Re: energy in UK

On 2025-04-17 21:05, KevinJ93 wrote:

On 4/17/25 2:28 AM, Don Y wrote:

On 4/16/2025 6:55 PM, KevinJ93 wrote:

On 4/16/25 3:49 PM, Don Y wrote:
 > On 4/16/2025 3:11 AM, Martin Brown wrote:
<...>
 > Here, the issue is the high PEAK demands that the ACbrrs place on
 > individual
 > subscribers.  We could probably get by on a 3-5KW plant -- but, only if
 > we could store and deliver for large loads (I think the ACbrr is ~14KW).
>
That's a very large residential A/C. Our 4-Ton unit (48kBTU/Hr) takes about 5kW and suffices a 2,900 sq ft house in northern California. (Don't you like all these antiquated units!)

>
That's the startup load.  An inverter for a (pure) solar solution would
have to tolerate that for some large fraction of a second/seconds.  I.e.,
you would NEED to be grid-tied in order to support such large loads,
even temporarily.
>

 14kW startup is about 60A LRA (locked Rotor Amperage). A single Tesla Powerwall 3 battery is rated for 185A LRA and it is very common to have two or more Powerwalls in a system which increases the available short term power. Our A/C has a 104A LRA spec.

What would happen if the inverter on the battery pack doesn't have that peak capacity?
I mean, an inverter might simply limit the maximum peak current without destroying itself, keeping itself all the time within safe limits. Would the motor still start, albeit slowly? Or would it stall and overheat? Perhaps motors could be designed co cope. I know my AC unit has an inverter inside to control the motor, so does my fridge.
...
--
Cheers, Carlos.