it is the most efficient in terms of energy transfer. I think it is lacking in terms of actual storage capacity. the upfront costs are also extreme.
ideally, every green energy farm would have a gravity well storage system nearby (like pumped storage) for the purposes of keeping discharge steady. Energy would be transferred into and out of this system pretty quickly, and stored in a more cost/size efficient storage option that could act as the true "battery" on dark days / longer periods of energy production downtime
I'll have to check out the specifics - but your full setup does not seem like an improvement for me. If alexa is down, I can open up the app on my phone for each smart device manufacturer and manually control things that way. They only need my local wifi network to be functional, internet access not needed.
Can a raspberry pi handle the server functionality I wonder?
I got an echo (alexa) for free and use it for home assistant. It only works when I have an internet connection. So when my internet is out, I cannot turn my lights on/off with it. I understand why, but i too would REALLY like to just have all functionality dependencies for home automation to be local.
so then we are free to allow any convention to take hold.
so why not use the multiple different potential pluralities to differentiate between same species, different species, and unknown species? I think the following would be the most intuitive!
Octopuses seems most intuitive and already assumes unknown species (ie used by children who dont even know what a species is)
Octopi sounds similar to a singular entity (no trailing s), so a group from a single species
Octopodes then could explicitly refer to multiple species together, as it changes the spelling a bit and also adds an s
Of course, conventions are not decided upon by a single persons thought process in a random internet forum - so I'm not sure why I wrote this out
this is the catch. you are perpetually in a mental struggle because all it takes is one big bad bet to undo enough of your work that it wasnt worth it. So the options portfolio that you are up 300% on is probably less than 10% of your entire portfolio. Whether it is or isnt under 10% is not actually important, the point is that the stress involved should begin snowballing past that point
not to mention you probably have a decent amount of money liquidated at any given time. for most people it is way for efficient to put the entire portfolio into an index, preferably a tax beneficial account like 401k or roth IRA, and then use all that extra time and energy bettering their workable skillsets so that they can increase their raw income and reduce the odds of unemployment.
That said, when i was unemployed for a year - I did a lot of options/crypto trading because i just had so much time on my hands. Since I've been back at a full time job, it's just too draining for not enough benefit. I can work a few hours of OT and guarantee more money that week than trading would get me, and the OT is way less of a struggle
On one hand I agree fully with this. On the other hand, if the government either is now or will eventually be owned by corporations then we might as well start setting a precedent of holding large corporations to the same standards as government.
What a great read. Saving this for additional research later. I also saw something related to harvesting some energy from the tides, which I think would fall under lifting or sinking stuff and virtual batteries. I wasn't convinced on being able to scale it, or get too much of significance out of it, so i didnt read too much into what the exact technical implementation was.
We seem to disagree on the storage numbers. Genuinely curious if my math is wrong on this. I did research a bit more about recent advancements in pumped storage since my first comment and found that my original numbers were almost an order of magnitude smaller than what would likely be built today since I had referenced older tech. So admittedly, pumped storage is much more feasible than my original attitude suggested - which is great because id love for it to be all we need. However, I'm still not sold on it's ability to act as sufficient storage, and I do not see in any way how it could possibly keep things running for multiple days, let alone years of energy as you suggest.
There is a reason we only talk about pumped storage in terms of its discharge rate rather than its storage. We dont really use it for storage. We use it to store the difference between peak and average energy demand, not the total actual demand. You keep the generators running near average all the time, fill the reservoir during the demand valleys and drain the reservoir during demand peaks. Discharge effects ability to actually reach the peak demand, while storage effects how long you can sustain the demand. My point is even if we could discharge as fast as we need to, the reservoirs would empty in less than a day if we needed to rely upon them while energy production was down.
There is a new project (snowy 2.0) in Australia that will have a notable storage capacity of 350,000 MWh .
Current energy usage in the US is over 10 TWh per day. 350,000 MWh = 350 GWh = .35 TWh. So we would need 28 of this brand new top-end pumped hydro stations to hold 1 days worth of US energy demand in reserve. It's ballpark feasible, but lets keep in mind that this plant is costing Australia ~$5-10 billion and is working with two dams that already exist. Very much still in short-term load balancing territory.
This would also lock up 500,000 liters of water per 10kWh. 1 days worth of storage for US: 10TWh / 10kWh = 1 x 10^9; then x 500,000 liters = 5 x 10^14 liters of water = 100 cubic kilometers* (26 trillion gallons). Storing 1 years worth of energy would be 100 km^3 * 365 = 36,500 km^3; which is 3 times the size of Lake Superior (12,000 km^3). I still dont see this as an energy storage solution. MAYBE if use seawater and find a cost-effective way to build facilities into the coastline?
*(1 x 10^12 liter = 1 km^3)
Also to keep in mind that all of this is assuming CURRENT demand, which excludes the incoming energy demand increase for electric vehicle adoption. that's about 2-4 kWh per gallon of gasoline. US uses about 369 million gallons of gasoline on vehicles per day. We can add almost another 1 TWh for that, and then still whatever is necessary for increased usage in general.
Completely agree with the hybrid approach wrt reducing emissions. I am talking more towards work that would be done concurrently with that.
> During this build all storage technologies where they make the most sense so that when that last 10% is needed, prices will have dropped
this is kind of the point of what I'm getting at. Without any investment, none of the storage technologies are going to make much progress. If not financial investment, then at least a time investment from research/science teams. then again, maybe opportunism/free market will take care of this and we can assume any progress that can be made will be made by people trying to make a name for themselves or be first to market. I'm still curious to size up what that progress might look like for discussion/entertainment purposes in any case
Good storage solutions would immediately pay dividends through arbitrage, which would keep electric prices stable, and then anywhere renewable energy generation is more than demand and storage is sufficient, that stable price point could come down below the cost of using coal/oil as well as any other continuous production method. We would be able to consolidate power generation over time, not just space, and realize gains from that. As in, use massive bursts of energy production to top off storage and use them to exactly meet demand. Maybe this opens the door for more alternative energy production methods as well (that are better suited for burst than steady)
it's also why "storage" is a very loose term for gravity based energy storage. at a massive scale it is still only best at storing/discharging the difference between demand and supply - while still trying to keep actual energy production as close to demand as possible at all times. It really should never be used to power a city the way we would use a battery to power our phone. As in, spend significantly less time charging it than discharging it
good point, and yes its a small scrap yard. I was trying to emphasis that it's possible for a full-time commercial operation moving heavy metal to involve less weight than what was referenced. The backyard pool paints a better picture though
Awesome response. I've come across the molten salt option but havent researched in depth. I saw it referenced as something a lot of scientists are hyping up, but I am not sure what kind of engineering challenges exist for implementation and maintenance.
Second paragraph is a bit too information dense, I had trouble following some of it. Renewable energy deficiencies will be localized, so i understand how wires help here. A larger connected area produces more stability, makes sense. Agreed with the carbon reduction priority to tackle coal and oil first. Surplus renewable power acting as a subsidy checks out, but that is skirting around the energy storage problem imo. Sounds like you are saying "instead of storing renewable energy, get more than you need and sell it back to the grid and then use those funds to buy the energy back later". This would certainly work for local consumers, but doesnt do too much to help the power grid itself manage what to do with the surplus energy. Sell it to neighboring power grids? Ties in to the first point about connecting a larger area - but what are the limits here? Can we physically connect the sunny side of earth to the dark side? (ignoring that it seems logistically/legally prohibitive)
the question really comes down to what should we be spending money on to get "better storage"? What are the best solutions for long-term local storage?
that is something people are doing. Also when you go down into rock, you are able to leverage pressure as energy storage as well - which is similar to what this article is about.
There was 1 design I saw where they have a large cylinder cut out of the ground but left in place (so it is loose). Pump water underneath it to raise the cylinder up, then flip the valve and the cylinder squeezes the water back out for power through gravity. I am not sure how the sealing works on that, probably similar to hydraulics
the 95% is misleading. it is barely storing or providing energy but it is a passthrough akin to plugging your phone into the charger 24/7 and saying your phone battery is providing 95% of the energy just because the wall outlet charges the battery first then the battery powers the phone (not an exact metaphor). If you unplug your phone and the phone dies 10 minutes later, you wouldnt say your phone has a good energy storage solution.
Pumped storage is great at what it does, no denying that. And what it does is allow energy production to remain near average while demand varies, and consequently allows energy production levels to be adjusted a bit slower. You aren't addressing the raw numbers though. It serves best as a compliment to a continuous energy production system. As an actual battery/storage solution, it is weak. So it will not be the solution used to store a massive amount of energy generated over a short period of time in order to be used over a longer period of time.
I agree they should be fully utilized, but I am trying to explain that if you fully utilize pumped storage you are still going to have an incomplete energy storage problem. Of course the water levels dont get near max or min capacity - it is designed to take out exactly what you put in as soon as possible or else there is too much risk. The raw storage capacity is small to medium sized - about 10 hours at max discharge (and max discharge might not be enough to keep up with demand entirely on its own).
Basically, the more energy you need to draw the faster you need to drain it and the more energy you want to store, the more massive your reservoir needs to be.
These things cannot be made 100 to 1000 times bigger, nor is there capacity to make 100 to 1000 times more of them. We are better off having them vs not having them but it isnt enough, and if we find a better solution it may become obsolete
95% stored energy by what measurement? See my other comment. It is not accessible to everyone, nor can it be made accessible to everyone, and the current storage capacity is a marginal fraction of what we actually use. It's a short term load balancing tool that operates within a small energy window.
Makes sense, it is definitely a useful tool. I just think it is insufficient to act as storage. It can be good at producing variable amounts of Watts on demand but not so good at storing enough Watt-hours to keep things running for very long. I can see a great appeal for it to help with load-balancing for a significant amount of choppiness between supply and demand on the hour timescale.
For something like solar, where we will want to store over half our daily energy production at peak storage (ideally 2-3 days worth I think) - I don't think it holds up. Additionally, it doesnt seem like a good bet as a primary mechanism for either storage or on-demand generation if energy consumption continues to increase due to the rather large coefficients involved for scaling it up.
"The United States generated 4,116 terawatt hours of electricity in 2021"[1]
4,116 TWh/year = 11.2 TWh/day
The storage capacities for the largest items listed on the wiki is on the magnitude of GWh. The scale goes kilo-, Mega-, Giga-, then Terra. So we are talking about a need on the order of a thousand pumped storage facilities per country. The US would need over 50 of them per state (on average) in order to keep everything running without production for 24 hours. Doesnt matter how many solar panels we have, if we get 1 dark day then we would run out of power. If we tried to rely on solar entirely, we'd also still need very roughly half that amount of storage just to get through the night.
lithium batteries are obviously much better suited for overnight storage, but I have no idea what the numbers are on how much lithium is physically available to use as such storage.
If we want to get on the order of monthly to yearly storage to allow, for example, solar panels in alaska to provide enough energy for a resident to get through months of darkness - I have no idea what the leading storage options are, probably lithium still
Moving 500,000 kg (over 1 million pounds) 7.5 meters (~25 feet aka the height of a house) will give you about 10 kWh of energy. This is equivalent to running a 425W device all day, like a small air conditioner. The relationship is linear. Double the weight or the distance to double the energy. All of the metal at a scrap yard I know of amounts to less than half that weight, for reference.
I'm also a fan because pumped storage is a really interesting storage method, but it is beyond niche. It is very tough to move that kind of weight around efficiently for what you get back. Pumping water to great heights is not easy either. (see also: moving rail-carts up a mountain)
ideally, every green energy farm would have a gravity well storage system nearby (like pumped storage) for the purposes of keeping discharge steady. Energy would be transferred into and out of this system pretty quickly, and stored in a more cost/size efficient storage option that could act as the true "battery" on dark days / longer periods of energy production downtime