AC coupling vs Hybrid inverter

[Zeebest001]

My current situation is - my solar installer wasn't familiar / still isn't familiar with Nem 3.0 (where us consumers get pennies on the dollar back feeding to our electric company). Because of this he sold us a Solaredge system explaining how we would have a close to 0 electric bill.

Upon researching myself our PG&E bill would still be around $300 a month because of NEM 3.0. Not even close to $0 a month.

I only want to install Solar once and I want to do it the best way possible. I want to make it clear, the installer SOLD us the Solaredge inverters and Optimizers but they have not been installed yet. We don't even have the solar panels yet. So from all my research it is better to get an EG4 or a SolArk from the get go, but if I am wrong and AC coupling is just as good cost effective as using a hybrid can you people please let me know.

Thank you

 

[Hedges]

Your profile says Puerto Rico, but I think you posted elsewhere that you're in California.

Correct, under NEM 3.0 it probably doesn't make sense to install grid-tie without batteries. Only if you would be consuming the power when it was made, like to feed A/C, but even then if thermostat cycles on and off (vs. a variable speed system always operating), I think it doesn't give you enough value.

Cancel the order.

Check with PG&E on what model hybrid and battery or ESS is acceptable. You can probably start the registration process on their website, which has pull-down menu of equipment. Only some of the equipment on CEC website is still acceptable, but I think PG&E's system will only allow you to select the ones which are.

It seems that EG4 18kpv and PowerPro are one ESS that can be used. I'm not sure which others already have the necessary approvals.

Solar Edge does have hybrids with battery, also Enphase, but I think the battery costs much more. I'm considering an SMA hybrid for my sister's install, also an expensive battery, but not on CEC list yet.

Any urgency to proceed right now? I think tax credits are available for several years. There are other brands coming available, Midnight for instance. Waiting will also let early adopters be the guinea pigs for new products.

Are you relatively high income, or low? California has mandated electric rates change to a flat fee for infrastructure, reduced kWh rate. And price will vary depending on income. This would reduce the benefit of making kWh cheaper yourself. Your income wouldn't affect savings (or cost) per kWh to roll your own power, but would affect the flat monthly fee. Don't know the rates yet, but turnkey installed PV + battery system might cost just as much as buying from PG&E.

 

[Zeebest001]

Thank you, yes I am in California as my main resident, I will change my profile. I am not really in a rush to install solar, it was my girlfriends idea and we had this "Solar Guy" do some non Solar work for us in the past and he gave us a really good install quote. This is the only reason we decided to go for Solar now. He said he was a Lead for a Solar Company near us for 10 years, so we trusted his judgement but after the weeks / months, I started researching and found him to really not know what he is doing. He understands that I want a refund of my Solar equipment that he sold me. He also left all the mounts electrical, conduit here in the rain. So the optimizers have been getting rained on until I finally moved them, heck the concrete he sold us he left out in the rain and it turned hard as a rock. All the accessories he sold us to get the job done (conduit, wire, mounts, rails, etc. He charged us $5,000 for, and I believe this to be VERY HIGH, he told us he was giving us a discount.

His labor is very fair price but if he doesn't know the current local energy programs I have little confidence in his ability to install the solar.

I don't have an income as far as a job so I will look into this program, thank you for that.

 

[Hedges]

Federal income tax credit of 30% for PV and battery systems installed on principal residence.
If you have no income and no tax, you don't benefit from that. But buyer demand, and prices, reflect it, putting you at a disadvantage.

Hang out here, learn how to design and install yourself, let the market shake out.
Bargains do appear (like new PV panels under $0.20/W, also used panels and inverters.)
Once you know what you want you may get the equipment cheaper.

Is your bill for summer cooling, or winter heating?
To power A/C, maybe a hybrid with small battery would buffer PV and A/C cycling on and off.
LiFePO4 said to have 6000 cycle life, so if capacity much less than one day's use, it might wear out in a fraction of the 16 years normally expected.
A/C equipment that runs constantly at variable speed might be better.

I'm not sure if NEM 3.0 separates export from import instantaneously, in one minute increments, or in 15 minute increments which might serve to buffer A/C cycles. Find out about that, and maybe batteries aren't needed.

 

[Zeebest001]

Our electric bill is around $5,000 a year. The heat is on gas, so it isn't from winter heating. Yeah our AC cycles on and off and it is a newer unit so not something we are looking to replace anytime soon. I will keep my eyes peeled for good deals on here.

Yeah from just hanging out here and watching a ton of Will's vidoes I am learning more and more everyday, I wouldn't want to touch the main panel though, I would have a Master Electrican do that part and also, I wouldn't want to go on my roof to install the panels, but I feel I am getting close to being able to pick out the parts I want.

Only questions I have now regarding solar panels is. I have watched videos stating that bifacial is ideal for ground mounted systems but the least ideal for roof installs, especially dark colored roofs and a low mounting system. So I am starting to think bifacial would be a waste of money and not needed for my roof install, thus would save me money not getting it.

 

[Hedges]

The panels that are least expensive is whatever is being sold cheap. Sometimes that might be a bifacial.
So far I've only got conventional, with plastic backsheet. I favor leading brands, because bad panels can degrade rapidly.

Here for instance is bifacial for $0.13/W. Unknown name, and this lot of liquidation units may be sold out by now.

Santan solar deal

Necro thread revival. Temp installed 8 of the NE panels yesterday and they are working great. Easy peasy with the EG Brightmount racks.

diysolarforum.com

Read up on NEM 3.0 and understand it. What is the time period over which it averages import and export, vs. logging them separately for different prices? If the time period is reasonably long compare to your on-off cycle, GT PV without batteries could work.

If you DIY GT PV for $1/W, that works out to $0.025/kWh (amortized over 20 years).
If A/C is on half the time and off half the time, half your production offsets consumption (saving you $0.50/kWh) and half is wasted on the paltry backfeed credit. So it costs you $0.05 instead of $0.025 per kWh used, still 1/10th the price of buying from PG&E.

The trick will be getting PG&E to allow an array producing 2x your consumption, so it can eliminate 100% of imports during cooling season.

With panels on ground mount not roof (and maybe inverter therefore DC wiring not on house), you don't have to add RSD boxes per panel.

Maybe zero export with CT on grid feed makes sense, lets you keep your rate schedule if you like it (instead of going time of use.)

Don't be afraid of messing with main utility panel. You turn off main breaker, remove cover (don't touch terminals coming from utility to main breaker), use DMM to confirm busbars or breaker outputs are cold. Plug in a new branch breaker, connect wires to it, put cover back on.
Your inverter connection to main panel needs to comply with 120% rule; that limits breaker amperage, inverter wattage, and where the breaker goes in panel.

 

[Ampster]

So from all my research it is better to get an EG4 or a SolArk from the get go, but if I am wrong and AC coupling is just as good cost effective as using a hybrid can you people please let me know.

NEM 3.0 has changed everything and I think getting a hybrid first makes sense if you are stuck with NEM 3.0.

AC coupling is a good way to leverage a previously installed GT system. That is what I have. I got into NEM 2.0 with an 8 kW Enphase system and then added a SolArk. It would have been more cost effective to start with the SolArk. Then, once you exceeded the limit of DC coupled solar panels you could always add some AC coupled solar. That is also a strategy for adding a few panels in another orientation or just a few extra panels without reconfiguring the strings. A final note, if you have frequent power outages you will have more flexibility with a DC coupled system as the majority of your production.

 

[Zeebest001]

Thank you for all the good info.

Yes I am stuck with NEM 3.0. We rarely if ever have power outages so we are not worried about that. We are on the same line as the local Hospital. Even if we have a power outage I am ok with that. Our goal is to eliminate paying PG&E, our goal was and still is to have as close to $0 if not $0 electrical bill.

Nem 3.0 doesn't make it worth it to feed PG&E with over produced electrical, our only option is solar during the day and battery at night. Also we have to use the roof and I saw someone post if it is under 10kw you don't have to get the roof permitted? If so, what permits do I need?

 

[Ampster]

If so, what permits do I need?

You will need a building permit from the City or County in which you reside. The biggest hurdle with a battery will be understanding the fire regulations which are unique depending on the Fire Marshall in your City or County. In my case I chose to go with a 20 kWh external enclosure to avoid those issues. More than that may require batteries to be separated by three feet for every 20kWh. That is where a knowledgeable installer can help. I used an online Engineer with some experience in Sonoma County to draw up the drawings and documents needed for the permit and pulled the permit myself. The NEM paperwork with PG&E consists of the approved building permit and the NEM application found online. I did all of mine online.

 

[Zeebest001]

You will need a building permit from the City or County in which you reside. The biggest hurdle with a battery will be understanding the fire regulations which are unique depending on the Fire Marshall in your City or County. In my case I chose to go with a 20 kWh external enclosure to avoid those issues. More than that may require batteries to be separated by three feet for every 20kWh. That is where a knowledgeable installer can help. I used an online Engineer with some experience in Sonoma County to draw up the drawings and documents needed for the permit and pulled the permit myself. The NEM paperwork with PG&E consists of the approved building permit and the NEM application found online. I did all of mine online.

Thank you I will start looking into this, So I don't need a building permit for the roof then, is that correct if it is under 10kw?

 

[Ampster]

So I don't need a building permit for the roof then, is that correct if it is under 10kw?

A new circuit requires a building permit, depending on the jurisdiction, so I would guess you will need a permit. The roof install is going to require engineering for the uplift loads but that can usually be provided online by the racking you decide to use. The rules vary by city and county but PG&E is going to want to see a building permit if one is required by your city or county. If you are in a large city or county you can probably get that answer online. I think it is safe to assume you will need a building permit unless you have information to the contrary.

 

[Hedges]

San Jose, if load is under a certain number of pounds per square foot and it is low profile, no structural permit.
We can get a permit on-line by filling out a form, and no one looks at plans until they arrive for final inspection.
Other places requested roof truss drawings regardless.

Your bureaucracy may vary.

Ampster - do you know if that trim I see around arrays is part of avoiding uplift? Or just cosmetic? Seems to me it reduces cooling.

 

[zanydroid]

Ampster - do you know if that trim I see around arrays is part of avoiding uplift? Or just cosmetic? Seems to me it reduces cooling.

It is cosmetic. I considered ordering some, but it was thankfully out of stock when I ordered all may parts. Because a little while later I decided it was bad for cooling.

I did wonder a while back whether there might conceivably be a situation where a RSD-exempt system might use trim for some compliance related things (IE protecting wires).

 

[zanydroid]

Thank you I will start looking into this, So I don't need a building permit for the roof then, is that correct if it is under 10kw?

You need a permit for all solar and all storage projects in my town. And most towns I can think of. I believe all towns in California are now required to accept solar permits via some standard simple/cheaper process for checking the projects. As long as you don't do something really bizarre like put on a weak roof or put them at an angle to the roof (instead of directly parallel) it's not a big deal.

EG for a new enough house, they verify the rafter spacing and dimensions of the wood. Then they verify that you plan to use legit railing, and your solar panels are placed in way that leaves enough emergency access for firefighters etc. Hiring out the plans to a solar plan drafting service should handle all this for you.

I don't have an income as far as a job so I will look into this program, thank you for that.

That program isn't out yet. I suspect a voter revolt will repeal it. But we'll see.

Also look for Resilience / Equity / Equity Resilience versions of SGIP (Self-Generation Incentive Program). Massive discounts on batteries. May need to use a contractor. For most areas in California you have to be under Equity / Resilience category (like high fire, lower income, etc) for funds to still be available.

 

[zanydroid]

The trick will be getting PG&E to allow an array producing 2x your consumption, so it can eliminate 100% of imports during cooling season.

Is PG&E able to say anything if you go for zero export (IE no NEM3 benefits, there are still some banking and demand-based compensation, just 5-10x worse than NEM2)? (The up-front application may cost more and take longer). IE, I think if you take some NEM3 benefits, it makes sense for them to cap you.

I'm pretty sure this has been explored California Solar & Storage Association as part of their defense against both versions of NEM3. I remember talking to a few folks associated with CALSSA about the studies that they did / loopholes they had ready to go to staunch the bleeding of business.

 

[caesarv]

You will need a building permit from the City or County in which you reside. The biggest hurdle with a battery will be understanding the fire regulations which are unique depending on the Fire Marshall in your City or County. In my case I chose to go with a 20 kWh external enclosure to avoid those issues. More than that may require batteries to be separated by three feet for every 20kWh. That is where a knowledgeable installer can help. I used an online Engineer with some experience in Sonoma County to draw up the drawings and documents needed for the permit and pulled the permit myself. The NEM paperwork with PG&E consists of the approved building permit and the NEM application found online. I did all of mine online.

Ampster, any chance of getting the name of the engineer? I am in Santa Rosa and am just beginning to deal with all of this. I will have 12 ground mounted solar panels, and am using an EG4 18Kpv hybrid inverter. Any other hints you may have would be helpful.

 

[Ampster]

I will Send you a message.