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Here is an after the fact implementation of how I power my refrigerator from the sun. This off grid system has been working great since may 2013. It is truly reassuring to know my groceries are safely stored regardless of utility power.

I have fulfilled the electrical code requirements (NFPA 70, TTS-171 Part 1) and power utility mandates for my area. If you have to perform the same on your home, all relevant certifications and approvals are needed.

Remember for solar power systems, bigger is always better. Never go borderline else your system will not be reliable for off grid applications.

Grid tie is NOT ALLOWED in my country. Also don't ever assume you will have utility power during a nationwide disaster (bad weather, riots, energy rationing, terrorism etc).

Here is a detailed write up on how I solar powered my entire home: https://www.instructables.com/id/Solar-Powering-My-...

Step 1: The Refrigerator.

Ideally an inverter refrigerator is the best bet but my old refrigerator needs 300watts when on. Basically any fridge will do but the more energy efficient means a smaller solar setup is needed.

There are the rare dc powered refrigerators that are actually more efficient than the inverter types. However should this unit fail on me, there are none sold in my country. I want to be able to go to a store and buy a replacement or repair my unit if possible in the event of failure.

Step 2: The Solar Panels.

I use eight 225watt monocrystalline panels to power my home and by extension, the refrigerator. They are wired 4 in series and 2 strings in parallel. I harvest up to 8kwh per day with these panels.

Mounting the panels on the roof can be via manufacturer mounting solutions or you can make your own with rigid pvc. I actually did a hybrid approach.

Here is how I perform cleaning of my panels" https://www.instructables.com/id/Maintenance-cleani...

Step 3: The Charge Controller.

I have an outback fm80 charge controller to route energy from the panels to the batteries. Mppt chargers are more efficient and economical for large solar systems.

Step 4: The Batteries.

I use 16 lifepo4 batteries at 25.6v. They are all wired in parallel with an energy meter per pair of batteries. Each battery has a switch for isolation. For the work I did on my battery bank, please read: https://www.instructables.com/id/Lifepo4-solar-stor...

My refrigerator uses 1.2kwh per 24hour period. My battery bank has 4kwh capacity.

My country's climate is hot. Lead acid batteries, although cheaper, have failed in less than 10months of use. If your maximum temperature is below 25C then you should be able to use lead acids. I have long abandoned lead acid technology in my home and car. Lifepo4 is safe, powerful and environmentally friendly.

Step 5: DC Distribution.

With the appropriate sized conductors, I have circuit breakers to protect all my components and also provide easy isolation for maintenance.

The attached chart shows the conductors sizes for DC power.

Step 6: The Inverter.

To get 120vac from 25.6vdc I have a 1000watt power bright pure sine wave inverter. Always use pure sine wave especially for motor applications.

Step 7: The AC Distribution.

I made a panelboard with din circuit breakers to get power to my house loads. I have a breaker dedicated to the kitchen area. Since my refrigerator uses 2.5Amp the circuit breaker for it is 6Amp single Pole. Here is how I built the panelboard: https://www.instructables.com/id/DIY-Circuit-breake...

Also in the panelboard I have an automatic transfer switch (ATS) shown at the bottom of the pic. This switch is controlled by my home automation system which will switch to utility power if the batteries get depleted.


My local power utility is actually my backup power source.

The control system for my home is detailed here: https://www.instructables.com/id/Creating-a-home-au...

Step 8: Powering the Refrigerator.

The outlet for the fridge is protected with a motor protector. This is only needed should I switch to utility supply. The inverter gives clean power.

So that is how I powered my refrigerator via the sun!
<p>Thanks for such a nice technology to save electricity which was used to another required task and this solar powered refrigerator can cool things for us by solar energy.</p><p>http://newmeditech.com/featured/solar-powered-refrigerator/</p>
<p>Super Insulation can make this simpler in my opinion. I am in Africa a lot, about 3-4 months per year. By the way ,about 1/5 the planet lives off the grid. And, they have freezers, seldom have fridges. But I am going to do an experiment soon for what I see, or call &quot;super insulation.&quot; I am going to measure electrical use for 30 days as they use normal. The add about 2 foot thick insulation around the sides. They are the same as Americans, they do not want things to look silly. Then make a night blanket about a food thick. This will cost about 15 USD because they use some form of grass to make beds, not normal, but normal for the off grid 1.5 billion. The off-grid are just in time eating.... Here is a too expensive, but great idea, using thermal mass, or the cooling of the earth method, very old tech, just forgotten, nothing new. There has been in the ground cellars for cooling since the beginning of time. Thanks, Andy Lee Graham of HoboTraveler.com - I am in Tours France, and will go to Togo on August 15, 2016 again. <a href="http://mikeshouts.com/groundfridge-underground-refrigerator/">http://mikeshouts.com/groundfridge-underground-ref...</a></p>
Perhaps.
<p>one perspective I would like to share is that the cost/payback rate of solar should not necessarily be looked at as a benefit, because it largely seems to be a detractor. Solar is expensive, can be very expensive, but the cost of not going solar is eventual and increasingly fast-paced destruction of the environment caused by an increasing reliance on dirty fuels and energy sources. You can finance a $17,000 (us$) car for about $250 a month, which is not cheap, but people do it all the time, and in fact people finance much more pricey vehicles all the time. You can buy you solar set up in chunks. Save for a few months and buy the distribution components, then later the panels, etc. I know this is not the most convenient, but it makes it feasible. You can also down size the system and make it modular, so the it can be expanded upon later; buy the components that have to be for a larger system, then only buy a couple batteries, maybe one solar panel, then later add other panels, batteries, and so on. To give you an example of the effectiveness of this method, I make less than $20,000 annually, I pay about $1,500 in monthly expenses, which includes car cost mentioned earlier, and over the course of the last six months I have saved approximate $700 to build a homemade CNC mill. I opened a savings account at a new bank, that has no transaction capabilities. $35 from every paycheck, from each of my 2 jobs, gets automatically deposited into the account, and unless I go to the bank to withdraw it, I don't have access to it. Any payment from any side jobs I do to make extra cash gets deposited here as well. So, every few months, I make a larger purchase towards my CNC mill. The same principle can be applied to the purchase of a solar power solution. When looked at like this it becomes a simple matter of timing and patience. I hope this helps.</p>
<p>very well said!</p>
<p>Agree with all the positive comments about the Instructable. The best feature was the periodic links to stages of the system in other Instructables.</p><p>One nagging question: Considering your self-stated payback period is over 20 years, and that isn't even really accurate because your batteries will die and need to be replaced long before that, why did you build this system?</p>
Lol. As with all my other projects. Because I wanted to. Creating systems has been my life long passion. It brings me joy far more than sex ever could (even though I do love that too). I don't drink, race, smoke, do drugs etc. My vice is creating devices that enrich my life and the lives of others.
<p>very well said.</p>
<p>thank you very much!</p>
<p>Far, far too expensive. About 5000 dollars for JUST a fridge system? No thanks. </p>
<p>WOW, what an incredible instructable, thank you so much for the treasure trove of information.</p>
Your welcome!
<p>Solar power has long been on my mind. I've always wanted to DIY. This was a great instructable, even though I'm not up on the lingo. However, it was so well written and illustrated with the images, that I'm pretty sure I could replicate it. That being said, I'd want to &quot;engineer&quot; a system that works for my needs, etc., so the neat thing about your instructable is that it made me understand components of the project. That's the kind of great information delivery that helps people draft designs and encourages them to ask questions from other DIY'ers and get out there and Just Do It! (Sure hope Nike doesn't sue for Trademark infringement use or something! LOL)</p>
Thank you kindly. This is exactly the sort of encouragement I had hoped to give.
<p>Very nice. Answers a lot of the questions that I have about a day-to-day system. I'm not comfortable though with building my own transfer switch. I love that it is automatic and is something that has dis-satisfied me with local solar vendors. Is there a commercial ATS that you could recommend? Are the requirements different if you want to default to solar and use mains as the backup?</p><p>I couldn't tell from scanning your instructable what the profile is for failover. </p>
Check your electrical suppliers for ATS. My default source is solar and the fail back is utility.
<p>Nice work and very well presented. Convert to USD is about $6k. My home electric bill is $55 monthly. It will be more than 100 months before I break even. I may do a scaled down version to run a LED TV (less than 100 watts). </p>
<p>Electricity here is so cheap, my payback period is actually over 20years!</p>
I must agree with everyone, that this is very well written, organized, and clear. So many links for details! it's a project, that's for sure, but your approach makes it accessible. One question on the charge controller (I'm about to search on) Q: What is Mppt you referred to? You indicated it's more efficient &amp; cheaper for larger systems. Can you explain this a bit?<br>Also, I bet your readers are interested in costs you paid for the system components.. Possibly links to your suppliers if that's not too inconvenient?<br>(maybe that's already provided in the detail links?)<br>I loved that you added the Thermal photo of the circuit heat (along with write sizing chart per loads [conductor diameter])<br>On batteries... would you have any info on the generally expected life cycle for these LiFePo4 25.6v batteries?<br>I'm sure readers want to know their cost... a sense of how much $$ is saved from paying grid power, and how long before battery replacement is required, but why this is ok because you saved so much money &amp; also maintained Electric (energy) autonomy.. and security!<br>Very valuable points depending on where you live &amp; how disruptive storms might be.<br>A) Tropical package <br>(stormy areas)<br>B) Economic/Political <br>-Argentina, Africa, the middle east and places like this!<br>C) Environmentally Conscious<br>Everywhere else that folks just want to lower pollution caused by burning power plants for electric production. All that extra ozone ages people much faster.<br>**So we need to project &amp; promote more ideas like this to help more people Go Solar. Thanks for your help in the process!
<p>Why do you put half your panels on one side, and the other half on the other side? Are those East and West facing panels?</p>
<p>to capture the most sun energy during the day.</p>
<p>This is the realistic way to go solar. Plan the needs of the essentials and otherwise stay on the grid. When the grid goes down, you have plenty to get by. The Biggest question is the duty cycle of the batteries.</p>
<p>thanks! the lifepo4 are rated for 2000 cycles at 100% DOD.</p>
Terrific job. Congratulations
<p>thanks!</p>
<p>That is really cool! How much did it cost to set up? It looks really expensive! :)</p>
<p>That is really cool! How much did it cost to set up? It looks really expensive! :)</p>
<p>I wish I knew how to solar power my house without getting electrocuted and destroying all my electrical things that need powering.</p><p>All this seems way too confusing for me to be able to understand it, in order to get it to work... </p>
<p>Me too! <br><br>I would love to be 'off grid' or at least partially off grid, I just don't understand how to go about it. Mostly, I use solar powered lights, each one having it's own attached solar panel. Not the best setup, but I don't know how to do it differently.</p>
Good job. I love the irony in using a giant ball of fire(the sun) to cool down other stuff!
True!
is 1000 watts enough?
Yup.
<p>Excellent, now for my effort!. </p>
Thank u.
<p>Very well written .Very informative from a friend of the pocket and the environment .</p><p>A third world dream and a a should be wish to enlightened developed one .</p><p>Allow me humbly to suggest some internet search to the point reader to resourcews for spares . Also some details on the process .</p><p>please make morre.</p>
Thank you. I will provide more details during this week.
<p>Thank you very informative and well written. </p>
Thanks Pete and Doreen!

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