Re: The Physics Behind the Spanish Blackout

On 6/12/2025 6:28 PM, KevinJ93 wrote:

Connecting a PV array to the grid automatically changes the client to a
ToU tariff.  So, if your array can't meet all of your needs (at the granularity
of the measuring system), you pay a BIG premium for the power you need to
import (even if you've exported enough to cover those needs as you are
reimbursed at a lower rate)

 The local utility is forcing all consumers onto a ToU tariff, regardless of whether they have solar.

That hasn't happened, here (yet?).  The economics simply don't make sense
from the consumers' point of view.  E.g., our monthly bill would
likely increase by 50% -- regardless of any steps we might take to
curb consumption (living without refrigeration is simply not an option)
When I originally looked into it, I figured it would be easy to shift
our *elective* power consumption to "off peak" hours.  Baking/cooking
(electric stove/oven), laundry, dishwasher, my servers, etc.
But, the ACbrrrr just swamps those other loads and it's not negotiable
during the day (peak hours obviously cover the times when refrigeration
is working hardest!)

And, if your array is out of service (e.g., having repairs done or roof
maintenance), then any savings the array might have realized quickly evaporate.

 Yes, definitely possible - that would possibly cost $5,000 or equivalent to one year's consumption without solar.

Neighbor just had her roof replaced.  Remove the panels.  Replace the roof.
Reinstall panels.  Wait for inspection before going back online.
I've not asked her what the change in electric costs were (she is "lucky"
in that she could leave the house unoccupied during the day and just
hope it doesn't get TOO hot inside for the ACbrrrr to bring it back
to a livable temperature LONG AFTER she had returned home from work.)

We looked at the ToU tariff thinking we could easily shift our consumption
to leverage any rate reductions.  But, most of the cooling load (which is most
of the load!) happens during on-peak hours (3P-7P); and the rate is ~50% higher
per KWHr during those times.  Hard to imagine the cost in comfort to appreciate
any real savings!

 I run off batteries/solar during the peak time in summer.

It would be hard for us to do that for all of the time that
refrigeration is needed.  E.g., it is now almost 1AM and it is
still 85F outside.  It was 95 at 10PM.   And 98 at 7PM.
110 this weekend.