A small modular emergency solar set up

people here will tell you no, but with a big enough panel (240 watt or bigger) and an mppt controller, and at least a 100 ah agm battery your be good to go. thats what I have in my system and worst case scenario earthquake etc I wont need a generator or fuel.
240 watt will give you at least 10 amps when the sun is overhead, more amps if you point it at the sun. That will easilly run an endless breeze fan, which I have and it uses about 2.5 amps. I charge laptops, cellphones, charge all my power tools, run a small inverter, swampcooler, I used to run a 12 volt fridge with it also. Roadpro makes a 12 volt cooker and I use that also to heat my food. if your car battery is dead, 240 watts will in about 3 hours put enough juice back into it to crank it over (that I tested when i left my headlights on overnight)
A 240 watt panel isnt small but it stores easily and will be easy to setup. Smaller panels require you to connect them together adding too much complexity.
Anything smaller than 240 watts wont give you any real amperage to do much, maybe charge some cellphones.
i adjust my electricity usage by the weather so to speak. my biggest power user are my swamp cooler, which uses about 3.5 amps, when its hot (sunny) its almost always running in the daytime. When its cloudy i rarely run the swamp cooler because its usually cooler, the less amps i'm getting goes straight to charging the battery so i have power at night time for my lights and to run my laptop. I dont use any appliance that need a generator. if i needed more power, i would just get another battery.
in your case during the day you can use solar to run your fan etc and save fuel for when you really need to run your generator.
But if your system is only for emergeny, you will need to keep your battery topped off when not in service.
My system is as simple as it gets.
sharp 240 watt panel
ecoworthy 20 amp mppt controller
145 ah battery

This is simply thinking out loud while wearing rose tinted glasses.


I'm sure I could use 3 100W collectors
several smaller rather than 1 large battery
I believe I saw a charge coupler ?? (proper lingo will come) that will supply either 12 or 24V
what about inverters?

Now once I have charged batteries I can move them as needed. A 12v lamp, radio and fan upstairs.

Maybe 2 batteries sitting beside the heating system driving the circulator pump. What kind of inverter?

What would our 8cu ft freezer require?

If it's winter maybe I can freeze water overnight for the freezer (I certainly could've last night), if it's summer I don't need heat.


Again I'm just thinking out loud and don't really know what I'm talking about and at some point will get pretty expensive.

It's been cloudy and rainy damp and miserable for about 4 days now and I'm thinking about a solar system I don't even have. Ya gotta love it.

Thanks, mj52

Solar only works when the sun is out, it has to be bright sun with few or no clouds. Generally when there is a storm in New England, the sun will not be out for a few days (quite well illustrated by the recent storm) . The general recommendation is have three days of storage. The long and short of it, buy a spare gas can, fill it with fuel stabilizer in the fall and use the generator.

Feel free to play around with solar as a hobby but don't try to justify it rationally for a small hobby system. If you are serious read up on how to do it right and you will come to the conclusion that the cost to do it right buys a lot of fuel for a generator.

Lights, fan might be simple enough but I wouldn't go solar for that. I'd get battery operated LED lanterns and fans with a bunch of low discharge rechargeable batteries at the ready. When you start talking pumps and freezer, you will need the same size system that anyone else that runs their home off grid. Pumps and compressors require a lot of power to get going, that requires a big inverter, big battery and big solar. Batteries get old used or not so every so often you have to replace them, more often if they are abused which is likely in a set up like this.

Another option may be to get the smaller battery to run lights and fan but recharge it with a stand alone charger when the generator does have to run. A lot of RV users do this daily while using the 120v items in their rig.

fwiw, +1.

Have you considered the portable power station type boxes? Around 100 bucks and have a 400W inverter, USB, LED, air compressor and jump box all in one. Maybe buy a couple of those and a 100Ah marine/rv battery. When the smaller batteries in the jump boxes drain down, hook the jumper cables up to the big battery, turn on the jumper cable switch and the rest of the box will still operate as if it were running off its internal battery.

This is what you need if you want to run the freezer


You'll end up money ahead and way less headache than babysitting batteries and mounting solar panels.

Those portable power or car jump start boxes are nice and convenience when you can't start your car or need a little power to run a radio during a picnic but I would guess those batteries are not designed for a high number of cycles and will not last long if used a lot.

Batteries are great for a UPS to keep a computer running or flashlights and portable lamps. Easy to use and have "instant power". For an emergency power system they deliver too little power for most loads, cost too much and have relatively short lives.

Most people do not properly design a solar/battery systems because they really don't understand how much power they need to run their loads. They build it too small to save money and then find out their system is not enough. Sure it will run a small fan, some low wattage lights and charge a laptop but when you start to add water pumps, refrigerators or even small AC units they will quickly find out that spending little gets them little.

Put it to you this way. A modern high efficiency refrigerator uses at least 1 Kwh per day or about 12 cents worth of electricity. In New England area in winter time will take roughly a 500 watt solar panel, 40 amp MPPT charge controller, 12 volt 400 AH 250 pound AGM battery, and a good quality 1500 Va TSW Inverter. About $2000 worth of equipment. If it is cloudy only gives you about 3 days until you have to shut down and will have to remain shut down for 3 days of bright sun shine to recharge. Want a to add a pump and use 2 Kwh per day. Double the cost.

There are two other options and both include a generator. Either option a fraction of the cost of solar and provide much more power.

You could build a hybrid system that uses a small Generator > Battery Charger > Battery > Inverter. Generator cycles on/off as needed to recharge battery. You can supply around 5 Kwh per day for roughly $1000 to $1500. I call it a Macgyver or Poor Man's UPS

Or buy a whole house Generator with LPG gas tank, operate everything your house like nothing ever happened and let your neighbors suffer for you.

Lots of ways to skin this cat. You can select solar which is the most expensive, least effective, and extremely limited. Or a much less expensive, more effective without extreme limitations. It is really that simple.

Whats also nice is that both the Yamaha and Honda inverter type generators come in the 2000watt version for not much more than the 1000watt.

Champion now has inverter generators in the 1000, 2000 and 3000 size range for a few years now. The 2000i is as quiet in eco mode as the red and blue units and run about half as much. Reviews on them and the customer service has been pretty good. The 3100i has remote start for around a grand but while having more surge ability than the EU3000is I'm told, is also louder. At full bore it's only 3 DB quieter than our Champion 3500/4000 open frame. I'd hate to be parked next to someone using either, the EU3000is idling along was annoying enough.

I have seen a number of people use "boxes" over their portable generators. They have sound proofing and an exhaust stack to allow the fumes to discharge up high. You can hardly hear it run even standing up next to it.

I tried to build a sound proof box for my little Coleman 1850 but the exhaust outlet made it hard to attach an external stack. So I have decided to get rid of the Coleman and get an inverter style. I just haven't decided to go with the Blue or Red one.

The blue ones are nice because they do not attract as much attention. Thieves see those red ones and go for it. That is why the champion is a good choice. I have the Honda EU2000i companion and love it. Would buy another in a hot second if i had to.

The OP originally said he only wanted to power a 12V fan, LEDs and an emergency radio. One of those jump boxes and a backup battery would do that fine and probably for a few days. The internal 20Ah battery in those is why I suggested he buy a 100Ah FLA as well.
I didn't read the "wanting to run a freezer" part until later, which is when I suggested the actual generator.
Yes the 2Ks are only a couple hundred more than the 1Ks but it seemed to me the OP was trying to go the cheapest route.