If NEM 3.0 then easier to oversize PV?

[stagepuppy]

I did a search and didn't find anything on this...

If new installations in CA are now under NEM 3.0, has anyone been able to way oversize their system? I guess for many of the IOU customers, they were generally only allowed to oversize by about 10% if I recall. Now that NEM 3.0 has cut compensation for export, it should not be such a big deal for planning for future EV or otherwise... so other than infrastructure/neighborhood transformer limitations, does PGE/SCE/SDGE still put a restriction on PV size?

 

[holeydonut]

I did a search and didn't find anything on this...

If new installations in CA are now under NEM 3.0, has anyone been able to way oversize their system? I guess for many of the IOU customers, they were generally only allowed to oversize by about 10% if I recall. Now that NEM 3.0 has cut compensation for export, it should not be such a big deal for planning for future EV or otherwise... so other than infrastructure/neighborhood transformer limitations, does PGE/SCE/SDGE still put a restriction on PV size?

Technically, the rule under both NEM 2.0 and NEM 3.0 is supposed to be that a homeowner can oversize their array compared to previous consumption if the homeowner plans on purchasing BEVs, installing a pool, switching to heat pumps vs natural gas furnace, etc.

I say "technically" because some a-hole at PG&E can still be absolute sh!t and block the install because someone is worried about their pension.

BTW, my neighbor in NorCal put in a 150% sized array (vs prior year consumption) a month ago under NEM 3.0 because he will be switching from NG furnace to heat pump. He did not produce a mechanical permit proving the work or HVAC upgrade.

 

[h2ofun]

Technically, the rule under both NEM 2.0 and NEM 3.0 is supposed to be that a homeowner can oversize their array compared to previous consumption if the homeowner plans on purchasing BEVs, installing a pool, switching to heat pumps vs natural gas furnace, etc.

I say "technically" because some a-hole at PG&E can still be absolute sh!t and block the install because someone is worried about their pension.

BTW, my neighbor in NorCal put in a 150% sized array (vs prior year consumption) a month ago under NEM 3.0 because he will be switching from NG furnace to heat pump. He did not produce a mechanical permit proving the work or HVAC upgrade.

Unless you have lots of money to burn, putting in more than you can use, like I did, is not for an ROI.

 

[skepticcyclist]

Wouldn't it be based more on what the transformers and localized grid can handle than how much they will be buying back? Our neighbor was denied solar because there were too many houses on our street that already had solar. If everyone put 150% of their use household use worth of panels on the roof, that would be a lot of energy going to grid during peak sunlight hours.

 

[wwu123]

Wouldn't it be based more on what the transformers and localized grid can handle than how much they will be buying back? Our neighbor was denied solar because there were too many houses on our street that already had solar. If everyone put 150% of their use household use worth of panels on the roof, that would be a lot of energy going to grid during peak sunlight hours.

I know in Hawaii several years back, the local Honolulu utility (HECO) started denying new solar applications depending on neighborhood saturation because of localized grid instability concerns - it wasn't the amount going to the grid per se, but rather that a localized cloud could cause all the solar in a neighborhood to suddenly drop, leading to sudden demand spikes.

Not sure how legit that really was, but to be fair to them, clouds in Hawaii are usually the fluffy cumulus ones, and can drift quickly with the trade winds. It can be raining hard in one neighborhood, and completely dry and sunny a few streets over... hence the abundance of rainbows as well....

 

[stagepuppy]

Wouldn't it be based more on what the transformers and localized grid can handle than how much they will be buying back? Our neighbor was denied solar because there were too many houses on our street that already had solar. If everyone put 150% of their use household use worth of panels on the roof, that would be a lot of energy going to grid during peak sunlight hours.

I recall reading something like that in this forum...

What would be the expectation from the utility's position as electricity use increases? 50% export vs 100% import in the neighborhood (I know, not realistic but a what if that certainly can be created)... Even further, as they bring large scale storage online, would they not be able to utilize several levels to store power from both their facilities as well as from residential? I can see the Castaic/Pyramid lake pumped storage (slow reacting) acting in concert with Megapack farms (fast reacting) to do this.

 

[jjrandorin]

What would be the expectation from the utility's position as electricity use increases?

Probably to go the way that Hawaii has, and not allow any NEM at all (no export to utility). That would be my guess. I personally feel they will get there sooner rather than later, as then it wont matter how large of a installation someone puts in, if they cant export it.

 

[BGbreeder]

I know in Hawaii several years back, the local Honolulu utility (HECO) started denying new solar applications depending on neighborhood saturation because of localized grid instability concerns - it wasn't the amount going to the grid per se, but rather that a localized cloud could cause all the solar in a neighborhood to suddenly drop, leading to sudden demand spikes.

Not sure how legit that really was, but to be fair to them, clouds in Hawaii are usually the fluffy cumulus ones, and can drift quickly with the trade winds. It can be raining hard in one neighborhood, and completely dry and sunny a few streets over... hence the abundance of rainbows as well....

That is definitely what happens; it can go from full sun to substantial shade back to full sun in minutes. That makes local grid balancing challenging, but not impossible.

Probably to go the way that Hawaii has, and not allow any NEM at all (no export to utility). That would be my guess. I personally feel they will get there sooner rather than later, as then it wont matter how large of an installation someone puts in, if they cant export it.

That is certainly one possibility.

My hope is that more attached storage / EVs and better microgrid management tools could make for tighter and simpler control of microgrids and thus the grid generally. That would include fast acting storage to smooth load variation and generation variance. Imagine if EVs could pause or increase charging in response to transformer level conditions in a neighborhood.

I think that at the end of the day neighborhood level microgrids make for greatly enhanced power reliability and stability.

I don't overlook the challenges that utilities will have when 90% of homes have an EV, and 40% have two or more, and 70% of the homes have heat pumps. That is a whole lot of demand, and a whole lot of copper in wires, transformers, and substations if we just copy our existing grid blueprints. I think that is neither wise, nor cost effective, nor good resource management. As more peak demand loads become available, they while help modulate the variation loads, but distributed peak loads will be a much cheaper outcome.

I do not underestimate the cybersecurity risks of all of this either.

As they say, YMMV...

All the best,

BG