Convert Grid-Tie system to Hybrid battery & GT.

[Mike90250]

Mod note, new thread started, old hijack post deleted.

[ATTACH=CONFIG]n333681[/ATTACH]
Summer 2015 I built the array that you see on my residential property. It is tied to the grid via net metering with my local power utility. I built it to provide about 90% of my average usage, and it is performing marvelously. There have been months that I produced more than I consumed, payed only my $12.31 administrative fee, and the overage was put into a credit account to be credited to the next month where I consume more than I produce. I understand that after 12 months, the overage, if any, will be paid to me by check. I also understand that if the amount paid to me reaches a certain threshold, then Uncle Sam will consider me a "utility", and then, that sucking sound I hear will be the evaporation of any benefit I may have hoped to enjoy. That is why I built it at 90%, as recommended by my electrician. I did all of the heavy construction, and he made all of the terminations. Naturally, he also handled all of the meetings with the electrical inspectors, power company inspectors, and handled the startup with the power company.

My power company actively welcomes any homeowner who is willing to go through this investment, as it relieves stress on the grid, relieves demand on the power generating equipment at the plants, and greatly reduces their cost of maintenance on equipment. They seem to love it!

Having said all of that, I now wish to add a battery bank system, to supply power to my residence, in the case of an extended power outage. My electrician is on a long-term mission trip, and will not be stateside for several months. I want to be ready with an equipment list when he returns, but I have absolutely no idea how to arrange all of the different devices... charge controllers, transformers, isolators, and lots of acronyms that kind of make my old brain numb.

Can anyone suggest a "Building Solar Battery Banks For Dummies" website that can shed some light without me having a PHD in electricity, and without pressure from sales people?

I am grateful for any suggestions. Thanks, Ron

Wow, that's going to be a job. (Adding a battery bank)
There is a pdf on the web of Solar power your home for dummies. V1 is free, V2 is newer and cost$.

Hard step is to locate where the battery bank is going to live. Even harder, is you are going to pay for a new, hardly ever used battery bank, every 5-9 years. That's the calendar life of a battery bank, 3 years if used hard, 9 years if on float and never used.

The Inverter will likely have to be re-located too, most hybrid inverters are only indoor rated. This may force a new contract with the electric company, and maybe new code requirements to bring entire system to 2017 requirements.

You will need to buy
New Inverter
Charge controller
Batteries
HV-DC rated switches, breakers, misc gear.
Backup Generator (for cloudy days when grid is down, hurricane blown lawn chairs smash PV panels and array does not work.....)

[ButchDeal]

Wow, that's going to be a job. (Adding a battery bank)
There is a pdf on the web of Solar power your home for dummies. V1 is free, V2 is newer and cost$.

Hard step is to locate where the battery bank is going to live. Even harder, is you are going to pay for a new, hardly ever used battery bank, every 5-9 years. That's the calendar life of a battery bank, 3 years if used hard, 9 years if on float and never used.

The Inverter will likely have to be re-located too, most hybrid inverters are only indoor rated. This may force a new contract with the electric company, and maybe new code requirements to bring entire system to 2017 requirements.

You will need to buy
New Inverter
Charge controller
Batteries
HV-DC rated switches, breakers, misc gear.
Backup Generator (for cloudy days when grid is down, hurricane blown lawn chairs smash PV panels and array does not work.....)

There is another option though I personally would prefer Mikes DC coupled solution. The other option is for an AC coupled solution.
It might (??) be simpler for the wiring as the existing inverter can be left where it is. You would have it connect to bimodal inverter and there would be no need for charge controllers. You likely would still need to bring everything up to current code.

Everything else about batteries would be the same.

you would need to buy
New bimodal inverter (likely the same as Mikes above)
batteries
HV-DC rated switches, breakers, misc gear.
Backup generator (optional in both cases assuming you can limit use or live without on extended cloudy days)

[jflorey2]

I now wish to add a battery bank system, to supply power to my residence, in the case of an extended power outage. My electrician is on a long-term mission trip, and will not be stateside for several months. I want to be ready with an equipment list when he returns, but I have absolutely no idea how to arrange all of the different devices... charge controllers, transformers, isolators, and lots of acronyms that kind of make my old brain numb.

Let me give you some general options:

1) Generator. If you have infrequent outages, a generator is the way to go. Simple, cheap, reliable.

2) No-battery system like the SMA Secure Power. Will give you some power while the sun is out at very little additional cost (over a regular SMA system.) You can add a $149 UPS for lights at night. If you already have an SMA inverter with that option, the cost is only the cost of a switch and an outlet. If not you would have to change inverters (expensive.)

3) "Conventional" DC coupled hybrid system. You would purchase a charge controller, batteries and a new hybrid inverter. You can do this with no changes to your existing panels if you use a HV charge controller (like the Scheider 80-600 or the Morningstar MPPT 600) but in most cases you'll want to rewire to a lower voltage. The solar feeds the charge controller(s), the charge controllers feed the battery, the battery feeds the inverter. Excess power is sent to the grid.

4) AC coupled hybrid system. You keep your existing inverter and add another hybrid inverter with battery. This is somewhat easier to install but a lot harder to get working right. If you have multiple string inverters (like, say, 3 3000 watt inverters) it gets a lot easier because you can use relays to drop the inverters one at a time as battery voltage reaches the setpoint.