How to add Batteries to a roof solar system?

**Mark2407** · 06-28-2019, 10:10 PM

Wow. I just realized. . . when the nation's power grid dies, then the natural gas company will be out of business. . . yes?
We might need to get an Electric water heater?

**Mike90250** · 06-28-2019, 11:25 PM

Originally posted by Mark2407

Hello, people.
.... so that when the terrorists destroy the country's power grid, we will have all the power we
need to run the house (2000 square feet, with constant AC, fridge and a spare freezer, electric stove/oven, many electronics, etc).....

All the power you need to attract the moths to the flame.

Yes it's doable. But expensive. you can reuse the panels, and that's about it.

**Ampster** · 06-29-2019, 02:22 AM

What Mike is saying is you will need a different inverter because that one will only work when the grid is up. It is known as a Grid Tie Inverter and it was not designed to use batteries. You need a more expensive hybrid inverter that can run your house off batteries and the sun. Or add a Tesla Powerwall or similar system to your existing inverter and solar panels. Plan on spending about $10,000.

**Mark2407** · 06-29-2019, 12:55 PM

Well, thanks for the replies, people.

Mike: "All the power you need to attract the moths to the flame. "
I hope that won't be a problem. Many houses around here have solar on the roof, so we won't stand out from the rest.
And AZ is a gun-friendly state. . . we have an adequate supply.
ALL of that stuff in your signature is Greek to me.

Ampster: OK, the big box in the garage is apparently a grid-connected inverter.
And I can not just tap into the AC that comes out of that Inverter. Darn.
Right. . . I need to catch the DC from the panels, and run that into some batteries. . . Yes?
The hybrid inverter that you mention. . . Would that Replace the existing inverter, or be in addition to it?
I'll do some research to find out what is a Tesla Powerwall. $10,000?! Eek.

So as not to waste too much of your time, can you suggest some links where I can read / learn about this stuff?

Thanks.

**ButchDeal** · 06-29-2019, 04:40 PM

Originally posted by Mark2407

Well, thanks for the replies, people.

Mike: "All the power you need to attract the moths to the flame. "
I hope that won't be a problem. Many houses around here have solar on the roof, so we won't stand out from the rest.
And AZ is a gun-friendly state. . . we have an adequate supply.
ALL of that stuff in your signature is Greek to me.

Ampster: OK, the big box in the garage is apparently a grid-connected inverter.
And I can not just tap into the AC that comes out of that Inverter. Darn.
Right. . . I need to catch the DC from the panels, and run that into some batteries. . . Yes?
The hybrid inverter that you mention. . . Would that Replace the existing inverter, or be in addition to it?
I'll do some research to find out what is a Tesla Powerwall. $10,000?! Eek.

So as not to waste too much of your time, can you suggest some links where I can read / learn about this stuff?

Thanks.

First off, the house will stand out from the others in an outage as it will have power, thus attracting people that might want it.
second, others have guns too...

on the inverter part there are two ways to convert to a backup type system. Bit involve adding a bimodal inverter.
one is DC coupled and you would replace your existing inverter with charge controllers, bimodal inverter and batteries.
the other option is AC couoled and you would ADD a bimodal inverter to the existing inverter as well as batteries.

A power wall would be an AC coupled solution. Outback power has some documentation on AC coupled solutions as well as their default DC coupled solutions.

**jflorey2** · 06-29-2019, 10:46 PM

Originally posted by Mark2407

Well, thanks for the replies, people.

Mike: "All the power you need to attract the moths to the flame. "
I hope that won't be a problem. Many houses around here have solar on the roof, so we won't stand out from the rest.
And AZ is a gun-friendly state. . . we have an adequate supply.
ALL of that stuff in your signature is Greek to me.

If you are at the point at which you are thinking about a shootout between the power-hungry villains and your intrepid family - you are so far into the weeds that it makes no sense to work on solar. Water, food and medical care are far larger problems than defending your working refrigerator from villains.

Generators make a lot more sense for backup.

**SunEagle** · 06-30-2019, 08:59 AM

I think that most people that want a solar emergency power backup system in case of a SHTF issue, do so because they really want to justify using a solar/battery system regardless of the cost.

**NCmountainsOffgrid** · 06-30-2019, 10:06 AM

saying you have a gun and you'll be one of the only ones with 'power', is like saying that 'gold' will somehow have a much greater value when the world 'implodes'....
the problem is that you can't EAT gold - the most valuable things when the world collides will the food&water, and secondly fuel... no amount of 'money' or 'gold' will matter.

but, that's just my take. Keep some beef jerky at hand. : )

**Ampster** · 06-30-2019, 10:37 AM

Originally posted by Mark2407

....

Ampster: OK, the big box in the garage is apparently a grid-connected inverter.
And I can not just tap into the AC that comes out of that Inverter. Darn.
Right. . . I need to catch the DC from the panels, and run that into some batteries. . . Yes?
The hybrid inverter that you mention. . . Would that Replace the existing inverter, or be in addition to it?
I'll do some research to find out what is a Tesla Powerwall. $10,000?! Eek.

So as not to waste too much of your time, can you suggest some links where I can read / learn about this stuff?
.......

I having been messing around with batteries, solar panels and LEDs for the past 18 years. I am not an expert and have had no formal education in electrical engineering. I do believe we all have the tools to teach ourselves informally.

This forum is a good resource because, unlike YouTube and Google searches, you have the opportunity to get feedback. Most of my projects have been to satisfy my curiosity. As they have become more expensive I have had to justify them based on a financial savings. When that looked less promising I rationalized them because I wanted the backup in case my power went out. It all depends of where we are standing. In my part of California my power company has had to shut down sections of the grid to prevent brush fires. In addition the power market is evolving and it is possible n the future that I might get compensation to allow the power company to utilize my battery power when the grid gets stressed. I already get compensated just to give them the ability to turn off my EV chargers when the grid is stressed.

I don't have a syllabus I can give you. My suggestion use what ever search engine you prefer. Those queries will often lead you back to threads on this forum. As you think about your goals be sure your planning is based on a realistic estimate of your needs.

**Mark2407** · 06-30-2019, 01:55 PM

Thanks for the replies, people.

Jflorey: You mean Gas generators? But they're Noisy! IMHO, Solar is better because it's less noticeable/obvious.

Ampster: thanks for your thoughtful and helpful comments.

OK,. . . I'll search and study. . .
DC coupled
AC coupled
Bimodal inverters
Charge controllers
Outback power

Mark2407

**Ampster** · 06-30-2019, 02:36 PM

Originally posted by Mark2407

Jflorey: You mean Gas generators? But they're Noisy! IMHO, Solar is better because it's less noticeable/obvious.....

I agree with jflorey that gas generators are less expensive than batteries, but I also don't like the noise and smell of generators and having to keep an explosive fuel around. That is why I went the more expensive route of batteries.

**PNPmacnab** · 06-30-2019, 04:04 PM

The solar world has been stuck on batteries for a long time. If the world ends as we know it, you need to learn how to live differently. You have a lot of power from those panels and you can just use it when it is there. Technically, you don't need batteries. I have refrigeration, hot water, dishwasher with heated dry, all the usual stuff and when I get around to it a clothes washer. And I've had no need for anything beyond my car battery. I do things when the sun shines. That is not where the market is and you can't get the equipment to do it. What are you going to do when you can't go down to Walmart and get another battery. I've watched a few prepper videos and the first thing that comes to mind is these people are all going to die in a real crisis.

**Mark2407** · 07-06-2019, 02:40 AM

PNPmacnab, I LIKE the idea.
Saves at least Some of the $10K expense, without batteries.
If we don't open the fridge when the sun is down, it will stay cold for (8 or 10?) hours.
But I don't understand what you said about
"That is not where the market is. . ."
I think you mean that the market would rather I spend $ on batteries, Yes?
and
"and you can't get the equipment to do it."
What equipment are you referring to? Surely it is available somewhere?
I think I'd need an inverter to convert the panels DC to the house AC, Yes?
Could the existing inverter somehow be made to work?
Mark2407

**Sunking** · 07-06-2019, 10:22 PM

Originally posted by Mark2407

Thanks for the replies, people.

Jflorey: You mean Gas generators? But they're Noisy! IMHO, Solar is better because it's less noticeable/obvious.

You cannot protect people from themselves.

How to add Batteries to a roof solar system?

How to add Batteries to a roof solar system?

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