Subject: EV - Powerwall Equivalence When I give talks on Emergency power to ham radio groups there seem to be people convinced they need a Powerall for backup of the typical 7 hours annual power outage. I point out that the average American home draws only about $1 worth of electricity in 7 hours (here in Maryland) and so spending $14,000 for $1 worth of electricity a year is something that should get serious thought.
I say a $200 generator and $15 can of gas is far more cost effective. But if they really must have a big battery, then I use these two slides to show people that buying a used EV or Plugin hybrid is a far more economical investment for emergency power than a power wall. http://aprs.org/EV-Powerwall.png A Nissan Leaf 3 years old costs about $9k and has the battery capacity of THREE Tesla Power walls that cost $21,000. Plus y ou can drive it the other 99.95% of the year for transportation... A plugin Prius has the battery capacity of a Power wall AND includes a 50 kW generator for power for a week! A Volt has the capacity of TWO power walls (Tesla's recommendation) plus the week long 50kW generator to boot. HOWEVER, the power wall will be a fantastic investment *when* the utility, PSC and politicians allow the owner to be paid the full retail value of his battery contribution back to the grid during peak demand. But that is NOT here yet. So, don't waste money on a power wall until that comes about.. Then a power wall can pay for itself in 2 years and provide whole-house battery backup for free! But not now... Bob, Wb4APR _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
