Planning a grid-tie system

jsim3 · December 2020

Hi everybody. I am beginning to plan a grid-tie system at my home in Los Angeles. I'd appreciate any direction anybody would care to give.

My experience is with generators and small off grid solar panels, and extensive home and industrial electrical work. However, I've recently been amazed at how cheaply I can pick up new solar equipment in LA, and want to start accumulating the supplies I will need in preparation for drawing up the plans and submitting them to the building department for permits. I know that this is somewhat backwards, but I figure, if I can't afford the equipment, I don't want to go through all the trouble of submitting plans!

I've measured my roof and found that I can fit twelve 270 watt panels on it. I'll want micro inverters because the roof gets shade in the afternoon and I'd rather have each panel feed the most it can into the grid. I can get Talesun 270 watt 60 cell panels for $110 each and Siemens/Enphase M215 microinverters for $50 a piece, all brand new.

For some reason, most solar arrays on houses near mine are quite a bit smaller that what I plan - I figure that those can;t supply much juice. But, I've done some rudimentary calculations and found that the panels will supply something like half my household's needs. Does that sound about right? We really don't use much electricity. Also, do you think that the panels and inverters are workable in my situation?

Many thanks for any advice.

solar_dave · December 2020

Step one, you have to understand what the interconnect rules are for your utility.

Step two, you may be required to pull permits and have a qualified electrician do the wiring.

I know here there are specific rules for roof set back for the fire department to allow roof venting incase of fire.
The utility her (APS) has many requirements for grid tie connections like accessible shutoffs ...

BB. · December 2020

As Solar Dave suggests... You really need to look at the permits and Utility requirements/approvals.

You are correct, GT Solar is a really good deal for the homeowner--Lots of energy for not that much cost. HOWEVER, the requirements can be a real pain. New NEC/Fire Safety requirements for roof setbacks (easier for fire department to access the roof in a fire), remote shutdown, etc.

Also, you need to look closely at your utility's rate plan for solar... In olden days, more or less, they would simply roll back your kWH billing (down to zero) for every kWH you generated... Generate 400 kWH a month, subtract 400 kWH off your bill (down to $5 a month minimum billing).

For me, in Northern California--I have to pick a time of use rate plan. And while I get a credit for kWH generated, they only apply to the time harvested... Looking for information for this post--I see new changes for Jan 1, 2021:

https://www.pge.com/en_US/residential/rate-plans/how-rates-work/rate-changes/e6/time-of-use-plan-e6.page

Timeline of Time -of-Use Plans E-6 and EM-TOU Season dates Peak Partial Peak and Off-Peak hours

Timeline of Time -of-Use Plans E-6 and EM-TOU Season dates Peak Partial Peak and Off-Peak hours

For me, I only generate "significant" energy until about 4pm or so... For 4-8 pm weekdays, I am paying a fair amount of $$$/kWH.
0.

Residential Time-of-Use

Rate Schedule E-6 and

Rate Schedule EM-TOU 8/ Time-of-Use Winter and Summer Peak, Part-Peak, and Off-Peak Energy Charges $0.32854 $0.25298 Summer Peak $0.40545 $0.49198 -34.862% ($35.73) $0.26312

Part-Peak $0.28701 $0.37354

Off-Peak $0.21179 $0.29832

Winter Part-Peak $0.23296 $0.31949

Off-Peak $0.21613 $0.30266 $0.09992

Hard to read, but winter off peak is $0.22 per kWH, to summer peak at $0.49 per kWH... (E6 TOU plan for my home presently)... And $10 per month minimum charge (electricity).

Some companies/states are prohibiting any new GT connections (Hawaii, Nevada, parts of Canada?, etc.).

Others are dropping the $/kWH costs for power down towards $0.06 per kWH, but charging a "per kWH delivery charge" ($0.06 or more)... And some companies are charging upwards of $48 per month minimum charges--Anything to "rebalance" the books.

And, our utility only is offerering a 10 year "grandfather clause" for new GT solar systems... They reserve the right to dink with the rate plans after 10 years (even if it makes GT solar no longer worth it)....

For shading, if the shade is from trees--They grow--Either you have to trim, or plead with your neighbors. If it shade from buildings/etc.., it is always possible that the neighbors will add on to their home and shade your array more.

There is a big discussion about a central inverter vs micro-inverters. I have had a central inverter fail--Relatively easy to fix (under warranty). Vs when micro inverters fail (have to go on roof, pull up panels, etc. to access any failed inverters). The older micro inverters seemed to fail more often than advertised at times... Your mileage may vary.

-Bill

mike95490 · December 2020

Beware of sellers offering non-compliant gear (inverters not meeting new #21 rules)

jsim3 · December 2020

Holy smokes, You guys are the bomb! (my niece's expression - I hope I used it correctly

I think that you saved me a whole lot of hurt! I read through the regulations for permitting and the fire department's requirements. I can follow those and it seems that I can satisfy what is required. However, the issue Solar Dave and Bill bring up about constantly changing utility charges is a vexing one. The service agreement may be good today (and I think it is), but may not be so great next year. Mike's observation of sellers offering non-compliant gear is spot on - I mean, how could they be so cheap?

My first approach to my solar use was to go off grid. I think that I'll investigate that route further. With several panels on the side of my garage and a couple of batteries, I can power a chest freezer, at least. That will be a good start. However, this route is limited. I am in a high fire brush zone and my land is glanced over each year for brush clearance. I don't know if they will see my three or four panels and force me to take those down. It's worth a shot because I need such a system at my cabin in the woods too.

Do you have any suggestions or observations about using off grid in an urban setting? I suspect that putting panels on a roof will get the attention of the building department, if not the fire department. But, a guy who sold me a solar panel told me to just go off grid - he has a huge array in a high fire brush zone and seems to get away with it, maybe because he is just outside of the LA city limits?

Can't thank you enough. I read through posts before posting mine and the greatest advice was, "Stop buying stuff!" I suspected that that directive would apply to me too!

RCinFLA · December 2020

There are lot of con men in solar install business. Don't do any lease or no-cost install contracts. You need to think about any entanglements if you are trying to sell your home with the installed solar. Prospective home buyers may not want to take over an existing contract, or worse, the contact states a total outrageous payment immediately due before house ownership is transferred.

Best to do your reseach and decide what certified equipment you want to buy then hire a reliable certified and licensed installer that agrees to install the type of equipment that you want and outright buy independent of installer. There may be a few incidentals that the installer knows is required for permitted installs that you overlooked.

Don't even think about doing a GT install without permitted install and UL certified equipment,

jsim3 · December 2020

Thank you RCinFLA! I'm aware of the con men and the entanglements. My neighbors have fallen for their sales pitch. LA is like a raging river of cons of all sorts! My great, great grandfather was a snake oil salesman, so I 'm pretty good at spotting them!

I'm pretty sure that I'm headed in the direction of off grid. And, indeed, the microinverters I was interested in are not #21 compliant! Research and a helpful website like this one are key.

jsim3 · December 2020

I woke up this morning and thought I would google, "power companies discourage home solar." I found many articles and chose one to read in the New York Times, "Rooftop Solar Dims Under Pressure From Utility Lobbyists." Now I get it. Depressing, but I'll try to work around it with small off grid experiments. Somehow, I can imagine the meter reader being instructed to report any solar array not approved. I'll make them easily removable and resetupable - probably play a game of cat and mouse!

mike95490 · December 2020

meters report any backfeeding, and also report it as consumption so you:
Get busted
pay for excess you give to the grid

jsim3 · December 2020

I don't understand, I've decided to go off grid. However, I do see that you have the same Listeroid that I have. Pretty cool.

wellbuilt · December 2020

Grid tied solar hardly seams worth it here in ny , A buddy of mine sells solar and I’ve sat in on a few sales .

At the end of the day a grid tied system with 32 320 watt panels ends up saving the home owner about
1000 buck a year .

There bill is 170 in the winter and 490 summer time .

It hardy seams worth the trouble for less then 84 bucks a month ?

It seams like a lot of trouble for that kind of money . Just saying

jsim3 · December 2020

Thank you, wellbuilt. Your observations are helpful.. If the metrics are comparable between NY and CA, I would be about $15 ahead a month! I was thinking about 12 270 watt panels. My, my, my. Neighbors of mine have much smaller arrays than what I was thinking of. Maybe they are saving $5 per month. Wahoo! Some of the allure of solar on your home is bragging rights and those are important things to Los Angeleans! I'll experiment with off grid and see if I can power a refrigerator or two, work up to an air conditioner. Maybe I'll save a few bucks a month without all the hassle of going grid tie.

Dave Angelini · December 2020

The 3rd way is kind of what you are thinking. Self Consumption. I have installed quite a few of these with the wildfires in the last 5 years.

The good parts, it does not need any utility requirements. You also keep the utility and do not hurt the resale value of your home.

The bad parts, you really need to do it safely so as not to void your home insurance. You probably need a permit where you live. You can't sell excess PV power. The Battery inverter is programmed not to sell excess. If you do, the Utility could shut down power and tell the county building department. This could escalate to a bad situation!

For rural areas and off the beaten path, like here where I am, the building department may not require permits depending on the self consumption design and specific information. Self consumption is an easy way to lower your bill and have back-up power for utility outages. If you do not care about back-up power, it probably is not worth it and a genset is the way most people end up, if they even care?

Below is the company I use for just about everything. They are from the 1800's and so they are bankable for being there for business people like me. https://solar.schneider-electric.com/installer/dave-angelini-offgrid-solar/

Self consumption link
https://solar.schneider-electric.com/solution/residential-self-consumption/

jsim3 · December 2020

I like this. Thank you Dave. It's like when I was a kid. I invented all sorts of things only to find out somebody beat me to it! In this case, I'm very happy about it.

So, I could put up a few panels on the side of my garage and power one or more refrigerators. I just hooked up two batteries, a controller and solar panel yesterday and found that I could power one freezer on the setup. The power from the sun kept the refrigerator going and the batteries charged. I was elated! Three panels on the side of my garage would probably not attract much attention from my home insurance company, the building department or fire department. If they do, I'll just take them down. I'll be taking them down seasonally anyway because I can use them at my cabin in the woods.

In the mean time I can pursue self consumption and begin the permit process when I'm ready. With a little research using the links you provided, I can already see that the route you suggest is affordable. I'll call the building department to see what is required. I wonder if they'll know anything about it. On their website it's either grid tie or nothing.

Thanks for all the help on this!

solar_dave · December 2020

I have considered converting my swimming pool off to a DC direct system to remove the utility from that part of my consumption (about 10kWh per day on average). It would help the overall utility bill reduction I am sure. Currently I am running it at night to get the best rate but I have been known to run during peak times to use up excess instead of send it back to the grid. AZ is interesting in that even though I have excess generation on the book the service delivery charges are pretty high which I hit usually about August and continue to about October.

My problem is I have not found anyone in AZ willing to consider such a system. As my current grid tie system is about 11 years old the panels a starting to weaken there output, about down 10% overall. Not sure if replacement panels and inverters would require a full inspection or if I could get away with a maintenance deal. I do have a good company to do the work, they did the pull and replace when I had the rood redone, pain is the *** but it was such a maintenance service.

jsim3 · December 2020

With every response to my questions, I am learning something new. Thanks for returning to my post solar dave! You say that at 11 years old your panels are weakening 10%. I've heard that panels are great after 25 years! Is that just a marketing pitch for used panels? There are a lot of them around here. I decided to go with new panels only because they are just barely more expensive than used ones, and because my wife didn't like the look of used panels with holes in the aluminum and scuff marks.

Regarding the possibility of a self consumption system for your pool, can't you simply come up with the components and show them to a contractor and say, "Can you do this?" It doesn't seem like the components are that much different than a grid tie system, just that the inverter won't send electricity that you generate back into the system. However, as a newbie, I may very well (probably) not see the problem clearly. Plus, who wants to be the guy who ends up being the test case for a contractor?

solar_dave · December 2020

jsim3 said:

With every response to my questions, I am learning something new. Thanks for returning to my post solar dave! You say that at 11 years old your panels are weakening 10%. I've heard that panels are great after 25 years! Is that just a marketing pitch for used panels? There are a lot of them around here. I decided to go with new panels only because they are just barely more expensive than used ones, and because my wife didn't like the look of used panels with holes in the aluminum and scuff marks.
Regarding the possibility of a self consumption system for your pool, can't you simply come up with the components and show them to a contractor and say, "Can you do this?" It doesn't seem like the components are that much different than a grid tie system, just that the inverter won't send electricity that you generate back into the system. However, as a newbie, I may very well (probably) not see the problem clearly. Plus, who wants to be the guy who ends up being the test case for a contractor?

Well that is my quandary, the solar guys don't want to do anything with the pool and the pool guys don't want to do anything with the solar. The other issue is the Sunray DC pump and equipment altogether is about $4000, not really an effective financial purchase.

Well panels do degrade, my reduction is just a SWAG at the reduction and I am sure that the panels are down a bit, but weather, temperature and a lot of factors come into play. Could it be the old inverter, doesn't really make a difference as my total power company bill was only about $600-700 this year. Not bad for having a Pool, three 3 ton AC units, 2 electric hybrid cars and all the other standard kinds of consumption.

jsim3 · December 2020

I think that I have good news. But I am wary.

The good news: It seems that LADWP (my electricity supplier) seems different than most other utilities - it's owned by the public. Thus, they want to encourage people to put solar panels on their homes. Is it a con? Here's what I found. I called up the LA Building Department and described the self consumption concept. He assumed that I was further north, in Edison country and said that I could certainly get a permit to install that system. Making it known that I was in LADWP territory, he suggested that I might actually consider a grid tie system - why not benefit from using the cost offset from using my solar fed into the grid? He described a system where 100% of the homeowners energy production is credited to the homeowner (unless you go over that, of course).

I checked on this, and it seems to be true. On this website: https://www.ladwpnews.com/ladwp-solar-interconnection-fees-information-and-faqs-summer-2020/, the cost for installing a system is presently free with LADWP. In the future it may cost $75 to $145. The Building Department charges something like $450 (not covered in the following article) and reports to LADWP that permits are in order. The power company connects the system free of charge.

On this website: https://www.energysage.com/local-data/net-metering/ladwp/, the monthly cost of solar is $10. LADWP sells power to us for the same cost we are paying now and it offsets that cost with the electricity we send into the grid from our Solar Array. [See LADWP Rate Schedules under What are LADWP's Rates and prices for net metering?] We get 100% credit for the electricity we send into the grid at the lowest rate (Tier 1), I would imagine. Our credits do not expire, but if we generate more than we consume, we'll never see a dime of that.

Could you guys double check my figuring on this and tell me if it's really good news? Thanks again for your help!

jsim3 · January 2021

Just to close out this discussion. I discovered from other LADWP users that the utility really offers a good deal that doesn't go away. I can probably recover my costs in 2 1/2 years! Pretty cool. All the best.

Planning a grid-tie system

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