Tesla Wants to Build a Battery for Your House

[donald]

Or $3600 over the ten year warranty period.

So not good enough. But consider Hawaii without net metering.

I expect there are millions of homes and business worldwide where shifting 3 kwh from daytime peak solar to the evening produces a real value of $3/day average. The ROI in this case likely exceeds the cost of borrowing to install the system. Plus it likely improves grid stability in residential neighborhoods in places like Hawaii. Less excess during the day. Reduced evening demand.

Tesla needs net metering to go away for this pricing to work. But it should go away.

And has Sunking believed until 24 hours ago, it is not so much about the technology claims, but the warranty. When the ROI is good, and Tesla or Bosch will stand behind the product for the entire investment period, the purchase becomes a rational decision.

[Amy@altE]

I just watched his announcement. His big (declared) focus is to use the batteries to replace fossil fuels with renewables, primarily solar. Note that saving homeowners money was not a stated objective, saving the planet was. <insert climate change deniers' comments here>.

But, let's do the extremely simplified ROI math.

The PowerPack batteries can be stacked up to 9. The 10kWh is for back-up, the 7kWh is for daily cycling, so let's play with that one. I haven't seen the specs for DoD, but let's use 50% for kicks and giggles (I am not well versed in lithium yet). 7kWh x 9 packs x 30 days a month x .5 DoD = 945kWh a month. That's maybe in the low to average usage range. $3000 x 9 = $27k, without the inverter(s) and solar. Let's pair that with a 10kW PV system, installed for $3/W, another $30k, to make the math easy, I'll throw in another $3k for the inverter or converter, assuming it needs something, totaling $60k for 945kWh a month. At $0.18 per kWh from the grid, that's $170 / month. That's 30 years ROI, except the batteries will not last 30 years, so there is no ROI without huge incentives. Unless saving the planet is considered a good return on investment ; )

I think there's nothing new about the announcement, except now there's a lot of marketing money and coolness factor put behind the old message of grid-tied battery backup solar systems.

[SunEagle]

I just watched his announcement. His big (declared) focus is to use the batteries to replace fossil fuels with renewables, primarily solar. Note that saving homeowners money was not a stated objective, saving the planet was. <insert climate change deniers' comments here>.

But, let's do the extremely simplified ROI math.

The PowerPack batteries can be stacked up to 9. The 10kWh is for back-up, the 7kWh is for daily cycling, so let's play with that one. I haven't seen the specs for DoD, but let's use 50% for kicks and giggles (I am not well versed in lithium yet). 7kWh x 9 packs x 30 days a month x .5 DoD = 945kWh a month. That's maybe in the low to average usage range. $3000 x 9 = $27k, without the inverter(s) and solar. Let's pair that with a 10kW PV system, installed for $3/W, another $30k, to make the math easy, I'll throw in another $3k for the inverter or converter, assuming it needs something, totaling $60k for 945kWh a month. At $0.18 per kWh from the grid, that's $170 / month. That's 30 years ROI, except the batteries will not last 30 years, so there is no ROI without huge incentives. Unless saving the planet is considered a good return on investment ; )

I think there's nothing new about the announcement, except now there's a lot of marketing money and coolness factor put behind the old message of grid-tied battery backup solar systems.

You have to remember that Musk has his fingers in solar PV as well as batteries. Sell more of both would be a big profit for him.

[donald]

Amy, you missed the point of why this is targeted at solar. You analysis is for off grid. This product is about shifting usage on grid to avoid purchasing expensive power.

If the ROI is positive on a financed system, buying it is a rational decision. The system is sized at 7kwh probably looking at typical grid supplied electricity from a smaller residential solar system. (perhaps a 6 kw array is typically sending the grid 3-4kwh during a typical sunny day).

The bigger picture is the question "Is solar cost effective without incentives and with rational electric rates". As you point in your numbers, it's not unless one believes in man made climate change.

But if this is nothing new, please tell me where I can buy a maintenance free 7kwh system with a ten year warranty for $3K.

[Sunking]

Elon said the system would work 'out of the box' with existing solar setups... As there is no inverter that comes with the battery, is it safe to assume this battery would integrate then into an existing inverter?

No it is not Safe to say that as it is not possible.

How is the battery charged? There are no charge controllers for a 450 volt battery, nor are there any off the shelf inverters. So how does it interconnect? No one can answer as it does not exist.

From the add it clearly states to be used to offset peak rates. That tells me it is intended to be charged by the Grid or a Grid Tied Solar System, and the energy released during Peak Hours. How much of that 7 Kwh is usable is mystery, but still waste a lot of energy that could be better utilized. Bottom line battery systems are loosers no matter how you spin it.

The real issue is conventional power generation as there is not enough of it. California is getting exactly what they asked for. SCREWED and the people who live there like it that way.

[Edge of Nowhere]

No real specs nothing to see here

I have been waiting for this announcement before I buy batteries for my new off grid home, I had no real hopes of it being a viable option and now I know. Vaporware, no real specifications have been shared to determine the viability. The risk of riding the bleeding edge is not worth it, I will will cut my teeth on some proven FLA GCs. It is a new home with no historical data only estimated need so I fully expect the batteries to be abused and misused while we get everything tuned, hopefully there will be some real world data and proven results when it comes time to replace them.

[Sunking]

I have been waiting for this announcement before I buy batteries for my new off grid home, I had no real hopes of it being a viable option and now I know. Vaporware, no real specifications have been shared to determine the viability. The risk of riding the bleeding edge is not worth it, I will will cut my teeth on some proven FLA GCs. It is a new home with no historical data only estimated need so I fully expect the batteries to be abused and misused while we get everything tuned, hopefully there will be some real world data and proven results when it comes time to replace them.

Use a Trojan Industrial battery with 60 years of track record in fork lifts. They have 8 year warranty and current testing indicates they are a 10 to 15 year battery cycles to 80% DOD. No one comes close to that at any price point. The Trojan Industrial line is the only battery out there to pass IEC 61427 testing so far up to 2500 cycles to 80% DOD and still counting. The test has been running since 2009 by independent test labs and Trojan. Its the real deal. Best bang for the buck at $300-Kwh.

[Edge of Nowhere]

Yup

Use a Trojan Industrial battery with 60 years of track record in fork lifts. They have 8 year warranty and current testing indicates they are a 10 to 15 year battery cycles to 80% DOD. No one comes close to that at any price point. The Trojan Industrial line is the only battery out there to pass IEC 61427 testing so far up to 2500 cycles and still counting. Best bang for the buck at $300-Kwh.

I was just reading your post about the recent testing Trojan has been working on, I will be buying Trojan batteries. I will be starting out with a single string of 105RE's, collecting data and some real life experience, I hope not to destroy them but we all pay for our education one way or another.

[Amy@altE]

Amy, you missed the point of why this is targeted at solar. You analysis is for off grid. This product is about shifting usage on grid to avoid purchasing expensive power.

If the ROI is positive on a financed system, buying it is a rational decision. The system is sized at 7kwh probably looking at typical grid supplied electricity from a smaller residential solar system. (perhaps a 6 kw array is typically sending the grid 3-4kwh during a typical sunny day).

The bigger picture is the question "Is solar cost effective without incentives and with rational electric rates". As you point in your numbers, it's not unless one believes in man made climate change.

But if this is nothing new, please tell me where I can buy a maintenance free 7kwh system with a ten year warranty for $3K.

I'm just playing devil's advocate. He said he wants to use these to replace fossil fuel. 7kWh isn't going to do that, which is why I scaled it up to an "average" size home usage.

I totally agree that maintenance free is the key here, Trojan's Industrial battery line comes within that price point, but I know a very small fraction of the population who would be able to keep them alive for over a decade.

The ROI is barely there on a financed grid-tied system without incentives, my point is increasing the cost to add batteries is going to greatly limit the number of homes that this is viable for. I'm assuming the 30% fed incentive will not be renewed next year, so it will be up to local incentives, which are currently sketchy at best.

Believe me, I want this to succeed, I'm just trying to add realistic numbers to the marketing hype. Awareness is good, and Elan Musk can certainly get a message out there.

[Sunking]

I was just reading your post about the recent testing Trojan has been working on, I will be buying Trojan batteries. I will be starting out with a single string of 105RE's, collecting data and some real life experience, I hope not to destroy them but we all pay for our education one way or another.

Smart move, RE's have some of the same technology (Smart Carbon) as Industrial line but make no mistake they are not the same. The Smart Carbon does make it possible to operate in PSOC range, but RE's do not have the mass the Industrial line has thus the difference in price per Kwh of capacity. Having said that the RE's are an excellent mid range battery.

[Sunking]

I totally agree that maintenance free is the key here, Trojan's Industrial battery line comes within that price point, but I know a very small fraction of the population who would be able to keep them alive for over a decade.

So what makes you think Lithium batteries are maintenance free or tough batteries? I think you know better than that.

Lithium are far from maintenance free, in fact they take a great deal of more monitoring and automation. They are also the most fragile battery there is with extremely poor thermal characteristics. All Tesla battery systems both in their cars and home units require liquid cooling which is a huge mechanical failure point and energy user along with the automation system to monitor them. Using Lithium Cobalt batteries in an electric vehicle is one thing and needed for an EV where energy density is the most important factor and fire is less of a concern. But Lithium Cobalt in a home is very risky and why they are not allowed to be shipped by airplanes. They can catch fire setting there doing nothing.

[donald]

I have been waiting for this announcement before I buy batteries for my new off grid home,

Something like the Tesla system is what you will joyfully replace your FLA batteries with in 3-5 years.

FLA is like Comcast. Both suck and everyone wants an alternative. But they are often the best choice for now. The Trojans Sunking is carrying on about look good, as long as you are not a complete dork with maintaining the system.

[Sunking]

Something like the Tesla system is what you will joyfully replace your FLA batteries with in 3-5 years.

FLA is like Comcast. Both suck and everyone wants an alternative. But they are often the best choice for now. The Trojans Sunking is carrying on about look good, as long as you are not a complete dork with maintaining the system.

He is buying Trojans. Tesla is pure vaporware. Maintenance free. What idiot told you that?

[Sunking]

I will be starting out with a single string of 105RE's, collecting data and some real life experience, I hope not to destroy them but we all pay for our education one way or another.

OK start with this as it should help you get the most out of the batteries. If you have questions start a thread or PM me.

[Sunking]

Something like the Tesla system is what you will joyfully replace your FLA batteries with in 3-5 years.

How is that possible to do in a Off-Grid battery system? Only in a Green Fantasy Dream can that be done, but not in the real world.