Help Deciding - Adding More Panels - Which Inverter String / Micro Which Direction South or West

[nifty-stuff.com]

Hey all, I could use some help!

My existing 3.96 kW system (10 years old) consists of:

• 18 REC 220 W panels
• 18 TIGO optimizers
• SMA Sunny Boy SB3000US Inverter

... and I need more power (probably double)!

My original plan was to add more panels + new TIGO optimizers + new inverter, but pretty much every solar installer just wants to do a new system in parallel.

I finally found one installer that has a GREAT track-record and we're going through possibilities. The one we're leaning towards: Swap-out TIGO and SMA inverter on my existing panels for enphase microinverters, add more panels with enphase, tie old panels into new panels.

Does that sound like a good plan? It's taking a system that is "working fine", removing / replacing those parts... so not cheap, but I figure my inverter is at the end of it's life and will need to be swapped out sometime soon anyway.

The next big question: Which Direction?!?

I was thinking about facing them West and playing the TimeOfUse arbitrage game with the EV rate plan where I could sell energy back at $0.48 and use it late at night / early morning when it's $0.17 https://www.pge.com/en_US/residential/rate-plans/rate-plan-options/electric-
vehicle-base-plan/electric-vehicle-base-plan.page

... but I haven't actually run the numbers to see if that rate plan / my gameplan of having the West-facing will be better than another rate-plan and having the panels south-facing.

One of the installers had a good point that if I face them west based on the existing rate-plan, that PGE could completely change rate-plans, net-metering, etc. and completely change all my calculations, etc.

I look forward to your thoughts and ideas!!!!

 

[kernel]

The installers should be willing to do either, but the labor cost is surely going to be high for a disassemble retrofit of your array compared to a parallel system and hey some companies have no motive when they could get more to do less.

Its 2 days of play for the retrofit and they have a harder time because it reveals the 1.25$/W some of these companies charge for installing the supplied equipment and probably figure if they werent putzing around your place doing it 2.5 times for less $/W they would be cleaning up on profit somewhere else.....

I hate these companies, but its their choice to provide service and at what price so i cant argue.

Your sma inverter could easily last 25 years or more but if you feel much better with the new gear, id do it in an instant and do it with a company who caters to the customer.

The time of use scheme...... you could model both versions on pv watts. You can get that done by the company and it wouldnt cost you more, they are going to model it anyway and should provide the solution to array placement for your goal.

I dont do ROI or TOU to ROI schemes, just nuts and bolts, so im hoping someone jumps in!

 

[nifty-stuff.com]

Thanks @kernel for the reply and thoughts!

the labor cost is surely going to be high for a disassemble retrofit of your array compared to a parallel system

Yeah, that's exactly what I was thinking too. I'm still considering the idea since the likelihood is high that I'll need to replace my SMA inverter soon anyway, and having the entire system on new Enphase inverters would help guarantee I don't need to touch anything else for a while, not have a mess of duplicate conduit, inverters, cutoff boxes, etc., and give me an easier path to adding more power in the future (from what I understand).

The time of use scheme...... you could model both versions on pv watts. You can get that done by the company and it wouldnt cost you more, they are going to model it anyway and should provide the solution to array placement for your goal.

Right?!?! I would have assumed the companies I've been talking to would just plug the data into their system and spit out the best config... but so far it seems all of them are just doing kW used vs. kW produced.... and nothing regarding my specific rate-plan (currently on PGE E-6, TOU, etc., which is frustrating. I could probably cobble something together using the green button export and excel, but that would be a PITA when someone could just use their fancy solar software.

 

[kernel]

Thanks @kernel for the reply and thoughts!


Yeah, that's exactly what I was thinking too. I'm still considering the idea since the likelihood is high that I'll need to replace my SMA inverter soon anyway, and having the entire system on new Enphase inverters would help guarantee I don't need to touch anything else for a while, not have a mess of duplicate conduit, inverters, cutoff boxes, etc., and give me an easier path to adding more power in the future (from what I understand).


Right?!?! I would have assumed the companies I've been talking to would just plug the data into their system and spit out the best config... but so far it seems all of them are just doing kW used vs. kW produced.... and nothing regarding my specific rate-plan (currently on PGE E-6, TOU, etc., which is frustrating. I could probably cobble something together using the green button export and excel, but that would be a PITA when someone could just use their fancy solar software.

See, this is a problem....... a huge one i see every season.
These companies either punch in total kWh yearly into a calculator or send it to a supplier and get some panels inverters and a combiner or two and then send that to the "full service dealer/installer"....... i have a huge problem with this. They charge from 600$-2000$ for "design",
Markup parts supplied 20% or more over cost or even over retail, then supply amd use marginal materials and equipment especially in balance of system parts*, then have a couple roofers "install" it and an "technician/electrician" who is usually not going to touch anything but ac wiring and not getting on the roof (who do you think wired the rooftop combiner...... the roofers!), then charge 1$ a freaking watt to "integrate" it.....

Crazy thing is, we design stem to stern, provide the best equipment amd integration, cater to the customer amd aesthetics of the home, offer all options within our technical capability, and are eager to integrate batteries and travel to remote locations........

I pull up in a 20 year old truck and cannot get the same reception as the range rover driving sales teams of michigan.....

We dont have to though we make fine exchange at half those costs! And since these companies dont do what we do, they cant get our customers and i dont want theirs...... ROI.......

This is the conversation i have in the "full service dealer installers offices when they ask or i ask to do their systems, no conflict of interest and i tell them exactly that i cant get their customers, dont want them and they couldnt possibly get our clients!

Lots of subs with that bit!

 

[kernel]

Google earth designers....... thats not what the premium cost of solar installations demands.
Its fraud or just taking advantage of folk.

 

[kernel]

So you know, pv watts is owned by the people....... it is everyones to use, we all pay for its use.

You can take the specs (and a terminology crash course) and enter the inputs, play with it etc. Takes 6 minutes to an hour to sort some serious questions. You can do it amd we can help, i mean i wont aside from this, but people here might just walk you through it for the benefit of the community.

I would start a new thread on doing the tou/ roi, some people live to count the beans, even other people beans

I cannot bring myself to do it, its like asking me to shovel your dog run after the snow melts! I dont even do roi on my personal machines, dont care.

No incentives, no grid connection, no worries. (Im terrible at the gas pump too, just put it in and squeeze without looking. Im not pushing my truck anywhere. Energy is the same im going to use it, like batteries........ they are like brake pads not idols of worship.)

 

[nifty-stuff.com]

A quick follow-up!

After a TON of searching, I found a great company and worked out what I'm going to do:

1. Remove the TIGO and SMA Inverter from my current system
2. Add 18 Enphase IQ7PD's to retrofit my existing 220-watt REC panels
3. Add 17 Hyundai 290-watt panels + IQ7 micro's
4. Tie the old and new together into one 8.89kW system!

I'm pretty excited!