PowerWall and "The Missing Piece..." Event

[Gtoffo]

Right, but for modularity and adaptability we need technical specifications on how it works in order to bring your own inverter etc...

That is why they are partnering up with other companies. When you reserve you will get called by an installer and they will take care of that for you (and discuss details as much as you want). Tesla won't take care of installation or anything else. That's not their business.

At least that's how I'm interpreting it.

 

[ThosEM]

So, when will we see a home charging hookup for the Model S that allows its battery to be used this way, without buying additional battery capacity? Here I am with about 60 KWh that I don't use in daily commuting, which could serve in a pinch (assuming I leave the car home), but there's no way to do that now.

This was one of the original attractions of EVs back when the Roadster first appeared, but which has been unrealized in practice. Is there a chance that it could happen now that the hardware/software has been worked out to use a battery in this way?

 

[BornToFly]

So, when will we see a home charging hookup for the Model S that allows its battery to be used this way, without buying additional battery capacity? Here I am with about 60 KWh that I don't use in daily commuting, which could serve in a pinch (assuming I leave the car home), but there's no way to do that now.

This was one of the original attractions of EVs back when the Roadster first appeared, but which has been unrealized in practice. Is there a chance that it could happen now that the hardware/software has been worked out to use a battery in this way?

Hopefully never, because there would instantly be a bunch of A-holes that would use Superchargers to charge their cars, so they can drive home and power their house with their car....

 

[Doug_G]

One post moved to snippiness

 

[RubberToe]

I think many people are missing the point of this announcement. I don't think it's so much about selling a product as it is unveiling an idea. A BIG idea. The marketing will come with time, because it's an inevitable consequence of the idea. What's important is that Elon has a vision for the future that could actually work. As he noted, the numbers are big, but we're already producing numbers like that every 20 years just in cars alone... which are more complicated and expensive to produce than the packs.

I for one feel somewhat optimistic after seeing that there is a vision developed by a relatively small company that could have consequences for the entire globe. This is stuff that world governments have completely FAILED to champion - they're elected to lead but the only place they've lead us is straight down the garden path. Left or right, democratic or communist - they've all failed. It's embarrassing that the private sector must lead the way... but as long as someone decides to lead, that's a Good Thing.

Finally there's a plan that could actually work and, most importantly, is actually achievable.

Don't worry about whether it'll work in your garage and save you piles of money... consider how this can work for the greater good. It's an example of thinking globally and acting locally if I've ever seen one.

+1000

I'll take vision and execution over stand up performance every time. I thought slide 1 starting with the Sun was absolutely brilliant. Deploying this on even a modest scale can/will be something that can change the world. If it can be done more economically than the current approach, Elon gets credit for "figuring it out" when entire countries and the world could not. Just like the Model S. My money is on Elon.

RT

 

[smartypnz]

Still not clear....

Are there tax incentives with this?

 

[AB4EJ]

Still not clear....

Are there tax incentives with this?

Probably not in most places, but there are many possible economic reasons. Consider the Power-pack - this can take the place of a commercial UPS for powering a computer room. The batteries for those (lead-acid) have to be temperature controlled, and still replaced every 5 to 7 years (if you want them to work when power goes out). Tesla's Li - ion batteries can be much longer lasting (not often replaced) - and the volume production of the systems can hold the price down. Also, you don't have to vent (explosive) hydrogen gas.

Liebert and other companies that make commercial UPS systems better take notice.

 

[dsm363]

I think you're safe.. this isn't a Steve Jobs moment.. and this isn't about cars. I really doubt there's going to be a "oh, one more thing..." moment.

Has Elon ever, really done the "oh, one more thing" thing to make a big announcement? I don't think so. That's Apple's gig, and I don't think Elon would usurp that.

At the Model S event in 2011 they did. He walked off the stage and George reminded Elon he forgot something. He came back on stage and joked 'One more thing' (think he said something like that) and announced there would be a performance version at launch.

 

[RDoc]

The 2/3.3 kW output seems a bit low for time shifting. That means the heavy 240V uses, e.g. AC, stove, oven, dryer, etc. have to remain on grid power since any one of them would be too much. What happens with 120V loads like dishwashers, disposals, refrigerators, etc. that combined with normal lighting, electronics, etc. could together go over the 3.3 kW peak rating? I'm not seeing how these would be all wired for normal daily time shifting use. For power outages, only a subset of circuits would be wired of course which would work fine.

If most homes need to have 2 or 3 of these units to meet their peak load needs then the financial calculations are quite different than assuming the full capacity will be used daily.

 

[Owner]

Thanks Dennis, we are in the same "neighborhood". I did pay PGE $157 dollars last year but I gave away electricity to them for several other years. I don't think my current consumption at best with this would net me about $200 at best case per year.

I don't work. :biggrin: So my usage is non-traditional.

I need to churn this idea a bit in my head and run some numbers. I want to from an environmental perspective do this if I can justify it.

On June 9, 2011, the California Public Utilities Commission (CPUC) approved the Net Surplus Compensation rate based on current market prices, which is between $0.03 to $0.04 cents per kilowatt-hour (kWh).

Seven Years of Solar | TESLA OWNER
Eight Years of Solar | TESLA OWNER

Your analysis would

I am in a very similar situation as you - solar for 7+ years and almost at annual $$ breakeven after reducing my electricity cost by over 90% while adding charging for 2 EVs.

But here is a quick and dirty ROI analysis for someone in the PG&E service area who is on the EV rate and fills the Powerwall during off peak hours and drains it during peak hours:

183 summer days * $.32 peak vs. off peak differential * 10kwh/day = $586 summer savings
182 winter days * $.20 peak vs. off peak differential * 10kwh/day = $364 winter savings

So a $3500 (+ inverter and installation) investment yields $950 annual savings and free backup during outages. Less than 5 year payback, assuming all 10kwh is usable. If it is like the Model S with only 75/85 = 88% usable it will take another 7 months to break even.

 

[jgs]

Hopefully never, because their would instantly be a bunch of A-holes that would use Superchargers to charge their cars, so they can drive home and power their house with their car....

I think you could fix that by requiring the owner to agree to a contract before enabling the v2g functionality. The contract would specifically ban this kind of behavior, with the penalty being you get your supercharging revoked. It probably wouldn't be hard to catch egregious offenders, they would exhibit very specific usage patterns.

Besides that, the hourly pay rate for doing it sucks. Let's be very optimistic: suppose your drive time to the SC is 15 minutes, your daily power consumption is 24 kWh, you keep your SoC low enough that you can drop those 24 kWh into your pack at 135 kW, you always manage to charge at that rate and you always get a stall as soon as you arrive at the SC. It takes you 11 minutes at the SC to get your 24 kWh, so your total time is 41 minutes round-trip. Let's assume your power costs you an expensive $0.30/kWh. You just made $7.20 for 41 minutes of work, a wage of about $10.60/hour. That's discounting the cost of wear and tear on your car and especially its battery pack. If your power is less expensive than $0.30/kWh (it probably is) or any of the other wildly optimistic assumptions are violated, you quickly drop from merely a lousy wage to sub-minimum wage. Now keep in mind that in order to do this minimum wage job, first you have to be a person who can afford a Model S. (Hmm, that makes the fact that the $10.60/hour is tax-free more valuable -- but the overall value proposition is still horrible.)

So, I think the universe of serial abusers, in real life, would be quite small. Not zero, there's always somebody. But not worth getting worked up about.

(As an alternative, maybe Tesla could install a bank of these near the SC bays: Blake Fall-Conroy)

 

[MarcG]

Did anyone who was at the event in person take photos of the different colored Powerwalls? I'd be interested to see what they look like (I'm guessing they match Model S colors?)

 

[wk057]

Posted my recording of the live stream for anyone who missed it:

https://www.youtube.com/watch?v=t3BfzomanZ4

 

[Merrill]

I am in a very similar situation as you - solar for 7+ years and almost at annual $$ breakeven after reducing my electricity cost by over 90% while adding charging for 2 EVs.

But here is a quick and dirty ROI analysis for someone in the PG&E service area who is on the EV rate and fills the Powerwall during off peak hours and drains it during peak hours:

183 summer days * $.32 peak vs. off peak differential * 10kwh/day = $586 summer savings
182 winter days * $.20 peak vs. off peak differential * 10kwh/day = $364 winter savings

So a $3500 (+ inverter and installation) investment yields $950 annual savings and free backup during outages. Less than 5 year payback, assuming all 10kwh is usable. If it is like the Model S with only 75/85 = 88% usable it will take another 7 months to break even.

Thanks for the info, I have a 4.5kW solar system and second meter for the Tesla. My yearly cost for the car is around $150 and this includes 5 months a year with no PG&E bill. The other 7 months my bill is around $150 a month, it would be nice to store the peak energy in the powerwall and then use it when I have no sun at night. Not sure how this would work or if it makes sense, if I could save $500 to $1000 a year I would then be close to $0. Need to learn more about this.

 

[ItsNotAboutTheMoney]

Hopefully never, because their would instantly be a bunch of A-holes that would use Superchargers to charge their cars, so they can drive home and power their house with their car....

I'd always thought Tesla wouldn't want to do it because within 10 years Tesla aims to get battery prices down to the point where:
- there's enough cars to make V2G worth it
- batteries are so cheap V2G isn't worth.

But, you're right, the higher arbitrage value would encourage additional Supercharging.

 

[austinEV]

Hopefully never, because their would instantly be a bunch of A-holes that would use Superchargers to charge their cars, so they can drive home and power their house with their car....

This is why I wish they had simply made supercharging pay-as-you-go. Free will cause headaches like this.

 

[wk057]

Shifting 7kWh per day (the daily cycle unit described, not 10kWh backup unit) @ 100% efficiency (not possible) is a shift of 2,555 kWh per year by buying off-peak and using battery power on-peak. At PSE&G ToU rates in NJ, assuming you shifted from off-peak to on-peak, that'd be a savings of about $0.14/kWh averaged over a year. So that would come out to $357.70/yr savings or about 8 years 5 months just to break even on a $3000 battery, not counting the inverter that is needed for this that isn't included. Factor in a realistic round trip efficiency of about 70-80% and you're looking at another 2 to 3.5 years to break even. Add in the inverter and you're adding additional years.

Honestly, this is horrible from an investment standpoint for this use case for someone without renewable generation.

Now, if you have solar panels already this could make more sense. Let's say the battery is used to level loads so that you completely eliminate 7kWh per day of on-peak usage. (Keep in mind it doesn't really matter that the max output of this pack is only 2kW if your on-peak time is > ~3.5 hours...)

Using the same PSE&G rates, that would be an average of $0.245 per kWh. Running that further would be about $626/yr saved (at 100% efficiency) and about $440/yr saved at the low end of the efficiency spectrum. This assumes you've already ponied up for solar, though. But from that perspective it's only five to seven years to break even which isn't nearly as bad as above and actually makes a good bit of sense.

 

[ItsNotAboutTheMoney]

I think you could fix that by requiring the owner to agree to a contract before enabling the v2g functionality. The contract would specifically ban this kind of behavior, with the penalty being you get your supercharging revoked. It probably wouldn't be hard to catch egregious offenders, they would exhibit very specific usage patterns.

Besides that, the hourly pay rate for doing it sucks. Let's be very optimistic: suppose your drive time to the SC is 15 minutes, your daily power consumption is 24 kWh, you keep your SoC low enough that you can drop those 24 kWh into your pack at 135 kW, you always manage to charge at that rate and you always get a stall as soon as you arrive at the SC. It takes you 11 minutes at the SC to get your 24 kWh, so your total time is 41 minutes round-trip. Let's assume your power costs you an expensive $0.30/kWh. You just made $7.20 for 41 minutes of work, a wage of about $10.60/hour. That's discounting the cost of wear and tear on your car and especially its battery pack. If your power is less expensive than $0.30/kWh (it probably is) or any of the other wildly optimistic assumptions are violated, you quickly drop from merely a lousy wage to sub-minimum wage. Now keep in mind that in order to do this minimum wage job, first you have to be a person who can afford a Model S. (Hmm, that makes the fact that the $10.60/hour is tax-free more valuable -- but the overall value proposition is still horrible.)

So, I think the universe of serial abusers, in real life, would be quite small. Not zero, there's always somebody. But not worth getting worked up about.

(As an alternative, maybe Tesla could install a bank of these near the SC bays: Blake Fall-Conroy)

Tesla is planning to move down the market for Model 3 and Gen 4 and sell in much higher volume at lower prices.

Imagine that the Supercharger is located near a relatively cheap food place. You park at the Supercharger, and while you charge your car you go inside and eat. You get something like a sandwich that costs close to or less than $10.60 while your car charges. You go home and you have no cooking, no dishes, no cleaning to do (which also saves you some peak-time electricity use).

I do think he has a point.

 

[beths11]

Posted my recording of the live stream for anyone who missed it:

https://www.youtube.com/watch?v=t3BfzomanZ4

Thanks for the post, I appreciate you making it so easy for me to watch.

 

[aznt1217]

Shifting 7kWh per day (the daily cycle unit described, not 10kWh backup unit) @ 100% efficiency (not possible) is a shift of 2,555 kWh per year by buying off-peak and using battery power on-peak. At PSE&G ToU rates in NJ, assuming you shifted from off-peak to on-peak, that'd be a savings of about $0.14/kWh averaged over a year. So that would come out to $357.70/yr savings or about 8 years 5 months just to break even on a $3000 battery, not counting the inverter that is needed for this that isn't included. Factor in a realistic round trip efficiency of about 70-80% and you're looking at another 2 to 3.5 years to break even. Add in the inverter and you're adding additional years.

Honestly, this is horrible from an investment standpoint for this use case for someone without renewable generation.

Now, if you have solar panels already this could make more sense. Let's say the battery is used to level loads so that you completely eliminate 7kWh per day of on-peak usage. (Keep in mind it doesn't really matter that the max output of this pack is only 2kW if your on-peak time is > ~3.5 hours...)

Using the same PSE&G rates, that would be an average of $0.245 per kWh. Running that further would be about $626/yr saved (at 100% efficiency) and about $440/yr saved at the low end of the efficiency spectrum. This assumes you've already ponied up for solar, though. But from that perspective it's only five to seven years to break even which isn't nearly as bad as above and actually makes a good bit of sense.

You're assuming no discount rate in money, but also the one thing you forget is the backup generator portion of it. Buying this battery + inverter + solar easily over comes the cost of a back up generator.

A simple Google search pulls these standby generator prices up.