Dude, 13.5 kWh for the battery is a pretty hard number. That would be 1,000 watts of power for 13.5 hours of use.

And a roof of solar panels can charge the battery in a day. Here is some math for you:
1 solar panel rated at 300 watts, for say 5 hours a day = 1.5 kWh. This is a 3'x5' panel.
So on a good day you would need 9 such panels at about 15 sq/ft each = 135 sq/ft of roof to fill a 13.5 kWh battery.
They sell complete "off the grid" kits - cause it works.

Your power bill can show you how many kilo Watts your home uses so you can get an idea of sizing a system.

More math; my car has an 82 kWh battery rated at 350 miles. That's .234 kwh/mile. Charging for 50 miles/day = 11.7 kWh.

So there is a big difference between "off the grid" and selling your excess power back to the grid, in terms of the system you might need.




I have no idea why you would think an ultra-high efficiency battery, super conducting or not, is needed to make this work.
What you really want is a "decent battery" and a 90% efficient solar cell (good luck with that).

Oh - Conservatives should know the difference between conjecture and doing the math.

Brewha wrote:

Blackout warnings again today. AC is cranked and pizza is in the oven.

HockeyDad wrote:

Thank you. It's this type of information that I originally asked for.
I don't see efficiency in your equations, though.
And most areas of the country, including TX and CA, don't come close to "perfect" conditions. And that's what your wattage is based on.

Central AC is about 3500 watts on average. So your battery will power it for 3 hours, but won't be able to charge your car as well. Tough choice on a hot day. No?
Or maybe it's cold outside. You have baseboard electric heat at 1500W per unit. How many rooms? How many hours? Same choice.

So you can see that it's not yet ready for prime time.
The laws are based on conjecture. Or finger crossing. Or maybe just a SWAG.

But thanks for the numbers. They are better than I thought, despite being woefully insufficient.

tailgater wrote:

You're welcome - glad to help.

Every component has a rated efficiency. System efficiency can be assessed once a design is done.
Once you settle on the requirement of a given home - and how you would use it - a system could be sized.

It's really is not as impractical as it may look though. And is does work when configure for an application. couple a points:
A typical 2,500 sq/ft home would prolly take 2 powerwalls and have 20+ solar panels. So double these numbers.
I only charge my car once a week - and can always go spend 20 minutes at a super charger.
But the thing to remember is that the system is scalable, and can be sized up if it is worth it.
"Worth it" is balancing the cost of the system against basically getting no electric bill - or just having some amount of off line power.

Brewha wrote:

But it is impractical.
That's why the government is compelled to force it on us.

Many of us have ditched our gas mowers for electric ones.
And many of us love the savings that a hybrid vehicle offers.

But CA and eventually the Feds are going to jam it all down our collective throats. Because it doesn't make sense for many of us.

And no matter if it has a 20 year warranty. That's a joke. Try replacing the battery on an EV that is only 15 years old.
And you say they'll recycle the battery? Ha! You know Pepsi says they'll recycle bottles. Don't fall for it.


I love electric motors and agree solar is a great way for individuals to save some money. But we can't shut down even one dino-fueled plant until we have reliable replacements. Not reliable most of the time. Reliable all of the time. And that's not solar.
But we're getting there. And when we finally do, I'll be first in line to upgrade.
Problem is, the progressive can't wait for progress. They'd rather mandate an agenda.

tailgater wrote:

Solution: Solar panels on the electric vehicles... and a small wind turbine on the trunk to charge the batteries while you're driving!

Brilliant!

MACS wrote: