Going off grid

Photowhit · February 2017

I have and like ground mounted panels, but might check with any inspectors, In theory ground mounted panels and wiring over 30 volts DC must have limited access. I actually never heard of anyone required to, but this would mean having your array fenced. (I think they put this in the NEC 2008-2011?, I wanted to put my system in up to code and thought Missouri only did 2005-2008, now at least one site says Missouri has no state required code.

I never fenced my array.

wellbuilt · February 2017

I can't wate to see what the fed figures out for the future

softdown · February 2017

Roof racking worked for me because I have a pretty flat roof available. Otherwise, cleaning off the snow and ice could be dangerous. That isn't hard to visualize.

I would guess the typical roof panels installations just wait patiently for the sun to remove the snow. That could be a long time in upstate New York....I would think.

wellbuilt · February 2017

The inspector seams very help full.
He is really in to the off grid thing , he offered to come out and walk me thru the Process
BB was saying in his post that a 3300 wh system should give a somewhat normal electric life .
So what would that system look like ?
I liked the samalex evo2224 inverter with 50 amp charger ..
Since I have a 50 amp charger I would think a 500ah battery would charge up at 10% rate .
Maybe 2 strings of GC 230 ah battery's for 460 AH would be close .
I was looking at 6 new Canadian solar 295 watt panels ( for 150 each ) with a voc of 45.7 for a mppt controler .
I was thinking this system would work for 10 years .
Could you guys tweek this for me . Thanks

softdown · February 2017

If you can afford that house, you should likely upgrade your solar system commensurately.

Bigger inverter...more batteries...more panels. Then you can run an electric fridge which actually makes sense these days. Makes sense because of cheap panels and efficient fridges.

I can't hardly believe we have a newcomer who isn't wanting a 4000 watt inverter with 800 watts of panels. AKA: bad planning.

It will take a significant effort to get solar savvy. One of my biggest endeavors....ever. I...got...lucky.

BB. · February 2017

OK... a 3.3 kWH per day system may look like:

Loads define the battery bank... 3,300 WH per day is a "medium" sized system. 24 or 48 volt system would be OK--Start with 24 volts and what seems to be an optimum system design of 2 days of storage and 50% maximum discharge:

3,300 WH per day * 1/0.85 inverter eff * 2 days storage * 1/0.50 max discharge * 1/24 volt battery bank = 647 AH @ 24 volt battery bank

Two solar array calculations... First is based on size of battery bank and 5% (weekend/summer cabin) to 10%-13% (>9 months off grid):

647 AH * 29 volts charging *1/0.77 panel+controller deratings * 0.05 rate of charge = 1,218 Watt array minimum
647 AH * 29 volts charging *1/0.77 panel+controller deratings * 0.10 rate of charge = 2,437 Watt array nominal
647 AH * 29 volts charging *1/0.77 panel+controller deratings * 0.13 rate of charge = 3,168 Watt array "cost effective" maximum

There there is sizing your array based on your loads and where you live. You know you area better--But picking Albany NY, fixed array, middle tilt (best all year round harvest):
http://www.solarelectricityhandbook.com/solar-irradiance.html

Albany
Average Solar Insolation figures

Measured in kWh/m2/day onto a solar panel set at a 47° angle from vertical:
(For best year-round performance)

Jan	Feb	Mar	Apr	May	Jun
3.09	3.89	4.40	4.46	4.67	4.92
Jul	Aug	Sep	Oct	Nov	Dec
5.02	4.91	4.56	3.88	2.83	2.73

Assuming the bottom three months you will use a genset to help (of course, you can prop the panels up for more tilt):

3,300 WH per day * 1/0.52 off grid system eff * 1/3.89 hours of sun (Feb average) = 1,631 Watt array (Feb break even month)

If you tilt the array to a higher angle:

Albany
Average Solar Insolation figures

Measured in kWh/m2/day onto a solar panel set at a 32° angle from Vertical:
(Optimal winter settings)

Jan	Feb	Mar	Apr	May	Jun
3.28	3.97	4.27	4.10	4.13	4.26
Jul	Aug	Sep	Oct	Nov	Dec
4.37	4.43	4.35	3.89	2.94	2.91

Realistically, not a much of an increase in harvest (for a fixed array).

For genset charging, you probably will want somewhere around a 10% to 20% rate of charge:

647 AH * 0.10 rate of charge = 65 amp (`minimum recommended) backup genset charging
647 AH * 0.20 rate of charge = 129 amp (~maximum recommended) backup genset charging

A 647 AH @ 24 volt battery bank will run your loads/inverter nominally (flooded cell lead acid battery):

647 AH * 1/200 AH per 1,000 Watts = 3,235 Watt max inverter and max recommended solar array wattage (rough numbers)

Assuming an average load of 5 hours per night for two nights (no daytime charging):

647 AH * 24 volts * 0.85 inverter eff * 1/10 hours per night * 0.50 max discharge = 660 Watt "average load" (20 hour discharge rate)
647 AH * 24 volts * 0.85 inverter eff * 1/8 hour discharge rate = 1,650 Watts max continuous loads (for less than 4 hours)
647 AH * 24 volts * 0.85 inverter eff * 1/5 hour discharge rate = 2,640 Watts max short term loads (minutes to hour)
647 AH * 24 volts * 0.85 inverter eff * 1/2.5 hour discharge rate = 5,280 Watts max surge (starting well pumps)

So--The estimated AC inverter would be ~1,200 to 1,500 Watts minimum (to start a refrigerator and run some other smaller loads).

The maximum "useful" inverter would be 1,650 to 2,640 Watts or so...

-Bill

Photowhit · February 2017

wellbuilt said:

BB was saying in his post that a 3300 wh system should give a somewhat normal electric life .

I think it's important to understand that Bill is referring to a modern, very efficient home. That uses gas or other for heating air and water. Of course also for 1 or 2 like minded people, with no energy hog hobbies or businesses.

Even then you would likely want to load shift somethings. I figure I use in that neighborhood most of the year. with 3-4 months of much higher use with an air conditioner during the summer. If you need air conditioning, think ahead!

I don't have (or want) a generator and have a somewhat over paneled system, now 5KW.

I would guess my 17 year old fridge uses close to 2Kwh a day during the warmish months, by it's self.

Please note, where I live, at 3.3 Kwh a day, I can argue an off grid system would be about grid parity, if installed by the home owner and with tax credits. The local Electric Coop charges $32.50 per month for the privileged of buying electric from them and @9 cents a Kwh. So $32.50 + $10 = 42.50 for 3.3kwh a day/100 kwh a month, 42 cents a Kwh. Of course I live in a rural area, where there's not a lot of interest or perhaps understanding about efficiency or conservation. Look at your electric bill and see how much electric you use.

BB. · February 2017

Yes... Energy usage is the result of a highly personal set of choices.

And, 3.3 kWatt*Hours per day is a small amount of energy (~100 kWH per month). Most people connected to the grid probably use around 500+ kWH per month... Add a few larger appliances (A/C, electric appliances, electric hot water, etc.), and you are looking at 1,000 to 3,000 kWH per month in more sever climates (south Texas in summer, far north in winter, etc.).

More or less, energy usage seems to go in steps of 3x... If 3.3 kWH per day is not enough--The next "larger" system step would be ~10 kWH per day.

You can squeak a system a bit larger (or smaller) by a factor of 2x (or x1/2)--I.e., you can add more panels and batteries with the existing inverter voltage and such. But if you want (for example) a 3x larger system--You need to go from 24 volts to 48 volts (new batteries, new AC inverter, new/bigger genset+charger, etc.).

The 3.3 kWH per day is an "aim point"... If you need 4.x kWH per day, you can add hardware to your existing system (for the most part).

-Bill

wellbuilt · February 2017

Soft down , I'm getting older now, I have to get ready for the day I can't work .
I will need someplace to live.
My son and I built the house in 70 working days and milled most of the lumber off the land around us .
It dident really cost much .
Inverters batterys and equipment cost a lot now , and more to replace when I'm old with no income.
So I would like to go with a smaller system that I can handle my self .
I was just thinking of building a small cabin, but wifey drew the plans then added a second floor and 2 car garage.
And it is still growing I need a shop? 24x 40
It is going to be 10 years before I need real power up there , and I'm sure there will be big advancements in solar hardware and batteries , so I'm not to sure about installing a full time system .
Photowhite,
I'm doing every thing I can to be efficient
i heat with wood or coal ,cook with gas , wood or home made wood coal.
Have radiant heat pipe in a stained concrete floor , I'm not sure how I'm going to fire it yet , but it won't be electric for sure.
R 30 walls r 60 ceiling . 3" Dow board in the floor .
No AC we need a sweet shirt at night in July and it's windy most of the time .
I don't think I can get the tax credits for a summer home part time. I'm going to check .

BB the system size is larger then I thought 647 ah battery 3000 watt of solar panels .
And the ground mounting is really unplanned for .
Could you tell me how many watts of solar could go on a classic 150/200 CC
What type of battery could I use to reach the 647 ah easy and cheep

westbranch · February 2017

See page 11 http://www.midnitesolar.com/pdfs/Classic_manual_REV_2056.pdf
top graph Cl 150 200 is below it,,,, the 150 is best for your app...

Photowhit · February 2017

wellbuilt said:
I don't think I can get the tax credits for a summer home part time. I'm going to check .

Could you tell me how many watts of solar could go on a classic 150/200 CC

Unless things have changed you can get the tax credit, 30% against any tax liability, for 2dn homes, so long as they aren't rented out.

The Midnite Classic 150 can cost effectively handle roughly 3000 watts of array in 24 volt systems and @ 5500 watts in a 48 volt system. Somewhat less for the Classic 200.

They have a string sizing tool here;
http://www.midnitesolar.com/sizingTool/

softdown · February 2017

Built the house from trees on the lot? I am officially impressed!

24 volt systems are OK up to roughly 2000 watts. 48 volt for future expansion and "power creep" as demand grows. 48 volt doubles the capacity of your lines and charge controller. 24 x 40 shop? You know about the start up surge of power tools. Everything lasts much longer if it is not being pushed to its design limits.

Panels are cheap now...take advantage...be set for life in that department. Batteries? You probably have the ability to move forklift batteries around. That is the best value in solar batteries. May last 15-20 years! Built for a hard life of deep discharges and aggressive recharging. Plus you can replace a dead cell. I wrote a thread about how I did it. Plus youtube has videos on it though they gloss over the details.

People are going to think you have money after viewing the house. You best have a plan for the property tax man. They want $2500/year for my pole barn! I am forced to sell and live on a sail boat.

wellbuilt · February 2017

It is mostly rough sawn hemlock , the only bought wood is 3/4 ply wood sheathing and some 12" ipi floor joist.
The beams holding up the pouch are 8x14x 20s we pushed them up In a snow storm .
My foundation is built on a granite ridge line With 8" of block worked pinned and 41/2" concrete slab over the top I pushed the dirt around it .
I would like to beleave that 2000watts would be enough to run the house , but I don't know.
I have a line on some canadein solar 295 watt panels 150 each .
The voc is 45.7 seems high , I will post the specs when I get them.
The shop tools will run on a genarator .
I may have to go cheep on battery's this year , I'm still trying to figure out a budget VS available time to work on the house.
And beleave me I just don't have money, I'm working like the rest of you guys.
Money goes fast I have 10 kids.
The tax man is a big problem , more so in ny .
My taxes are 1600 a month at home .
I hope the tax man goes easy on me, I'm thinking 3500 bucks a year ,but I'm in the middle of nowhere.
I am a sailer all so , and planed to retire on a sail boat but wilfey knees went out and can't live climbing in and out of a boat .
I want to work as long as I can ,but every year I get slower .
The way things are going , we all mite end up living in a cardboard box.
After all we just trade our savings for crappy medical care

softdown · February 2017

Do you have an "S" on your chest by any chance?

Does "wellbuilt" have something to do with 10 children?

wellbuilt · February 2017

No S On the chest , and the kids are due to the lack of cable tv and the movie Chanel.

wellbuilt · March 2017

I was wondering if any one can help me pick a inverter .
I was thinking about a samalex EVO2224 from this site 1250 bucks or so .
I have seen a few reviews and the specs on the unit seem like what I need .
But would I be better off going with a magnum or out back . ?

westbranch · March 2017

Wellbuilt, if you add a list of what equipment you now have into your Signature line and an assessment of what your loads are going to look like. The reason I ask is that that discussion sort of stopped a few posts back with BB advising that you are on the border of potentially needing a 48 Volt setup.
the EVo models both have transfer switch built in , that is a good feature for when you want to run heavier loads off the gen set... the fact that it has a charger built in also is good as you do not have to add that additional part...Same warranty as Magnum OB is 3 years longer but more $$ and ~same DC charge out put 55A vs EVO@50A

wellbuilt · March 2017

Thanks for the reply west branch , I have no equipment yet I can't make a move with out you guys advising me .
As far as loads I'll have a Samsung frig running lights , cell phone charging I pad charging
there will some kind of tv / sadalite / internet set up .
Washer dryer 2/3 people living there in 7 to 10 years.
I've been studying bills post for days rolling the numbers around in my head.
I get lost when I try to figure out my loads , I have no loads yet , I'm not sure who will be living there ?
Things are getting more efficient every day , 7 to 10 years could make a big differences in battery's and other things .
But I will need power now , so we can work there and get some fishing done .
So I'm thinking bills 3300watt system should be ok for now any way .
I was looking at the specs on other inverters and a 4000 watt inverter doesn't use any more power on stand buy or power save , so it doesn't really cost me any extra power to get a larger inverter .
I have interstate battery availability here 8x 235 each plus tax =2000 +- 385 ahx2 770 ah .
gc 215 could work but I would need 3 strings of 4 84 each x12 =1000 +- . 645 ah
Bill was thinking 645ahswould work for me ?
I will need to get water out of my well but I'm thinking that will be a different system .
My well is 745' deep , I get about 2/3 gallons a min water level is 335 feet down to 550 , in average rain fall .
I'm thinking about a solar pump that pumps into a tank when the sun is out .
I'm going to have to make a move in the next few weeks

westbranch · March 2017

what I was trying to point out is that for more $$ you don't get much more charging capacity (ie + 5A) , but you do get more 120V amps in some cases, each option is a bit different. I started with a 1500W inverter and separate charger, have been happy with it, it's nice to know I have solar still if the charger calves out, I like redundancy where you have 2 of everything if you can... use the gen for big tools T saw, compressor, inverter for smaller tools.. may upgrade when we are there full time for the winter.... we need more PV up first... the fridge is the biggest load to feed and it is quite efficient. Let us know what you decide...

wellbuilt · March 2017

Hi Cathryn , thank for the offer .
But I try to buy thru our forum supporter if possible .
John

littleharbor2 · March 2017

Cathryn is a spammer. She posted this ad 51 times last night.

mcgivor · March 2017

littleharbor2 said:

Cathryn is a spammer. She posted this ad 51 times last night.

At least the avatar chosen for her, the look of supprise and dismay is fitting

wellbuilt · March 2017

West branch , I think the evo 2224 has a solar charger pass thru of 50amps
the charger is run at 70ams I think , with power factor corected .
I think I will go with the evo .
I worked with a out back 3000 watt 24 volt and didn't like how the controler worked , very confusing for me
I have a freedom 1000 in my sail boat that has been there since 88 and it just works with no problem .
The magnum was easy but , since then every thing has gotten complicated .
It would be nice if I can buy 1 unit and stick with it .
What do you think about running 2 units ? One for the frig and lights 24/7 and when we are not there .
The larger one for day time.
If it was just me I could run on a small bank and off solar panels for day time and just go to bed when it get dark

wellbuilt · March 2017

I figured some thing was up.
If I wanted to buy from china I could have my daughter send me stuff .
She sends stuff back and fourth all the time.
She speaks 6 different languages so it's pretty easy

BB. · March 2017

Since most people off grid will need a backup genset--I would suggest that getting one, with a Watt*Hour meter of some sort, and live on the genset for a month and see how much energy (per day) you would use (helpful if you do not have any idea what you will use).

The other option would be to just live in the house like you would "off grid", read your energy usage every day (and/or get a whole house energy monitor) and see just how low you can get (this would mean uplugging everything, and only powering the loads you would be living off grid). Good practice for the family too. I got down to ~175 kWH per month (~9 kWH per day) with my family of four (gas appliances, not really living off grid--But after I had changed lights to CFL, new fridge, a couple computers, TV, washer, gas drier, etc.).

Otherwise, just get a Kill-a-Watt meter and monitor for a few days each appliance you plan on installing in your new place and put in a spread sheet.

http://www.theenergydetective.com/
https://www.solar-electric.com/kiacpomome.html

The 3.3 kWH per day is a minimum to aim for. Energy usage is a highly personal set of choices--What works for one family may not work for another.

-Bill

westbranch · March 2017

I just discovered this package is NOW available from ''the NAWS store'' ...a bit more than what you wanted to start with at $3386
https://www.solar-electric.com/midnite-solar-mnevo2224-cl150-prewired-system.html

But you might look at the benefits of an all in one package -
Inverter/ charger , Classic 150 Charge Controller and the Electrical box is prewired includes 3 Surge protectors , the WBjr , 3 circuit breakers, 2 batt temp sensors, 5 yr warranty on E- box
specs here

http://www.midnitesolar.com/productPhoto.php?product_ID=647&productCatName=Inverter Systems, Pre Wired - Off Grid&productCat_ID=20&sortOrder=1&act=p

wellbuilt · March 2017

Hi bill, I have 3 genarator s now 200035004750 watt but the house has no wire in it yet .
We put the windows in in November and left there won't be appliances or even people living there for 7/10 years .
Every thing I buy will be the most efficient as possable at the time I move there .
I like Samsung ( or my wife likes Samsung) I know the washer and dryers don't burn much power.
The refers are getting better every year.
We are staying there when we are working ,but that can't tell me any thing.
We live out of a cooler and have a diet of skittles and beer .
We go to bed after dinner
I ran a watt meter on my frig and freezer and it was around 1500 watts for the day at 70o
but I have 10 kids and the frig is open day and night .
Lights 12 out side 10 watts 12 inside 10 watts 20 watts an hour x10= 200 watts plus Samsung tv with box and wi fi 85 watts 5/600 watts.
6 watts to charge phones and I pad 24 hrs x2 185 watts
radeaint floor heat off wood stove 20 watt x 24 hrs =500
that's about all I need A lot of that power would be run day in day lite off solar power.
Should I over panel to have more power to burn day in the day time .
9000 wats a day seems lik a lot of juice .

wellbuilt · March 2017

West branch , I was looking at the E panel , it seems like a good deal .
I added the components up and off the top of my head , they would cost 2900 dollars with just adding up the things I know I need .
Im sure my inspector would like to see that box since I really don't know how to wire all that stuff together.
I do have a lot of work to do with a small budget .
I'm not sure how much money I can throw at the power system now .
Where could I cut corners for this year ?
I could swing the e box , inverter , classic combo .
I have a deal going for 10 295 watt solar panels voc 45.5 i was thinking 3 parallel strings of 3 for 9 panels with 1 extra for 2655 watts and fill up my classic 150 .
The only place to skimp would be the battery's , may be I could limp buy for a few years on 8 gc 215.
What about adding a second 24 volt system if I need more power in 10 years .

BB. · March 2017

Design/build a 1,000 watt hour per day system.

Use genset during the day (tools fridge freezer) and the off grid system at night for lights, laptop, 12 volt rv pump, cell phone charger, etc. (Quiet time).

Small system not too expensive, and if parts get stolen, you are not out $10,000's from your pocket.

-Bill

Estragon · March 2017

I did pretty much what Bill is suggesting for years while renovating my cabin. I had a couple of golf cart batteries in a 220ah 12v 300w system for lights, etc. at night. Ran a generator for tools and charging while working during the day. The charger died, but I still use the inverter, and kept the batteries for backup.

By the end of it, I hsd a pretty good idea of what I wanted and what the trade-offs were.

Going off grid

Comments

Albany
Average Solar Insolation figures

Albany
Average Solar Insolation figures

Categories

Going off grid

Comments

AlbanyAverage Solar Insolation figures

AlbanyAverage Solar Insolation figures

Categories

Albany
Average Solar Insolation figures

Albany
Average Solar Insolation figures