off grid in texas

willy

hi i just found this forum. I've been living off the grid for over a year now starting in a 18 foot travel trailer for the first 6 months till cabin fever got me.i'm now living in my as of yet unfinished 12 x 24 cabin powered by 3 x 45 watt harbor freight panels and 8 x energizer 6 v.d.c. deep cycle batteries in 12 volt configuration (sam's club specials).i back this up with a 3600 watt gen and a 67 c.c. (harbor freight) to gm alt. generator.110 is supplied by various 100 - 250 watt spot inverters. I've had no power issues till recently when i got internet (guess i'm an addict..lol).phase 2 i plan about 300 watts of panels and add 4 more batteries bringing bank up to 1200 ah and maybe a 400 watt wind turbine,we have plenty of wind here.i experimented with an inverter powered cube fridge (5 c.f.) and found even tho i used a 1000 watt inverter and the fridge runs on 105 watts (checked with a meter) I've concluded i need a pure sine setup.I'm still researching brands and doing needed power calculations.the neighbors power has gone out three times in the last year ,mine 1 time for scheduled maintenance (15 minutes..lol)
I look forward to networking with all the members here for new ideas and i'll try to share what I've learned.
Thanks for the forum
always remember a dependent man is a slave.

BB.

Re: off grid in texas

Welcome to the forum Willy!

Slow down a bit. Need to answer some questions and think about what you want the system to do.

willy wrote: »

hi i just found this forum. I've been living off the grid for over a year now starting in a 18 foot travel trailer for the first 6 months till cabin fever got me.i'm now living in my as of yet unfinished 12 x 24 cabin powered by 3 x 45 watt harbor freight panels and 8 x energizer 6 v.d.c. deep cycle batteries in 12 volt configuration (sam's club specials).

In general, the HF 45 Watt (total?) panels are not going to do well for you long term. You should get standard "glass panels" made with mono or crystalline silicon wafers. They will last longer and should scale up larger. New panels are current in the $2-$1 per watt range (or less). Never cheaper and probably not this cheap ever again.

Starting with the battery bank. Batteries are the one thing that need can be easily damaged if not properly charged and loaded. You have a fairly large battery bank and not very much solar panels for it. The typical range of charging is 5% to 13% rate of charge. Do you know what the AH capacity of each battery is? Guessing at 6 volt @ 200 AH batteries, the solar panel math would look like:

• 8 batteries * 6 volt * 200 AH * 1/0.77 panel+controller derating * 0.05 rate of charge = 623 Watt array minimum
• 8 batteries * 6 volt * 200 AH * 1/0.77 panel+controller derating * 0.10 rate of charge = 1,247 Watt array nominal
• 8 batteries * 6 volt * 200 AH * 1/0.77 panel+controller derating * 0.13 rate of charge = 1,621 Watt array "cost effective" maximum

As you can see, the present panels you have are no where near enough to actually support a "cycling" off grid battery bank.

Do you have grid power now (even if not the most reliable)? If so, then you should be looking at getting an AC battery charger on those batteries and use a hydrometer to measure and log your temperature corrected specific gravity. Otherwise, until you get enough solar panels (recommend 5% minimum rate of charge), you are going to have to use the genset (or grid power) to keep those batteries "happy".

It is very easy to knock years off a lead acid battery bank if it is not properly charged (or over charged, or electrolyte levels are left to go too low and expose plates, etc.).

i back this up with a 3600 watt gen and a 67 c.c. (harbor freight) to gm alt. generator.

What sort (brand/model) of AC inverter do you have to charge your battery bank--You need to make sure that it is properly charged and maintained.

110 is supplied by various 100 - 250 watt spot inverters.

I would suggest getting a Kill-a-Watt type meter and measure your kWatt*Hours per day of AC power you use. Then size the battery bank and array to support that.

I've had no power issues till recently when i got internet (guess i'm an addict..lol).

People tend overestimate the amount power the solar power system can generate and underestimate how much power they really use. Accurate measurements of your energy usage and hard nosed math on what your system can produce is needed.

You might want to look at a Battery Monitor (like the Tri-Metric). It will help you manage your battery bank, and hopefully save them from an "early death".

phase 2 i plan about 300 watts of panels and add 4 more batteries bringing bank up to 1200 ah and maybe a 400 watt wind turbine,we have plenty of wind here.

WAIT... Even with the battery bank you presently have--You need way more solar panels (and new charge controller).

Personally, I am not a big fan of small wind power--I would suggest getting your system optimized with solar power (and genset for poor weather). Once you are stable, you are certainly able to try wind and see what it does for you.

i experimented with an inverter powered cube fridge (5 c.f.) and found even tho i used a 1000 watt inverter and the fridge runs on 105 watts (checked with a meter) I've concluded i need a pure sine setup.

A 1,000 watt inverter (good brand and very good/heavy 12 volt cabling) is needed to run even a small fridge. Typical refrigerator compressors (and well pump motors) can easily have 5x starting surge current vs run current.

A true full sized energy star refrigerator probably needs around 1,200-1,500 watt AC inverter to run the fridge (and a few lights and other light AC loads).

I'm still researching brands and doing needed power calculations.the neighbors power has gone out three times in the last year ,mine 1 time for scheduled maintenance (15 minutes..lol)

Off grid systems still need preventative maintenance and constant monitoring. The hardware is pretty rugged. Glass solar panels should last 20-30 years, AC inverters and Chargers/charge controllers 10+ years, etc...

Batteries are the wild card. "Cheap" deep cycle batteries should last 3-5 years.... Mid quality perhaps 6-8 years, and $$$$ 10-15+ years. But all batteries can be destroyed in months/weeks/days with improper operation.

Don't forget properly sizing wiring and using fuses/breakers to protect against short circuits. Your battery bank is capable of 1,000's of Amperes into a dead short. Nothing like watching some 4 AWG wire glowing read hot and burning insulation falling off of it with no way to stop the current.

I look forward to networking with all the members here for new ideas and i'll try to share what I've learned.
Thanks for the forum
always remember a dependent man is a slave.

We are all volunteers here--And we should thank our host every once in a while (Northern Arizona Wind & Sun) for starting/hosting this forum free of charge for everyone here to use.

-Bill