PowerWall and "The Missing Piece..." Event

[beeeerock]

A pure capitalist would be neither dismayed nor surprised by the source of the innovation and vision.

LOL, no argument from me on that!

I just feel complete dismay when I look at all the politicians around the world, sucking up big pay cheques and spending all their time worrying about who should be allowed to get married and plotting how they can get oil out from under their neighbour's sand without them noticing. If we just used our heads we'd realize we don't actually need that oil... but we might have to forego some stupid profits for a few years to make it happen.

It comes down to how our economies work... based on *growth*. There is no recognition that growth can't continue indefinitely unless we figure out how to make the planet larger. Imagine if we managed to reach the 2 billion units Elon mentioned. Great business opportunities along the way. But what happens when it's built out? We'll be reduced to replacing dead panels and cells and the economic drive tied to energy will become a minor part of the economy. Just the opposite to what we know today. That's a staggering economic transition!

 

[mwulff]

People here have commented on why they won't buy this product. Here are my thoughts as to why I am going to line up (all alone) outside Tesla here and buy the very first unit I can get my hands on.

First power here is expensive (with a capital E).

- Grid power costs $0,33 pr kWh (all prices in $US) and 80% of that is tax.
- Solarpower shipped to the grid can be used inside of an hour with no penalty. Hence the grid is a 1-hour battery.
- Solarpower sold back to the grid gives me $0,195 pr kWh.

Since we are not home at noon and can't use our solarpower this means that we effectively become an underpaid generator for the grid. The Powerwall would allow us to run without the grid for approx. 150-250 days pr year. It really makes solarpanels a much better deal than before and as an added bonus the tax-man never sees a dime.

Our daily usage is between 8-14 kWh's and with just a little work we could probably get below 8 kWh all the time.

So to sum it up: I want this powerwall and I wanted it yesteryear.

 

[bwa]

The Powerwall would allow us to run without the grid for approx. 150-250 days pr year.

There's going to be a lot of numbers here that make good sense for a lot of installations. I just found this one and realized this is one of them: during low solar generation seasons, you're going to suck up more utility energy anyway, so not having enough battery juice for all day during low solar generation seasons is OK since you're going to end up using other sources anyway.

And, if you don't like this and have more money, you can invest in a bigger system, with more solar generation, battery capacity, converters, electronics, and wiring, and you will be less utility dependent. The small unit size of the pack isn't an impediment.

I'm surprised someone said 9 packs is the max. That's kind of an esoterically medium sized amount that would be too small for some particular installations. I'm guessing it just throws you to a different product grouping and you get the "business" boxes at that point, probably some type of set of 3 dimensional boxes, like smaller versions of some of the utility picture depictions posted here.

 

[dennis]

I'm an environmentalist and a solar owner for over 7 years...

But I'm not even slightly inclined to get one. Convince me am I missing something?

My situation:
1. power generation on an annual basis is even
2. i have variable rates
3. i charge the Tesla in the middle of the night
4. I generate 75% of the energy during 4 months of the year (I'm just guessing here!!!)
5. I don't have big problems with power going out in the last few years and would not pay $3500 to solve that anyways.
6. I pay $10 (guessing here) to stay connected to the grid per month.

I'd have to add more solar to be able to go off grid.

I want to be excited about this and am for some people.

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.

 

[sub]

I've got an 8kw solar system on my house and produce more energy than I need, not sure I can take advantage of this financially but I'm one of those that likes the idea of being off grid. However, and maybe someone else can answer this, would batteries not make significant financial sense on new builds? I know there are fees and expenses to hooking to the grid on a new home, put that toward batteries and skip the hookup completely. I plan to build a house in the future on acreage, never going on grid with this system is the way to go.

 

[mwulff]

I've got an 8kw solar system on my house and produce more energy than I need, not sure I can take advantage of this financially but I'm one of those that likes the idea of being off grid. However, and maybe someone else can answer this, would batteries not make significant financial sense on new builds? I know there are fees and expenses to hooking to the grid on a new home, put that toward batteries and skip the hookup completely. I plan to build a house in the future on acreage, never going on grid with this system is the way to go.

I believe this is only really feasible in really sunny regions where large houses are the norm. You need a significant solar-array to stay off the grid completely, especially if you have an EV or two that needs charging. But it could be done for sure.

 

[MITE46]

I don't see a good ROI for standard tiered rate customers...which are the majority? I guess they can move over to TOU, but then, it would be interesting to see how utilities might shift the pricing due to these home battery systems.

With the Solar City stuff, I thought they had to relocate the critical loads to be fed off the inverter so in the event of a power outage, those loads could be island-ed and powered safely. I also thought there was a lot of regulation that prohibits battery systems from powering loads that are not behind an inverter if you are grid tied. Any one know?

I think the presentation was a good eye opener for people who never thought a battery could power a home and the big CO2 picture.

 

[Ampster]

........... I also thought there was a lot of regulation that prohibits battery systems from powering loads that are not behind an inverter if you are grid tied. Any one know?
.....

Yes, you are correct, if you are powering loads in front of an inverter you are grid tied and have to meet those regulations. The advantage of powering loads after the inverter are that you do not need permission to operate as far as I understand it. Many inverters can switch those loads back to the grid when the batteries are low and need charging. I have an Outback Radian inverter that does that seamlessly.

 

[Foghat]

I don't see a good ROI for standard tiered rate customers...which are the majority? I guess they can move over to TOU, but then, it would be interesting to see how utilities might shift the pricing due to these home battery systems.

With the Solar City stuff, I thought they had to relocate the critical loads to be fed off the inverter so in the event of a power outage, those loads could be island-ed and powered safely. I also thought there was a lot of regulation that prohibits battery systems from powering loads that are not behind an inverter if you are grid tied. Any one know?

I think the presentation was a good eye opener for people who never thought a battery could power a home and the big CO2 picture.

Solarcity only has to offer a package deal that is cheaper per kWh then the utilities. The time of use is not a restriction. Overall cost/kWh is. I also think Elon's presentation opened the eyes for a lot of things. First and foremost the world can become 100% renewable within many of our lifetimes... That is super compelling and motivating to a few of us out there.

 

[allz]

Looking for a video from event, no chance to find it.. lost 30min.. no luck. :/

 

[Dave EV]

10 year life
$7500/3652.5 = $2.05/day + cost of money.

JB Straubel talked about a near-future $100/kW power electronics cost at the now infamous storage symposium.
So 10kWh/5kw => $500 power cost.
At $300/kWh => $3000 battery cost.
That's $3,500 for batteries and power electronics.
$x for everything else.
Let's say they want gross margin g.
I'm hoping that they've aimed for $5k before shipping, for psychological reasons.
Then
$5k = (1 + g) x ($3.5k+$x)
g = 20%, $x = $666.67
g = 30%, $x = $346.15

Maybe doable if they aren't seeking high margin? I'm hoping that Tesla is looking at this as a cell demand driver, in order to get the Gigafactory investment, rather than trying to make a fast buck on the back of CA's storage targets.

Just wanted to congratulate you on nailing the price of the PowerWall just over a week ago!

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.

The daily cycled version is only 7 kWh, and you have to take into account efficiency losses when charging and discharging which is 92% round-trip.

 

[anticitizen13.7]

I think this presentation was more for investors. The storage business is 1000x more important for business and utilities right now. The home aspect is only relevant to people in a few specific states (in my opinion--it's a very nice tool to have for every home, but not at the price points without solar and without time of use restrictions).

Tons of businesses use batteries now in large quantities. This is going to turn that market completely upside-down.

I get that sense too. The reaction in this thread is somewhat ambivalent overall... While the investors short term thread reaction is gleeful.

 

[1208]

Maybe they want to turn off all the lights and then turn them on and show how the batteries are powering the entire event. That wouldn't be very impressive during the day but at night, it would definitely get the point across.

You called it right! :smile:

 

[MITE46]

Yes, you are correct, if you are powering loads in front of an inverter you are grid tied and have to meet those regulations. The advantage of powering loads after the inverter are that you do not need permission to operate as far as I understand it. Many inverters can switch those loads back to the grid when the batteries are low and need charging. I have an Outback Radian inverter that does that seamlessly.

Your critical loads have to be connected to the Outback Radian yes? For many existing homes, that's going to be quite difficult and expensive? Especially, if the critical loads is off of a subpanel say in the master bedroom? How much was the Outback Radian? Couple thousand at least right?

 

[Gerardf]

The big message of today to my opinion is a break-though in the costs of energy storage, openng up a very much wider market for energy storage and completely new use cases.

It seems the products of new Energy 'division' are offering the best ROI now for the large systems, as well as for specific residential cases in areas where the price difference between peak & low electricity price is high. Next to that there are also economic use cases now in areas where the power is not stable.

I see that Tesla already has several significant projects ongoing at utilities, but also in data centres. For Data centres the offering is very interesting, as they need a solution that is low maintenance and has a high energy density, as room is expensive at data centers. The lower price that Tesla now offers will result in strong business there, and will keep Tesla busy for some time. As soon as the GigaFactory is producing the price for energy storage will even get lower, as a result there will be more residential use cases that come within ROI range. For now Tesla will have more than enough production scale up to do to be able to deliver 'just' the data centre & utility markets, as well as some special residential markets. There is no production capacity in LiION to cover a worldwide residential market now anyway, that will even require more GigaFactories to come online. As someone stated in the investor section, Tesla will be production constrained for many years to come.

On the other hand I feel Tesla is actually road mapping wide deployment in the residential use cases as well. Looking at the spec's I noticed that the new system has a 350 - 450 V DC, actually exactly the same DC voltage range as our cars !
I feel this is no coincidence. I can imagine our car to later be directly DC-charged from this via some interface box, or (even more interesting) connecting the car via that interface to the same 350-450V inverter for Vehicle-to-Grid (or micro-Grid) use.

So, for those not seeing the residential use case for themselves yet, have some patience and give it time for the big projects to enable even more GigaFactories and bring the cost down for residential use cases. Very much like waiting for the Model-3 price levels to be enabled by the Model-S sales.

 

[matbl]

While I guess this will make sense for people with high electricity prices where solar power makes sense (I pay 11 cents per kwh and live in sweden so...) there is one thing I don't get.
Max continous output is 2 kw? That's kind of low isn't it? Not enough to even boil some water?
Even if it would make sense to get these, just for it to equal my current feed into my house I would need nine of them connected 3 per phase? And I have a pretty standard 3*25A feed (240V phase-neutral).

 

[deonb]

While I guess this will make sense for people with high electricity prices where solar power makes sense (I pay 11 cents per kwh and live in sweden so...) there is one thing I don't get.
Max continous output is 2 kw? That's kind of low isn't it? Not enough to even boil some water?
Even if it would make sense to get these, just for it to equal my current feed into my house I would need nine of them connected 3 per phase? And I have a pretty standard 3*25A feed (240V phase-neutral).

You guys with your 240V 10A kettles... boiling water takes longer in the U.S. (It actually seriously does.)

But yeah, you need 4 of these things just to power a heat pump.

 

[WarpedOne]

Try to think in shades of gray and not only in black/white.
Yes, 2kW is lowish by itself but when added to 3kW from grid it becomes 5kW with only 3kW grid connection.
Two units become 7kW.

Here in my part of the world we pay for electricity in three parts:
- maxim line power (breaker rating): fixed price/month
- transportation: we pay ~$0.10 per each kWh supplied to our home at 3kW max. Higher breaker ratings have higher transportation cost.
- consumption: we pay another ~$0.10 per each kWh "consumed" at 3kW max. Price is again dependent on breaker rating.

So, in the end we are charged three times for each kWh consumed. This scheme is set up so that small residential (flat) owner/renters pay low electricity bills but larger consumers end up paying superlinear rates.

Buying a tesla means a fatter breaker to be able to charge with 8kW and higher cost per kWh. With two daily units for $6k one can skip upgrading power feeds to his garage. ROI can be less than 2 years.

I'm glad tesla didn't draw things out to opaque, I might still have oportunity to grab some more shares before they skyrocket...

 

[Benz]

Anybody got a link to a recording of the event. It was a bit too early for me (5am).

 

[ReversePolarity]

Seeing that solar powered homes can get a 30% tax rebate off the $3.5k purchase, it still seems that there wouldn't be too much incentive to purchase one if your bill is already $0, unless being "energy independent" and reducing the night time energy draw is an important to you. But its definitely the way to kill off fossil fuel power plants although that'd require a bit of govt willpower

I'd get one for the office (no solar) if the power company offers a sizeable enough discount for me to charge the battery at night and use it during the day...