Tesla aims to unveil ‘Solar Roof’, next gen Powerwall and new Tesla charger on October 28 - Polidicks

[media]https://twitter.com/elonmusk/status/779003462742794240[/media] [QUOTE]The CEO also confirmed earlier this year that a new generation of the product was coming to market by the end of the year. Tesla is expected to start production of its new ‘2170’ battery cell at the Gigafactory around the same time and the company said that it will find its way in the energy storage products before the battery packs for Tesla vehicles. Musk also said that with the merger with SolarCity, which is expected to go to a vote just before the planned event on Oct 28, Tesla will be integrating the inverter with the Powerwall. [/QUOTE] [url]https://electrek.co/2016/09/22/tesla-solar-roof-powerwall-tesla-charger-oct-28/[/url]

Solar roof? Like, solar panels? Are they efficient enough where the effects would be noticeable, other than when the car is not being used all day and just sits and charges? E.g. how much would solar panels extend battery life

[QUOTE=Kylel999;51090276]Solar roof? Like, solar panels? Are they efficient enough where the effects would be noticeable, other than when the car is not being used all day and just sits and charges? E.g. how much would solar panels extend battery life[/QUOTE] For your home, not the car.

Solar shingles already exist.

[QUOTE=Zephyrs;51090338]Solar shingles already exist.[/QUOTE] Lithium batteries already exist.

[QUOTE=Zephyrs;51090338]Solar shingles already exist.[/QUOTE] Electric cars already existed, too. Didn't mean they couldn't have been done better.

[QUOTE=Humin;51090538]Lithium batteries already exist.[/QUOTE][QUOTE=ZombieWaffle;51091006]Electric cars already existed, too. Didn't mean they couldn't have been done better.[/QUOTE]Yeah I'm with Zephyrs on this one, drawing a big "so what?" in my head right now. Unless there's some truly groundbreaking technology in photovoltaics this is just going to be another iteration of solar panels plus battery for homes, the difference is a marginal increase in performance (because of the battery) and in a complete package. At some point the efficiency increase becomes pointless because the user is not going to be able to take full advantage of it. Everything offered here can be replicated with home-built panels using deep cycle batteries and recycled/second-hand components for far cheaper.

Perhaps the point is to drive up demand and drive down costs over time. Tesla is a name people now know. I myself can't bring to mind any companies (around here) that offer the same thing off the top of my head; as a consumer I would have to probably build one myself.

Well if they have any sense they'll market and brand this towards the affluent type who can afford this as a brand name solar power and energy storage source which is becoming "fashionable" in certain crowds so that may be a decent market for them to go for. It's also just in line with Musks general mission statement. Who knows, maybe that solar acquisition will yield something good.

[QUOTE=Humin;51090538]Lithium batteries already exist.[/QUOTE] [QUOTE=ZombieWaffle;51091006]Electric cars already existed, too. Didn't mean they couldn't have been done better.[/QUOTE] Except that solar shingles are the solar roadway meme of roofing. They are impractical, inefficient, and needlessly expensive, and that's before you get to the part where houses generally aren't angled and oriented correctly for maximum solarity. They've been tried. They have failed abysmally. Solar panels on top of a basic roof are cheaper, more efficient, easier to maintain, and already come in a wide variety of low refractive designs to minimize the aesthetic impacts of glare. We are talking about tech that is less effective than alternative methods. Any tech that improves solar shingles, or anything related to them, can be applied to regular solar panels just as easily, if not more so. Even if Musk is talking about doing exactly that, and simply putting panels on top of a basic roof, that's already being done all over the place. There's already a few commercial complexes taking it a step further by integrating the panels into the roof itself, and using sealants between the metal framed panels, sometimes with integrated polycarbonite shields, to provide a durable, water tight, impact resistant roof that can be easily repaired with a screw driver, a tube of silicone, and an exacto knife. You are both talking about things that have absolutely nothing to do with this. It's almost like you don't have any point to raise. What exactly is Musk doing that's new here? It's literally being done right this very instant without any input from him one way or the other.

[QUOTE=Zephyrs;51091636]You are both talking about things that have absolutely nothing to do with this. It's almost like you don't have any point to raise.[/QUOTE]What do you mean they have nothing to do with this? Electric vehicles are possibly the closest comparisons you could make to solar panels prior to Tesla's vehicles. It's more like you're trying to ignore the similarities as much as possible rather than no one having a point.

[QUOTE=Humin;51091971]What do you mean they have nothing to do with this? Electric vehicles are possibly the closest comparisons you could make to solar panels prior to Tesla's vehicles. [B]It's more like you're trying to ignore the similarities[/B] as much as possible rather than no one having a point.[/QUOTE] OK. I'll bite. What's the closely linked relationship between a car and a roofing material? Best I can come up with is that they both involve electricity, and there's probably some material overlap because both are exposed to the environment. Nothing beyond a tangential connection. The point is that solar roofing is not new or innovative tech. It exists, and is already in large scale use. Musk is jumping into the market. I don't see why that's particularly noteworthy. He's going to wrap it up, put a sleek package on it, and sell it at high markups. There's definitely money there, but that doesn't make this revolutionary in any way.

[QUOTE=Zephyrs;51092075]OK. I'll bite. What's the closely linked relationship between a car and a roofing material? Best I can come up with is that they both involve electricity, and there's probably some material overlap because both are exposed to the environment. Nothing beyond a tangential connection. The point is that solar roofing is not new or innovative tech. It exists, and is already in large scale use. Musk is jumping into the market. I don't see why that's particularly noteworthy. He's going to wrap it up, put a sleek package on it, and sell it at high markups. There's definitely money there, but that doesn't make this revolutionary in any way.[/QUOTE] I'm interested in what the solar roof will be because solar shingles in the past have been pretty shit for the reasons stated. If Tesla merges with Solar City then they will be the largest solar panel installer in the USA. Right now you might think Tesla doesn't have to do with Solar panels but they kind of do have their fingers in all the supporting bits. Tesla's cars have high performance and much more complex inverters than what you need for solar. They have experience with batteries for the cars, which can significantly improve how dependant you are on the grid. That allows solar panels to be competitive in states and countries without net metreing or other poor incentives if they can get the cost low enough. They could create a highly integrated system that no other company would be able to match, and could potentially save the consumer a lot of money.

They have a lot of tech. Nobody denies that. Lot of it's only tangentially relevant though. For example, the inverters for the cars have to deal with wildly variable loads that can reach upwards of 600kw. Besides 600kw being an [B]insanely[/B] large solar array (I'm personally looking to set up 20-22kw, which is already enormous by residential standards), they have weight, as well as space restrictions, since it's in a car. Heat management is more complex in a car. Ground tech has very few weight and space limitations, and the loads don't have that much wild variation. Radiating heat on the ground isn't nearly as much of an issue either. Plus, you can just run multiple small inverters to prevent critical failure points that knock out huge parts of an array, and make maintenance easier. On the ground you can make things big, cheap, and efficient. The operational environments and requirements have almost nothing to do with each other.

[QUOTE=Zephyrs;51092296]They have a lot of tech. Nobody denies that. Lot of it's only tangentially relevant though. For example, the inverters for the cars have to deal with wildly variable loads that can reach upwards of 600kw. Besides 600kw being an [B]insanely[/B] large solar array (I'm personally looking to set up 20-22kw, which is already enormous by residential standards), they have weight, as well as space restrictions, since it's in a car. Heat management is more complex in a car. Ground tech has very few weight and space limitations, and the loads don't have that much wild variation. Radiating heat on the ground isn't nearly as much of an issue either. Plus, you can just run multiple small inverters to prevent critical failure points that knock out huge parts of an array, and make maintenance easier. On the ground you can make things big, cheap, and efficient. The operational environments and requirements have almost nothing to do with each other.[/QUOTE] It's obviously not a case of dropping one in from the car and it just works. But should be easy enough for Tesla's team to build an inverter for domestic solar. One of the issues with battery storage is that it requires a high end and complex (expensive) inverter to work.

[QUOTE=Morgen;51092426]It's obviously not a case of dropping one in from the car and it just works. But should be easy enough for Tesla's team to build an inverter for domestic solar. One of the issues with battery storage is that it requires a high end and complex (expensive) inverter to work.[/QUOTE]No it doesn't, not at all. I said above that using second-hand and recycled (i.e. repurposing an existing inverter) components give the average user all the performance they could ever need. This is about as revolutionary as machining a tea cup from a billet of titanium alloy, it's neat but at some point you need to step back and recognize that [I]this is a [U]teacup[/U] we're talking about.[/I] [editline]23rd September 2016[/editline] Zephyrs 22kW solar power system is a great example of what I'm talking about, that's enough to power a home, garage, and demanding appliances like welders and electric forges. This is already a few steps beyond what the average home needs, it's crossing into the realm of a small business. Meanwhile for your average home with average demand the necessary materials and components can be assembled at home from second-hand sources, scrap, and through purchasing blemished and defective components at greatly diminished cost.

[QUOTE=JumpinJackFlash;51096286]No it doesn't, not at all. I said above that using second-hand and recycled (i.e. repurposing an existing inverter) components give the average user all the performance they could ever need. This is about as revolutionary as machining a tea cup from a billet of titanium alloy, it's neat but at some point you need to step back and recognize that [I]this is a [U]teacup[/U] we're talking about.[/I] [editline]23rd September 2016[/editline] Zephyrs 22kW solar power system is a great example of what I'm talking about, that's enough to power a home, garage, and demanding appliances like welders and electric forges. This is already a few steps beyond what the average home needs, it's crossing into the realm of a small business. Meanwhile for your average home with average demand the necessary materials and components can be assembled at home from second-hand sources, scrap, and through purchasing blemished and defective components at greatly diminished cost.[/QUOTE] If you want to build a system your self and piece it together with second hand stuff then you can probably do that. You can hardly expect the biggest solar installer in the US to rely on second hand parts though. But Tesla's power wall only works with Solaredge inverters in its current form which are pricey. I expect that the charger will be something that integrates with the new Power wall and takes DC straight from it as well instead of converting to AC and back to DC in the car. The battery system increases how self reliant you are on power by quite a bit. It makes a huge amount of sense in places without net metreing. Without a battery system most of Zephyr's power from his array is going to end up back in the grid and not used by him unless he works from home or something, which is fine if he has net metreing.

[QUOTE=Morgen;51098356]If you want to build a system your self and piece it together with second hand stuff then you can probably do that. You can hardly expect the biggest solar installer in the US to rely on second hand parts though.[/QUOTE]Completely missing the point. [QUOTE]The battery system increases how self reliant you are on power by quite a bit. It makes a huge amount of sense in places without net metreing.[/QUOTE]Like I said twice now the amount of use a solar system powering an average household isn't very much, low enough to be served by second-hand, repurposed, recycled, or improvised solutions. [QUOTE]Without a battery system most of Zephyr's power from his array is going to end up back in the grid and not used by him unless he works from home or something, which is fine if he has net metreing.[/QUOTE]Do I need to start quoting myself? Lead-acid batteries work fine for 99.999999% of the time, in fact some solar panels, an inverter, cables, and a battery bank could all be found at a large hardware supplier probably for less money than all of this. Here, Zephyrs said it best:[QUOTE=Zephyrs;51092075]The point is that solar roofing is not new or innovative tech. It exists, and is already in large scale use. Musk is jumping into the market. I don't see why that's particularly noteworthy. He's going to wrap it up, put a sleek package on it, and sell it at high markups. There's definitely money there, but that doesn't make this revolutionary in any way.[/QUOTE] Independent panels, solar shingles, some weird "solar window" shenanigans all accomplish the exact same thing, nothing about this is groundbreaking at all. Unless Musk reinvents the wheel and somehow makes it also brew coffee, this isn't much to get excited about. Sure it's neat that Tesla is going to be doing this but it's not something wildly impressive and actually I'm beginning to question if it's smart for Tesla to be doing this in light of everything that's been going on. Tesla as a company hasn't been doing super great and Solar City's performance has been objectively terrible for awhile, hence the merger. On top of that cheap, homebuilt solutions and cheap, Chinese-manufactured panels are very cost-effective solutions that, as I said several times, covers the exact same need perfectly fine and does it cheaper to boot. So what, are they going to ride the ~Tesla wave~ and use the brand name to sell to Tesla owners? I don't see anyone else buying an overpriced solar roof, so unless there's far more rich Musk fanboys out there than I'm estimating this doesn't seem like a very good idea.

On the lead acid note. Lead acid is still used in many UPS situations because the drawbacks of lead acid batteries don't matter on the ground. So what if they are big? So what if they are heavy? It's the ground. Build a bigger tin shack for them. Lead acid batteries partnered with ultracaps to handle power surges and the delay in switching between supplies, is becoming a common solution in commercial environments. Especially datacenters. They love the insulating layer of ultracaps to provide rock solid, uninterruptible, perfect sinewave AC. Lithium batteries have two uses for home storage that I see. 1. Places with variable rates, and net metering. If you can buy electricity at 5 cents during the night, and sell it at 20+ during peak hours, there's money. 2. Completely off grid solutions. Both of those situations deal with repeated deep cycling. That's where lithium batteries excel. In any other situation, the benefits of lithium just aren't important enough to justify the higher prices. Even in an area with lots of power outages, you aren't looking at hundreds of full cycles every year. The third option that I can see as a possibility is using batteries to provide fast DC charging to cars. The problems, as I've mentioned in the past, are that there really isn't a target market for that, since practically nobody needs to go home to add 150 miles to their car over lunch, and that it requires very beefy equipment, on top of requiring even larger battery packs. (most houses don't use hundreds of kw a day, so huge packs for off grid storage are excessive) There might be commercial use of this, but commercial should be able to just get tied into the grid and throw a big inverter at it, like Chademo stations already do.

[QUOTE=Zephyrs;51104866]On the lead acid note. Lead acid is still used in many UPS situations because the drawbacks of lead acid batteries don't matter on the ground. So what if they are big? So what if they are heavy? It's the ground. Build a bigger tin shack for them. Lead acid batteries partnered with ultracaps to handle power surges and the delay in switching between supplies, is becoming a common solution in commercial environments. Especially datacenters. They love the insulating layer of ultracaps to provide rock solid, uninterruptible, perfect sinewave AC. Lithium batteries have two uses for home storage that I see. 1. Places with variable rates, and net metering. If you can buy electricity at 5 cents during the night, and sell it at 20+ during peak hours, there's money. 2. Completely off grid solutions. Both of those situations deal with repeated deep cycling. That's where lithium batteries excel. In any other situation, the benefits of lithium just aren't important enough to justify the higher prices. Even in an area with lots of power outages, you aren't looking at hundreds of full cycles every year. The third option that I can see as a possibility is using batteries to provide fast DC charging to cars. The problems, as I've mentioned in the past, are that there really isn't a target market for that, since practically nobody needs to go home to add 150 miles to their car over lunch, and that it requires very beefy equipment, on top of requiring even larger battery packs. (most houses don't use hundreds of kw a day, so huge packs for off grid storage are excessive) There might be commercial use of this, but commercial should be able to just get tied into the grid and throw a big inverter at it, like Chademo stations already do.[/QUOTE] If you have a solar array then you are going to cycle your batteries evey day unless you massively oversize your system. A UPS is a great application for lead acid batteries for other reasons than size, lithium batteries don't like sitting at 100% charge for a long time. Most people also don't have a UPS at home either and they are intended for servers more than anything else. A lithium battery UPS would cost a lot more upfront and degrade fairly quickly. Lead acid also deals with heat better, so you don't need a liquif cooling system in your UPS. For solar though you will cycle the pack evey day, it won't sit at 100% more than a couple of hours a day before the output from the array starts to drop, and you can fit a decent amount of power in a relatively small space. A lot of people don't even have a garden to build said shack, an 8 kWh lead acid array is fairly large. You could put a lithium pack inside your house on a wall like a combi boiler if you really wanted to, most people aren't going to dedicate a room to their lead acid battery array.

[QUOTE=Morgen;51107009]If you have a solar array then you are going to cycle your batteries evey day unless you massively oversize your system.[/QUOTE] Uhh....why exactly do you think that? If you are tied to an active grid, you won't cycle. That's the whole point. Batteries in a home solution serve no purpose beyond acting as a UPS*, providing completely off the grid capability, or taking advantage of net metering combined with peak hour rates. Why would you cycle when you are tied to the grid? If you are tied to the grid, you deposit and withdraw power to the grid as needed. The only reason to cycle the batteries when you are tied to the grid is to take advantage of variable rates. That aspect exists completely independently of solar panels**. *or a cheaper backup solution that takes a few seconds/minutes to activate. Your computer cares about uninterrupted power. Your fridge? Not so much. **You don't need solar panels to charge at night, and discharge during the day. Solar panels are nice with variable rates because they perform the best around the same time as electricity selling for the highest rates, but that is equally true with and without batteries discharging during peak hours. It's a separate topic entirely. [editline]26th September 2016[/editline] [QUOTE=Morgen;51107009]For solar though you will cycle the pack evey day, it won't sit at 100% more than a couple of hours a day before the output from the array starts to drop, and you can fit a decent amount of power in a relatively small space. A lot of people don't even have a garden to build said shack, an 8 kWh lead acid array is fairly large. You could put a lithium pack inside your house on a wall like a combi boiler if you really wanted to, most people aren't going to dedicate a room to their lead acid battery array.[/QUOTE] You're seriously overestimating the size of a lead acid battery bank. 6 deep cycle cells the size of a conventional car battery is in the 8kwh range. That's not a shed. It's not as slick and tiny as a lithium pack, and it's certainly a hell of a lot heavier than the lithium bank, but it's definitely not enormous.

[QUOTE=Zephyrs;51107324]Uhh....why exactly do you think that? If you are tied to an active grid, you won't cycle. That's the whole point. Batteries in a home solution serve no purpose beyond acting as a UPS*, providing completely off the grid capability, or taking advantage of net metering combined with peak hour rates. Why would you cycle when you are tied to the grid? If you are tied to the grid, you deposit and withdraw power to the grid as needed. The only reason to cycle the batteries when you are tied to the grid is to take advantage of variable rates. That aspect exists completely independently of solar panels**. *or a cheaper backup solution that takes a few seconds/minutes to activate. Your computer cares about uninterrupted power. Your fridge? Not so much. **You don't need solar panels to charge at night, and discharge during the day. Solar panels are nice with variable rates because they perform the best around the same time as electricity selling for the highest rates, but that is equally true with and without batteries discharging during peak hours. It's a separate issue.[/QUOTE] Why would you pull from the grid when you can use your own energy? The Powerwall is intended to cycle every day, for 10 years at least. They scrapped the one intended for backup only power awhile ago. It would only make sense to pull from the grid in states with very very good incentives. The Powerwall makes solar much more viable in most states. [video]https://youtu.be/jB6jyy0Joq8[/video]

Why wouldn't you want to exchange with the grid? Consider the 4 grid tied situations. A - No solar power. No battery. You have to pull all power from the grid. B - Solar. No battery. You exchange with the grid. For flat rates it's just subtracting your solar panels from your usage. For variable rates, the solar panels are producing the most power at roughly the same time as peak rates. C - No solar, but battery. For flat rates it makes zero sense outside of backup power. For variable rates, you can possibly flip some power for profit, at the cost of cycling an expensive battery. Potentially profitable, but generally quite marginally so. D - Both solar and battery. More or less combine B and C. Maybe the battery lets you sell some stuff back during peak hours, but that's true with or without the panels. Maybe it lets you align your solar production with peak hour rates, but that's some pretty damn thin margins over just selling night time grid power back at peak rates. The only situation where D has substantial benefits beyond UPS/backup power while you are grid tied is when you can't sell power to the grid at all, which is a similar situation to just being off the grid period. In a lot of locations you can sell it back. You might not have equal exchange rates, but for the battery to be worth the cost, it needs to fit in between the margins between what you get for selling vs consuming. That's a really tight space to fit into, and still have it be financially worth the substantial investment in the battery. Any cost that doesn't fit into those margins can be treated as the price you pay for a backup power solution. Do I need to make a shitty MSpaint diagram to illustrate the margins I'm talking about? I feel like I'm failing to explain this in a way that is connecting.

[QUOTE=Zephyrs;51107476]Why wouldn't you want to exchange with the grid? Consider the 4 grid tied situations. A - No solar power. No battery. You have to pull all power from the grid. B - Solar. No battery. You exchange with the grid. For flat rates it's just subtracting your solar panels from your usage. For variable rates, the solar panels are producing the most power at roughly the same time as peak rates. C - No solar, but battery. For flat rates it makes zero sense outside of backup power. For variable rates, you can possibly flip some power for profit, at the cost of cycling an expensive battery. Potentially profitable, but generally quite marginally so. D - Both solar and battery. More or less combine B and C. Maybe the battery lets you sell some stuff back during peak hours, but that's true with or without the panels. Maybe it lets you align your solar production with peak hour rates, but that's some pretty damn thin margins over just selling night time grid power back at peak rates. The only situation where D has substantial benefits beyond UPS/backup power while you are grid tied is when you can't sell power to the grid at all, which is a similar situation to just being off the grid period. In a lot of locations you can sell it back. You might not have equal exchange rates, but for the battery to be worth the cost, it needs to fit in between the margins between what you get for selling vs consuming. That's a really tight space to fit into, and still have it be financially worth the substantial investment in the battery. Any cost that doesn't fit into those margins can be treated as the price you pay for a backup power solution. Do I need to make a shitty MSpaint diagram to illustrate the margins I'm talking about? I feel like I'm failing to explain this in a way that is connecting.[/QUOTE] Yeah it's a tight space to fit into but that's what the Gigafactory is for. Tesla already have their cells down to ~$190 per kWh before the Gigafactory is even producing cells. Obviously though there's a lot of other stuff involved in the Powerwall besides the cells though. If you have net metreing it's great. But a lot of Europe and several states, including Nevada don't and you get charged considerably more than you get paid. There's a ton of lobbying against it as well and people that go hurr dur solar doesn't work without subsidies. If Tesla can get a product cheap enough to fit in that margin then it helps solar a whole lot with all the political uncertainty of subsidies.

[url]http://www.ncsl.org/research/energy/net-metering-policy-overview-and-state-legislative-updates.aspx[/url] Lot of info on net metering there. One problem I have with battery as a solution to poor legislation allowing the sale of power to the grid is that the battery bank is a long term investment. Lets say that you are in a state that doesn't let you sell back at all, or you can't sell back at the same price. Will that be the case in 10 years? How about 5? The thinner your margins are, the longer it will take for the bank to pay for itself. If you can sell any power right now, you could easily be spending a sizable lump on the battery bank, and in a couple years legislation allowing full net metering kicks in, making the pack worthless as anything other than a backup solution. That's a rather bleak outlook on ROI.

If Trump wins the presidential election then we are probably fucked in terms of what solar will get. We will see what they can get the price of the new Powerwall down to. If they can integrate their own inverter or make it work with cheap ones then that will be quite helpful as well. I think 8 kWh is probably enough capacity for a single unit so just need to optimise for cost. If states don't have net metreing already then I don't know if they would add it in the future. There's a lot of push back. Nevada just pushed it out so I don't know if they would bring it back. The UK slashed how much you get paid per kWh recently as well. People always bring up the argument that it's an issue because the grid wasn't built to handle it. Maybe it would be better to subsidise the battery setup instead so power companies are satisfied. Tesla are extremely optimistic about this though, with Musk stating that 60% of the Gigafactory output (150 gWh annually) could go to static storage solutions.

When are we going to see a system for using electric cars as a power source when they're not in use? Be good to put that 100kWh battery to good use when it's sitting idle, instead of having to buy a separate battery just for the house.

[QUOTE=Morgen;51108193]If Trump wins the presidential election then we are probably fucked in terms of what solar will get.[/QUOTE] Net metering is a state legislative issue right now, not a federal one. Trump could conceivably impact tax credits, but that has more to do with the panels than the batteries. Federal regulation barring net metering would most likely get fought pretty hard. Even Texas wouldn't be at all happy about that because they are on an isolated power grid, so federal regulation like that would be perceived as infringing on state rights. [QUOTE=ultradude25;51108338]When are we going to see a system for using electric cars as a power source when they're not in use? Be good to put that 100kWh battery to good use when it's sitting idle, instead of having to buy a separate battery just for the house.[/QUOTE] Well you typically aren't home during the day, so when your panels are generating power, the battery isn't actually there, and this would require you to give up precious range if you weren't very carefully scheduling how and when you used the car.

[QUOTE=ultradude25;51108338]When are we going to see a system for using electric cars as a power source when they're not in use? Be good to put that 100kWh battery to good use when it's sitting idle, instead of having to buy a separate battery just for the house.[/QUOTE] It doesn't really make much sense to use a car as a home battery for reasons Zephyrs stated. Plus the chemistry is different, a car battery is optimized for power output, Powerwall is optimized for cycling. People in your house probably wouldn't appreciate it if you drove off with the power supply either. I'm sure some EVs will do it, rumblings about Tesla adding it but we will see. Only time I could see it being useful and economically viable is during emergencies.

[QUOTE=Morgen;51109810]It doesn't really make much sense to use a car as a home battery for reasons Zephyrs stated. Plus the chemistry is different, a car battery is optimized for power output, Powerwall is optimized for cycling. People in your house probably wouldn't appreciate it if you drove off with the power supply either. I'm sure some EVs will do it, rumblings about Tesla adding it but we will see. Only time I could see it being useful and economically viable is during emergencies.[/QUOTE] is there anywhere where they go into more detail of the chemistry of both systems?