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I have high hopes for ARES [1]. just a heavy train on a hill with a regenerative break. Add lots of tracks, multiple trains per track, solar above the rails. Av
by jfoutz 10y ago
I have high hopes for ARES [1]. just a heavy train on a hill with a regenerative break. Add lots of tracks, multiple trains per track, solar above the rails. Avoids needing all the water for pumped hydro storage. none of toxic stuff to deal with when batteries have reached their end of life. Zero carbon emission (aside from whatever is required for manufacturing) is just hugely appealing.
If solar prices continue as they have for another 3-5 years, the question is going to be pretty clear, how do we store all of this insanely cheap power. I'm a little mystified we're not taxing carbon emissions and subsidizing storage. But hey, there are clearly powerful forces at play, that don't agree with me.
[1] http://www.aresnorthamerica.com/ http://www.aresnorthamerica.com/
- james0001 10y agoI disagree with you but I don't think I'm one of those powerful forces
- leereeves 10y agoSounds like a good idea, but i do worry about how much overcapacity in energy storage would be required to handle the worst case scenario (a significant, extended drop in wind and solar output).
- aaronblohowiak 10y agoYou can use natural gas for backup on demand energy generation. It isn't all or nothing.
- leereeves 10y agoAnd who pays for the backup on demand energy generation when it isn't in use?
- bainsfather 10y agoThe same people who pay for it now, the consumers. Electricity grids have massive 'problems' with balancing themselves as demand varies throughout the day. Currently there are e.g. open cycle gas turbines on standby - they are paid a retainer in return for always being available, plus are price per MWh when they are generating. For the UK you can see them http://www.gridwatch.templar.co.uk http://www.gridwatch.templar.co.uk, also see https://en.wikipedia.org/wiki/National_Grid_Reserve_Service https://en.wikipedia.org/wiki/National_Grid_Reserve_Service
- leereeves 10y agoThat works fine for a daily cycle. The backup plants still get paid every day. But will it work for a yearly cycle, where solar/wind output varies from year to year? Can a backup plant survive a year or two when it isn't needed and therefore isn't paid?
- krapht 10y agoI'm extremely skeptical that ARES will ever be cost efficient. Potential energy is proportional to mass * g * d_height - any reasonable grid storage option will need to be moving truly enormous amounts of mass. Back of the napkin here: California consumes 9.54 * 10^17 Joules of electricity / year, or 1.09 * 10^14 Joules / hour. Suppose we wish to hold in storage enough energy to supply to grid for twelve hours, since the sun does not shine at night. Assume we have a 100% efficient method of recovering potential energy stored on a train. Suppose we find a suitable mountain with a 1000 meter height differential. Then according to e = mgh, we would need to shift a load of 1.33*10^11 kilograms to supply twelve hours of electrical demand. Let's assume we use the cheapest rock we can to fill this mass. I assume you can get wholesale pea gravel for $8 a metric ton. Then the cost of gravel alone is $1.07 billion. That doesn't sound so bad, but remember, this project will need ~1333500 100-metric-ton freight cars. Suppose they cost $120,000 / ea. Then suddenly, the cost of the train cars is 160 billion. This is on the order of magnitude of the entire California yearly state budget. And also ignoring a bunch of other cost factors that will increase the total price by another 1-2 orders of magnitude. Pumped storage hydroelectric is viable precisely because the reservoir holds your water for essentially free. Train cars are far, far more expensive.
- giarc 10y agoTrue, but all your math assumes that energy is used equally all 24 hours of the day. A large chunk of energy is consumed during the day, when the sun is shinning. Much less is used at night when the trains need to supply energy.
- krapht 10y agoIf anything I think my estimate is too conservative. Electrical storage must be adequate to meet demand in the worst case. The minute somebody's grandmother freezes to death because of brownouts due to wintry, overcast skies in December, and there will be riots in the state legislature.
- sitkack 10y agoNo, we are long over designing systems for the worst case. This is what got us where we are today. The smart grid is about keeping grandmother alive tonight while drying your clothes during the light cycle tomorrow.
- deleted 10y ago[deleted]
- mabbo 10y agoThe problem: Gravitational potential energy isn't a very efficient storage format. 1kg elevated 1m is only around 10j. A 10,000kg mass elevated 1km would be 98Mj- only 27kWh. And only with perfect conversions, which you won't get. Each Tesla powerwall holds 14kWh for around $8000 each, and that price may fall over the.
- beamatronic 10y agoIf it's cheap to store the energy, and you can store it at large scale, the conversion factor starts to look less important. If anyone had looked at the amount of energy that goes into an ICE car versus what makes it to the rear wheels, would we have autos today?
- micheljones 10y agoYeah, especially with the front drive ones! :P
- zackmorris 10y agoJust to put this in perspective - a gallon of gasoline holds about 33 kWh (about 10 kWh of electricity after thermodynamic losses). So lifting 10 tons a km vertically only gives you about 1-3 gallon of gas, give or take (however motor efficiency could be 95% which helps). There is merit to lifting large loads like this, but IMHO they should be concentrating on weight instead of distance. Which basically takes us back to pumped hydro because we just don't have anything on the order of a million tons or more that can be moved cheaply and easily. I could maybe see a large carpet rolling a layer of sand or stones up into a cinnamon roll so it's self supporting. Probably not the safest place to stand under though!
- sqeaky 10y agoWhat about using old shipping containers just filled with rock and dirt found on site? If someone started with a hill or mountain at an almost suitable grade, then what they dug out to grade the slope properly could be put in second hand shipping containers at the top of a hill. Bring the containers up or down one at a time to get the power in or out. Maybe have some one site solar or wind generation to try to bring and extra container up every once in a while. People generally don't want steep slopes for much anyway so even the property ought to be cheap, it could even be municipal property for maximum cheapness. The hardest part of any of this is the all electric trains with efficient regenerative brakes.
- state_less 10y agoAs neat as this sounds, in a Rube Goldberg sort of way, batteries seem more reliable without the moving parts. The new Lithium Titanium batteries are amazing. 10k cycle before loss of ~20% capacity and fast charge/discharge cycle of 6 min. Since they last a long time, less e-waste. And lithium is supposed to be relatively recyclable when the time comes. We used to think building heliostats made more sense, but it turns out cheaper cells won out to complexity. I suspect this will be repeated in the energy storage market. https://www.google.com/search?client=safari&rls=en&q=LTO+cell&ie=UTF-8&oe=UTF-8 https://www.google.com/search?client=safari&rls=en&q=LTO+cel...
- sqeaky 10y agoI would tend to agree that solid state is better than moving parts for reliability, but we have been building trains for like 150 years and the parts here that move seem to be just really big weights. We also don't have batteries that can do city scale storage economically, but a series of trains seems intuitively do-able. This is just intuition so could be wrong, but trains seem so simple.
- state_less 10y agoTrains are not reducing in price like lithium batteries are. Lithium battery prices are coming down yearly. If it continues at this rate, I think we'll have a story like this about energy storage in 5-10 years where the price makes renewable storage the goto choice for general energy needs. That would be awesome, planet earth could use some good news like that.
- fsloth 10y agoI would like to point out that moving parts are what keep our civilization running. Intricate moving parts. To feed the intuition:There are machines that have run with minimal maintenance for hundred years, such as the original newcomen engines used to pump water away from mines. Each time an assault rifle is fired lots of small parts work together in a delicately timed dance. Now, take an AK-47 - due to it's massive parts and loose fitting it can be filled with dirt and sand and happily continue operation. And, it's quite hard for me to imagine the turbines in electric plants and all the "piping" around them are any less "rude goldbergish" than the Ares system would be. Machines are quite durable if they are designed that way.
- aaronds 10y agoWhat about Cryogenic storage? http://www.bbc.co.uk/news/science-environment-37902773 http://www.bbc.co.uk/news/science-environment-37902773 I haven't looked into it much, but from the little I've seen it looks promising.
- winter_blue 10y agoWhat about a global power grid? Whichever side is receiving sunlight would power the other side of the Earth. We've already got communication cables running worldwide, couldn't we add cables for transmitting power? Perhaps, electric cables will weigh orders of magnitude than optic fiber comm links, but would it be infeasible?
- kevinnk 10y agoYou can't transport power that far without massive transmission losses. Communications cables use repeaters and fiber optics, so they don't have nearly the same problem. https://en.m.wikipedia.org/wiki/Electric_power_transmission#Losses https://en.m.wikipedia.org/wiki/Electric_power_transmission#...
- WJW 10y agoWhy not use superconducting cables? https://www.extremetech.com/extreme/182278-the-worlds-first-superconducting-power-line-paves-the-way-for-billions-of-dollars-in-savings https://www.extremetech.com/extreme/182278-the-worlds-first-...
- pjc50 10y agoBecause they're very expensive and require liquid nitrogen cooling? Which itself represents energy consumption, so instead of losing energy as resistive losses you're spending it on cooling. What's more likely is some form of energy-to-liquid-fuels process that runs during times and places of excess energy. The fuel can then be stored, pumped, trucked etc to other locations. This already exists, it's just not price-competitive with fossil fuels.
- XorNot 10y agoCooling benefits from insulation - the energy loss does not scale as an exponential factor, and levels off very dramatically (the deep sea is already very cold).
- WalterBright 10y agoOne way to deal with night time electricity demands is to increase the cost of it. This will push demand to the daytime. There's no reason to have uniform power rates 24 hours when the cost of providing electricity will vary dramatically from day to night.
- jk563 10y agoIs this a real issue? My understanding was that there is a significantly lower demand for electricity at night. This is reflected in my energy tariff at least (daytime ~3x cost per kWh over night time).
- WalterBright 10y agoElectric rates are the same around here 24/7. If it's more expensive to provide baseline load at night, increase the night rates. Elastic uses of power, like charging car batteries, running the dryer, heating the water heater, etc., can be shifted to when power is cheaper. I.e. reducing demand for night power is a cheap and effective means of dealing with the sun not shining at night.
- ZeroGravitas 10y agoTraditionally, the oversupply due to keeping coal and nuclear running at their optimum is available at night, when the demand is lower. Many locations, like yours, already account for this by charging lower prices at night to incentivize people to shift their load to these times e.g. putting the dishwasher on a timer so it runs overnight. Many pumped hydro stations store energy at this time too, often they were built specifically to pair with nuclear stations to better map a steady supply to a variable demand. In areas that are ideal for solar, and roll out solar heavily, they may end up in the opposite situation, with the supply and demand mismatch reversed and so try to push usage to the middle of the day by dropping the prices then. Since most usage is during the day due to air-con load and the fact that people sleep at night, this may mean lower prices overall. Once you add the internet into the equation, rather than the blunt instrument of a block of hours at a lower charge you can do things like have specific plugs for electric cars or an irrigation pump on a farm that can respond on a second by second basis to over or undersupply of electricity by using more or less in exchange for a cheaper rate. This is called "demand response" and while it happens already with big industrial users, it's getting cheaper and easier for it to be used by more and more users. One neat product that already exists is an internet connected car charger that checks the carbon content of the grid and charges your car overnight only when the wind energy is a big part of the mix.
- lmm 10y agoWe should tax carbon emissions but we shouldn't subsidize storage. Anyone who developrs efficient storage will be able to make money on the energy markets directly (buy low and sell high). Let solar+storage compete on a level playing field with zero-carbon sources that can offer baseline power without requiring storage (hydro, nuclear, geothermal...)
- crdoconnor 10y agoMany governments (state and local) are in a position where taxing carbon isn't a possibility but subsidizing low-carbon forms of generation is. They should not be handicapped.
- lmm 10y agoThey shouldn't be subsidizing one form of low-carbon generation but not another. That will distort the market and lead to buying subsidized forms that are more expensive overall.
- crazy2be 10y agoI agree in principle, but given the huge proportion of energy which comes from fossil fuels, a carbon tax would have to be huge (and hence unpopular) if it were to match the market competitiveness of subsidies. That is, to subsidize solar 33% (our current subsidy in the US), you would have to make a carbon tax equivalent to 50% of the current price of fossil fuels, or about $1.50/gal. This is obviously politically untenable in the United States. The happy medium is probably to do a bit of both, and work toward the middle. Smart, targeted subsidies for carbon-neutral sources, and small, gradually increasing carbon taxes.
- DennisP 10y agoYou can get away with a higher carbon tax if you return the money to the population. In fact, there's a fair amount of popular support for basic income. Meanwhile a leading idea for carbon pricing is a flat fee per ton with the money returned to the population, equal amount per capita, which essentially is a small basic income funded by the carbon tax. British Columbia has a revenue-neutral carbon tax (in their case by reducing payroll taxes accordingly) and reportedly it's popular. The opposition party ran against it and lost.
- mnkypete 10y agoPotentially relevant, with much less moving parts: A bigger kind of "Hubspeicherkraftwerk" (not sure about the english name, wikipedia does not offer one ;)) - carve out a large cylindrical block of a mountain and pump water below. http://www.spektrum.de/news/ein-granitblock-voller-energie/1061069 http://www.spektrum.de/news/ein-granitblock-voller-energie/1... (In German, though the pictures should be enough)
- 24gttghh 10y agoWhy not fill the rail cars with batteries as the ballast?
- ChuckMcM 10y agoWhat a fun system. I've added it to my notebook with the German 'hydraulic rock' (http://heindl-energy.com/ http://heindl-energy.com/) system. The latter doesn't need a hill. What I like about the train system is that it should be cost effective and can be built without water. Cost effective because steel and concrete seem to be the bulk of the cost. The lack of water makes it more useful in places like the desert where water tends to evaporate over time and is hard to come by. It would interesting to understand the maintenance burden relative to the renewable energy source it is paired with. Another, less talked about, issue is replacing peaker plants. Here is an article from 2015 on why that is a good idea (http://www.aiche.org/chenected/2015/04/battery-storage-takes-on-gas-peaker-plants http://www.aiche.org/chenected/2015/04/battery-storage-takes...) using batteries. Even a "small" ARES system it would seem could address some of this need. The challenge being its hard to build something like that in an urban area.
- gene-h 10y agoWow, I thought I had seen it all when it comes to energy storage, but this really takes the cake though. That piston is enormous! It might be the largest moving machine ever constructed if it was built.
- Your_Creator 10y agoI agree with you on solar. From my perspective, any energy we don't capture and harvest from the Sun as it hits Earth is wasted. Now allow me to offer you a different view on my buddy; Carbon. Carbon itself is a commodity and should be handled as such. We need it to make graphene, synthetic diamonds and carbon nanotubes which will in turn become the new silicon for the next decade or so. What if all those things can be as accessible as what is common today? We must harvest every last molecule of carbon for this end. That include the crap we have overloaded the atmosphere with. I've already come up with a system for this that needs some fleshing out. With it we can make better solar panels, water filters, textiles of immense tensile strength, relativistic electrical conductivity and insulation. Carbon is the fourth most common element in the universe or at least from what we can see. We must keep it that way if we want complete proliferation of this next generation of desktop and mobile quantum computers in every part of human society. So we need to capture and reclaim it from every corner of the Earth because the end goal is totally worth it.
- kwhitefoot 10y agoBuild a proper electricity grid and sell power from sunlit areas to dark areas. You need the grid anyway. At the same time insist that all new dwellings are built to passivhus standard. Also arrange for all plugged in electric vehicles to be able to supply power to reduce peak demand from the net. All this is scaleable and mostly going to happen to some degree anyway and avoids the need for massive capital projects that are susceptible to corruption.
- namlem 10y agoThe problem is high start up cost and high real estate cost. Batteries are small and you can purchase and deploy them in small quantities.