[Green] Re: Should GREEN cover batteries? (decision about negative instantaneous-power)

[Tony Li <[e-mail]>]

Hi Benoit,

>> - Retain instantaneous-power as int32.  Add a comment saying that negative values are for power generating components.
> That makes sense.
>> - Nameplate-power becomes a int32. Same comment.
> Thinking some more about it (and contradicting myself in my previous email), I am wondering whether it make sense?
> Nameplate is a rating, not a flow. A 750 W supply is rated 750 W; what does a negative rating mean, since there is no instant at which a nameplate value is being measured in some direction. 


How do you model a 750W power supply?  Right now, I see no way.

> Proposal: keep uint32, but fix the description.

IMHO, that’s insufficient.  

>> - Total-energy-consumed becomes a int64. Same comment.
>> - Delete total-energy-delivered.
> I would keep the previous two together, as uint64.  A sign is sufficient for a rate but insufficient for an accumulator. Instantaneous power is a value at an instant, so the sign carries the direction with no loss.  A UPS battery that cycles daily has a net counter that oscillates around zero forever and conveys nothing: you lose the energy throughput, and you lose round-trip efficiency (delivered/consumed), which for a battery is the single most useful derived figure there is.


Then this feels completely inconsistent with the instantaneous power.

Tony