please explain further. For stored water to convert potential energy to work or power, it has to move from a higher level to a lower level. How does that work with underground reservoirs? I'm not saying it's not possible, but I need help understanding the logistics of how that would work.
Andrew, underground reservoir could be custom-built, an abandoned mind or a natural geologic feature such as a large aquifer. You use reversible turbine/pumps at the bottom (or in stages along the way). They pump water up into an above-ground reservoir at night (or when wind is blowing) and let it flow back down, driving the turbines, when you need power.
To my knowledge no one has done it, but it's been studied a lot. This link has some info.