Tesla Wants to Build a Battery for Your House

[Sunking]

Charge controller included: "Single phase and three phase utility grid compatible." Certainly you understand that Tesla needs to integrate the charge controller. This is a system, not a battery.

Do you think Tesla just forgot this system will need an inverter? It doesn't seem to be included. But the beta systems installed to date seem to have the inverter from tesla.

It is not made for off-grid. It is made to buy power from the POCO and use later. What are you crowing about? There is nothing special about the battery. A Trojan Industrial battery runs circles around it.

[Samsolar]

So please tell us exactly where to find a Charge Controller and Inverter made to work with a 450 volt battery? Please tell godsend to answer. Inverters can be found, but battery Inverters made in in that voltage range are usually measured in MW, not KW. No such thing as a 450 volt charge controller.

Does anyone have a reference to the 350VDC or 450VDC numbers thrown around in this thread or are these just best guesses?

[Amy@altE]

Does anyone have a reference to the 350VDC or 450VDC numbers thrown around in this thread or are these just best guesses?

It's in their specs. http://www.teslamotors.com/powerwall

[donald]

It is not made for off-grid. It is made to buy power from the POCO and use later. What are you crowing about? There is nothing special about the battery. A Trojan Industrial battery runs circles around it.

You see, it's about the warranty. It's alllll about the warranty.

Did anyone (who is open mined) run the numbers for peak shaving based on their electric rates? Maybe assume 2-3kwh used per day over ten years? The system probably breaks even in the $.20 -.30 range. It seems that in some markets the utility could finance the system with a positive cash flow to the owner.

[Sunking]

You see, it's about the warranty. It's alllll about the warranty.

There are a lot of batteries with 10+ years of warranty. There is nothing special about the battery and has had ZERO TESTING with ZERO track record. Warranty does not mean squat.

[russ]

You see, it's about the warranty. It's alllll about the warranty.

Did anyone (who is open mined) run the numbers for peak shaving based on their electric rates? Maybe assume 2-3kwh used per day over ten years? The system probably breaks even in the $.20 -.30 range. It seems that in some markets the utility could finance the system with a positive cash flow to the owner.

You post this stuff and talk about open minded?

Before the utility does that they would time shift excess baseline power from night periods to meet peak requirements.

Contrary to what some feel, the utility does not exist to give you freebies.

[donald]

You post this stuff and talk about open minded?

Before the utility does that they would time shift excess baseline power from night periods to meet peak requirements.

Contrary to what some feel, the utility does not exist to give you freebies.

I'm talking about home metering rates. What are you talking about? The 7kw system is not going to be installed in homes with flat rate metering. The 7kwh produces daily savings over the life of the unit for users with demand based pricing. Not complicated. Discounted present value of the costs vs. savings determines the viability of the system.

Solar only potentially amplifies the savings by not selling power back to the utility at a discount and using it in the evening.

[Samsolar]

It is not made for off-grid. It is made to buy power from the POCO and use later. What are you crowing about? There is nothing special about the battery. A Trojan Industrial battery runs circles around it.

A secondary use might be to store POCO power, but the primary use is to store your solar production during the day to use at night when your panels are not producing power. Tesla also believes that there is a market for these in places where there is no grid/POCO at all and there is unlikely to be one anytime soon if ever.

Saying something can run circles around something else is nice, but it really doesn't quantify the difference between them. Perhaps you could offer more details/data on the advantages and disadvantages of the Trojan battery *system* you mention? I'm sure you know what they are, but others like myself do not.

I'm slightly suspicious that the Tesla solution might do a few things that the Trojan battery you mention does not.

[russ]

I'm slightly suspicious that the Tesla solution might do a few things that the Trojan battery you mention does not.

Make money for Musk if nothing else.

[Stuntman]

Powerwall with existing solar

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? I'm no electrician and have only just yesterday signed papers for my solar PV system to be installed.. so forgive me if that is an ignorant question... I was just thinking of the Powerwall cost, plus installation, plus inverter.. the installation and inverter would cost almost as much as the battery.. UNLESS it could utilize the existing inverter...

Thanks!

[J.P.M.]

Over the years I've sort of noticed a positive correlation between how early in game someone chooses to buy into a new technology and how much they actually know about that technology - early adoption, less subject knowledge. Same with other things like time shares or solar leases. In general, at least to my view, that is, more subject knowledge, later adoption is also usual and common.

[donald]

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? I'm no electrician and have only just yesterday signed papers for my solar PV system to be installed.. so forgive me if that is an ignorant question... I was just thinking of the Powerwall cost, plus installation, plus inverter.. the installation and inverter would cost almost as much as the battery.. UNLESS it could utilize the existing inverter...

It doesn't need an inverter for the target home solar market. It needs a DC to DC converter apparently. Figure the average on grid solar install is going to take an electrician a half day. We know this system has a sophisticated control system. We know the 7kwh system is designed to instal to existing grid tie solar. It's unlikely there is a major hardware piece missing.
The 10 kwh system will probably frequently need substantial additional expense.

[J.P.M.]

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? I'm no electrician and have only just yesterday signed papers for my solar PV system to be installed.. so forgive me if that is an ignorant question... I was just thinking of the Powerwall cost, plus installation, plus inverter.. the installation and inverter would cost almost as much as the battery.. UNLESS it could utilize the existing inverter...

Thanks!

I'd wait for the installs and see what develops rather than rely on what someone with skin in the game says. Maybe it's a great system, but saying so don't make it so. Time will tell.

[Ian S]

Did anyone (who is open mined) run the numbers for peak shaving based on their electric rates? Maybe assume 2-3kwh used per day over ten years? The system probably breaks even in the $.20 -.30 range. It seems that in some markets the utility could finance the system with a positive cash flow to the owner.

Here in Phoenix under the existing APS demand rates for residential, every kW for the highest power peak in a "summer" month costs the customer ~$15. There are only about 20 non-holiday weekdays days in the month where the demand rate is operative. Assume the 7 kWh Tesla system can provide 4 kWh for peak shaving 20 days per month. That probably provides a reduction of ~3 kW in the power peak subject to the demand rate. That's a savings of about $45/month. Winter demand rates are less but I estimate you could save perhaps $30/month. Or $3600 over the ten year warranty period.

[Ian S]

A Trojan Industrial battery runs circles around it.

Please be more specific. Especially regarding parameters such as cycle life, warranty, cost, maintenance, size, weight, etc.