Tesla Wants to Build a Battery for Your House

[pleppik]

The Gigafactory is currently under construction and Elon has been tweeting about the new product that is not a car.... My thought is this will be a relatively small battery designed for on grid battery back up. Likely to be distributed exclusively through Solar City at least initially and require grid tie and some sort of monitoring agreement. Not enough capacity for off grid use and more costly than FLA. All speculation of course but I thought it would be a good time to revive the thread.

You are right that the mystery product will probably be some sort of battery.

But I'm still hoping it's a personal spaceship.

[DanKegel]

Related article:

http://www.technologyreview.com/news/536336/inexpensive-electric-cars-may-arrive-sooner-than-you-think/

"The true cost of lithium-ion batteries in electric cars is a secret closely held by manufacturers. And estimates of the cost vary widel... But a peer-reviewed study of more than 80 estimates reported between 2007 and 2014 determined that the costs of battery packs are “much lower” than widely assumed by energy-policy analysts.
The authors of the new study concluded that the battery packs used by market-leading EV manufacturers like Tesla and Nissan cost as little as $300 per kilowatt-hour of energy in 2014. That’s lower than the most optimistic published projections for 2015, and even below the average published projection for 2020. The authors found that batteries appear on track to reach $230 per kilowatt-hour by 2018."

[Johann]

Related article:

http://www.technologyreview.com/news/536336/inexpensive-electric-cars-may-arrive-sooner-than-you-think/

"The true cost of lithium-ion batteries in electric cars is a secret closely held by manufacturers. And estimates of the cost vary widel... But a peer-reviewed study of more than 80 estimates reported between 2007 and 2014 determined that the costs of battery packs are “much lower” than widely assumed by energy-policy analysts.
The authors of the new study concluded that the battery packs used by market-leading EV manufacturers like Tesla and Nissan cost as little as $300 per kilowatt-hour of energy in 2014. That’s lower than the most optimistic published projections for 2015, and even below the average published projection for 2020. The authors found that batteries appear on track to reach $230 per kilowatt-hour by 2018."

So since a tesla has a about a 80 kwh battery, per your statement that battery would cost about $24,000.

[Living Large]

So since a tesla has a about a 80 kwh battery, per your statement that battery would cost about $24,000.

That figure is not far from what some people on a Tesla forum are suggesting the cost would be to replace new today. Closer to $30K.

[FishGun]

Will probably be something like this:

http://www.asd-sunstorage.com/wp-content/uploads/2013/11/brosch%C3%BCre-englisch_druck.pdf

A battery bank and some smarts. A few people doing it but I agree with a few earlier posts: Tesla will most likely win on econ of scale and wow factor.

[SunEagle]

Will probably be something like this:

http://www.asd-sunstorage.com/wp-content/uploads/2013/11/brosch%C3%BCre-englisch_druck.pdf

A battery bank and some smarts. A few people doing it but I agree with a few earlier posts: Tesla will most likely win on econ of scale and wow factor.

There have been a number of companies starting to provide a solar energy "storage system". While all of the advertisements looks cool you rarely see what the cost is for the system. Without that data it is hard to calculate what it costs to generate a kWh from the "storage system" to compare what it costs to purchase that same kWh from the Utility.

Until those "storage systems" gets down in cost where they are comparable to what the POCO charges per kWh then they will still only be a rich persons toy and not something that common folk can afford.

[DanKegel]

Yup. Everyone knows it's going to be batteries with smarts, and that
laptops, phones, and electric cars are driving battery technology
to the point where it will make sense for solar... but nothing's quite
ready for mass market yet. Ideas are cheap; execution is tough.
The next five years are going to be interesting.

[Ian S]

There have been a number of companies starting to provide a solar energy "storage system". While all of the advertisements looks cool you rarely see what the cost is for the system. Without that data it is hard to calculate what it costs to generate a kWh from the "storage system" to compare what it costs to purchase that same kWh from the Utility.

Until those "storage systems" gets down in cost where they are comparable to what the POCO charges per kWh then they will still only be a rich persons toy and not something that common folk can afford.

That storage can work in the near future when you use it to smooth your peak power requirements under a demand rate plan. Here in Arizona, based on APS' existing Demand rate structure, reducing your peak by 1 kW over a couple of hours every day during the summer will reduce your monthly bill by about $15. That's a big payback!

[J.P.M.]

That storage can work in the near future when you use it to smooth your peak power requirements under a demand rate plan. Here in Arizona, based on APS' existing Demand rate structure, reducing your peak by 1 kW over a couple of hours every day during the summer will reduce your monthly bill by about $15. That's a big payback!

Maybe it's time for the POCO's to get in the battery business. They seem to be scrambling after missing the boat on the chance to control the rooftop solar market 10 or so years ago.

[SunEagle]

That storage can work in the near future when you use it to smooth your peak power requirements under a demand rate plan. Here in Arizona, based on APS' existing Demand rate structure, reducing your peak by 1 kW over a couple of hours every day during the summer will reduce your monthly bill by about $15. That's a big payback!

I think APS asking for $3/kw solar connection charge is a little too much. And the option of going to a TOU plus Demand charge may not be much better.

But I could build a simple "load shed" system for a home for a lot less than what that battery will cost you to reduce your peak load.

[DanKegel]

Yeah - demand management is probably the sweet spot for the moment.
Demand charges will drive development and widespread use of both demand management systems and storage systems at some point.

Is it already economical to do peak shaving with batteries that survive 5 years of daily charge/discharge cycles in Arizona?
If you save $15/month for 5 years, that's $900. Can you buy a replacement battery for that little yet?

As battery lifespans increase, the economics will make peak shaving storage systems widely economical. It's just a question of when.

[Ian S]

I think APS asking for $3/kw solar connection charge is a little too much. And the option of going to a TOU plus Demand charge may not be much better.

But I could build a simple "load shed" system for a home for a lot less than what that battery will cost you to reduce your peak load.

When it's 110F at 5PM, is your load shed system going to turn off my AC? Because, if it doesn't, I don't see how it could cut my power enough to make a difference. And if it does, I'm going to be extremely uncomfortable. The battery however could get recharged cheaply and shave the peak every single day as it must do to avoid the demand charge. And it's not going to affect my comfort.

[DanKegel]

The load shedder could turn everything else off at 5pm.

It could also just turn up the thermostat 1 degree at 5pm. Come to think of it, so could a programmable thermostat.

Yes, a battery would let you avoid that. Is there one up to the task yet? How much does it cost per year to buy one and replace it when it wears out?

[Ian S]

Yeah - demand management is probably the sweet spot for the moment.
Demand charges will drive development and widespread use of both demand management systems and storage systems at some point.

Is it already economical to do peak shaving with batteries that survive 5 years of daily charge/discharge cycles in Arizona?
If you save $15/month for 5 years, that's $900. Can you buy a replacement battery for that little yet?

As battery lifespans increase, the economics will make peak shaving storage systems widely economical. It's just a question of when.

@ $300/kWh, that would give you a 3 kWh battery. Theoretically, with a triangular shaped peak, that would give you a maximum reduction of 1 kW over 6 hours. I think 3 hours would be sufficient and would provide a safety margin. So I think we're really close. Note however, that you'd only save the $15/month during the 6 month summer rate period. The rest of the year you might only save $10/month. Plus, you'd need some smart controlling so that the peak shaving occurs at the right time of day summer and winter.

[SunEagle]

@ $300/kWh, that would give you a 3 kWh battery. Theoretically, with a triangular shaped peak, that would give you a maximum reduction of 1 kW over 6 hours. I think 3 hours would be sufficient and would provide a safety margin. So I think we're really close. Note however, that you'd only save the $15/month during the 6 month summer rate period. The rest of the year you might only save $10/month. Plus, you'd need some smart controlling so that the peak shaving occurs at the right time of day summer and winter.

I agree that in certain climates shedding high loads (like AC) may make living uncomfortably. So it would come down to what each person (or household) believes is a the higher priority. Comfort or Cost reduction.

Yet being comfortable by owning a very expensive energy storage system that may save me $150 annually and take decades to pay for itself would not be my first motivation. I would look for other ways to stay comfortable that is less costly.

But then again that is my opinion. My wife has her own opinion which is why my home's average electric usage (June through September) is around 2000 kWh.

I am thinking of sending her on a cruise to Antarctica during those months but the cost for that is much more than what I would save on my electric bill.