Re:The price of solar power just fell 50% in 16 months
by gpm on Tuesday May 03, 2016 @06:19PM
(#11624711)
The number actually needed is a bit lower than that (I estimate half a billion), but the general question still stands.
Variable electricity needs already mean we use less electricity at night time [0]. Shift electricity expensive processes preferentially run at night to the day and using 80%/120% seems like a reasonable rough approximation. So we need 4,686,400,000,000 / 365 / 2 * 0.8 ~= 513,5780,822 kwh in the '12 dark hours'
Between current supplies nuclear hydro and wind we account for approximately 30% of electricity generation [1], on the assumption that electricity generation from these is constant, but can't be ramped up during the night, we get about 4,686,400,000,000 / 365 / 2 * 0.3 = 1,925,917,808 kwh. Leaving 3,209,863,014 kwh needed from storage, or 501,541,095 powerwalls.
Variable electricity needs already mean we use less electricity at night time [0]. Shift electricity expensive processes preferentially run at night to the day and using 80%/120% seems like a reasonable rough approximation. So we need 4,686,400,000,000 / 365 / 2 * 0.8 ~= 513,5780,822 kwh in the '12 dark hours'
Between current supplies nuclear hydro and wind we account for approximately 30% of electricity generation [1], on the assumption that electricity generation from these is constant, but can't be ramped up during the night, we get about 4,686,400,000,000 / 365 / 2 * 0.3 = 1,925,917,808 kwh. Leaving 3,209,863,014 kwh needed from storage, or 501,541,095 powerwalls.
[0] http://www.eia.gov/todayinenergy/detail.cfm?id=13131
[1] http://www.eia.gov/tools/faqs/faq.cfm?id=427&t=3