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Just following up here - I've been told by an experienced solar engineer that most "dual flow" meters have a 2-10 sec interval over which flow is "netted".

Hi all, I'm hoping to understand on what timescale the CA utility smart meters integrate usage. I believe the intent of "net billing" is there is no "net metering" happening, meaning imported energy is accumulated in bucket A, and exported energy in bucket B. Those buckets then have different...

I recently asked about High voltage (>48) vs 48v ESS to an engineer at SMA, see their response below. I found it helpful.

It makes a lot of sense to me that the trend of ESS voltage increasing over time (12 -> 24 -> 48 -> ??) will continue. SMA's upcoming Sunny Boy smart energy hybrid inverter (just shipped this past week to SMA's distributors) only works with HV batteries (90v+ IIRC), which is really telling. But...

Thanks! Schneider has what I'm looking for. It has a built in charge controller for pulling data from the AC side and storing it. But Schneider inverters (and charge controllers) seem to be quite expensive, are they mostly used in commercial settings? Any thoughts on whether they're worth the...

Thanks, should I think about the dangers of high voltage differently on the storage circuit vs generation circuit? I suppose if a DIYer is willing/planning to go well over 100v on panel strings, then they should also be willing to go >>48v on the storage side, assuming they follow the same...

Thanks, not sure how I missed that victron option. Victron Multiplus 2 is the only model with a UL1741 listing, though its not clear to me that a UL1741 is actually required? From digging through the NBT Rate Schedule , "Special Condition 7", it seems like UL1741 listing is one option, but not a...

@400bird thanks, makes sense. the less reliable stuff seems suited well to non-mobile cases where the grid is the reliable backup and the solar is more about saving money/environment. This mostly applies in residential areas where the grid is very stable I suppose.

Thanks! I'm building some grid-tied systems for neighbors in San Francisco, and I'm finding these battery systems have much higher C rating than cost-optimal for small grid-tied applications. would love to have a C rated LiFePo4 system with C=0.25 so its cheaper and safer. For example, my ideal...

I came across a few out there which are grid tie capable but are not UL certified. But yeah my understanding is: UL1741 ~= California Rule 21 compliant ~= anti-islanding features for improved grid stability. After more reading, I've realized that UL1741 has nothing to do with Power Control...

I was hoping to build a system with discrete charge controllers on each string, 48v battery system, and grid tied inverter. This allows me to decouple the solar facing specs (number of MPPTs / MPPT voltage range / etc) from the inverter specs. One motivation is to be able to scale up or down my...