Adding 1 or 2 PW to existing 2 PW / SDG&E?

[NathanielHrnblwr]

I have 2 PW. Debating on adding 1 or 2 more or alternatively replacing HVAC that is double SEER as 2 PW can barely squeak by during peak hours with HVAC running and can't power the house with both compressors running at the same time - draw is higher than 10kW.

Has anyone recently ordered 3-4 PW in SDG&E territory? When I ordered my 2 in 2020, SDG&E still required NGOM meter for any set up with more than 10kW ESS, but I believe this changed afterwards. Adding one may not be worth the effort, but adding 2 to total 4 would give me 20kW with total storage of 54kwh. Curious if there's new limitations on this side of ESS in this area.

 

[BGbreeder]

Personally, I would look into the HVAC upgrade first, and then see where you are. I suspect that getting a true variable speed, high efficiency compressor and fan might change your power needs significantly.

Batteries are likely to just get cheaper on an inflation adjusted basis.

All the best,

BG

 

[NathanielHrnblwr]

Yeah, that was my first consideration. It's about 20k for the HVAC with high SEER, however I have read those same higher SEER units are less reliable than ol bessy 10 SEER that's been going strong for 20 years. Plan B was more PW, but unsure of the complications of a "Large" ESS nowadays and am curious if there has been any local issues with them.

 

[BGbreeder]

Yeah, that was my first consideration. It's about 20k for the HVAC with high SEER, however I have read those same higher SEER units are less reliable than ol bessy 10 SEER that's been going strong for 20 years. Plan B was more PW, but unsure of the complications of a "Large" ESS nowadays and am curious if there has been any local issues with them.

I think that you are right, and it is worth digging around to figure which systems are reliable and which don't, as well as what happens if one actually does fail. Some vendors don't appear to stock repair parts. "Broken" seems to equal "replace".

The isn't much to 'ol Bessy, and what there is has been developed over decades, so yes, pretty reliable.

Four powerwalls may not necessarily be "large", but your particular local details are the determining factors.

In general, larger ESS imposing more restrictions on your connection to the grid. Tesla explicitly calls out allowed impedance levels, for instance, but there are also the issues of whether your local transformer is up to a larger ESS, and it's potentially large backfeed. So, yes, there are issues, but most have a work around, though not necessarily low cost.

All the best,

BG