BajaNomad

110v Residential Fridge on Solar

WestyWanderer - 12-2-2020 at 09:25 PM

Can someone out there that runs a 110v residential fridge on solar fill me in on what their system looks like? The in-laws are looking to get rid of their propane fridges and move to a 110v residential style fridge. I’m pretty confident we can run it on their current system based on my math, but wanted to talk with someone that does it. Thanks in advance

BigWooo - 12-3-2020 at 05:59 AM

A really good energy star fridge will draw about 850 watts per day in the winter, and about 1100w on a hot summer day. A middle of the line fridge will draw about 950-1000 watts on a winter day and about 12-1300 watts plus on hot summer days.

Beware of inverter fridges. Everyone thinks because it says inverter, it's low energy draw. That is not always the case. Many inverter fridges draw more than good regular energy star fridges.

Beware that many small apartment fridges draw more power than full size fridges.

Knowing the watts there are a ton of online calculators you can use to determine the size solar you need. Also the guys at Arizona Wind Sun will be happy to consult with you and help you get it right.

bkbend - 12-3-2020 at 08:25 AM

I have in the past but don't remember the numbers enough to be of much help. However I can offer a couple of other items to consider beyond the numbers.

There will be cloudy days, make sure you have enough reserve battery capacity to cover that.

Use a pure sine wave inverter. I lost a compressor motor after 24 months of use on modified sine wave.

My solar controller kept a log of amp hours it dumped into the batteries each day, check yours to see what % of battery is being used without a refer and then factor in what you will use with one. It also kept track of the time it took to get the batteries up to full charge. Than can give you a rough indication of your real world panel capacity.

Check the wire gauge in each leg between the panel and the house wiring, increasing the amperage used will increase resistance and cause loss of available juice and/or create a fire hazard. I doubled the previous owners panel wattage and battery capacity and had to replace all the wiring.

larryC - 12-3-2020 at 09:07 AM

Good info from both BK and Woo. I would add that the power usage of a refer will go up in really hot weather. My refer used about 850 to 1000 watts on a winter day but in the summer time when the ambient temps in the house were 95 degrees it used upwards of 3000 watts a day. Mine has a built in ice maker which adds watts also. I used a Kill-a-watt to determine usage, ymwv.

Bob and Susan - 12-3-2020 at 11:07 AM

fridg only uses electricty when the motor/compressor is running...

dont open the door and its really economical too...

small fridges use less electricty

mtgoat666 - 12-3-2020 at 12:51 PM

Quote: Originally posted by Bob and Susan  

dont open the door and its really economical too...


Susan,
It is even more economical if you unplug the refrigerator.

Since you are not opening it, you don’t need to plug it in :light:

John Harper - 12-3-2020 at 06:43 PM

Quote: Originally posted by lencho  
Quote: Originally posted by larryC  
My refer used about 850 to 1000 watts on a winter day but in the summer time when the ambient temps in the house were 95 degrees it used upwards of 3000 watts a day.
Hey, tocayo-- are you by chance talking about 3,000 Watt-hours in a day? Otherwise this doesn't make sense. :?:


That's what his Kill A Watt meter tells him, kilowatt-hours.

http://www.p3international.com/products/p4400.html

John

[Edited on 12-4-2020 by John Harper]

tecatero - 12-4-2020 at 06:47 AM

LG or Samsung linear inverter motor refrigerators. Pulls minimal amps. I have 2 on solar. Never spike or pulse, like they were built for solar

larryC - 12-4-2020 at 08:40 AM

Quote: Originally posted by lencho  
Quote: Originally posted by larryC  
My refer used about 850 to 1000 watts on a winter day but in the summer time when the ambient temps in the house were 95 degrees it used upwards of 3000 watts a day.
Hey, tocayo-- are you by chance talking about 3,000 Watt-hours in a day? Otherwise this doesn't make sense. :?:


Yes, those watt hour usages are all in a 24 hour day. Divide by the nominal voltage of your system (12, 24 or 48) and that will give you the amp hours used.
The point was with a 30 degree increase in ambien temps in the house the power consumption tripled. So it makes a big difference where you are in Baja. On the west coast where the temps are typically lower you will use less power than if you are in the central and east coasts of Baja during the summer months.

[Edited on 12-4-2020 by larryC]

greta-inbaja - 12-6-2020 at 07:43 PM

Hi, I used a kilowatt meter this summer to check our power consumption. We are on the sea of cortex side, south of Cabo Pulmo. I have a big fridge only unit without a freezer,—- MId summer, midday.. very full fridge.. used 1.4 kWh in 24 hr period.. When the fridge first kicked on it used 183 watts and 1.82 A then decreased to 140 watts, 1.59 amps..
when not running it used only 1.8 watts and .05 amps.
We also have a chest freezer .. it used .8 kWh in a 24 hr period.. when running midday it used 87 watts... this was during a very hot day,, We use the big fridge only unit and the chest freezer to give us more storage since we are an hr from town. .. we only have 400 amps of battery and we are right on the line, maybe a little under these days if we have a bunch of fans running plus lights.. and water pump. We do have a lot of panel though.. 3500 watts, we used to have 800 amps of battery and that was great.. had to whittle out some bad ones. Hope this helps

WestyWanderer - 12-6-2020 at 11:04 PM

Thank you Greta, that is exactly the info I was looking for. Much appreciated.