M8B Utility open for business

M8B Utility open for business

Just got the 26 panels put in (360W per panel) and I am making electricity, same stuff my car uses to go.
Woo Hoo!

CharleyBC | April 9, 2019

Good stuff! We got our PV put in even before the car showed up. 24 x 330. For a while there we were generating more power than we could use.

surfpearl | April 9, 2019

Welcome to the Solar Club, congrats!

Rt002k | April 9, 2019

Whew, you dodged the bullet of accidentally putting in a different octane than the car takes.

Welcome to the club!

CST | April 9, 2019

Welcome to solar - you'll love it!

lbowroom | April 9, 2019

Thats a big system. I only have 18. Congrats.

gmr6415 | April 9, 2019

We've got almost 10kW and solar hot water. We did it in 2009. You can now purchase M3 battery packs from wrecked cars for $12k to $15k. I wish I knew someone who knows batteries and solar well enough to hook them up to my system. I'd do it in a heartbeat. M3 battery packs are selling for half of what it would cost for the same capacity in PowerWalls. If you could hook up he M3 radiator, coolant pump and the BMS that would be even better.

shawncordell | April 9, 2019

Very nice system... I have 28 panels. Just waiting on Tesla to hurry up and install my powerwalls now.

I’m powering my house and two Teslas. No energy bill in 2 years!

jjgunn | April 9, 2019

I thought this thread was going to be peeps asking a question for Magic 8 Ball to answer.

Generate 9.3 kW? I think? Pretty cool stuff!

Magic 8 Ball | April 9, 2019

Yup, 9360 W. A quick peek at around 3 this afternoon showed about 6 kW production and now at just before 6 it is making about 2 kW.

vmulla | April 9, 2019

Congrats!!! Did you go Tesla or some other kind of panels?

Magic 8 Ball | April 9, 2019

We went with LG LG360Q1C-A5 360 watt 60 cell. I feel a bit bad about not having Tesla bid but I went with the guy I went with since he is a bit of pioneer in CA solar (2001), has been involved in getting (good) legislation through, did the in laws house some years back and was highly thought of by them. It worked out great. The install is clean with all hard conduit (no flex stuff) and was done in a day and a half. The first hour I spent with the crew chief and we we discussed several options of where the conduit, penetrations, etc. could go and he was open to any ideas I might have (love working with people like that). The entire crew was great.

calvin940 | April 9, 2019

I am just in the design/quote process. Looking at around 10kw (27 panels). Need to re-shingle and get Fascia, Sofits and gutters replaced first. All expected to be done by summer. I am pretty sure I am not going to be able to get ahold of a Powerwall because basically you just can't get them. Too bad. Will be using an inverter made by same co as panels and then looking into a panasonic battery. I can't wait to be self sufficient and remove a decent portion of my carbon footprint.

swilliams102 | April 9, 2019

Welcome to the club, free electricity!!!
22kw, zero electric bill in over ten years
120 panels
2 1kw wind turbines
3 on/off grid arrays
3 off grid arrays
12kw back up propane generator w/ dedicated 500 gallon propane tank
Wood/mini split A/C heat pump
Electric water heater
Well water
Tesla M3 Performance
Nissan Leaf
Zero bills - priceless
Could not be happier
Hope you do the same

AZTesla | April 9, 2019

My panels are going to be 10 years old in November 2019. 52 Sharp ND-198U1F's (54 poly cell units) = 10.3 KW with a 10.1KW Fronius IG Plus inverter. Very nice system when it was installed. Coincidentally, they will achieve their ROI this year, too :)

nwfan | April 9, 2019

Congrats M8B on your solar system and welcome to the solar club.

@shawncordell, who's your provider? Are you able to bank excess power?

My 17kw system averaging 70kw currently. Hope to be pushing 100kw at peak production
later in the summer. Dealing with shading from trees that ring my property.

mcmack15 | April 10, 2019

We are putting on a new addition and replacing our 1 car garage with a 2 car garage (GC expects to start mid May), and a friend of my son-in-law that has been doing solar for over a decade is going to be installing up to maybe 28 panels to cover 100% of our electrical bill. We are not considering going the generator route------do many folks go with this option in conjunction with the roof panels? Pro's, con's?

CST | April 10, 2019

Curious, what is your inverter setup?
I have 28 340w panels with 250w micros - I thought they'd put the 300w micros but it would have exceeded my main panel's rating. I get some clipping but the efficiency of the panels is great. Already pulling in 50kWh per day when the sun is shining.

andy.connor.e | April 10, 2019


The way i see it, is you either spend money on a generator or spend money on batteries. If you have a 200A panel, a 200A generator could cost $22k, not including installation costs which includes a 4" concrete slab, and potentially a 200A ATS (automatic transfer switch) for when the power goes out. All in all, that kind of money could buy you two powerwalls easily. And powerwalls dont have the maintenance associated with a generator, nor do powerwalls make that kind of noise when they kick on.

My dad was looking into a generator, and reading the specs on them, they have to kick on once per week for 5-10 minutes automatically so they dont seize up. If you're willing to drop $30k on a backup generator, i would just get a single powerwall to start and see if you need more backup power. Having solar though, i'd really be surprised if you'd ever need an extensive backup power source.

andy.connor.e | April 10, 2019

I tried to convince him to get a couple powerwalls instead of the generator, and he seemed fixed on the notion that powerwall requires solar. And didnt really have a response when i told him that you could just hook the powerwall up to the utility for charging. Still has not bought the generator nor inquired about the powerwalls.

If we use the worst case scenario numbers on Teslas website, you would spend about $24,200 for 3 powerwalls and installation costs, which is only a couple grand more than the generator cost. And you could argue that 3 powerwalls is quite a bit more than you need.

gballant4570 | April 10, 2019

Nice! About a year & a half ago I was looking at solar - we were looking at an 18 kw system, I believe it was 52 panels or so. We got three quotes, one was from Tesla. Those three quotes all included recommendations for tree removal to make the project feasible. Interestingly, the three tree removal recommendations were not similar to one another.... My wife & I love the trees, and in the end decided that we would not pursue solar and do something else. That something else is currently plugged in out in the barn..... and we signed a contract with our utility for 100% renewable power supply, which is all wind in this case. I have not entirely given up on the idea of solar at some point though.....

disapr | April 10, 2019

Congrats on the setup.

I'd really like to get Solar - We just aren't sure if we are going to be in this specific home for 30 years since the ROI on solar seems to be about 25 years. Wish the costs would come down, or maybe I just need to buy panels and DIY it.

mcmack15 | April 10, 2019

Thanks Andy---great information. I will look into powerwalls to learn more a out them. We rarely lose our power. In close to 40 years in the same house we may have lost it a half dozen to a dozen times, and never for more than 12 hours---usually just for 5 or 6 hours. When we bought the house the realtor---after we closed---told us our section of the street was on the same connection for electricity as the local hospital, and that the houses right around us, including ours, were always the 1st to get the power back.............we think she was correct based upon our 40+ year test period here.

calvin940 | April 10, 2019

I'd love a powerwall but if I ordered now I suspect I would not be able to have it delivered before the end of the year from what I hear so that doesn't fit with my timeline unfortunately.

CST | April 10, 2019

@disapr - that is an incredibly log ROI for solar. Mine is about 7 years, and since I just financed the entire thing on a 20 year loan, out-of-the gate with tax rebates, I'm paying $70/mo less on the loan than I was to PG&E, so the ROI period is irrelevant to me.

CST | April 10, 2019

log = lo(n)g.

h2ev | April 10, 2019

We just signed the agreement on a 11.8kW system. 36 Panasonic 330W panels and Solaredge optimizers. It'll probably be 3-4 months between waiting on permit and getting final inspection before it'll be up. Should've looked into it towards the end of last year, would've earned 15yrs of SREC instead of 10.

gballant4570 | April 10, 2019

andy.connor.e, I was also looking at this situation as well. A Kohler 20kw propane backup generator that would basically make a power outage fairly transparent was heading toward 20k in my case. If I could have been content with a location right outside the wall of the house, that could have been pared back a fair amount, but not having any gas or propane on the site currently was also a cost factor that would have been added on to the generator installation cost. I looked into PowerWalls as well (first choice actually) and at the time they required a solar array to be in place for the wiring and setup and tax credit, or at least that is what a Tesla rep told me at the time. I believe that is different now, and I also have a new garage nearly finished with plenty of space for 3 PowerWalls - I haven't given up on that idea either.... but foir now when the power goes out I'm still manually switching and hooking up a large portable generator, and fooling with gas containers....

andy.connor.e | April 10, 2019

Dont forget theres a 30% solar federal tax credit this year. It drops by 4% each year until its gone after 2021. NYS also offers up to $5000 state credit. I'd do it now if you can. Dont know how many years it will take for solar prices to come down 30% to match what you could get today. If you can do it, do it. We have no idea what the price of electricity will look like if electric car demand increases significantly, which would increase the electricity demand.

andy.connor.e | April 10, 2019


I think the reasoning for the solar array to be in place in order to get the credits, is because the tax credit is for a solar installation, and would not cover ONLY powerwall installation as that is not solar. I think the whole system together having the solar and battery storage, you would get the credits for the entire setup as the whole system is the complete solar setup, if that makes sense.

FifthOnLeft | April 10, 2019

@disapr: ROI on solar is much faster than 25 years. I recently install a 8.5kW system in the Bay Area. With discount and tax incentive, the ROI on my system is about 7 years based on our current consumption of roughly 15MWh per year (2 EVs plus central AC in the summer, using TOC plan).

On a clear spring day, the system already produces over 55kWh and can easily exceed 60kWh/day in the summer. Solar efficiency is getting better and is proving an effective and cheap solution to renewable energy.

gballant4570 | April 10, 2019

I believe that the design of the PowerWall and the parts/methodology for wiring into the house was based on having a solar array in place. Six weeks ago I overheard a conversation while in the Tesla SC getting my tires rotated in which a fellow was asking about PowerWall without solar, and the response he was getting is the basis for my thinking that perhaps that has changed. I already knew about the tax credit part, and was interested in PowerWall with or without it, but ran into the issue when looking into installation in the absence of solar..

andy.connor.e | April 10, 2019

The only thing that doesnt really show a good ROI, is the solar roof. Just because its pretty ridiculously expensive. The benefit being that you dont need to replace your roof after 30 years.

Magic 8 Ball | April 10, 2019

We went with Solar Edge 7600H-U Inverter and Solar Edge P370 (370W) Optimizers.

Just got home from a morning drive/walk and had to plug the car in since my system was already overproducing. I actually have to pay a penalty for overproduction until PG&E presses a key on a keyboard somewhere (they don't come out and inspect themselves). I either have to consume more than my system makes or turn the system off to avoid penalties for now.

Magic 8 Ball | April 10, 2019

Depends on your array size but most systems will pay for themselves in 7-8 years. My in laws have smaller system they put in 11 years ago and and it is paid off and producing. This is, IMO, the best year to put in solar. The credits are going down after this year and panels are at the cheapest they have been. The only way to come out ahead after this year is if panels go way down to offset the credits you would have otherwise gotten.

andy.connor.e | April 10, 2019

Agreed with @M8B. Prices would have to come down 30% over the next 3 years to compete with the federal tax rebate currently on solar, which BTW, that credit can get rolled over to future tax years unlike the EV tax credit.

Rt002k | April 10, 2019

It may surprise some of you to know that there are areas outside of the CA that don't get as much sun, so payback periods can actually be longer. And payback period greatly depends on the cost of electricity in your area.

CST | April 10, 2019

@M8B - you must have an older meter - my smartmeter showed outgoing from day one and when the approved my system, I started getting credit. Before that, I just reduced my power usage.

Magic 8 Ball | April 10, 2019

I have smart meter, yes I show outgoing right now and everyone pays a penalty on outgoing until PG&E gives their "official" approval (usually two weeks after install).

Magic 8 Ball | April 10, 2019

@Rt002k You bring up a good point, thanks.

Rt002k | April 10, 2019


The payback period on my 6.56kW array in Oregon was somewhere around 12 years. And now we are selling our house 1 year in. Oops.

Rt002k | April 10, 2019

Is the solar roof "worth it" if you're in @calvin's situation and you are also in need of replacing your roof?

TabascoGuy | April 10, 2019

@Rt002k That's a new twist on "Paying it Forward". I hope the new owner appreciates it as much as you.

Rt002k | April 10, 2019

@Tabasco - I hope they do too. It did get priced into the home some, but not the entire amount.

andy.connor.e | April 10, 2019

Solar roof would be like 6x the cost of a new roof for me. I need a new roof in at least 2 years. Solar roof finance estimate on Teslas website says it'd be about as much as my vehicle finance cost right now. I'd be willing to replace my car payment with a solar roof payment, and effectively not have an electricity bill. But dam, that is a pretty huge chunk of cash.

shawncordell | April 10, 2019

@nwfan I’m with Green Mountain(Texas) and yes, I’m able to bank excess.

I have 28 panels with 14 micro-inverters as opposed to one central inverter. If one panel is shaded by a cloud(or anything for that matter), it doesn’t bring the whole system down.

TabascoGuy | April 10, 2019

@andy, If I were under 30 I would seriously consider both because not having electricity or gasoline costs for the life of the roof would work out financially. Being 60, well that doesn't math out so well.

Magic 8 Ball | April 10, 2019

@shawncordell The system I have has a central inverter with power optimizers on the panels which does the same thing as the microinverters.

TabascoGuy | April 10, 2019 if M8B Utility had some creative financing options.

andy.connor.e | April 10, 2019


Yeah completely agree. I could afford the solar roof next year, but it would be a very long time before i could afford the Tesla to go along with that roof. Its a good start though.

Rt002k | April 10, 2019

I would be concerned M8B Utility's customer service responses would include too many "Reply hazy, try again" or "Cannot predict now".

Come to think of it, that sounds like Elon time.