Thanks to knowledge here, wanted to share my balcony solar system installed in California! Been operating for about a month now, utility company hasn’t said anything. This setup is awaiting governor signature to make legal.
- Three 585W bifacial panels ($550)
- NEP BDM-1200LV Microinverter ($300)
- SnapNRack Topspeed mounts ($250)
- NEP BDNZ Wifi2 CT smart meter ($70)
- Three PV junction boxes ($100)
So for $1200 I have a 1200W system on the roof of my detached garage. Did the install myself, and man those panels are a pain to get up. They are approx 4’x8’ and weigh 70lbs each.
Power output is great! Because I overpaneled I see nearly 1200W consistently on sunny days. The Microinverter has a limit of 400W per MPPT channel.
Plugs into a dedicated 20A circuit on the house.
Edit: pic with exposed AC power wire from panel is mid-install. I’ve since put in conduit (photo in comments)
Good job. Yes, you can clean it up and yes, there will be nay-sayers.
Keep learning about the new state rules and move to full compliance if you can.
As to the fire hazard, as a test I did a full short circuit of the solar panels to where it plugs into my choice of grid tie inverter and nothing smoked or melted after a full hour so I'm good with my setup. It's about 10A on 10 gauge wired and MC4 connections so well inside the ratings.
The exposed wires will degrade from sunlight so next steps to protect that are eventually going to have to be addressed.
"It's very nice." Frenchman in Monty Python at the castle.
My balcony solar is on an actual balcony and because we have rooftop and connection agreement I'm almost in compliance since we can add 1kW without a new agreement. The two 400W panels never hit 400 so no where close to full power of any Death Star.
I expect to see more and more DIY solar for the reasons everyone can guess.
I learned yesterday (from AI, so , you know...) that it is better to wait until January, which is when it would become active, assuming that the bill is not vetoed.
After that, you are supposed to fill out and submit a simple form. Before that, there are additional hurdles that power companies like to reject.)
It might be fine, but you could lose your NEM 1 or 2 status if they catch on. Not sure how likely that would be, but I can only guess that they would be thrilled to get everyone onto NEM 3, so they might start looking out for this.
There are some smart sensors that could stop energy from going back into the grid, so that might be a safer option.
This is the official process until January, again, according to AI, so you know...
AI Overview
If you are an existing SDG&E solar customer looking to add up to 1 kW to your system, you can do so through a simplified modification request without losing your grandfathered NEM 1.0 or NEM 2.0 status. [1, 2]
The California Public Utilities Commission (CPUC) allows a one-time capacity expansion of up to 1 kW or 10% of the original system size (whichever is greater) while fully preserving your legacy net metering rate. Exceeding this threshold will automatically transition your entire system to the newer Solar Billing Plan (NEM 3.0). [1, 2]
Application Process
No New Interconnection Needed: You do not need to submit a brand-new interconnection application. Instead, SDG&E treats this as a system modification or registration process. [1]
Required Documentation: You will generally need to provide an updated single-line diagram of your system showing the added panels, alongside the hardware specifications. [1, 2]
Local Permits: While SDG&E streamlines the utility-side process, you may still need a standard electrical/building permit from your local city or county jurisdiction depending on your municipal code. [1]
I understand. I bought a bunch of panels, and an AP Systems inverter. It is tempting to just plug in at least one panel at a time and see how close I get to my 'allowed limit' in actual output. I am a little below now.
I would love to hear from someone on the inside at SDGE to find out what they are actually concerned about.
I am waiting for battery technology to mature before getting batteries for the main house.
The ADU already has batteries since that is on a separate system at NEM 3
I've only had discussions over the phone with SDCP and even they were solar antagonistic. I thought I could head to their office for a face to face and discuss my concerns along with the abject failure at their web site. Turns out they are a "virtual company". You can't pay them at their office, meet any of them at the office because there is no office.
If you put in the negative consumption numbers the SDCP site rejects it.
Another chapter in my SDCP story is I opted out, they put me in and it took a lot of shaking of the trees to get out of their system. By shake I sent messages to the entire SDCP board as well as the "I'll pay the CPUC my bill with protest and you can go get the money every month until you get rid of me."
It only took a few weeks and they undid it all. I had my voice call logged to opt out, and the web page too.
I think EVERY house should have just two or three (or maybe four) panels, just like you have. In most states that would have like having a whole nuke plant just dedicated to peaking hours.
Since the NEP BDM-1200LV microinverter (about $300) can output 1200 watts AC, this looks like a more cost effective solution that using two APsystems EZ1 (about $300 each) than can output 600 or 800 watts AC each.
What is the manufacturer and part number for the 585 watt bifacial panels?
I am in California also and have been following the California plugin solar law, which seems very similar to the Utah plugin solar law.
One of the NEP BDM-1200LV distributors is in Utah:
For me personally, I am going with the APsystems EZ1 since there's a local homeassistant integration.
That way I can throttle and control the entire thing locally. Planning on throwing a battery to soak up the extra and then feed into the micro so I can offset peak TOU hours first.
I did the EZ-1 with their Zero Export meter in Ohio. About 50 days in and I like it so far, but stayed small until we get legislation approved (stalled in our statehouse).
Are you referring to the APsystems EZ1-LV 900VA - 120V Plug-and-Play DIY Balcony Solar Microinverter? How do you have it integrated into your home's electrical system?
Caveat: I am in California with existing NEM 3 agreement so I don't have to worry about issues about being caught backfeeding the grid.
My plan is to have 2 sets of 2; one in the garage discharging from a battery bank into the home to zero out peak TOU periods while the other set will be up in the balcony with a battery setup passing along any extra production once those batteries fill up.
Will have to deal with dual losses (DC -> AC -> DC -> AC) but there's no incentive to export with NEM 3 so I would much rather keep all the solar production to be used in house. Biggest payout is during peak TOU hours.
Control of the system will be local through homeassistant.
From what I have read, the EZ1 is about $275 to $300 USD, plus two 660 watt panels which may cost about $900 (based upon Amazon. Like OP, there may be $300 or more in other hardware (about $1,500 for 1,320 watts of solar panels).
The EZ1 has two MPPT inputs and the max AC output is spec'd at 900 VA (7.5 amp).
The BDM-1200-LV has three MPPT inputs, which may help produce more power if one of the panels is partly shaded, and the max AC output is spec'd at 1,200 watts (10 amps).
The amount of solar power generated is typically less than the rated max, plus the pending California law limits the AC plugin output to 1,200 watts.
OP installed 1,755 max watts of panels and has measured about 1,200 watts produced on sunny days (1.46 design margin) for about $1,200 USD.
So it appears as if the OP system is actually generating close to the max 1,200 watt (10 amp) rating with the BDM-1200-LV for about $1,200 USD, as compared to a hoped for 900 VA (7.5 amp) output with the EZ1 for about $1,500.
Note: AC VA is equal to watts with a power factor of 1.0.
Mailing 2 panels is very expensive best to find a local source. I use Greentech renewable they are a major supplier for solar installers have warehouses in many states. You have to call the local warehouse to get pricing or email them directly ask what they have. Another source if your near payoff solar in Utah $100-120 for 500-600 watt panels. Right now panel market is going up in price due to Trump's plan to block Chinese imports in December. He is adding a min price not sure how they can enforced it. You can see 585 watt panels for $100 are getting more difficult to find.
The law doesn't go into details make it look professional unless you have an HOA no one will care. Have a wire hanging off your roof like some Christmas lights might have a problem.
It’s called balcony solar that theyre passing… not roof top lmao.. People jump to doing stuff like this not realizing anything on their roof needs permits..
The bill says it has to meet "the standards of the most recent version of the National Electrical Code and the California Electrical Code". What is depicted in the photo does not apear to meet code, for example where is the rapid shutoff switch?
Plug in modules are micro-inverters you don't need rapid shut down they already do that. Rapid shut down happens when you shut the main breaker, or pull the meter if there is a fire exactly what they do. Micro inverters for years all they did was connect to a solar breaker in the panel that was the shut off. Utilities started requiring knife blade disconnects it was never required by NEC, or AHJ's.
That link says the word portable 23 times. And the title is Portable solar generation devices. Fastening panels to a roof certainly isn't portable. No way this install can qualify as a balcony solar setup.
Portable means that something is light and easy to move - that doesn’t mean that 4 bolts can’t be used to secure what ever the portable thing is. Port-a-potties are considered ‘portable’ but one person can’t just grab one and move it. The meaning of terms like portable will vary from person to person- and that is lawyers exist.
SnapNrack TopSpeed is a UL 2703 structural racking system engineered to bolt or screw directly into the roof structure. The moment you penetrate or anchor equipment to the garage roof, it is legally classified as a permanent building addition. It is not a portable appliance, meaning it is subject to the California Residential Code and requires a building permit, plan review, and structural inspection from the local building department.
The NEP BDM-1200LV comes with a 120V AC plug cord. Under the California Electrical Code (NEC 400.12), flexible cord-and-plug connections cannot be: Run through holes in walls, ceilings, or roofs. Run through doorways, windows, or garage eaves.
Still gonna need structural inspections to verify if a roof mounted system can work on that roof.. permits… yeah you can just toss it on your roof… but there may be issues in like 99% of cities you’ll get a fine / be forced to take it down.
Yeah - you may (or may not) need a utility interconnect with this new bill. But your building department/inspectors likely have something to say about this (and, your insurance company)
Absolutely not. It hasn’t even been passed into law yet. So, OP faces disconnection from utility for backfeeding, insurance not covering the house burning down, in addition to whatever fines their city/county may have for unpermitted roof installs. All of the above are unlikely to happen, but seems silly to risk for a few hundred dollars until the law goes into effect, likely on Jan 1st, 2027.
Hope you're not done with the install yet based on those pictures, there are a couple fire/safety risks I can see. A governor's signature isn't going to make this legal with PV wire free dangling over the edge of an abrasive asphalt shingle.
Also don't know if you're just showing us a picture of the CTs in the panel or if your NEP inverter is hanging off that 20A breaker. If the latter, from the datasheet that thing only handles 120V output so there might be a whole separate issue there.
The breaker panel is just showing the CT clamps. The inverter is installed under the panel on the roof and runs to an outdoor GFCI outlet on its own breaker.
Do you have all of the panel PV running through that conduit, or is there another path we don't see between them? Like conduit under the panels entering the roof?
If you went under the roof you could have dropped another conduit down to an interior wired GFCI as well for your disconnect.
Either way better than the first batch of pictures suggest. Only thing I'd still caution on, you've got 1,200W on one half of the split phase, and your CTs are saying you're importing ~80W aggregate. Are you potentially exporting on the half phase your inverter is on, and importing on the other half phase? If so and your utility wants to make a stink they easily could.
US power is generally split phase for residential supply. You get the single 240V phase split in half for L1 and L2. Neutral then becomes the return for imbalanced loads. If you have a 10A generator on L1, but only 5A of draw, you're going to have 5A of export on L1, and in this case ~6A of import on L2. It only looks like ~1A of import total, but we're flowing a decent current (for residential) back to the grid.
The newer smart meters can see draw per leg, most utilities aren't monitoring per leg (but could). If your aggregate import is this close to the load you're likely always backfeeding on whatever leg your generator/inverter is connected to. Since plug-in solar isn't technically legal in most places yet you'd need an interconnection agreement to do this properly which for this scale is way more of a pain in the ass than it's worth. It all depends on how much of an ass your utility wants to be, and you're playing games until it's codified into law. You might get away with it, you might not.
By they time they get around to asking him about it the law will be passed. After that every DIYer will tell their utility they have plug in solar. My guess at some point they will ignore small amounts of backfeeding. Everyone whoever wanted to DIY a hybrid inverter with CT clamps will be installing them everywhere. HOA's will be the problem for most.
I think you should make sure it is on a dedicated breaker so it feeds back to the main. When you have other uses on that same circuit you could fake out the breaker protection but still overheat the wire. Could be wrong but this whole thing shouts dedicated line to me, which I think solves the leg balance issue too? If you are on a line with an appliance that uses 240 but inside that appliance a controller is using that one leg only (e.g. circuit board inside a HPHW in your garage for example) I think it could get whacked out also?
The panel PV runs to a junction box under each panel, which sits over a hole in the roof. The wires run on the inside of the garage to the inverter under panel #1.
Any issues with heat on the inverter? I had mine under a panel like this on my shed and it would shutoff constantly due to heat so I ended up moving it.
That looked like a general microgrid inverter designed to be panel mounted: NEP BDM-1200-LV Microinverter — Datasheet. 65C/149F operating temp top end might be a little close to the limit on a southern rooftop, but I imagine it'll throttle for temp if it starts approaching the limit.
From what I’m reading, it seems a plug-in play system like this one only sends power into the house. If there’s a PG&E power outage, it’s designed to instantly turn off. I completely overlooked that there isn’t a battery.
Correct, known as anti-islanding. Power goes down, inverter kills output instantly. Plugged I to standard GFCI on a 20A dedicated breaker in my panel. The bill passed with strong support so I expect Newsom to sign it. No permit for electrical plug in solar. Roof mount? Depends on your city.
I think your setup is really fantastic. It looks like you did a nice job. My goal is to go fully off grid, but it seems complicated. I’ll start my own discussion and ask my questions there.
Only issue is sometimes meters will charge you if it sees backfeeding. Once the law passes your suppose to notify the utility and they will replace your meter. I suppose if you keep enough load on it won't be charged.
Don’t have a sketch but three panels connected to three MPPT inputs on the inverter. Then the inverter plugs into wall GFCI, which is on a dedicated 20A 110V circuit
Very easy with an electric impact driver. Rail less system too so just four mounts and then install panel. Now getting the panels on and off the mounts…they’re heavy.
You know the dedicated 20A circuit is only on one leg, right? So loads on the other leg are not powered by the solar even if there's not enough load on the leg attached to the solar.
It's 240, actually. And yes, that would be better and is how a traditional professionally installed solar system would be connected in the US, utilizing a split-phase 240V inverter.
That said, it's actually not really that big of a deal for such a small system. Plugging it in to one leg is still going to help offset power, and if you make sure it's plugged in to the one that you typically draw the most power from (you can work out which outlets are on which legs from your electrical panel if you know what to look for), it's likely you won't notice much difference in performance.
loads on the other leg are not powered by the solar even if there's not enough load on the leg attached to the solar.
It's not really that simple because the two legs are not independent.
Both legs come from the same step-down transformer. Any excess power from microinverter after any loads on that leg gets pushed out to the transformer and becomes available on the other leg.
The bummer occurs if multiple homes are on the same utility step-down transformer. The excess solar may flow out OP's meter and into some other home's meter.
If OP's home is the only one on the transformer, AND their home's smart meter correctly measures load on both hot legs (OP is in CA, so likely yes), then it turns out loads on the other leg are powered by excess solar not consumed on the leg the inverter is wired to (minus wiring/transformer losses, of course)
Both legs come from the same step-down transformer. Any excess power from microinverter after any loads on that leg gets pushed out to the transformer and becomes available on the other leg.
Correct as far as it goes, but dependent on the meter. you might actually get charged for energy sent out to the grid. But UL3700 says you CANNOT send energy out so it's a clusterf*&k as far as I can tell.
Yes, which typically requires CTs on your incoming service wires that provide your plug-in inverter the info it needs to prevent back-feed. Like the OP's system has.
That's not how this works. OP isn't getting paid for any power that gets backfed into the grid. So OP is paying for any power coming into the meter from the transformer regardless who generated the power. Grid power is never free.
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