I really like this idea, can't come soon enough

kkesp · March 31, 2015

Elon Musk says Tesla will unveil a new kind of battery to power your home. After seeing online that the big reveal will be made soon I went looking for info. I think this will be a game changer for RV's as well. What really caught my eye was this little blip "The Toyota Mirai, which uses a hydrogen fuel cell, gives owners the option to remove the battery and use it to supply electrical power to their homes. That battery can reportedly power the average home for a week when fully charged." I was flying with a guy a few months ago who was telling me his brother was working on this project for Toyota. I was only half listening because I never imagined it being allowed to come to the consumer marketplace.

Mastercraft · March 31, 2015

"Elon Musk says Tesla will unveil a ........"

I love these "outside the box" thinkers, way ahead of their time.

Putting this claim in rough perspective, without considering the need for a serious inverter to be paired with this battery, let's see how big and heavy a lead acid battery would be to cover this load.

What is the average electric power usage? Not sure, but let's say it's about 1000kW hrs per month. That would be a sub $200 electric bill in most parts of the country. (If your usage is less or more the number at the end will scale up or down based on the 1000 number)

1000 kW hrs per month = 250 kwhrs per week. 250 kwhrs = about 42,000 amp hrs @ 6V @ 100% depth of discharge

Let's bump it up to about 80,000 amp hrs @ 6V @ 50% depth of discharge.

Lead acid batteries have an energy density of about 2500 watt hrs per cubic foot ( 6V, 400 amp hr Trojan L16E battery 100#, about 1 cubic foot in volume each)

Sooooo - 80,000 amp hrs * 6V = 480,000 watt hrs ..... Divide by 2500 watt hrs per cubic foot = 192 cubic feet and would weigh about 10 tons

That's roughly 192 Trojan L16E batteries (about 7"x13"x16") to cover this load.

Let's say Elon Musk's team has developed a battery that has 10 times the energy density of a lead acid, that's still a washing machine sized battery that weighs a ton.

With all that said, even if Elon's new energy storage device is free and lasts forever, there is no free lunch. I would still have to charge my batteries......technically possible year round in Arizona if you have acreage for solar panels. Other parts of the country, not so much.

..... was that the alarm clock ..... I was ~~dreaming~~ Eloning

bockofma · March 31, 2015

Now THAT is exciting!

Regards,

Michael

dascom · March 31, 2015

For several years now the railroad has been installing H2 fuel cells as powerfail backup.

Kinda costly solution that works good but like any generator, someone got to carry the fuel.

Even with 40% to 50% efficient diesel generators and the fuel holding 4.88 Kwh / pound,

Mastercraft's 1,000Kwh / month use is 400# or ~~50 gal diesel just to charge the batteries.

each month. And that is optimistic numbers, Ya got to get the power from somewhere.

That all said, I am very excited about the Tesla goal of 10 cents / watt-hour batteries.

chirakawa · March 31, 2015

And, just about the time these new generation batteries go into production, the environmentalists will come in and shut down the plant because of the hazardous waste threat.