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Tesla Motors Announces a New Home Battery

289 points by jnaveen 12y ago

LeonM 12y ago
I've always been wondering why there have never been affordable local power storage solutions on the market. I'd love to have a battery like this to store excess power from solar panels. Returning power to the grid is a waste in both efficiency and money (you just make the power company richer). Unless you live in Germany (where there are laws forcing power companies to buy excess energy back against peak price), a battery should be the way to go.
- edent 12y ago
  The UK also pays domestic solar producers for feeding in to the grid - it also pays for the generation as well.
- skrause 12y ago
  > Unless you live in Germany Not anymore. The price you get from your power company has been consistently lowered over the last years, now you only get about half of what you pay the power company for the electricity you use.
- repsilat 12y ago
  I guess the big questions are, - How do battery charge/store/discharge efficiencies compare to transmission losses? - How do capital investments to support returning power to the grid compare to the cost of batteries? One thing I'm fairly confident of is that just having batteries (without solar panels) to do peak-flattening temporal "arbitrage" can't make economic sense. If it did, power companies would do it themselves and keep the profit.
  - pbowyer 12y ago
    > One thing I'm fairly confident of is that just having batteries (without solar panels) to do peak-flattening temporal "arbitrage" can't make economic sense. If it did, power companies would do it themselves and keep the profit. They're trialling that right now in the UK: http://www.itv.com/news/anglia/2014-12-15/power-boost-as-biggest-battery-in-europe-is-tried-out/ http://www.itv.com/news/anglia/2014-12-15/power-boost-as-big... http://www.edie.net/news/6/Smarter-Network-Storage-Energy-battery-project-Leighton-Buzzard/ http://www.edie.net/news/6/Smarter-Network-Storage-Energy-ba...
- pjc50 12y ago
  affordable Because so far batteries have been improving in cost/Ah only very gradually? And generated grid power from fossil fuels has been historically cheap?
- Johnythree 12y ago
  Like many others, I've lived on solar power (no grid, no generator) for two decades now. No problems, no fuss. In rural areas, wind powered battery storage was commonplace 100 years ago. Perhaps if you bothered to do a little research....
- wil421 12y ago
  >Unless you live in Germany (where there are laws forcing power companies to buy excess energy back against peak price), a battery should be the way to go. You can get power companies in the US to buy your excess energy. The co-op that supplies my power will set up a meter if you have your own power source. If your total usage is less than what you created they will buy the power from you (not the best rate). They will even give you money back for installing solar cells [1]. 1. http://energy.gov/savings/cobb-emc-solar-rebate-program http://energy.gov/savings/cobb-emc-solar-rebate-program
- cplease 12y ago
  > Unless you live in Germany Many populous U.S. states have net metering, New York and California inclusive.
gizmo 12y ago
It looks like Elon wants to ramp up production in the new Gigafactory right away, and create home batteries from the excess capacity. A Gigafactory running at full capacity should bring the cost of lithium ion batteries way down. Electric cars haven't hit the mainstream yet, so he has to do something with the excess capacity, and this looks pretty straightforward. So even if he sells these batteries at the break even point, he'll still get much closer to an economically viable Model 3, because the battery is such an expensive part in an electric car and this will bring the price of batteries down. (I'm not sure if my reasoning makes sense though, because the Gigafactory isn't anywhere near finished yet, and according to wikipedia it won't hit full capacity until 2020.)
- bsilvereagle 12y ago
  Home batteries have arguably fewer cycle times than a battery in a Tesla. By selling these, Tesla is essentially selling beta models to figure out kinks in the factory, in the batteries, etc, before putting them into their mainstream vehicles that have to suffer huge temperature gradients, lots of recharge cycles, etc.
- skore 12y ago
  If I recall correctly, battery production is currently a bottleneck for Tesla production and one of the major reasons why there is a waiting period of a few months after ordering. So I'm not sure to what extent he depends on home batteries to find a use for excess capacity, even if Model 3 isn't available yet.
- higherpurpose 12y ago
  What will be even more interesting is when he builds 10x the capacity of the Gigafactory, which he said he expects to happen in the future. At that point batteries should be completely commoditized and sold only slightly above raw material cost (which is great news for EVs).
- Aaronneyer 12y ago
  Looks like they might finish the Gigafactory by 2016: http://www.hybridcars.com/gigafactory-could-open-ahead-of-schedule-in-2016/ http://www.hybridcars.com/gigafactory-could-open-ahead-of-sc...
Already__Taken 12y ago
Can someone explain to me why being able to build off the electrical grid is worth all this effort since you're still going to need running water, sewage, bins collecting, broadband and a number of other things?
- mgkimsal 12y ago
  Not sure most of those need physical connections. We can drive our garbage to the dump and also compost. We could dig a well, and we have a septic tank. We could get satellite internet. Physical connections for electricity is about the only absolute, unless you go solar, but then there's not a good storage mechanism for cloudy days (from what I can tell).
- ibz 12y ago
  I get water from my well, have a septic tank in my backyard and use a 3G connection (there is no landline connection available where I chose to live). Getting off the electric grid would be nice, not to mention it would be cheaper too!
- oloboWd 12y ago
  Water and sewage -- Most people in rural america and even in semi-suburban america already use their own wells and septic systems for water and sewage. Likewise with trash, many people drop their trash off at the dump/recycling center themselves. Broadband, yep, no DIY solution there but various forms of wireless internet are available that make it quite feasible to have a completely unwired home if not disconnected.
  - skrause 12y ago
    But still the question is, why would I want that? I'm all for distributed power generation, but it can still be optimized better when it's connected to a grid.
    - angrybits 12y ago
      It's an independence thing. If that isn't important to you, none of this is going to seem terribly useful.
unwind 12y ago
Could someone please fix the truncated title? My editorial advice would be to just cut from the semicolon.
fidotron 12y ago
It will be interesting to see the market reaction to this regarding the value of electricity generation companies. Governments that lean too heavily on taxes or state run monopolies for energy generation should also be concerned. There are places that tax generation from sources like the wind (for example, Nova Scotia), so I wouldn't be surprised if we see solar tax appear.
- lsaferite 12y ago
  Thinking about it, why wouldn't utilities jump at this and make it a standard part of every install? It would allow them to lower the demand-based generation due to every house having a local buffer of storage. They could easily monitor the levels on all the packs in a sector and know ahead of time when they are going to need more capacity which they can fill with better generators like gas turbine or nuclear.
caniscrator 12y ago
If we were able to create individual or community power grids; imagine how much infrastructure could just be removed. Maintained by the individuals owning it, instead of these stupid power companies and the way they work now.
- deleted 12y ago
  [deleted]
m-i-l 12y ago
In addition to doing things like storing any excess solar power you might have, it could also be used to charge up at night on off-peak rates ("Economy 7" in the UK) and release during the day to reduce your peak rate electricity consumption - whether it would be financially worthwhile to do so would depend on a number of factors.
PhantomGremlin 12y ago
Sure, Musk makes it sound sexy, but do we really need to use Lithium in a stationary application? I'd probably be happier with a battery that weighs twice as much but costs half as much. Those might not be the exact tradeoffs, but that's the general idea. However, I don't know much about the details of battery technology, so I could be completely wrong. If traditional technologies such as lead-acid were up to the task, then someone would have already made a big business out of using them. Does that make sense?
- offgridquest 12y ago
  Lithium batteries are not only lighter, but smaller. The typical home today to go off grid in the U.S. is a tiny house or a motorhome. The reason is, it's very cost prohibitive for the amount of power you need. Batteries are the most expensive part of that equation. If you live in a 3000 sq foot house and run a $250 per month electric bill, it might take 50 $130 golf cart batteries to power your house for a day or two, and you replace them every 4-5 years. Or you could go with Iron Edison batteries that should last a lifetime. They are equivalent to about 4 golf cart batteries, and the only requirement is to re-fill them with liquid. They cost about $4,000 each, and are yet still very heavy. The lithium batteries will take up about 1/5 the size and even less weight, and should last much longer than the golf cart batteries, but not as long as the Iron Edison. But space and weight requirements down so much will bring down costs with overseas shipping and trucking bills to a minimum compared with the alternatives. Think what great success in small batteries has done for cell phones. Not that your home needs to be mobile, but I see cars with solar panels and homes with solar shingles... both always charging.... as a great use of the sun as an energy source.
  - yourapostasy 12y ago
    Is that $4000 figure for the 12V battery made out of 800Ah 1.2V cells, rated at "400Ah @ 5hr, 450Ah @ 20hr" shown on their web site for $3880? I've always wondered why more fixed site solar PV systems do not use iron nickel technology; it it is initial cost, I wonder what makes this technology so expensive. Some day I want to look into the feasibility/advisability of a continuous automatic feed of distilled water to keep iron nickel batteries constantly topped off, and a hydrogen outgas capture mechanism (preferably passive) which takes that output of the iron nickel batteries and feeds it as the input into a hydrogen cell.
brudgers 12y ago
So, where does lithium come from? It comes from the Earth, of course, but it doesn't require strip mining or blowing the tops off mountains like other resources do...most often, lithium is found in briny underground ponds. The liquid is pumped out and left to dry in the sun. TANSTAAFL https://duckduckgo.com/?q=lithium+pond+photos&iax=1&ia=images&iai=http%3A%2F%2Fwww.sciencephoto.com%2Fimage%2F438264%2Flarge%2FC0115790-Lithium_evaporation_pond-SPL.jpg https://duckduckgo.com/?q=lithium+pond+photos&iax=1&ia=image... Mining is mining. There isn't a "green" form. Tearing holes in the earth is not the worst ecological damage or the great health risk. The big problem is the water...and it will run downhill from the Andes and wherever else Lithium is mined and into the Ocean. The house off the grid is built on industrial infrastructure.
- SideburnsOfDoom 12y ago
  You can get energy out of a lithium battery several times, which puts it well ahead of tearing holes in the earth to mine coal. No, it's not permanently "off the grid" as it depends utterly on the whole industrial infrastructure, but it not continually tied to the grid like a power line running to a coal-fired power station.
  - brudgers 12y ago
    TANSTAAFL. You can't get any energy out of a battery until you put energy in ... alas more in than out per the laws of thermodynamics.
    - SideburnsOfDoom 12y ago
      yeah no kidding. It would have been a diversion to mention solar; which Musk is also betting on, not co-incidentally. Solar in similar: it depends utterly on the whole industrial infrastructure, but is not continually tied to the grid like a power line.
    - sigkill 12y ago
      Obviously TANSTAFL but the clear point here is you can burn coal only once. Solar panels + Li-ion can be reused atleast 500 times (assuming standard Li-ion batteries that crap out after 500 full cycles).
nacnud 12y ago
Does anyone know if these could be a feasible energy store for people living on the Moon or Mars?
PanMan 12y ago
What would be the advantage of these LiPo batteries over traditional lead-based batteries? In car's, I understand weight (and volume) are really important, but for stationary usage these seem way more expensive / Wh stored?
- jerf 12y ago
  I'm also curious about their lifetime. My laptop batteries are pretty weak after three or four years. It's much easier to justify $thousands as a one-time purchase than $thousands/year. For many of its applications, this is going to have to beat a generator. Which, come to think of it, probably means that if they're pitching this as a way off the grid it is precisely because it won't be even remotely competitive with a generator.
  - higherpurpose 12y ago
    You charge your laptop everyday. So it depends on how often you recharge them, which means it will depend on how big of a battery you'll buy. If you buy a 100 KWh battery (probably around $10,000-$15,000), I think that should last most Americans at least several nights to a week? So it might approach 10 years before it starts degrading, and then probably a few more years of charging it every day. I assume's Tesla's batteries will be relatively high-quality as well.
    - lsaferite 12y ago
      Isn't the idea that you keep it topped of and use it when grid power is expensive or missing? That usage pattern would involve multiple charge cycles, perhaps even 365 in a year. I guess it would actually follow the Tesla charging patterns fairly close as well. What is the estimated lifetime of a Tesla's battery?
      - vidarh 12y ago
        If the battery has sufficient excess capacity, you can split it into multiple banks of smaller batteries, and cycle which ones you charge and which ones you use. Add a small computer and you can use whatever logic gives you optimal charging/discharge patterns to optimise for lifetime.
meesterdude 12y ago
Awesome! and great news for the renewables. Right now, if there's a storm or what have you you can lose your heat, your power, your water - everything. Its a bit like the mainfraime/terminal days - everything is centralized, and represent single points of failure for the citizens it serves. But with energy you create yourself, and things like water recycling or indoor farms, we could go fairly far in self-sustaining units. And instead of the grid, there could be local community sharing so if your power/water goes out you can pull from a local grid. It doesn't need to be in every home, but something more distributed means more resiliency in the system overall, and thats handy in a lot of scenarios. All that's a ways away though - but making the energy storage better / cheaper is an important step. But I'm curious of the environmental factors in battery production / lifetime / recycling, can anyone comment on the impact these batteries represent?
vermontdevil 12y ago
Wonder how this would compare with Bloom Energy Server[1] I recall Apple made some purchases or investments in these products. [1]http://www.bloomenergy.com/fuel-cell/energy-server/ http://www.bloomenergy.com/fuel-cell/energy-server/
harkyns_castle 12y ago
Go go Musk you bloody champion. If we can harness the sun, waves and wind and store it in batteries, and perhaps making those batteries is bad, it's a better solution than continually burning fossil fuels that are destroying our forests, species, economies, and faith in humanity. I say keep doing what you're doing (unless I'm proved wrong).
psaintla 12y ago
Why is living off the grid the main objective here? I live in a suburban area that occasionally has power outages. Right now I'm considering the purchase of whole house generator but if I could have a battery instead I'd do it.
- Filligree 12y ago
  You can have a battery instead. You can get a battery right now; lead-acid will work just fine, if we're talking power outages of an hour or less. House-sized UPS systems are a thing. An expensive thing, mind you, though I don't know how expensive.
  - psaintla 12y ago
    Yeah, I looked into that and last I checked it is prohibitively expensive. If this is a viable alternative I can see two great uses. 1.) Whole house UPS 2.) A way to take advantage of significantly lower night time electric rates.
joosters 12y ago
Have Tesla solved any of the problems that have prevented people from selling large storage batteries in the past? A big issue is that you don't get that many charge cycles, especially with lithium-based batteries. So, filling up the battery with solar power during the day, then running your house from the battery in the evening, will soon fall to pieces if the battery doesn't last a decent number of years.
phreeza 12y ago
The 'living off the grid' angle is a red herring. The main application of this would be solving the peak load problem, ie smoothing out the load on power stations throughout the day. It is not clear to me how a LiPo batter is better suited for this than other battery types though, especially since weight is not a concern for a stationary battery in your home.
- alex-g 12y ago
  I wonder if this even needs to be something in the home. Wouldn't it also make sense to install these things, in bulk, in a place where they could service several homes? Say, at the block level. If it is part of power distribution infrastructure as opposed to a consumer product, then that simplifies some of the safety and maintenance issues; concerns like weight or volume are even less important if they are housed in a dedicated structure.
  - phreeza 12y ago
    This is being done. Power companies have shipping containers full of batteries hooked up to their grids. I have read better stories but the first thing I found googling just now is this http://www.abc.net.au/news/2015-01-07/ausnet-trialling-new-system-to-curb-power-outages-on-hot-days/6004454 http://www.abc.net.au/news/2015-01-07/ausnet-trialling-new-s...
    - sehugg 12y ago
      That's still a pilot program, though. The Wikipedia article has a good summary of various tech and installed systems: http://en.wikipedia.org/wiki/Grid_energy_storage#Batteries http://en.wikipedia.org/wiki/Grid_energy_storage#Batteries
  - spydum 12y ago
    See fairbanks alaska: http://www.telegraph.co.uk/technology/3312118/Worlds-biggest-battery-switched-on-in-Alaska.html http://www.telegraph.co.uk/technology/3312118/Worlds-biggest...
- 12y ago
quarterwave 12y ago
I have home back-up power based on an inverter charging a lead-acid battery (located in a sheltered area outside the home), which costs about $100/kWh. Usage is about 1-2 hours discharge per day. No matter how well serviced, I've found these batteries don't last beyond four years. Hence I'd pay even $400/kWh for a well-engineered deep-cycle battery that is safe, maintenance-free, and will last at least 10 years. Excluding balance of system, even.
- jacquesm 12y ago
  > No matter how well serviced, I've found these batteries don't last beyond four years. Wow, that's really short, especially with such a shallow discharge pattern.
  - msandford 12y ago
    Not necessarily! We don't know how deep the battery is being discharged. But we can make a guess. 4 * 365 = 1400 cycles. http://www.mpoweruk.com/images/dod.gif http://www.mpoweruk.com/images/dod.gif According to that chart (which is an approximation of course) 1400 cycles corresponds to about a 40% depth of discharge. Which isn't terribly shallow. The other variable is the discharge rate, and the higher it is relative to battery capacity the worse the efficiency and also the propensity to fail early. A lot of times doubling the pack size can extend the pack life by more than two because the increased efficiency (the internal resistance is lower) reduces the depth of discharge by more than half. http://batteryuniversity.com/_img/content/crate1.jpg http://batteryuniversity.com/_img/content/crate1.jpg Of course it feels totally ridiculous to only use 20% of the nameplate capacity of the system, and much worse than using 40% which you can sort-of rationalize as "half" but if it decreases your dollars per joule, it might be worth it. EDIT: I should also mention that if you're constantly charging and discharging and you don't mind a little energy loss you should look at nickel-iron batteries. They're not terribly efficient nor are they cheap in absolute terms but they're basically bulletproof. http://en.wikipedia.org/wiki/Nickel%E2%80%93iron_battery http://en.wikipedia.org/wiki/Nickel%E2%80%93iron_battery http://ironedison.com/ http://ironedison.com/
    - 12y ago
jacquesm 12y ago
It's very hard to beat lead-acid on: - $/Wh - number of cycles - ability to be recycled at eol - loss of capacity over the lifetime of the battery (or beyond!) - safety It is easy to beat on - power density - weight - maintenance - mechanical stability (especially for fluid based cells) - installation cost (lead/acid requires a sealed enclosure venting to the outside to get rid of free oxygen and hydrogen) The same batteries that work well for automotive applications will not do that well when you're building a storage cell for a house. Lithium-ion does not have a whole lot of edge over lead-acid deep cycle gel cells when it comes to stationary applications. The biggest issue with Lead-acid is that if you don't water them (if you use fluid based cells rather than gel based cells) that sulfur bridges can grow between the plates causing a cell to be shorted out. Gel based cells don't have that problem and are common in deep discharge setups.
- lsaferite 12y ago
  I'd imagine in this case they are looking at the economy of scale they'll be able to gain when producing these out of the gigafactory. I'd be interested to see the $/Wh cost difference once it comes fully online.
  - jacquesm 12y ago
    Tesla batteries retail for $30K@85KWh, so approximately $350/Wh, Lead-acid deep discharge is about $10000/100KWh, so approximately $100/Wh. That's a pretty large gap.
    - lsaferite 12y ago
      Fair enough. But the pros/cons of each tech would need to be balanced against the $/Wh cost. Once the gigafactory is fully online I thought I'd read they were shooting to drop the pack cost in half? If that were true then it'd be 175 vs 100 and the pro/con list would be much more important, right?
      - jacquesm 12y ago
Sir_Substance 12y ago
This still doesn't solve the essential problem with these batteries: They're about $20k each, and they only last about 4 years.
- dm2 12y ago
  The Model S 85kW battery pack is estimated to cost $12,000 and is estimated to last 10+ years. The SolarCity Battery field-test uses 10kW Tesla batteries and is leased for $1,500 upfront and $15 per month. So, if the batteries degrade, it's Tesla/SolarCities responsibility to fix or replace them. The Gigafactory will likely reduce costs significantly. http://www.theverge.com/2015/2/13/8033691/why-teslas-battery-for-your-home-should-terrify-utilities http://www.theverge.com/2015/2/13/8033691/why-teslas-battery... Essential problem solved?
  - Sir_Substance 12y ago
    The list price for that pack according to these people is 44k. http://www.greencarreports.com/news/1096801_tesla-model-s-battery-life-how-much-range-loss-for-electric-car-over-time http://www.greencarreports.com/news/1096801_tesla-model-s-ba... It looks like you drank the tesla dealers coolaid: http://my.teslamotors.com/forum/forums/tesla-model-s-85kw-battery-replacement-cost http://my.teslamotors.com/forum/forums/tesla-model-s-85kw-ba... Bad luck.
    - dm2 12y ago
      This clearly states that the cost for a replacement 85kW battery will be $12,000. http://www.teslamotors.com/blog/2013-model-s-price-increase http://www.teslamotors.com/blog/2013-model-s-price-increase "We have received many requests for a Battery Replacement Option. We are happy to now offer this option for all three battery variants. This option will provide you a new battery anytime after the end of the eighth year at a fixed price. Prices are as follows: $8,000 for the 40 kWh battery, $10,000 for the 60 kWh battery, and $12,000 for the 85 kWh battery. You will be able to purchase this additional option through your MyTesla page in the near future." I can't imagine that they would raise the price by 4 times. Where is the source for the $44,000 listed on the article you mentioned? If there are 7,000 18650 batteries in a Tesla S battery pack and it's reasonable to assume that Tesla can produce (Gigafactory) these for $1 then the $12,000 seems perfectly reasonable. The current estimate for the cost of 18650s for Tesla is less than $2. It's already been stated that the cost of a battery pack is less than a quarter the cost of the car, so the $44,000 is nothing but false. http://www.technologyreview.com/news/516961/how-tesla-is-driving-electric-car-innovation/ http://www.technologyreview.com/news/516961/how-tesla-is-dri...
forgotAgain 12y ago
Source Bloomberg article http://www.bloomberg.com/news/articles/2015-02-12/tesla-planning-battery-for-emerging-home-energy-storage-market http://www.bloomberg.com/news/articles/2015-02-12/tesla-plan...
offgridquest 12y ago
We have all lived through the improvements in construction with tools that don't need to be plugged in and phones that are unplugged. The next logical step is homes that are unplugged and self power generating. There is an incredible gap in society in the U.S. created by the tax code whereby if you make $25,000 and are a family of 5, you receive enough tax and food benefits and medical insurance to be equal to the person that makes $65,000 per year. And if your income increases to $45,000, you will be losing money, so there is no motivation to reach that point. The Living Off The Grid topic has gone viral because those stuck in the gap seek a way up without increasing income, because it's hard to increase income without hurting oneself. But the idea of downsizing and saving up has become popular with it. Getting a little plat of land and a trailer or a tiny house for a time while saving up.... growing food, having chickens, all are ways to save up and gain without actual cash income increase. Adding solar power to the mix helps prevent power bills. It is also a terrific way to fire the local monopoly power company, who may or may not in your area have any decency of customer service. Without competition, why would they have to care. But the off grid movement is pulling the carpet out from under these government allowed monopolies and forcing competition. In the same stroke, it removes the tax burden from the homeowner that was included in the electric bill. If you have a solar or wind power system and charge your Tesla car too, then you have a completely tax free energy system. It sounds like it's taking away from the government, but the neat thing is, this can also be used to alleviate financial strain on the government. If you can provide a self powered mobile home with rain-water collection to section 8 housing, then the government is also saving on those utility expenses. And land is cheaper a little further out. I recently bought 10 acres in Creek county Oklahoma. The power company wanted $10,000 to add one pole into the land and connection. I opted that it was better to spend that money on a solar power system. The same was true of water with huge expense, so I opted for rainwater and later to add a well. The up front costs associated with being on the grid for many rural areas, or adding more power poles is really more than costs will continue to be as they come down down down for self power generation. This is all exciting to me. We have to consider total impact. Hydro power is still a hugely terrific producer of energy. Rain that fills the lake.... the lake is a battery.... stored to produce energy. So rain makes our energy. This is still a much better solution than building batteries for large power needs. Yet the infrastructure and labor required to put in poles and wires is too high for homes in light of these modern developements. I look forward to an exciting and bright future. ~David Webster Offgridquest.com and Facebook's Living off the Grid
slfnflctd 12y ago
Yawn. I've been following this concept, and a wide array of very talented scientists working on it, for years now. Any of the below projects, should they ever see the light of day (you'd think out of this many, at least one will make it eventually), stands a good chance of being quite superior for this application in just about every way: http://www.eosenergystorage.com/technology-and-products/ http://www.eosenergystorage.com/technology-and-products/ http://www.ambri.com/technology/ http://www.ambri.com/technology/ http://www.ultrabattery.com/technology/ http://www.ultrabattery.com/technology/ http://www.axionpower.com/Technology http://www.axionpower.com/Technology http://www.lightsail.com/ http://www.lightsail.com/ http://www.drexel.edu/now/archive/2014/November/MXene-clay/ http://www.drexel.edu/now/archive/2014/November/MXene-clay/
- ThomPete 12y ago
  Very rarely the best solution wins.
  - bengali3 12y ago
    Agreed. Also, which definition of 'win' is agreed upon here. Win by efficiency? Win by market cap? Edit: hint, look out for the very talented marketers
krenoten 12y ago
Are orange and red terminals confusing to users? (I'm an electronics noob, maybe this is a convention)
boris 12y ago
Today I went to pick up two 100AH lead-crystal batteries for a long-run UPS (we now have regular load-shedding here in South Africa). If I believe all what I have read about them online, they are amazing, compared to lead-acid. Crazy heavy though (33kg each).
CapitalistCartr 12y ago
I'd love to have a self-contained electrical system for my house. I'd preferentially wire my home with a DC grid alongside the AC, but there's no standard. Do I run 120v, 240v, 5v, 12v? Which interface do I use? Barrel connectors, USB, cigarette lighter? If we have a large-scale movement to household DC, we'd have these things hammered out without me rewiring every appliance. If these obstacles were overcome, almost everything in my house could run on DC. Most stuff either converts to DC internally, or doesn't care.
- fredkbloggs 12y ago
  There are standards, many of them, just as there are many different standards for AC power worldwide. Your DC system design will be governed by practical technical considerations in concert with economics. The physics of low-voltage systems are such that they are viable only when current is low; otherwise, a 5V or even 12V system will require prohibitively expensive heavy-gauge wire in order to provide the proper voltage at the point of use. So modern DC systems are typically all 48V or even higher now (people are building solar systems with system voltages of 600VDC!). That does not mean you need to run those higher voltages within your home, but from a practical perspective you probably want either 24V or 48V unless your house and/or current needs are very small. To figure this out, you need to consider the following: - What devices do you need to supply? Often this is the true governing factor although switching regulators are very efficient and inexpensive up to a few amps. - How much current do you need to supply to a particular location (this depends on the power consumption of what you're running)? - What is the distance from the panel to the point of use? The longer the distance, the greater the voltage drop across a wire of a given size (and the higher the cost of larger wire). As for connectors, there are only a couple of sensible answers. USB is fine for 5V/1A needs, but you're not going to want to run a bunch of 5V wiring separately from the higher-voltage wiring you're going to need anyway. The proper approach here is something like http://www.powerwerx.com/adapter-cables/usbbuddy-powerpole-12v-usb-5v-device-charger.html http://www.powerwerx.com/adapter-cables/usbbuddy-powerpole-1..., which will happily work in either a 12V or 24V nominal system. You can of course make other power supplies from all-in-one ICs like http://www.mouser.com/ProductDetail/RECOM-Power/R-78W90-05/?qs=sGAEpiMZZMsc0tfZmXiUnUkNRh%2feR2rThZf2%252bPpU02Tot4ByAEAirQ%3d%3d http://www.mouser.com/ProductDetail/RECOM-Power/R-78W90-05/?... and a small project box; larger currents and other voltages are available too, of course. These make good replacements for wall warts. But you don't want to be wiring any of that in your house; instead, you want to use Anderson Powerpoles in a single-voltage (probably 24V or 48V) system. They are properly rated for DC use at these voltages and plenty of current (up to 350A if you need it, which you won't). They can be installed in blocks of 4 2-blade connectors in standard wall boxes, with neat, professional plates. They can be easily crimped onto appropriate-gauge wire by amateurs. They are code-compatible and safe, unlike the dangerous practice of using receptacles designed for 120VAC or some other existing local/regional standard. They provide a reliable connection and reliable disconnection, and if crimped properly they will not fray, crack, or loosen within a very large number of connect/disconnect cycles. The other low-voltage DC "standard" that is popular, the barrel-type "cigarette lighter" connector, provides only 7A at 12V, is bulky, and does not offer a reliable connection. While it is popular in automotive applications, more serious users of DC power -- the Powerpole is very popular among amateur radio enthusiasts -- avoid the barrel type connectors for these reasons. The only real decision to make is whether to use 24V or 48V, which will depend primarily on the questions I noted above. Higher voltages are certainly possible, but watch out! Switches rated for higher DC voltages (especially at currents much more than 1 or 2A) are hard to find and expensive. Your standard "AC quiet switch" that you can buy for $2 at the local hardware store is rated for 125V AC ONLY. It is not safe to use with any DC system, although in practice it's probably acceptable for 12V systems at a hundred milliamps or so. For more practical applications, you will need to be sure that your equipment is equipped with proper switches, or no switches at all; you will also need to make sure that any hard-wired DC circuits (such as for lighting) are properly switched. Where you have flexibility in the voltage accepted by your equipment, you will need to trade off the higher cost of switches and other passive components at higher voltages against the higher cost (or voltage drop) associated with wiring at lower voltages. You will quickly learn to read spec sheets and rating stamps carefully when you work with DC. The last thing I'll mention is that you may not really want to do this. At my location, there are often several months with extremely limited power; even the inverter's 25W base consumption dictates that it be on an hour a day or less if at all possible. For that reason, anything I have that needs smallish amounts of power continuously (such as a freezer, reading lamp, phone charger, etc.) gets DC. But in general, it's simply more convenient to use off-the-shelf devices. I can and do make my own power supplies, but I don't really want to go re-power my laser printer or table saw (which by the way has an AC-only induction motor in it). For higher-power devices, off-the-shelf is the way to go; it's much cheaper and the inverter's overhead is amortized over a lot of consumption anyway. If you have a larger system that can easily supply 100W or more on an indefinite basis, you probably don't need to bother much with DC; it'll be easier to just leave the inverter running all the time. A DC-powered well pump or freezer might be worthwhile, but I wouldn't go converting anything else. Most people are putting in enormous (to me) solar systems now; 10kW is common. With a system that large, you'll probably be fine even if it's overcast. For reference, I have 700 watts, and with endless stretches of 6-hour overcast days in winter, DC is the only way to fly. But your needs are likely to be very different indeed, especially if you have (as we're discussing here) adequate storage. The days of custom-wired 12VDC off-grid living are basically over unless your budget is extremely limited.
buckett 12y ago
Maybe having a battery pack like this at home would mean you could recharge your Tesla car much faster as you're not limited by the grid supply to your home? A bit like having your own Supercharger station at home?
diltonm 12y ago
We could have used this last week. A pole was damaged (I don't know how, just that it was damaged) and in the middle of a sunny day we lost power for 1.5 hours. Really looking forward to this technology.
PinguTS 12y ago
The question is: Will it be new battery just for homes or will it be a recycled/repurposed battery from 'old' Teslas? It think it will be the later one. Elon is just thinking ahead. There is nothing really new in this story. Everything is just made up. It is quite accepted within the industry, that when the car battery has a capacity of less than 70% to 80% it needs to be replaced. But what should the car company, in this case Tesla, should do with battery? Of course, it will be re-packaged and as such repurposed for other use. What other use case is there? The other use case is Solar, especially as his friend runs a Solar company. What in incident.
phkahler 12y ago
When will homes be built with sensible electricity distribution? So often they put the breaker panel in the basement. I want a small utility room or closet where I can install inverters or this battery. I want to be able to run 220V to my stove, laundry, garage (car charging), battery storage, and AC relatively easily - none of these is in the basement (except the laundry in some home I've lived in). Also, if a basement floods, how is one supposed to go down there to access the panel without risk? And it's darkest down there too. It just seems to be the stupidest place to put it. What's up with that?
- dpark 12y ago
  What's up is that most people don't want a big breaker panel in a room they spend time in. It's ugly. Sticking the panel in a closet doesn't work, because it generally violates codes twice, once for the fact that all the clothes/random junk in the closet blocks access to the panel, and a second time for the fact that even empty, most closets don't provide sufficient clearance all around the panel to meet code requirements. If I were building a new house, I'd consider putting the panel on the main floor and just hanging a big painting to hide it (which still violates code, but it's pretty trivial to take down a painting).
Shivetya 12y ago
I disagree that the long term storage stationary storage is extraordinary, at least from the individual home standpoint, it does have great utility application (for windfarms/hydro/etc) and likely would help some businesses offset day time surcharges by charging storage at night. Still for home use, I would prefer a large lithium pack to be outside my home.
wavesum 12y ago
What puzzles me is the timeframe presented. What is the point of starting production in 6 months if the gigafactory is not up yet, and TSLA is production constrained just making the car batteries?
Iv 12y ago
The last piece for a wind-solar future. Ok, if this really comes to the market and can store 12-24 hours of a typical household consumption, we may be able to live off solar and wind.
ChuckMcM 12y ago
Seems like just yesterday [1] I was saying they could do this if they wanted to. :-) The first challenge is to make the operational cost of a solar + battery system less than the cost of buying your power straight from the grid. The second is to include capital costs in that calculation and still come out at break even or ahead. [1] https://news.ycombinator.com/item?id=9055177 https://news.ycombinator.com/item?id=9055177
BurningFrog 12y ago
Tesla could offer an "attachment" to their cars that let them serve as a home battery when parked. You'd have to let it charge up before going driving, but for home owners who don't drive much, that could be very cost effective. Unless I'm missing some complication?
- thinkcontext 12y ago
  Batteries have a limited number of charge/discharge cycles. If you use your car to power your home you'll have to replace the batteries that much sooner, at a cost of $thousands. Electric car buyers are paying a premium to have the batteries be mobile, better to use them for that application.
Altenuvian 12y ago
I see 'em audiophiles drooling over this. just look at this homemade battery in some audiophiles basement: http://6moons.com/industryfeatures/roadtourlivingvoice/3.html http://6moons.com/industryfeatures/roadtourlivingvoice/3.htm...

289 points by jnaveen 12y ago

LeonM 12y ago

I've always been wondering why there have never been affordable local power storage solutions on the market. I'd love to have a battery like this to store excess power from solar panels. Returning power to the grid is a waste in both efficiency and money (you just make the power company richer). Unless you live in Germany (where there are laws forcing power companies to buy excess energy back against peak price), a battery should be the way to go.

edent 12y ago
The UK also pays domestic solar producers for feeding in to the grid - it also pays for the generation as well.
skrause 12y ago
> Unless you live in Germany Not anymore. The price you get from your power company has been consistently lowered over the last years, now you only get about half of what you pay the power company for the electricity you use.
repsilat 12y ago
I guess the big questions are, - How do battery charge/store/discharge efficiencies compare to transmission losses? - How do capital investments to support returning power to the grid compare to the cost of batteries? One thing I'm fairly confident of is that just having batteries (without solar panels) to do peak-flattening temporal "arbitrage" can't make economic sense. If it did, power companies would do it themselves and keep the profit.
- pbowyer 12y ago
  > One thing I'm fairly confident of is that just having batteries (without solar panels) to do peak-flattening temporal "arbitrage" can't make economic sense. If it did, power companies would do it themselves and keep the profit. They're trialling that right now in the UK: http://www.itv.com/news/anglia/2014-12-15/power-boost-as-biggest-battery-in-europe-is-tried-out/ http://www.itv.com/news/anglia/2014-12-15/power-boost-as-big... http://www.edie.net/news/6/Smarter-Network-Storage-Energy-battery-project-Leighton-Buzzard/ http://www.edie.net/news/6/Smarter-Network-Storage-Energy-ba...
pjc50 12y ago
affordable Because so far batteries have been improving in cost/Ah only very gradually? And generated grid power from fossil fuels has been historically cheap?
Johnythree 12y ago
Like many others, I've lived on solar power (no grid, no generator) for two decades now. No problems, no fuss. In rural areas, wind powered battery storage was commonplace 100 years ago. Perhaps if you bothered to do a little research....
wil421 12y ago
>Unless you live in Germany (where there are laws forcing power companies to buy excess energy back against peak price), a battery should be the way to go. You can get power companies in the US to buy your excess energy. The co-op that supplies my power will set up a meter if you have your own power source. If your total usage is less than what you created they will buy the power from you (not the best rate). They will even give you money back for installing solar cells [1]. 1. http://energy.gov/savings/cobb-emc-solar-rebate-program http://energy.gov/savings/cobb-emc-solar-rebate-program
cplease 12y ago
> Unless you live in Germany Many populous U.S. states have net metering, New York and California inclusive.

gizmo 12y ago

It looks like Elon wants to ramp up production in the new Gigafactory right away, and create home batteries from the excess capacity. A Gigafactory running at full capacity should bring the cost of lithium ion batteries way down. Electric cars haven't hit the mainstream yet, so he has to do something with the excess capacity, and this looks pretty straightforward. So even if he sells these batteries at the break even point, he'll still get much closer to an economically viable Model 3, because the battery is such an expensive part in an electric car and this will bring the price of batteries down. (I'm not sure if my reasoning makes sense though, because the Gigafactory isn't anywhere near finished yet, and according to wikipedia it won't hit full capacity until 2020.)

bsilvereagle 12y ago
Home batteries have arguably fewer cycle times than a battery in a Tesla. By selling these, Tesla is essentially selling beta models to figure out kinks in the factory, in the batteries, etc, before putting them into their mainstream vehicles that have to suffer huge temperature gradients, lots of recharge cycles, etc.
skore 12y ago
If I recall correctly, battery production is currently a bottleneck for Tesla production and one of the major reasons why there is a waiting period of a few months after ordering. So I'm not sure to what extent he depends on home batteries to find a use for excess capacity, even if Model 3 isn't available yet.
higherpurpose 12y ago
What will be even more interesting is when he builds 10x the capacity of the Gigafactory, which he said he expects to happen in the future. At that point batteries should be completely commoditized and sold only slightly above raw material cost (which is great news for EVs).
Aaronneyer 12y ago
Looks like they might finish the Gigafactory by 2016: http://www.hybridcars.com/gigafactory-could-open-ahead-of-schedule-in-2016/ http://www.hybridcars.com/gigafactory-could-open-ahead-of-sc...

Already__Taken 12y ago

Can someone explain to me why being able to build off the electrical grid is worth all this effort since you're still going to need running water, sewage, bins collecting, broadband and a number of other things?

mgkimsal 12y ago
Not sure most of those need physical connections. We can drive our garbage to the dump and also compost. We could dig a well, and we have a septic tank. We could get satellite internet. Physical connections for electricity is about the only absolute, unless you go solar, but then there's not a good storage mechanism for cloudy days (from what I can tell).
ibz 12y ago
I get water from my well, have a septic tank in my backyard and use a 3G connection (there is no landline connection available where I chose to live). Getting off the electric grid would be nice, not to mention it would be cheaper too!
oloboWd 12y ago
Water and sewage -- Most people in rural america and even in semi-suburban america already use their own wells and septic systems for water and sewage. Likewise with trash, many people drop their trash off at the dump/recycling center themselves. Broadband, yep, no DIY solution there but various forms of wireless internet are available that make it quite feasible to have a completely unwired home if not disconnected.
- skrause 12y ago
  But still the question is, why would I want that? I'm all for distributed power generation, but it can still be optimized better when it's connected to a grid.
  - angrybits 12y ago
    It's an independence thing. If that isn't important to you, none of this is going to seem terribly useful.

unwind 12y ago

Could someone please fix the truncated title? My editorial advice would be to just cut from the semicolon.

fidotron 12y ago

It will be interesting to see the market reaction to this regarding the value of electricity generation companies. Governments that lean too heavily on taxes or state run monopolies for energy generation should also be concerned. There are places that tax generation from sources like the wind (for example, Nova Scotia), so I wouldn't be surprised if we see solar tax appear.

lsaferite 12y ago
Thinking about it, why wouldn't utilities jump at this and make it a standard part of every install? It would allow them to lower the demand-based generation due to every house having a local buffer of storage. They could easily monitor the levels on all the packs in a sector and know ahead of time when they are going to need more capacity which they can fill with better generators like gas turbine or nuclear.

caniscrator 12y ago

If we were able to create individual or community power grids; imagine how much infrastructure could just be removed. Maintained by the individuals owning it, instead of these stupid power companies and the way they work now.

deleted 12y ago
[deleted]

m-i-l 12y ago

In addition to doing things like storing any excess solar power you might have, it could also be used to charge up at night on off-peak rates ("Economy 7" in the UK) and release during the day to reduce your peak rate electricity consumption - whether it would be financially worthwhile to do so would depend on a number of factors.

PhantomGremlin 12y ago

Sure, Musk makes it sound sexy, but do we really need to use Lithium in a stationary application? I'd probably be happier with a battery that weighs twice as much but costs half as much. Those might not be the exact tradeoffs, but that's the general idea. However, I don't know much about the details of battery technology, so I could be completely wrong. If traditional technologies such as lead-acid were up to the task, then someone would have already made a big business out of using them. Does that make sense?

offgridquest 12y ago
Lithium batteries are not only lighter, but smaller. The typical home today to go off grid in the U.S. is a tiny house or a motorhome. The reason is, it's very cost prohibitive for the amount of power you need. Batteries are the most expensive part of that equation. If you live in a 3000 sq foot house and run a $250 per month electric bill, it might take 50 $130 golf cart batteries to power your house for a day or two, and you replace them every 4-5 years. Or you could go with Iron Edison batteries that should last a lifetime. They are equivalent to about 4 golf cart batteries, and the only requirement is to re-fill them with liquid. They cost about $4,000 each, and are yet still very heavy. The lithium batteries will take up about 1/5 the size and even less weight, and should last much longer than the golf cart batteries, but not as long as the Iron Edison. But space and weight requirements down so much will bring down costs with overseas shipping and trucking bills to a minimum compared with the alternatives. Think what great success in small batteries has done for cell phones. Not that your home needs to be mobile, but I see cars with solar panels and homes with solar shingles... both always charging.... as a great use of the sun as an energy source.
- yourapostasy 12y ago
  Is that $4000 figure for the 12V battery made out of 800Ah 1.2V cells, rated at "400Ah @ 5hr, 450Ah @ 20hr" shown on their web site for $3880? I've always wondered why more fixed site solar PV systems do not use iron nickel technology; it it is initial cost, I wonder what makes this technology so expensive. Some day I want to look into the feasibility/advisability of a continuous automatic feed of distilled water to keep iron nickel batteries constantly topped off, and a hydrogen outgas capture mechanism (preferably passive) which takes that output of the iron nickel batteries and feeds it as the input into a hydrogen cell.

brudgers 12y ago

So, where does lithium come from? It comes from the Earth, of course, but it doesn't require strip mining or blowing the tops off mountains like other resources do...most often, lithium is found in briny underground ponds. The liquid is pumped out and left to dry in the sun. TANSTAAFL https://duckduckgo.com/?q=lithium+pond+photos&iax=1&ia=images&iai=http%3A%2F%2Fwww.sciencephoto.com%2Fimage%2F438264%2Flarge%2FC0115790-Lithium_evaporation_pond-SPL.jpg https://duckduckgo.com/?q=lithium+pond+photos&iax=1&ia=image... Mining is mining. There isn't a "green" form. Tearing holes in the earth is not the worst ecological damage or the great health risk. The big problem is the water...and it will run downhill from the Andes and wherever else Lithium is mined and into the Ocean. The house off the grid is built on industrial infrastructure.

SideburnsOfDoom 12y ago
You can get energy out of a lithium battery several times, which puts it well ahead of tearing holes in the earth to mine coal. No, it's not permanently "off the grid" as it depends utterly on the whole industrial infrastructure, but it not continually tied to the grid like a power line running to a coal-fired power station.
- brudgers 12y ago
  TANSTAAFL. You can't get any energy out of a battery until you put energy in ... alas more in than out per the laws of thermodynamics.
  - SideburnsOfDoom 12y ago
    yeah no kidding. It would have been a diversion to mention solar; which Musk is also betting on, not co-incidentally. Solar in similar: it depends utterly on the whole industrial infrastructure, but is not continually tied to the grid like a power line.
  - sigkill 12y ago
    Obviously TANSTAFL but the clear point here is you can burn coal only once. Solar panels + Li-ion can be reused atleast 500 times (assuming standard Li-ion batteries that crap out after 500 full cycles).

nacnud 12y ago

Does anyone know if these could be a feasible energy store for people living on the Moon or Mars?

PanMan 12y ago

What would be the advantage of these LiPo batteries over traditional lead-based batteries? In car's, I understand weight (and volume) are really important, but for stationary usage these seem way more expensive / Wh stored?

jerf 12y ago
I'm also curious about their lifetime. My laptop batteries are pretty weak after three or four years. It's much easier to justify $thousands as a one-time purchase than $thousands/year. For many of its applications, this is going to have to beat a generator. Which, come to think of it, probably means that if they're pitching this as a way off the grid it is precisely because it won't be even remotely competitive with a generator.
- higherpurpose 12y ago
  You charge your laptop everyday. So it depends on how often you recharge them, which means it will depend on how big of a battery you'll buy. If you buy a 100 KWh battery (probably around $10,000-$15,000), I think that should last most Americans at least several nights to a week? So it might approach 10 years before it starts degrading, and then probably a few more years of charging it every day. I assume's Tesla's batteries will be relatively high-quality as well.
  - lsaferite 12y ago
    Isn't the idea that you keep it topped of and use it when grid power is expensive or missing? That usage pattern would involve multiple charge cycles, perhaps even 365 in a year. I guess it would actually follow the Tesla charging patterns fairly close as well. What is the estimated lifetime of a Tesla's battery?
    - vidarh 12y ago
      If the battery has sufficient excess capacity, you can split it into multiple banks of smaller batteries, and cycle which ones you charge and which ones you use. Add a small computer and you can use whatever logic gives you optimal charging/discharge patterns to optimise for lifetime.

meesterdude 12y ago

Awesome! and great news for the renewables. Right now, if there's a storm or what have you you can lose your heat, your power, your water - everything. Its a bit like the mainfraime/terminal days - everything is centralized, and represent single points of failure for the citizens it serves. But with energy you create yourself, and things like water recycling or indoor farms, we could go fairly far in self-sustaining units. And instead of the grid, there could be local community sharing so if your power/water goes out you can pull from a local grid. It doesn't need to be in every home, but something more distributed means more resiliency in the system overall, and thats handy in a lot of scenarios. All that's a ways away though - but making the energy storage better / cheaper is an important step. But I'm curious of the environmental factors in battery production / lifetime / recycling, can anyone comment on the impact these batteries represent?

vermontdevil 12y ago

Wonder how this would compare with Bloom Energy Server[1] I recall Apple made some purchases or investments in these products. [1]http://www.bloomenergy.com/fuel-cell/energy-server/ http://www.bloomenergy.com/fuel-cell/energy-server/

harkyns_castle 12y ago

Go go Musk you bloody champion. If we can harness the sun, waves and wind and store it in batteries, and perhaps making those batteries is bad, it's a better solution than continually burning fossil fuels that are destroying our forests, species, economies, and faith in humanity. I say keep doing what you're doing (unless I'm proved wrong).

psaintla 12y ago

Why is living off the grid the main objective here? I live in a suburban area that occasionally has power outages. Right now I'm considering the purchase of whole house generator but if I could have a battery instead I'd do it.

Filligree 12y ago
You can have a battery instead. You can get a battery right now; lead-acid will work just fine, if we're talking power outages of an hour or less. House-sized UPS systems are a thing. An expensive thing, mind you, though I don't know how expensive.
- psaintla 12y ago
  Yeah, I looked into that and last I checked it is prohibitively expensive. If this is a viable alternative I can see two great uses. 1.) Whole house UPS 2.) A way to take advantage of significantly lower night time electric rates.

joosters 12y ago

Have Tesla solved any of the problems that have prevented people from selling large storage batteries in the past? A big issue is that you don't get that many charge cycles, especially with lithium-based batteries. So, filling up the battery with solar power during the day, then running your house from the battery in the evening, will soon fall to pieces if the battery doesn't last a decent number of years.

phreeza 12y ago

The 'living off the grid' angle is a red herring. The main application of this would be solving the peak load problem, ie smoothing out the load on power stations throughout the day. It is not clear to me how a LiPo batter is better suited for this than other battery types though, especially since weight is not a concern for a stationary battery in your home.

alex-g 12y ago
I wonder if this even needs to be something in the home. Wouldn't it also make sense to install these things, in bulk, in a place where they could service several homes? Say, at the block level. If it is part of power distribution infrastructure as opposed to a consumer product, then that simplifies some of the safety and maintenance issues; concerns like weight or volume are even less important if they are housed in a dedicated structure.
- phreeza 12y ago
  This is being done. Power companies have shipping containers full of batteries hooked up to their grids. I have read better stories but the first thing I found googling just now is this http://www.abc.net.au/news/2015-01-07/ausnet-trialling-new-system-to-curb-power-outages-on-hot-days/6004454 http://www.abc.net.au/news/2015-01-07/ausnet-trialling-new-s...
  - sehugg 12y ago
    That's still a pilot program, though. The Wikipedia article has a good summary of various tech and installed systems: http://en.wikipedia.org/wiki/Grid_energy_storage#Batteries http://en.wikipedia.org/wiki/Grid_energy_storage#Batteries
- spydum 12y ago
  See fairbanks alaska: http://www.telegraph.co.uk/technology/3312118/Worlds-biggest-battery-switched-on-in-Alaska.html http://www.telegraph.co.uk/technology/3312118/Worlds-biggest...
12y ago

quarterwave 12y ago

I have home back-up power based on an inverter charging a lead-acid battery (located in a sheltered area outside the home), which costs about $100/kWh. Usage is about 1-2 hours discharge per day. No matter how well serviced, I've found these batteries don't last beyond four years. Hence I'd pay even $400/kWh for a well-engineered deep-cycle battery that is safe, maintenance-free, and will last at least 10 years. Excluding balance of system, even.

jacquesm 12y ago
> No matter how well serviced, I've found these batteries don't last beyond four years. Wow, that's really short, especially with such a shallow discharge pattern.
- msandford 12y ago
  Not necessarily! We don't know how deep the battery is being discharged. But we can make a guess. 4 * 365 = 1400 cycles. http://www.mpoweruk.com/images/dod.gif http://www.mpoweruk.com/images/dod.gif According to that chart (which is an approximation of course) 1400 cycles corresponds to about a 40% depth of discharge. Which isn't terribly shallow. The other variable is the discharge rate, and the higher it is relative to battery capacity the worse the efficiency and also the propensity to fail early. A lot of times doubling the pack size can extend the pack life by more than two because the increased efficiency (the internal resistance is lower) reduces the depth of discharge by more than half. http://batteryuniversity.com/_img/content/crate1.jpg http://batteryuniversity.com/_img/content/crate1.jpg Of course it feels totally ridiculous to only use 20% of the nameplate capacity of the system, and much worse than using 40% which you can sort-of rationalize as "half" but if it decreases your dollars per joule, it might be worth it. EDIT: I should also mention that if you're constantly charging and discharging and you don't mind a little energy loss you should look at nickel-iron batteries. They're not terribly efficient nor are they cheap in absolute terms but they're basically bulletproof. http://en.wikipedia.org/wiki/Nickel%E2%80%93iron_battery http://en.wikipedia.org/wiki/Nickel%E2%80%93iron_battery http://ironedison.com/ http://ironedison.com/
  - 12y ago

jacquesm 12y ago

It's very hard to beat lead-acid on: - $/Wh - number of cycles - ability to be recycled at eol - loss of capacity over the lifetime of the battery (or beyond!) - safety It is easy to beat on - power density - weight - maintenance - mechanical stability (especially for fluid based cells) - installation cost (lead/acid requires a sealed enclosure venting to the outside to get rid of free oxygen and hydrogen) The same batteries that work well for automotive applications will not do that well when you're building a storage cell for a house. Lithium-ion does not have a whole lot of edge over lead-acid deep cycle gel cells when it comes to stationary applications. The biggest issue with Lead-acid is that if you don't water them (if you use fluid based cells rather than gel based cells) that sulfur bridges can grow between the plates causing a cell to be shorted out. Gel based cells don't have that problem and are common in deep discharge setups.

lsaferite 12y ago
I'd imagine in this case they are looking at the economy of scale they'll be able to gain when producing these out of the gigafactory. I'd be interested to see the $/Wh cost difference once it comes fully online.
- jacquesm 12y ago
  Tesla batteries retail for $30K@85KWh, so approximately $350/Wh, Lead-acid deep discharge is about $10000/100KWh, so approximately $100/Wh. That's a pretty large gap.
  - lsaferite 12y ago
    Fair enough. But the pros/cons of each tech would need to be balanced against the $/Wh cost. Once the gigafactory is fully online I thought I'd read they were shooting to drop the pack cost in half? If that were true then it'd be 175 vs 100 and the pro/con list would be much more important, right?
    - jacquesm 12y ago

Sir_Substance 12y ago

This still doesn't solve the essential problem with these batteries: They're about $20k each, and they only last about 4 years.

dm2 12y ago
The Model S 85kW battery pack is estimated to cost $12,000 and is estimated to last 10+ years. The SolarCity Battery field-test uses 10kW Tesla batteries and is leased for $1,500 upfront and $15 per month. So, if the batteries degrade, it's Tesla/SolarCities responsibility to fix or replace them. The Gigafactory will likely reduce costs significantly. http://www.theverge.com/2015/2/13/8033691/why-teslas-battery-for-your-home-should-terrify-utilities http://www.theverge.com/2015/2/13/8033691/why-teslas-battery... Essential problem solved?
- Sir_Substance 12y ago
  The list price for that pack according to these people is 44k. http://www.greencarreports.com/news/1096801_tesla-model-s-battery-life-how-much-range-loss-for-electric-car-over-time http://www.greencarreports.com/news/1096801_tesla-model-s-ba... It looks like you drank the tesla dealers coolaid: http://my.teslamotors.com/forum/forums/tesla-model-s-85kw-battery-replacement-cost http://my.teslamotors.com/forum/forums/tesla-model-s-85kw-ba... Bad luck.
  - dm2 12y ago
    This clearly states that the cost for a replacement 85kW battery will be $12,000. http://www.teslamotors.com/blog/2013-model-s-price-increase http://www.teslamotors.com/blog/2013-model-s-price-increase "We have received many requests for a Battery Replacement Option. We are happy to now offer this option for all three battery variants. This option will provide you a new battery anytime after the end of the eighth year at a fixed price. Prices are as follows: $8,000 for the 40 kWh battery, $10,000 for the 60 kWh battery, and $12,000 for the 85 kWh battery. You will be able to purchase this additional option through your MyTesla page in the near future." I can't imagine that they would raise the price by 4 times. Where is the source for the $44,000 listed on the article you mentioned? If there are 7,000 18650 batteries in a Tesla S battery pack and it's reasonable to assume that Tesla can produce (Gigafactory) these for $1 then the $12,000 seems perfectly reasonable. The current estimate for the cost of 18650s for Tesla is less than $2. It's already been stated that the cost of a battery pack is less than a quarter the cost of the car, so the $44,000 is nothing but false. http://www.technologyreview.com/news/516961/how-tesla-is-driving-electric-car-innovation/ http://www.technologyreview.com/news/516961/how-tesla-is-dri...

forgotAgain 12y ago

Source Bloomberg article http://www.bloomberg.com/news/articles/2015-02-12/tesla-planning-battery-for-emerging-home-energy-storage-market http://www.bloomberg.com/news/articles/2015-02-12/tesla-plan...

offgridquest 12y ago

We have all lived through the improvements in construction with tools that don't need to be plugged in and phones that are unplugged. The next logical step is homes that are unplugged and self power generating. There is an incredible gap in society in the U.S. created by the tax code whereby if you make $25,000 and are a family of 5, you receive enough tax and food benefits and medical insurance to be equal to the person that makes $65,000 per year. And if your income increases to $45,000, you will be losing money, so there is no motivation to reach that point. The Living Off The Grid topic has gone viral because those stuck in the gap seek a way up without increasing income, because it's hard to increase income without hurting oneself. But the idea of downsizing and saving up has become popular with it. Getting a little plat of land and a trailer or a tiny house for a time while saving up.... growing food, having chickens, all are ways to save up and gain without actual cash income increase. Adding solar power to the mix helps prevent power bills. It is also a terrific way to fire the local monopoly power company, who may or may not in your area have any decency of customer service. Without competition, why would they have to care. But the off grid movement is pulling the carpet out from under these government allowed monopolies and forcing competition. In the same stroke, it removes the tax burden from the homeowner that was included in the electric bill. If you have a solar or wind power system and charge your Tesla car too, then you have a completely tax free energy system. It sounds like it's taking away from the government, but the neat thing is, this can also be used to alleviate financial strain on the government. If you can provide a self powered mobile home with rain-water collection to section 8 housing, then the government is also saving on those utility expenses. And land is cheaper a little further out. I recently bought 10 acres in Creek county Oklahoma. The power company wanted $10,000 to add one pole into the land and connection. I opted that it was better to spend that money on a solar power system. The same was true of water with huge expense, so I opted for rainwater and later to add a well. The up front costs associated with being on the grid for many rural areas, or adding more power poles is really more than costs will continue to be as they come down down down for self power generation. This is all exciting to me. We have to consider total impact. Hydro power is still a hugely terrific producer of energy. Rain that fills the lake.... the lake is a battery.... stored to produce energy. So rain makes our energy. This is still a much better solution than building batteries for large power needs. Yet the infrastructure and labor required to put in poles and wires is too high for homes in light of these modern developements. I look forward to an exciting and bright future. ~David Webster Offgridquest.com and Facebook's Living off the Grid

slfnflctd 12y ago

Yawn. I've been following this concept, and a wide array of very talented scientists working on it, for years now. Any of the below projects, should they ever see the light of day (you'd think out of this many, at least one will make it eventually), stands a good chance of being quite superior for this application in just about every way: http://www.eosenergystorage.com/technology-and-products/ http://www.eosenergystorage.com/technology-and-products/ http://www.ambri.com/technology/ http://www.ambri.com/technology/ http://www.ultrabattery.com/technology/ http://www.ultrabattery.com/technology/ http://www.axionpower.com/Technology http://www.axionpower.com/Technology http://www.lightsail.com/ http://www.lightsail.com/ http://www.drexel.edu/now/archive/2014/November/MXene-clay/ http://www.drexel.edu/now/archive/2014/November/MXene-clay/

ThomPete 12y ago
Very rarely the best solution wins.
- bengali3 12y ago
  Agreed. Also, which definition of 'win' is agreed upon here. Win by efficiency? Win by market cap? Edit: hint, look out for the very talented marketers

krenoten 12y ago

Are orange and red terminals confusing to users? (I'm an electronics noob, maybe this is a convention)

boris 12y ago

Today I went to pick up two 100AH lead-crystal batteries for a long-run UPS (we now have regular load-shedding here in South Africa). If I believe all what I have read about them online, they are amazing, compared to lead-acid. Crazy heavy though (33kg each).

CapitalistCartr 12y ago

I'd love to have a self-contained electrical system for my house. I'd preferentially wire my home with a DC grid alongside the AC, but there's no standard. Do I run 120v, 240v, 5v, 12v? Which interface do I use? Barrel connectors, USB, cigarette lighter? If we have a large-scale movement to household DC, we'd have these things hammered out without me rewiring every appliance. If these obstacles were overcome, almost everything in my house could run on DC. Most stuff either converts to DC internally, or doesn't care.

fredkbloggs 12y ago
There are standards, many of them, just as there are many different standards for AC power worldwide. Your DC system design will be governed by practical technical considerations in concert with economics. The physics of low-voltage systems are such that they are viable only when current is low; otherwise, a 5V or even 12V system will require prohibitively expensive heavy-gauge wire in order to provide the proper voltage at the point of use. So modern DC systems are typically all 48V or even higher now (people are building solar systems with system voltages of 600VDC!). That does not mean you need to run those higher voltages within your home, but from a practical perspective you probably want either 24V or 48V unless your house and/or current needs are very small. To figure this out, you need to consider the following: - What devices do you need to supply? Often this is the true governing factor although switching regulators are very efficient and inexpensive up to a few amps. - How much current do you need to supply to a particular location (this depends on the power consumption of what you're running)? - What is the distance from the panel to the point of use? The longer the distance, the greater the voltage drop across a wire of a given size (and the higher the cost of larger wire). As for connectors, there are only a couple of sensible answers. USB is fine for 5V/1A needs, but you're not going to want to run a bunch of 5V wiring separately from the higher-voltage wiring you're going to need anyway. The proper approach here is something like http://www.powerwerx.com/adapter-cables/usbbuddy-powerpole-12v-usb-5v-device-charger.html http://www.powerwerx.com/adapter-cables/usbbuddy-powerpole-1..., which will happily work in either a 12V or 24V nominal system. You can of course make other power supplies from all-in-one ICs like http://www.mouser.com/ProductDetail/RECOM-Power/R-78W90-05/?qs=sGAEpiMZZMsc0tfZmXiUnUkNRh%2feR2rThZf2%252bPpU02Tot4ByAEAirQ%3d%3d http://www.mouser.com/ProductDetail/RECOM-Power/R-78W90-05/?... and a small project box; larger currents and other voltages are available too, of course. These make good replacements for wall warts. But you don't want to be wiring any of that in your house; instead, you want to use Anderson Powerpoles in a single-voltage (probably 24V or 48V) system. They are properly rated for DC use at these voltages and plenty of current (up to 350A if you need it, which you won't). They can be installed in blocks of 4 2-blade connectors in standard wall boxes, with neat, professional plates. They can be easily crimped onto appropriate-gauge wire by amateurs. They are code-compatible and safe, unlike the dangerous practice of using receptacles designed for 120VAC or some other existing local/regional standard. They provide a reliable connection and reliable disconnection, and if crimped properly they will not fray, crack, or loosen within a very large number of connect/disconnect cycles. The other low-voltage DC "standard" that is popular, the barrel-type "cigarette lighter" connector, provides only 7A at 12V, is bulky, and does not offer a reliable connection. While it is popular in automotive applications, more serious users of DC power -- the Powerpole is very popular among amateur radio enthusiasts -- avoid the barrel type connectors for these reasons. The only real decision to make is whether to use 24V or 48V, which will depend primarily on the questions I noted above. Higher voltages are certainly possible, but watch out! Switches rated for higher DC voltages (especially at currents much more than 1 or 2A) are hard to find and expensive. Your standard "AC quiet switch" that you can buy for $2 at the local hardware store is rated for 125V AC ONLY. It is not safe to use with any DC system, although in practice it's probably acceptable for 12V systems at a hundred milliamps or so. For more practical applications, you will need to be sure that your equipment is equipped with proper switches, or no switches at all; you will also need to make sure that any hard-wired DC circuits (such as for lighting) are properly switched. Where you have flexibility in the voltage accepted by your equipment, you will need to trade off the higher cost of switches and other passive components at higher voltages against the higher cost (or voltage drop) associated with wiring at lower voltages. You will quickly learn to read spec sheets and rating stamps carefully when you work with DC. The last thing I'll mention is that you may not really want to do this. At my location, there are often several months with extremely limited power; even the inverter's 25W base consumption dictates that it be on an hour a day or less if at all possible. For that reason, anything I have that needs smallish amounts of power continuously (such as a freezer, reading lamp, phone charger, etc.) gets DC. But in general, it's simply more convenient to use off-the-shelf devices. I can and do make my own power supplies, but I don't really want to go re-power my laser printer or table saw (which by the way has an AC-only induction motor in it). For higher-power devices, off-the-shelf is the way to go; it's much cheaper and the inverter's overhead is amortized over a lot of consumption anyway. If you have a larger system that can easily supply 100W or more on an indefinite basis, you probably don't need to bother much with DC; it'll be easier to just leave the inverter running all the time. A DC-powered well pump or freezer might be worthwhile, but I wouldn't go converting anything else. Most people are putting in enormous (to me) solar systems now; 10kW is common. With a system that large, you'll probably be fine even if it's overcast. For reference, I have 700 watts, and with endless stretches of 6-hour overcast days in winter, DC is the only way to fly. But your needs are likely to be very different indeed, especially if you have (as we're discussing here) adequate storage. The days of custom-wired 12VDC off-grid living are basically over unless your budget is extremely limited.

buckett 12y ago

Maybe having a battery pack like this at home would mean you could recharge your Tesla car much faster as you're not limited by the grid supply to your home? A bit like having your own Supercharger station at home?

diltonm 12y ago

We could have used this last week. A pole was damaged (I don't know how, just that it was damaged) and in the middle of a sunny day we lost power for 1.5 hours. Really looking forward to this technology.

PinguTS 12y ago

The question is: Will it be new battery just for homes or will it be a recycled/repurposed battery from 'old' Teslas? It think it will be the later one. Elon is just thinking ahead. There is nothing really new in this story. Everything is just made up. It is quite accepted within the industry, that when the car battery has a capacity of less than 70% to 80% it needs to be replaced. But what should the car company, in this case Tesla, should do with battery? Of course, it will be re-packaged and as such repurposed for other use. What other use case is there? The other use case is Solar, especially as his friend runs a Solar company. What in incident.

phkahler 12y ago

When will homes be built with sensible electricity distribution? So often they put the breaker panel in the basement. I want a small utility room or closet where I can install inverters or this battery. I want to be able to run 220V to my stove, laundry, garage (car charging), battery storage, and AC relatively easily - none of these is in the basement (except the laundry in some home I've lived in). Also, if a basement floods, how is one supposed to go down there to access the panel without risk? And it's darkest down there too. It just seems to be the stupidest place to put it. What's up with that?

dpark 12y ago
What's up is that most people don't want a big breaker panel in a room they spend time in. It's ugly. Sticking the panel in a closet doesn't work, because it generally violates codes twice, once for the fact that all the clothes/random junk in the closet blocks access to the panel, and a second time for the fact that even empty, most closets don't provide sufficient clearance all around the panel to meet code requirements. If I were building a new house, I'd consider putting the panel on the main floor and just hanging a big painting to hide it (which still violates code, but it's pretty trivial to take down a painting).

Shivetya 12y ago

I disagree that the long term storage stationary storage is extraordinary, at least from the individual home standpoint, it does have great utility application (for windfarms/hydro/etc) and likely would help some businesses offset day time surcharges by charging storage at night. Still for home use, I would prefer a large lithium pack to be outside my home.

wavesum 12y ago

What puzzles me is the timeframe presented. What is the point of starting production in 6 months if the gigafactory is not up yet, and TSLA is production constrained just making the car batteries?

Iv 12y ago

The last piece for a wind-solar future. Ok, if this really comes to the market and can store 12-24 hours of a typical household consumption, we may be able to live off solar and wind.

ChuckMcM 12y ago

Seems like just yesterday [1] I was saying they could do this if they wanted to. :-) The first challenge is to make the operational cost of a solar + battery system less than the cost of buying your power straight from the grid. The second is to include capital costs in that calculation and still come out at break even or ahead. [1] https://news.ycombinator.com/item?id=9055177 https://news.ycombinator.com/item?id=9055177

BurningFrog 12y ago

Tesla could offer an "attachment" to their cars that let them serve as a home battery when parked. You'd have to let it charge up before going driving, but for home owners who don't drive much, that could be very cost effective. Unless I'm missing some complication?

thinkcontext 12y ago
Batteries have a limited number of charge/discharge cycles. If you use your car to power your home you'll have to replace the batteries that much sooner, at a cost of $thousands. Electric car buyers are paying a premium to have the batteries be mobile, better to use them for that application.

Altenuvian 12y ago

I see 'em audiophiles drooling over this. just look at this homemade battery in some audiophiles basement: http://6moons.com/industryfeatures/roadtourlivingvoice/3.html http://6moons.com/industryfeatures/roadtourlivingvoice/3.htm...