Ah, you are correct with the daily usage amount. I figure in about 10-15 years, that will drop to maybe 1/4 of the daily use with the solar->battery->car upgra

Ah, you are correct with the daily usage amount. I figure in about 10-15 years, that will drop to maybe 1/4 of the daily use with the solar->battery->car upgrade that society will engage in. So, I'd stretch it out quite a bit further than 40 years.