That might all be true, except for 2 things:

1. If Elon can get enough early adopters to buy in, he might get his costs down. If this were $2K instead of $3,500, those numbers change quite a bit.

2. If the night power is provided by hydro or wind and the day peak power is provided by natural gas generators, then by time-shifting your power, you're producing less CO2. This matters more to some people, less to others, but it is a point to consider.

Yea, I have to say, if we had a carbon tax, a lot of this suddenly would make sense...

I'm against a carbon tax for more than one reason, but I understand the thought process behind it...

I have to say that I agree here...

If I owned a property out in the county, if grid power wasn't 100% reliable (it is where I live), if I just needed limited power at a second home, this might make a perfect off-grid system connected to solar and wind power...

If enough people do just that, then millions of these can be made. Anything produced by the millions becomes cheaper (more or less).

As the price comes down, this then starts to make sense for more in-city use cases.

I've long said that batteries and solar were too expensive, this is the first home battery system where I'm reconsidering that view point.

Now get solar cheaper and you'll have a convert. :D

I am going to assume all your numbers are correct, I didn't do the math.

Lets say that is true. Then what that also says is that it is darn close to break even, if not slightly profitable now by 3% over 10 years.

That isn't exciting, but it is a big change over a year or two ago's cost.

The other thing is what happens to the numbers if the price of this goes down by 20% and the price of power during the day goes up by 20%?

Run the numbers again and I suspect they'll be a smashing success.

Volume does wonders for any manufactured product, if they can produce millions of these, they might cut the cost by enough to make... millions of them worthwhile. :)

Elon Musk has the money and the will to bet on that, he can build a million of them on spec, counting on selling them if he drives the price down far enough

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I've been a vocal critic of batteries and solar on this forum for many years now, but I've also said that my primary issue was price.

Get the price down and much of my criticisms go away.

Because that is what it is called...

https://www.google.com/search?...

"synonyms: parallel"

Nationally about 7% of power is lost due to transmission losses of all kinds.

It costs more than 7% more money to have distributed generation than it does to do it centrally.

Right now in the US, it costs about $4 a watt to install solar on a house. Utilities can do it at scale centrally for about $2 per watt.

That is half the price, far less than transmission losses could make up for.

Not at all, you misunderstand completely...

I'm one of those "old guys"...

The last price reported for this system that was being tested was $13,000. At THAT price it is stupid and dumb.

At $3,500 I feel completely differently about it. I've long said that price is the primary problem with batteries, renewable, etc.

This still doesn't make sense to to me personally, today, because I don't pay a "time of use" charge for my power. I pay less than 11 cents per kWh, day or night.

However, if I paid twice that during the day, this would just about make sense, even without solar power.

If it costs $1,000 to have it installed, then just using it to charge at night and use during the day, it would have about a 10 year payback, which is the same as the warranty.

And this is the first commercial version, it may well be half the price in 5 years. If so, then it becomes a no-brainer for anyone paying time of use charges, or anyone with a solar power system who doesn't get net-metering.

I live in Texas and I don't know anyone with a heat pump...

I do know lots of people who heat with natural gas however...

Now that I think about it... I don't think I've ever lived in a home without natural gas, but I could be mistaken... maybe that is just Texas?

And people used to club their women and drag them back to their caves as well, what's your point?

That it was done in the past is not a good reason.

What was the humidity on those days? I suspect it was rather dry air.

We don't actually get that many 40+ C degree days in Texas, but when you combine it with humidity, it is crushing.

Ahh, it must be a dry heat... At night, the temp DOESN'T drop to the mid 20s, in fact, in the summer, it often stays around 35C all night long.

You grew up in another way of life... I've read 100 year old newspapers from the Dallas area (back when it was a horse town), and no one did anything during the day. Work had to be done from sunrise to about 10am, then stopped until mid-afternoon, it was simply too hot and humid to function...

So no, they didn't do anything in that heat 100 years ago either, because of the humidity. Now we have AC to fix that, at least for indoors. Outside is still crushing, we go outside to play for half an hour and everyone is done. Even the pool gets too warm in August to really enjoy, it is like taking a hot bath.

I have been highly critical of the idea of home battery systems and solar power.

At the prices that this would have cost a year ago, I was right.

At $3,500 for a 10 kWh battery? I'm reconsidering that position. Critically this price is not subsided, which means it works everywhere, not just in CA or some place that rebates are in effect.

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Forget solar power for a minute... If you live in an area that prices power differently during the day than at night... You could recharge this at night and run off it during the day.

If you pay 12 cents per kWh at night and 24 cents per kWh during the day, even with no solar power at all, if you use the whole 10 kWh battery each day, you'd save $438 per year in power bills.

Assuming it costs $1,000 to install, that would pay for itself in 10 years. That by itself isn't very exciting, but it also isn't crazy either. All that has to happen is for the price to go down when the new battery plant goes online, or for power prices to rise. It also has the benefit of balancing the load on the power grid a bit, reducing peak draw during the day and using the excess power at night.

Actually... you're right, I would have to agree with you...

It is easy to allow one's own person use case to color their views of things... My Mother has 3 megabit ADSL and any time I go to her house, it is painful to me, but to her, it is "normal". She has never had anything faster.

How about we aim for 25/25 then for everyone? 10/10 is too slow for a long term plan, IMHO. :)

Or better yet, how about we plan for and build out gigabit to everyone! :) AT&T just laid fiber in my neighborhood and is going to soon offer gigabit speeds (up and down!) for $120 per month, but with a 1 TB data cap (that is not nearly enough for that speed IMHO).

10/10 and even 25/25 sounds great today, and for a lot of people it would be nice, but if you're going to do a national roll out, think big and plan for the future. 100 years ago (give or take) we laid copper phone lines across the whole country. Why don't we now replace all that with fiber across the whole country and replace the whole phone system with fiber to every home.

https://www.google.com/webhp?s...

I found that to be interesting...

US per capita emissions of Carbon in 2010 were 17.56 metric tons.

China was 6.19 metric tons and India was 1.67.

My concern is that if India and China were to rise even a small amount, it would wipe out anything the US could do.

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To be blunt, I'm willing to accept some changes, if all of humanity is willing to do it. I think some of the resistance you see and hear about comes from the fact that some Americans believe that we'd do all the suffering while others would continue polluting.

It is the belief that "if China and India don't do it as well, then we might as well not bother".

This is what was so broken about the original Kyoto Protocol, it was unfairly harsh towards nations such as the US. Even China doesn't really like it, and I quote:

"Negotiations were held in Lima in 2014 to agree on a post-Kyoto legal framework that would obligate all major polluters to pay for CO2 emissions. China, India, and the United States have all signaled that they will not ratify any treaty that will commit them legally to reduce CO2 emissions."

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Going back to the first point.... consider that the US current emits about 3 times as much CO2 per person as China. If the US reduced this by 50% and China increased to match the per-person output, the total would be far higher than it is today due to the number of people they have.

So the question becomes... to reduce worldwide emissions to 50% of current levels, the US would have to reduce to about 9 metric tons per person and China would have to reduce to 3 metric tons per person.

Could the US do that? Probably, but it would be a big change, we haven't been that low since probably before WWII.

Could China reduce to 3 metric tons per person? That is likely to be quite hard, and they may simply not be willing to accept the standard of living that provides.

Now you might ask, "why should China have to live with 3 when the US gets 9?" The simple answer is, "we got here first and we aren't giving it up".

Which is why I have said over and over, we might be better off adapting to the future that is coming rather than fighting it, because if you really think Americans are going to 3 metric tons per person, you're nuts.

Trying to force the whole world to that level would likely start WWIII. You might think that sounds silly, but I don't think it is. Wars have been fought over much less, protecting your way of life is as solid a reason as any to engage in violence.

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So the question becomes, what global level is acceptable and what level for each nation is acceptable?

Getting the US to cut is one thing, getting the whole planet to cut is quite another, and I just don't think getting all of Earth to cut 50% is going to happen.

10 megabit strikes me as the minimum acceptable in 2015.

My Mom has 3 megabit ADSL, the fastest offered to her home. She is just outside of the service area of TWC, it is her only option.

That is slow. :)

Perhaps not, lots of conversations going on, and then this silly thing called the real world :)

A 200km range battery would probably work, it isn't ideal, but it probably is enough for a second car for most people.

Of course, the trick is the $1,000 price. You used a bicycle battery, which is fine, but that isn't what this conversation is about (or at least I don't think it is).

Get me a CAR battery that does that and then I'll be impressed.