diy solar

diy solar

Need Advice on what to do.

shopper33

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Nov 24, 2021
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I am trying to figure out the best solar generator, solar panels, and possible batteries to store some of the solar power for a potential power outage. I want to run some basic appliances each day such as a skillet, blender, foreman grill, etc... for making food. I want a solar generator that can handle this for possibly a few weeks. I am so new to this stuff, but need to learn quickly as I believe we have some power outages coming this winter. I would love to hear your ideas.
 
Your first step should be performing an energy audit so you know how much power you use. This is the cornerstone to building a backup system.

There are links to a couple audit tools in my signature. There are also some in the resources section.
 
In power outage you cook with propane, natural gas, or charcoal. Batteries are an expensive way to cook especially for a few weeks. Forget about it.
 
i know this is a silly question how much money ya willing to spend and are you willing to go used on the parts.. also buy a kill a watt meter that is a no brainier.. love that thing.. also are you going to do the work or have some one else do it. what is the building regs there.. where i am there is none in phillips ct kansas however there are things ya have to look at if hooked to a grid... .. i say buy the panels used the all in one inverter charger built in one box.. and batterys for the dark times.. they are called hybrid. and generator for when the sun is not out first a kill a watt meter .. get reading do the math
 
Bubba1 is right on here. Anything that is going to require heat is better supplied with propane. Buy a propane camping stove that you can connect to a 5 gallon barbecue tank.

Your real priorities should be lights, communications, and refrigeration. To keep the lights on, the refrigerator running, and maybe an hour or two of computer/TV time, I'd guestimate you'll need around 2.5kWh of power. That is very doable on a solar system, but it NOT a trivial amount of power.

Assuming you need 2.5kWh of power in the middle of winter, with 2.5sunhours of light, you'd need about 1000W of panels to accomplish this. This power level typically would require a 24V system.

Let's say you want 2.5kWh of power per day, and need 2 days of autonomy for 1 day of cloudy weather. Assuming you don't want to drain a deep-cycle battery more than 50% the math works out to be 2500Wh X 2days X 2Xbattery capacity = 10,000Wh of battery capacity. At 24V, that would be 10000Wh/24V =417Ah of battery. Look at Trojan L-16s for that power level.

So, what do you need?

420Ah of battery at 24V (or maybe 300Ah of Li battery)
1000W of solar panels (1500W might be better for this size battery)
24V capable charge controller 40+amp (60A for 1500W of panels)
24V inverter, maybe 2000+W (A 3000W AiO might replace the charge controller and inverter)

It's doable! Start shopping.
 
Bubba1 is right on here. Anything that is going to require heat is better supplied with propane. Buy a propane camping stove that you can connect to a 5 gallon barbecue tank.

Your real priorities should be lights, communications, and refrigeration. To keep the lights on, the refrigerator running, and maybe an hour or two of computer/TV time, I'd guestimate you'll need around 2.5kWh of power. That is very doable on a solar system, but it NOT a trivial amount of power.

Assuming you need 2.5kWh of power in the middle of winter, with 2.5sunhours of light, you'd need about 1000W of panels to accomplish this. This power level typically would require a 24V system.

Let's say you want 2.5kWh of power per day, and need 2 days of autonomy for 1 day of cloudy weather. Assuming you don't want to drain a deep-cycle battery more than 50% the math works out to be 2500Wh X 2days X 2Xbattery capacity = 10,000Wh of battery capacity. At 24V, that would be 10000Wh/24V =417Ah of battery. Look at Trojan L-16s for that power level.

So, what do you need?

420Ah of battery at 24V (or maybe 300Ah of Li battery)
1000W of solar panels (1500W might be better for this size battery)
24V capable charge controller 40+amp (60A for 1500W of panels)
24V inverter, maybe 2000+W (A 3000W AiO might replace the charge controller and inverter)

It's doable! Start shopping.
What would be a system that could do all of this?
 
What would be a system that could do all of this?

OK, let's look in more detail the contents of my post above....

420Ah of battery at 24V (or maybe 300Ah of Li battery) I previously used this battery and would recommend it. You'll need four of these 6V batteries to make a 24V battery bank. I think they are about 350$ each right now.
1637862002240.png
1000W of solar panels (1500W might be better for this size battery) This is going to vary with your local area. Don't buy panels through the mail! Shipping cost is as high or higher than the cost of the panels themselves. Buy locally off of Craigslist. Last year I was buying 245W panels for 55$. Pick anything in the 240-320W range. That's what the best deals appear to be in right now.

24V capable charge controller 40+amp (60A for 1500W of panels) Here is an Epever 60A controller. If you bought 4 250W panels, you could wire them in 2S2P. That would make up to 40A at 25V charging. If you bought 6 250W panels you could wire them in 3S2P and still stay safely within the controllers 150V limit.
1637862273695.png
24V inverter, maybe 2000+W (A 3000W AiO might replace the charge controller and inverter)
Cheaper units have NEMA plugs only I'd consider this Samlex. Make sure you get a Pure Sine Wave inverter to run a refrigerator.
1637862666343.png

Here is a higher quality unit (I have this one) that does NOT have NEMA sockets. It is hard-wired directly into the home's main electrical panel. It features pure sine-wave power, split-phase 120V/240V output, and had a built-in generator charging circuit. This is a serious off-grid inverter.
1637862878805.png

Finally, the panel racking. I designed and built these rotating arrays. They work well for me. They are mostly made out of readily-available unistruts, that can be welded together.


Everybody here will have their own opinions on what's best for you. This is what I would put together.
 

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