diy solar

diy solar

Learning. Could use some guidance.

DEEP WOODS WARNERS

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Dec 14, 2019
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So I just purchased 20 acers of of heavily wooded property. I'm building a hand built log home the primitive way.
Most I plan to have for power is
***110v:
Fridge 800watts
Wood burner blower 200watts
Microwave (MAYBE DOWN THE ROAD)
Possibly 2 t.v.s
***12v:
(16) l.e.d. lighting
(2) 12v ceiling fans

I need to be able to go on battery power for 5 to 7 days. As winter can get and stay gloomy.
On top of solar panels I also plan on using 2 wind generators.
This is a semi budget build. I have no problem dropping $5k on this build for off grid power.
I'm wanting 48v bank with a 12v step down converter.
What's the best configuration of solar panels to use?
Do I need to find 48v panels?
I just purchased 10 sunpower 327 watt panels for $500 and will be buying 6 more if these panels will work. Unfortunately I pulled the buy trigger then thaught omg do my panels have to be 48v?
No I'm not a solar expert by any means lol. (As you can tell)
So here's what I'm thinking.
*** outback solar charge controler 80amp
*** 16 sunpower 327watt mono panels.
*** 2 complete Nissan leaf batterys( have 1 already)
*** I haven't picked a bms yet.
*** haven't picked a inverter yet.
*** 2 wind generators 450watts.
*** 1 48v to 13v step down converter 100amp
*** 12v fuse panel 16 slots
*** all the safety breaker/disconnects.
****THIS WILL ALL BE STORED IN A POWER SHED ATTACHED TO THE BACK OF THE HOUSE****
The reason for the 80amp charge controler is I plan on over sizing my solar array beings I'll need all I can get on gloomy winter months.
I'll likely get a much smaller charge controller for the wind generator.
This cabin is only 800 sqft. Later down the road I may run 220v for a well pump. Or get a washer/dryer if the wife threatens with divorce lol.
Our stove is wood so no power needed there.
There is no shore power for miles. So a grid tie is not a option. Plus I want it as primitive as the wife will let me get away with.
Guys thankyou for any and all help or advise. I'm a pretty easy going guy I'm just new to all the solar/off grid power terms and acronyms. So if you could speak english lmao.
The pictures are what my land looks like and the style home I'm building minus the bathrooms. Instead of a bathroom and bedroom downstairs, the space will be split and made into 2 bedrooms.
 

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No, your panels do not have to be 48v. Generally you need the voltage from your solar array to be higher than the battery voltage so you'd hook panels in series to achieve that within the maximum voltage your charge controller permits on it's PV input. If you post a link to your exact model Midnight SCC we can tell you how many panels you could hook in series. Post a link to the solar panels you have too, or a picture of the spec label on the back of the panel.
 
No, your panels do not have to be 48v. Generally you need the voltage from your solar array to be higher than the battery voltage so you'd hook panels in series to achieve that within the maximum voltage your charge controller permits on it's PV input. If you post a link to your exact model Midnight SCC we can tell you how many panels you could hook in series. Post a link to the solar panels you have too, or a picture of the spec label on the back of the panel.
I will do so. I just learned my wind turbin backup idea wont work. That has to be 48 volt or it wont send enough threw the 2nd charge controller. So that will be on hold for a while.
Here the charge controller. Sorry my mistake it's a outback.
Outback Flexmax 80 FM80 MPPT 80 AMP Solar Charge Controller https://www.amazon.com/dp/B008MOITL8/ref=cm_sw_r_cp_apa_i_r619DbZJN1X80

SunPower High Efficiency 327W Mono Solar Panel 327 Watts
 

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OK, those panels are high voltage panels. With the FM80 you can only hook 2 of them in series so for 16 panels you'd have 8 paralleled sets of 2 panels resulting in a maximum of 51 amps and a maximum of 129.8v, well within the FM80's ability.

There is enough headroom in the ratings of the FM80 that you don't, IMO, have to worry about very low air temperatures increasing the panel current and voltage beyond what the FM80 can handle.
 
Your fridge is rated at 800 watts, likely that would be the peak draw not its normal consumption. Fridges are cyclic temperature controlled and might only chew less than 1kWh a day. A chest freezer retasked as a fridge can be as little as 300 Wh a day.

To work out your 5 to 7 days of battery power you need to work out how many kWh your essentials will use over that period. A watt meter will give you all the info you need. Hook up the device under measurement to it, let it do a normal day's use and the meter will tell you how many kWh it has consumed. An example of one (for 240v) from ebay. Check the FAQ section, Will has done a youtube clip regarding working out how much battery capacity you need to last X days.
 
OK, those panels are high voltage panels. With the FM80 you can only hook 2 of them in series so for 16 panels you'd have 8 paralleled sets of 2 panels resulting in a maximum of 51 amps and a maximum of 129.8v, well within the FM80's ability.

There is enough headroom in the ratings of the FM80 that you don't, IMO, have to worry about very low air temperatures increasing the panel current and voltage beyond what the FM80 can handle.
I hate to ask. I'm learning tho and dont want to screw up. Would it be possible to see a diagram of how to connect these?
And dose the solar side seem enough to charge the 27kwh battery bank in a day?
See I'm concerned about my reserve as well. Need to be sure this system can hold its own for 7 days in a low sun light situation with what I'm running in the cabin.
I'd love to learn the formulas for sizing the batteries and solar panels to my needs. But really need the wisdom of knowledgeable people to ensure I'm on the right path before I pull the trigger on all these purchases.
I have no issues buying the 2nd nissan leaf car battery. But if it's not needed I can put that money towards something else. Thankyou for your fast response and taking it easy on me. I feel these are dumb questions to most that I'm asking.
 
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Your fridge is rated at 800 watts, likely that would be the peak draw not its normal consumption. Fridges are cyclic temperature controlled and might only chew less than 1kWh a day. A chest freezer retasked as a fridge can be as little as 300 Wh a day.

To work out your 5 to 7 days of battery power you need to work out how many kWh your essentials will use over that period. A watt meter will give you all the info you need. Hook up the device under measurement to it, let it do a normal day's use and the meter will tell you how many kWh it has consumed. An example of one (for 240v) from ebay. Check the FAQ section, Will has done a youtube clip regarding working out how much battery capacity you need to last X days.
I'll do so. Was just hoping for a definitive answer quick while I learn and see what i need. Cabin isnt built yet. I'll be building the power shed soon so I have some sort of power to charge drills saws ect... heck I might even be staying in the shed till cabin is dryer in. But I know I gotta get solar side nail down and parts all here by spring so I can hit the ground running. God bless and thankyou again.
 
If its a bright sunny day (not necessarily hot) 16 of those panels would produce about 27kWh in 5.5 hours. You won't get that sort of power in that time frame since the sun angle will be changing the array output over the day. There are links to insolation maps in the FAQ that will tell you how much sun you can expect on a good day in your area. I'm about to cash in for the night. I'm sure someone else will pick up helping you, there's always lots of activity overnight my time.
 
If its a bright sunny day (not necessarily hot) 16 of those panels would produce about 27kWh in 5.5 hours. You won't get that sort of power in that time frame since the sun angle will be changing the array output over the day. There are links to insolation maps in the FAQ that will tell you how much sun you can expect on a good day in your area. I'm about to cash in for the night. I'm sure someone else will pick up helping you, there's always lots of activity overnight my time.
Thankyou so much. Your information is much appreciated. Sleep well.
 
I'd suggest 2 EU2200Si generators for the construction phase & to have on hand for backup. They can be paralleled or run on an alternating schedule to keep the run time balanced & conserve fuel.
Arrange your temporary power layout with the construction tools in one panel & living loads in the downstream one. Install a wattmeter after the tools panel to begin data gathering. (Daisy chained outlets will do if on a pole for starters)
 
I'd suggest 2 EU2200Si generators for the construction phase & to have on hand for backup. They can be paralleled or run on an alternating schedule to keep the run time balanced & conserve fuel.
Arrange your temporary power layout with the construction tools in one panel & living loads in the downstream one. Install a wattmeter after the tools panel to begin data gathering. (Daisy chained outlets will do if on a pole for starters)
I will likely run off a generator for a few weeks. But I do plan on putting the solar in right away. I wont likely buy 2. Heck I likely wont run anything except my cheapo 6000watt generator. Those Honda generators are expensive and small. Thankyou for the idea tho.
 
Quick update!!!
I'm officially off grid. We made the leap.
Purchased a 16x50 amish cabin and we live here full time in Michigan.
I have also purchased 6 solon blu 220watt PV panels and a epever tracer 100amp 150volt charge controller.
I'm currently running off 4 lead acid interstate srm27 batteries and a 12v 3k watt harbor freight inverter .
I'm currently looking to upgrade. I have 20 more 220watt panels and want a 48v inverter/charger.
And want to learn about the lifepo4 3.2 eve battery bank.
 
In your original post you mentioned a 110VAC refrigerator. Are you aware that 12V compressor refrigerators are becoming more common and reliable? The ones I'm aware of are intended for RVs, so they probably need a cabinet around them (no sides).

They're probably expensive compared to a cheap dorm fridge but may be more efficient than using an inverter.
 
In your original post you mentioned a 110VAC refrigerator. Are you aware that 12V compressor refrigerators are becoming more common and reliable? The ones I'm aware of are intended for RVs, so they probably need a cabinet around them (no sides).

They're probably expensive compared to a cheap dorm fridge but may be more efficient than using an inverter.
Yes iv seen a few. Biggest issue i see is there small. We have 3 kids and a baby on the way. So far we fare pretty well. Iv shot 6 deer and keep them outside in the cold freezer that is 12v. But its off right now considering its pretty cold in Michigan. As for our Samsung 110v fridge it is using surprisingly low power. It is inverter technology maybe thats why.
Either way this spring the 20 other panels will be up. And battery bank will increase. So here's to hoping.
 
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