Re: The Physics Behind the Spanish Blackout

On 14/06/2025 12:35 am, john larkin wrote:

On Fri, 13 Jun 2025 01:03:01 -0700, Don Y
<blockedofcourse@foo.invalid> wrote:
 

On 6/12/2025 6:36 PM, KevinJ93 wrote:

  >> I calculated the cost of the wear and tear on the battery is (very)
  >> approximately $0.25/kWh.
  >
  > So, if you have a surplus, it makes sense to make it available (even though
  > whether or not you have a buyer may be uncertain on any given day)
  >
  >>  > What sort of capacity do you have and how easily do you "top it off"
  >>  > purely from solar?
  >>
  >> I only have 27kWh of storage (2 Tesla Powerwall units). In the summer
  >> I average 20-35kWh per day of surplus generated by solar. So if the
  >> battery has discharged to 25% (own use plus any exported) in the
  >> evening it can be fully recharged the next day.
  >
  > We use about 25KWHr/day (it's not "hot" yet).  So, would need to generate
  > about 50KWHr daily to meet that sort of storage ability.  Without
  > resorting to
  > a tracking collector, I think we're limited to about 6.5 usable solar hours
  > daily.  So, would need ~8KW from an array to "bank" that much.
>
Our usage is very similar (somewhat higher in peak summer - last July 4th we
consumed ~70kWH).

>
Our daily *average* will approach that (about 65KWHr) once it gets hot.
Or humid.  (Or both).  So, 50KWHr won't even meet our daily needs
(assuming we could bank it without having to take a loss using
the grid as that bank)

 We leave the gas heat on all year... never touch the thermostat.
 Most all the world wants a/c, and wants to keep the windows closed and
the mosquitoes out. Air conditioning 9 billion people is going to take
a lot of power.

Most of it generated locally by solar panels (and the occasional wind turbine) and backed up "power wall" style batteries.
Lenin's passion for rural electrification is so nineteenth century.
--
Bill Sloman, Sydney