A Forum run by Enthusiasts of MidNite Solar

General Category => General FAQ'S => Topic started by: Little Bit on March 28, 2018, 09:00:43 AM

Title: living of grid
Post by: Little Bit on March 28, 2018, 09:00:43 AM
Hello
we moved to St Croix USVI we are living with a honda gen at night I turn it off to cut it some slack The problem is the fridge the boss is not happy I want to eventually build a off grid system  solar panel wind turbine for now inverter and batterys can some one lead me in the right direction buy some stuff and look forward to the future

                                                                                                        Thanks
                                                                                               Little Bitt 
Title: Re: living of grid
Post by: Matrix on March 28, 2018, 09:47:46 AM
I saw in your welcome post that you said 3000k

- Does that mean you want to spend 3 thousand dollars
- Or that you think you need 3000 kilowatt hours kWh (per day? / month? / year?)
- Or that you think you will use 3000 Watt hours Wh per day.

If either of the latter 2,  what do you base that on?    Have you done any load calculations to come up with that number? 

3000 Wh's per day is doable.   Take  look at the link to my system in the signature. 

Last night for 15 hours of not solar charging I used right at 105 Amp Hours (Ah) meaning I used about 2646 Wh's at 25.2 volts of battery.  That took me down to 76% State of Charge (SOC).  And so that means,  as long as I have sun for the day time hours,  I could MAYBE do that for 2 nights and be down to about 50% SOC and then be in desperate need for a charge. 

Some recommend that you have up to 5 days battery Autonomy.   But for being in the Caribbean you might get away with less.

Here at 9:56am in Florida I am already making 1211 Watts from my solar system and happily charging the batteries and running my light loads. 

Title: Re: living of grid
Post by: Matrix on March 28, 2018, 10:12:27 AM
First you are going to have to know with some pretty hi degree of accuracy,  what your daily loads will be.   If you do not have a Kill-A-Watt meter (https://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU) ... you can get a rough idea using this tool (https://www.altestore.com/store/calculators/load_calculator/)

Then using this Off-Grid Design tool (https://www.altestore.com/store/calculators/off_grid_calculator/) you can get a rough idea of the size your system needs to be and what (in a ball park) it might cost. 

But it seems like you are in a pretty desperate situation,  I hope you did the homework before you got there an know most of this stuff already.  Also,  Don't rely much on YouTube.  I saw yesterday where Jesse decided to finally go on grid (https://www.youtube.com/watch?v=16rC650s69I) because of his failed solar experiment that seemed to last all  a few years.   Then there were at least 2 shredding response videos ... again neither of whom I would take advice from, because seems at least one of them is doing some pretty dangerous stuff and calling himself and expert.   What's the point of any of this?  They did not plan from what I can tell.  Looks like they bought 3-4 100W panels in some kind of kit.  System was way undersized for what they where trying to do.

You will get a load of help here from these helpful and wise folks.
Title: Re: living of grid
Post by: Matrix on March 28, 2018, 10:18:39 AM
One other thought.  Build with the future in mind.  If you are going all in  ... dont try to start off small and expand.  It does not work out well in many cases.   If right now you just want an inverter and batteries,  get an inverter that will grow with you.   I would suggest 48v ... but if not, no smaller than 24v.   And since you say you are not getting the solar array right away,  you will need either a charger for the batteries,   or an Inverter / Charger.

A good start with a decent price point might be something in the Samlex EVO series.    Could also look at Schneider Conext SW series or Outbacks stuff. 
Title: Re: living of grid
Post by: ClassicCrazy on March 28, 2018, 11:43:30 AM
If you want the best refrigeration efficiency consider getting a DC  type fridge freezer combination. Their is an Amish company that is making some that used quality Danfoss compressors and had a separate compressor for freezer and fridge so you could run them independently - make freezer fridge, or both of fridge or freezer.  Nice thing about that is you don't need an inverter to run all the time and can have a smaller PV system . So maybe the higher cost of shipping this out there would offset price of other components of PV system ?  Something to think about .
If interested call them and make sure about their product - I think some of their stock is imported from China and some they make there.
http://www.thesolarfreeze.com/SolarFreezer.html#
They are Amish so you probably have to have them call back.
Probably forget the wind generator if you have lots of sun - wind generators take a lot of maintenance where solar panels don't take much of any .

The first thing  you need to do to design a system is to analyze all your loads and determine how much power you need or want in the future so you can get the correct amount of batteries and PV to make them happy .

Larry
Title: Re: living of grid
Post by: Matrix on March 28, 2018, 02:09:11 PM
Now see what you've done Larry.  Made me go and start looking.   My current 25 cubic ft AC fridge runs about about 2.4 - 2.7 kWhs per day.  Just found a full size Samsung AC fridge (https://www.bestbuy.com/site/samsung-24-6-cu-ft-french-door-refrigerator-with-thru-the-door-ice-and-water-stainless-steel/4980442.p?skuId=4980442) that claims it does 475 kWh per year, or 1.35 kWh per day.  Wow that wold be a huge chunk out of my daily usage.   ;D
Title: Re: living of grid
Post by: Westbranch on March 28, 2018, 08:41:29 PM
Matrix, just how large is 'full size''?

We have a no frills top freezer GE 18 ft3 that uses < 1 Kwh per day, bought in Sears, regular stock etc, etc.  Model GTE18GMHDRES 319...  You just have to start looking at the yellow EPA tags... they just want to sell you the $2000 model

Samsung apparently also has what I call their 'Latin ' model,  only available in Mexico and S, that has consumption similar to our GE and a lot cheaper than in N.A..
Title: Re: living of grid
Post by: ClassicCrazy on March 29, 2018, 12:13:07 AM
This might be the one the Amish in Indiana are making with the two sides and two compressors that I saw at the energy fair this past summer.
https://www.ebay.com/itm/SunStar-Solar-DC-Powered-Chest-Freezer-21-cu-ft-/112396940824?_trksid=p2349526.m4383.l4275.c1

Or same thing here with more info

http://www.warehouseappliance.com/?t=SunStar-21-Cubic-Foot-DC-Electric-Chest-Style-Refrigerator-%26-Freezer&listing=194013055257e57bb0dc584

The Amish out here in Wisconsin would never think of using solar  - but out east they do .

Larry
Title: Re: living of grid
Post by: Matrix on March 29, 2018, 09:01:55 AM
Quote from: Westbranch on March 28, 2018, 08:41:29 PM
Matrix, just how large is 'full size''?

...  You just have to start looking at the yellow EPA tags...
Well it says it is a 24.6Cu Ft 3 door and his yellow tag said "Estimated yearly operating costs (at 10.65 center /kWh) was $51 or 475 kWh /year.     475 kWh / 365 = 1.3 kWh per day ... which is better than 1/2 of my 2007 25Cu ft 2 door unit.  Seems pretty impressive if Samsung can really pull it off.   BUT ... seems a good number of reveiwers were having trouble with it icing up and/or the ice maker icing up regularly.    So might not be a good unit,  but what caught my eye was the possibility of larger units out there having 475 kWh / year as  a possibility.
Title: Re: living of grid
Post by: ClassicCrazy on March 29, 2018, 10:17:24 AM
The defrost heaters are what probably takes up a lot of the energy .  Icing problems could indicate high usage in humid climates - door open a lot . But could also be problem with a defrost heater.  It all depends on which technique they are using to defrost the coils. In the old days it was just a resistance heater around the coils. Perhaps newer fridges have something  else like maybe hot gas bypass which is how ice machines warm up the coil to drop the ice.  Not sure.

I have a fridge that is all manual defrost and I don't have to do that too often in the summer . Manual defrost is just putting everything in a cooler or the other freezer , unplug it , leave the door open and let any ice melt , and then dry out the fridge of any moisture. Doesn't take me too long on a warm day  - my fridge is out in the shed so free refrigeration all winter - zero kwh ! ( I do put in some jugs of warm water now and then in the winter to keep it from freezing though. )

Larry
Title: Re: living of grid
Post by: Matrix on March 29, 2018, 10:57:58 AM
Yeah I think that freezing up is what the gripe is.   Some people were claiming it iced up.  then I found one review that said,  they turned off the energy saver mode and it did not ice up any loner.  To me that says,  it turns on or up the defrost cycle which ='s more kWhs.   I also see the reviews go back to 2012 or 13.  So this isn't the newest of the new.  And I doubt without the energy saving mode you are going to see those low kWhs of 475.  But even still,  I have seen units up around 650-700 kWh /year which is still much lower than what I am doing. 

Interesting what is out there on the AC side ... and will be more interesting in the next round of Energy Star requirements,  just what the manufactures will do.   But I do not know when the next round of requirements will be required or even if the mandates will be followed.  There is a lot up in the air about that right now.

I wonder where the OP went?