Thoughts about how to represent storage on PVOutput


#1

I’m trying to get my head around how to get data into PVOutput that best represents energy going into and coming out of storage. For reference, my current set up is at https://pvoutput.org/intraday.jsp?id=8562&sid=6943&dt=20171017&gs=3&m=0 and I’m showing energy flow into / out of the battery as an extended parameter (as well as state of charge, and battery voltage (as I’m interested in what it is during an outage when it isn’t tracking the grid)).

PVOutput by default treats generation and consumption as special quantities for calculation of net load, and applies ToU tariff rates to them to work out daily net positions.

While the sun is shining and my battery is charging, I don’t want to treat the energy going into the battery as grid consumption (as PVOutput would rate it, for example, at Peak rates if it occurs during Peak Time), but I could possibly treat it as self consumption. That would mean that export would be correct (PV - self consumption - storage).

When I am discharging the storage overnight, I don’t want to treat the source of energy as coming from the grid - that’s not correct. I could pretend it is moonlight PV (but that would probably really confuse PVOutput), in as much as it is “free”, and offsets consumption at that time.

Alternatively, I could treat it as negative load, so the sum of actual load and negative load add up to zero, and thus no consumption from the grid.

The combination of treating charging a battery as load (e.g. self consumption) and negative load is probably closest to reality, and probably doesn’t require PVOutput to have a brand new category of energy, but…

What would be really good is if PVOutput had the concept of storage, and flows to and from storage were recognised as just that.

I’m interested in peoples thougths on this (especially BB’s).