With all of the natural disasters in Puerto Rico demonstrating a pretty weak power system, we all decided to get my MIL a generator. And to make sure it would be the easiest to use, I lobbied to use a solar system. That way, we don't have to worry about filling it up all the time.
But doing ALL of that will take time, so part one is the bulk of the system- storage and inverter.
Some may remember my recent question about cheap HF inverters, and the key point was that you need real power to start a fridge.
I found some interesting choices out there, but one accidentally stood out. The Giandel 2200/4400 pure sine wave inverter actually has a 300w solar charge controller. So we got it on Amazon, and sent it to Puerto Rico.
For now, I'll passively charge it with a trickle charger, but I've added the ability to use a car to charge it faster when there is an extended blackout.
Step one, the base.
Since it is going to be capable of being charged with the car, it needs to be on a mobile platform (moving 100lb of batteries can be an issue otherwise)
this is a simple 1000lb stuff dolly.
I just screwed in some 1x boards to fill in the big hole.
Then a box to contain the batteries. 
These two things were gotten an the nearby Home Depot.
Which was oddly well stocked and not empty of stuff, considering the damage to homes and buildings just a little west of here. Some are totally destroyed. And apparently a lot are still sleeping outside.
Very interested in this. Have you done a test to see how much she uses on a normal day?
Batteries are a total bitch to ship to Puerto Rico, so my plan was to get what I can on the island. But that also means deep cycle marine batteries are pretty common.
So I got 2 100Ahr batteries. Better to not over discharge and my estimate was just over 1200 Whr a day for the fridge and the TV/cable. And that's the min requirement.
The wires go to the inverter, while the Anderson plug goes to its partner installed on the car battery.
last step, add inverter and wire. 
That is just held to the lid with screws.
And that's it, until we come back in July and I install the 3 100w panels. Sun is VERY plentiful on this side of the island, and it should easily recharge what should be used on a daily basis. The proof will be in the pudding.
When it's done, I'll use it to run a washing machine all of the time. That way the system will constantly be used and fresh.
Super simple, quiet, and reasonably cost, imho. The inverter was $300, batteries another $200, and stuff another $100. I'm sure I could have done a cheaper case on wheels, but we have barely any tools down here. Add another $230 for the solar panels, and it will be just over $800.
That is a lot more than a cheap gas generator, sure. But the reality of a 90 yo woman keeping that fed twice a day adds a huge cost to that system, let alone some helpers doing that a lot. Generators with super long run times are over $1000.
Stampie said:
Very interested in this. Have you done a test to see how much she uses on a normal day?
No, really hard to so far away, so I just took my best educated guess. After some google searching, I calculated about 1300 Whr per day. And the sun we will see per day will charge that pretty easy.
In reply to alfadriver :
This is cool. I like the two stage system. 12 volt LED strip lights are cheap and very bright. I've used them and a car battery after a hurricane here. Might be a pain to wire a separate 12 volt lighting system but you wouldn't have the inverter loss.
In reply to Stampie :
That's a good addition to this system. Better than the puck lights that use batteries.
Very interesting.
I don't know exact specifics, but there are highly efficient refrigerators that are a good match to solar systems. No fancy ice-makers and such, just super efficient compressors and lots of tight insulation. They market them for off-grid use.
If you look in Home Power magazine or Mother Earth News, they have ads.
I have a book called "Solar Living Sourcebook" that has a lot of good info on systems like this. Worth a look.
In reply to TVR Scott :
Well, living off grid isn't the goal, we can't get a new fridge. All we need is to keep the food ok, and have some entertainment when there is a disaster. Which has happened twice in 2.5 years.
For real off grid living, yea, there are some amazing options.
I grew up living off solar power...a fridge is a tough ask unless you have a lot of panel wattage. We had a LP fridge we hooked up during those times we really needed to keep something cold. Of course...I grew up in the 80s and panels were a lot weaker then....the biggest problem isnt even the panels, its the battery bank you need to keep a fridge going through the night...to give you an idea...we had I think 12 deep cycle marine batteries....it wasn't enough, though to be fair we had to power the rest of the house as well and not just a fridge
Can you set up a windmill to turn a car alternator to charge the batteries ?
or I remember someone using an old bike as pedal power to turn an alternator ,
lots of interesting ideas out there......
In reply to californiamilleghia :
You can, but there are better designs out there that generate power at a lower speed.
But that, too, isn't much of an option for us.
The real hope is that the next power outage is as short at this one was, which was not quite 4 days. The system is getting better, but so seem are the disasters.
In reply to Wicked93gs :
Hopefully, these new energy star rated fridges are as good as the ratings say they are.
What are your plans to "harden" the solar panels from damage during a storm?
TVR Scott said:
Very interesting.
I don't know exact specifics, but there are highly efficient refrigerators that are a good match to solar systems. No fancy ice-makers and such, just super efficient compressors and lots of tight insulation. They market them for off-grid use.
If you look in Home Power magazine or Mother Earth News, they have ads.
I have a book called "Solar Living Sourcebook" that has a lot of good info on systems like this. Worth a look.
FYI, I'd be looking for RV fridges. My "Truckfridge" is quoted at using about 480Whr/day, and it'll run straight off 12v DC so there's no inverter loss. You can either use 120v AC to charge the batteries (when available) or there are AC/DC models. They have bigger models as well. I know that's not what Alfa is planning but it's an option.
sleepyhead the buffalo said:
What are your plans to "harden" the solar panels from damage during a storm?
My thought is to make them mobile. Storms can be seen many days in advance so they can be moved to a safe spot.
The back yard is very clear of trees, and the reflection off the house will help, too.
Cool project.
Two questions.
Is the battery box vented so you don't get a accidental buildup of hydrogen when the batteries are charging?
Will the car put out enough amperage at idle to charge the batteries? Most of them don't put out much amperage until the RPMs get above 2k.
As an add, I've had good luck with Grape Solar panels. They are 100 watts and Home Depot carries them for about $100 each. You may be able to get them delivered to the island store and save you some freight.
Home Depot link for panels.
In reply to Toyman01 :
It's not vented, yet. When I put on the trickle charger today, I'll add some vent holes.
We will see on the car, but I can't expect anyone to keep it high. If we can get to July, it won't end up being an issue.
And the panels will come from amazon, as the HD panels are really expensive down here.
edit, checked on the HD panels, and they can't be shipped to PR...bummer.
You won't need very many holes to vent- just one would be fine. The amount of elemental hydrogen that is released by these is all from the acid decaying, and if you're taking care of it properly it won't be very much at all.
In reply to Toyman01 :
Hey, thanks for the link! I was looking for some cheap panels and this looks better than the Harbor Freight ones.
Toyman01 said:
Cool project.
Two questions.
Is the battery box vented so you don't get a accidental buildup of hydrogen when the batteries are charging?
Will the car put out enough amperage at idle to charge the batteries? Most of them don't put out much amperage until the RPMs get above 2k.
As an add, I've had good luck with Grape Solar panels. They are 100 watts and Home Depot carries them for about $100 each. You may be able to get them delivered to the island store and save you some freight.
Home Depot link for panels.
Update where this question gets really important.
Went to go fill up the car, and darned if the alternator light is on....Looking under the hood suggests this has been a problem for some time. Ugh.
So we'll be living on edge until July. At least the trickle charger will get it well prepared for one day. And then I'll make the mobile solar panel set up.
Knock on wood.
