DIY Solar Panels

[Brazos Hunter]

WOW is all I can say!!!!

I now have rated 7,830 watts and 64.8 amps at 72 volts (18 panels) and 1,800 watts and 24 amps at 24 volts (12 panels)! Now, I will not realize those values because the original glass on all are shattered. I will have to repair them all and should see 2/3 or so of their rated values ex voltage. This is still far more than we will need and I will more than likely put some up for barter.

Here is a pic of the 72v panels rolled up and stacked (yes, they are flexible). Oh, and thank you again David (91cavgt)!

[bwssr]

wow.....let me know if ya need help

[Brazos Hunter]

Originally Posted by bwssr

wow.....let me know if ya need help

After we unloaded them we metered one of the 72's and 24's in the shade and am impressed.

Will do brother!

[Brazos Hunter]

Here are the specs on the big panels, Sunpower 435's:



Here is the official datasheet with electrical and mechanical characteristics, test conditions, warranty and certifications for the Sunpower E20 435 watt solar panels, model # SPR-435, SPR-435E, SPR-435NE, SPR-E20-435, SPR-435NE-WHT.
•STC Peak Power (+/i5%) Pmax: 435 watts
•CEC PTC Rating Pmax: 400.2 watts
•Module Efficiency: 20.1%
•AC kWh generated based on NREL PV Watts estimate
•AC power monthly: 52.5 kWh
•AC power per year: 630 kWh
•Rated Voltage Vmp: 72.9 V
•Rated Current Imp: 5.97 A
•Open Circuit Voltage Voc: 85.6 V
•Short Circuit Current Isc: 6.43 A
•Maximum System Voltage: 1000 V IEC, 600 V UL
•Series Fuse Rating: 20 A
•Solar Cells Technology: 128 Maxeon mono-crystalline
•Front Glass: High transmission tempered glass with anti-reflective coating Shattered
•Dimensions: 81.36" x 41.18" x 2.13" inches
•Weight: 56 lbs
•Junction Box: IP-65 rated with 3 bypass diodes
•Output Cables: 27.55 inches, MC4 multi-contact connectors
•Frame Construction: Anodized aluminum alloy type 6063, silver No frames
•Operating Temperature Range: -40F to +185F
•Maximum Wind and Snow Load: 50 psf, 2400 Pascals, front and back
•Hail Impact Resistance: 25mm, 1 inch hail at 23 m/s or 51 mph
•Product Warranty: 10 years
•Power Warranty: 25 years
•Certifications: UL listed (UL 1703), Class C Fire Rating


Website:
http://www.freecleansolar.com/SunPow...els-s/4583.htm

[Brazos Hunter]

http://www.oasismt.com/usedsolar.html

[burn'n feather]

http://www.amerescosolar.com/

TOMBALL,TX

[Brazos Hunter]

I was wrong on the count of the larger ones. I have 30, not 18.

[91cavgt]

Originally Posted by thomason

So I have an off grid cabin, no water, no electricity - so here is my plan and what I have been doing so far.

Been using 2 deep cycle marine 12 volt batteries tied together to power up laptop, charge laptop, 6 volt batteries for spin feeders, cell phone, 3 to 4 lights usually only 1 or 2 at any one time for the past 5 months and have never ran out of power. I now want to expand my system and only want to do this once – cannot afford mistakes.

What I want to power use in my cabin – here is my plan

-Running water pump for water coming off the house - 250 gallon roof catching system - low pressure
-Small TV to catch weather if bad occasional or small use
-One to 3 lights at any one time but small 9 or 6 watt bulbs could use up to a total of 5 at one time
-In IT so on the Laptop a lot, charge phone, Wi-Fi, laptop charges - yes-Verizon tower 1 mile away so I can work from the cabin sorry already told boss.
-Microwave on a very small scale
-Maybe a toaster for 1 or 2 pieces of bread – I can toast them on the stove if needed
-5000 watt AC if very hot - Texas can be hot
-Fans most of the time
======================================
Renogy Solar 400W Poly Starter Kit :4pc 100W Solar Panel +30A Charge controller - not sure what I need to do with regards to the charge controller

Power Bright PW3500-12 Power Inverter 3500 Watt 12 Volt DC To 110 Volt AC

EdgeStar - 80 Quart 12 Volt DC Portable Fridge/Freezer - Gray

4 - Deep Cycle trolling motor batteries

Use cabin only on Weekends - so do you feel this will meet my needs? I am keeping a watchful eye on the specifications on appliances to keep things as low as I can.

I think what you picked out will be a good start, but will not be able to power everything that you want, especially when the sun goes down.


The biggest downfall to the system you listed above is the batteries. Most trolling motor batteries are only about 50 amp/hr or so. If you had 4 of these then you are looking at 200 amp/hr capacity, which means that only 10 amps of current is available for the batteries to last 20 hours without being recharged before they get too low. This might be sufficient for the lights, fans, and water pump. But once you add any big power demand devices(toaster, A/C, microwave) then it will take a LOT of power very quickly from the battery bank.


The second possible problem is running an A/C off of a 3500 watt power inverter. When you have a power inverter that is barely able to run a device, the power inverter will be working very hard to produce the power and it typically won't be as efficient when maxed out. It is like towing a 10,000 pound load with a 1/2 ton base model V6 pickup. Yes, it can do it but you will be pushing the truck VERY hard and it won't get as good of fuel economy as say towing the same load with a 3/4 ton diesel truck.

Also when the A/C compressor turns on, it pulls a LOT of power. This will make the power inverter pull a LOT of power, which will drop the battery voltage. The battery voltage will drop more with a smaller battery bank. If the voltage drops too much, the power inverter will shut off, even if the power inverter is big enough to run the A/C.



I think the solar panels you picked out is a good start, and may be enough for your needs. The nice thing about solar panels is if you see you don't have enough then you can always add more down the road.


When it comes to the charge controller, the one that comes in the kit will probably be sufficient for the 4 panels. If you had to add more solar panels then you would want to add another charge controller at that time, or replace the charge controller that comes in that kit now for a bigger one which would leave you room to upgrade in the future, without having to replace or add to the charge controller in the kit.

[Brazos Hunter]

I figured I would start here then go to the classifieds then craigslist then eBay. I am looking to trade or sell some of my large panels for batteries, charge controllers and wire...I am not in a rush but the sooner, the better.

[12 point]

Great thread. Pardon me for not being up on terminology, but I hope to have the panels mounted on a frame that is supported off the ground with a sturdy pole or poles. Have read of others who did this because of not wanting the panels on the roof. The whole panel assemblies adjust to the optimum angle of the sun as the earth turns. I realize this won't be cheap.

http://www.backwoodssolar.com/zomewo...Fc1AMgodJhEALQ

http://www.craftbrewingbusiness.com/...-at-woodchuck/

http://www.reuk.co.uk/Solar-Tracker.htm


Is there some way a grid tie system could be modified to still have power during an outage? Maybe some type of automatic switch?

[91cavgt]

Originally Posted by Waggoner

Great thread. Pardon me for not being up on terminology, but I hope to have the panels mounted on a frame that is supported off the ground with a sturdy pole or poles. Have read of others who did this because of not wanting the panels on the roof. The whole panel assemblies adjust to the optimum angle of the sun as the earth turns. I realize this won't be cheap.

http://www.backwoodssolar.com/zomewo...Fc1AMgodJhEALQ

http://www.craftbrewingbusiness.com/...-at-woodchuck/

http://www.reuk.co.uk/Solar-Tracker.htm


Is there some way a grid tie system could be modified to still have power during an outage? Maybe some type of automatic switch?

You can put together a system that is a hybrid of a grid tie and an off grid system. These hybrid systems bring together the best of both worlds. In a hybrid system, you have your solar panels, a battery bank, and a hybrid controller that acts as the charge controller as well as the grid tie power inverter. The system will mainly focus on keeping your batteries charged. Once they are fully charged, the hybrid controller sends the solar power to the built in grid tie power inverter automatically so you end up with the best of both worlds.

If the power goes out, the hybrid controller senses this and some of the hybrid controllers automatically use the built in grid tie power inverter to power your house off of the battery bank! It sounds and works amazing, but the price is very high. They are also not very common due to their price so finding one is not a simple task.



When it comes to solar panels mounted on a pole that automatically adjust their angle depending on where the sun is in the sky, these too are expensive but are VERY nice to have. Most solar panels when fixed mounted will put out their maximum amount of power only a couple of months out of the year, and only for about 2 hours each day. This is only if they are originally mounted directly facing the sun. When the seasons change, the sun is at a different part of the sky and thus your solar power output will not be as high. During the morning or evening hours, solar output with a fixed mount is very low, even though you may have a great amount of sun light due to the panels not aimed directly at the sun.

Now if you have a sun tracker system your power output will still be the same at it's maximum, but instead of that solar panel only having it's maximum output for about 2 hours each day, the maximum output will be spread out over a period of about 6-8 hours each day. In the end, with a good sun tracker system you will see approximately 30% more power output.

Most of the time you see companies using a sun tracker system when they don't have any more room to mount solar panels. This way they can take advantage of all the space they have and get as much power as possible from the panels. For a typical person like one of us, the only reasons why a sun tracker would make sense is if you too don't have much room to put solar panels, or you want to impress others, or you want to get as much out of your solar panels as you possibly can. Otherwise, just buying a couple more panels than you were planning on will be cheaper than buying a sun tracker system, and in the end you'll end up with about the same amount of power.

[12 point]

Thank you 91cavgt for your very informative response and thread. If I decide to do this, you may not be very far from the location . The idea of not having the solar panels on the roof is a big plus to me. This is on a ranch where the house cannot be seen from any road. I just gotta make sure the cows can't get anywhere near the panels. :-)

[thomason]

thank you for your comments on what systems I am trying to start with, my biggest question is really about batteries, I just do not get or understand the best option for what my needs are. I can use the deep cycle batteries until I get a better battery system or at least for now. Knowing that I only use the place for weekends want to use a 5000 btu air conditioner for hot days in the summer as well as lights and maybe a small refrig what is the best battery option. 6 volt golf batteries, maybe 6 of them tied together? again thank you for all your expertise and help for me and others. thomason

[Brazos Hunter]

Several have sent me PM's/text's as of late about solar so I figured I would bump this back up as well as post an updated pic of the panel I just completed.

[bfree]

thanks for sharing

[Brazos Hunter]

Oh yea, a pic may help.?

Here is one of the 72v panels ready to install.

[Whale]

Tagged

[Brazos Hunter]

I finally had a quasi free hour so I removed the three little 12v panels totaling 45 watts off my shop and installed the completed 435 watt 72v panel. As soon as I purchase a quality meter I will post values. BTW, I plan to add two more on my shop.

[antp510]

This has been a great thread!

However my ADD is making it hard to learn anything...

Would it be possible for someone to just give me a shopping list for what I might need?

I want to power a light, a fan, and have the ability to charge a phone and an Ipad. I realize an ipad requires more to charge than a iphone... And maybe both at the same time.

I think the hooking up process would be easy just making sure I have the right components that compliment each other.

I can store the battery outside and just run the cables inside... This will be inside my hunting blind...

I appreciate any help you guys can give me... Also if I can spend just a little more and have the ability to power more stuff that would be cool too!

[Brazos Hunter]

Originally Posted by antp510

This has been a great thread!



However my ADD is making it hard to learn anything...



Would it be possible for someone to just give me a shopping list for what I might need?



I want to power a light, a fan, and have the ability to charge a phone and an Ipad. I realize an ipad requires more to charge than a iphone... And maybe both at the same time.



I think the hooking up process would be easy just making sure I have the right components that compliment each other.



I can store the battery outside and just run the cables inside... This will be inside my hunting blind...



I appreciate any help you guys can give me... Also if I can spend just a little more and have the ability to power more stuff that would be cool too!

A very simple, basic system would be Harbor Freight's 45 watt system. Add two 6v solar batteries and you are set. The charge controller has two USB outputs that you can charge devices with. Just be sure and get a 12v fan and you are good to go.

[antp510]

Thanks! I appreciate it, its on the list!

[91cavgt]

Originally Posted by antp510

Thanks! I appreciate it, its on the list!

and to add to that, if the Harbor Freight controller does not put out at least 2.1 amps on the USB outlet then just find a cigarette lighter adapter that has a USB outlet on it that is designed to charge your Ipad. The Harbor Freight charge controller has a 12 volt outlet that you could plug that cigarette adapter into. Problem solved on the cheap.

[Brazos Hunter]

I know this is a solar thread but I'm going to bring up something a little different. Still green energy though.

I am about to start fabricating a large wind turbine to replace my little 50watt 12v one. I will be running a Permanent Magnet DC motor as the generator. 2.5hp, 180DCV, 7.5A, 4,000RPM. If my math is correct, using the power equation, at 4k RPM this will produce 1,350 watts of power! Grant it, it will not see 4k but still...

[Dusty Britches]

Originally Posted by Brazos Hunter

I finally had a quasi free hour so I removed the three little 12v panels totaling 45 watts off my shop and installed the completed 435 watt 72v panel. As soon as I purchase a quality meter I will post values. BTW, I plan to add two more on my shop.

Attachment 732343

that sure looks well shaded, BH.

[Brazos Hunter]

It is actually in full sun most of the day. Right now it is kicking out a little over 400 watts!

[Backwoods101]

Awesome thread What do you think it would cost me to run an 800sq ft cabin off grid?

[Brazos Hunter]

It all depends on what all you want to provide power to and how efficient they are.

[Backwoods101]

Pretty much everything. The cabin will be our retirement home one day.

[Brazos Hunter]

The average house tied to the grid consumes 2 1/2-3 1/2kW per day. With that said, if not designed and built for off grid, somewhere in the neighborhood of 2kW solar plus a generator or other means to charge the batteries when it is cloudy for days on end.

[huntr51]

Good info

[huntr51]

[Backwoods101]

Originally Posted by Brazos Hunter

The average house tied to the grid consumes 2 1/2-3 1/2kW per day. With that said, if not designed and built for off grid, somewhere in the neighborhood of 2kW solar plus a generator or other means to charge the batteries when it is cloudy for days on end.

What would be a ballpark figure on the cost of a system that could produce that?

[Brazos Hunter]

Originally Posted by Backwoods101

What would be a ballpark figure on the cost of a system that could produce that?

$1/watt plus $1,500+ in charge controllers, inverters, batteries, and wire. So, $3,500 on the very bottom end. Realistically, closer to $5k for a descent setup

[Backwoods101]

Originally Posted by Brazos Hunter

$1/watt plus $1,500+ in charge controllers, inverters, batteries, and wire. So, $3,500 on the very bottom end. Realistically, closer to $5k for a descent setup

Not bad, I was thinking closer to $10,000. Thanks

[91cavgt]

Originally Posted by Backwoods101

Not bad, I was thinking closer to $10,000. Thanks

Let's put together a basic setup that is solely based off of being off the grid, and setup in mind that you are not going to use as much power as you currently use.


Solar Panels;

There are a LOT of places that you can find panels. You can either score the way Brazos Hunter did with the broken panels, and put some work into them to make them useable again, or you can buy new ones. SolarBLVD.com is a pretty good place to find some decent prices on solar panels.

https://www.solarblvd.com/product_in...oducts_id=3028

Here are some that are 24 volt, 250 watt, and put out around 8 amps of peak current. Add to that the fact that they are $170 each and it is a good deal! (68 cents per watt)

Let's say 6 of these for a total of $1020 for panels.



Charge controller;

Here is a Xantrex charge controller. Xantrex makes some good things. I've got one of their 1k watt pure sine wave power inverters and it is a hoss.

https://www.solarblvd.com/product_in...oducts_id=2552

This one can take in up to 40 amps of current and up to 140 volts DC input. But wait, if you add up the above solar panels, in direct light you end up with 48 amps which is too much, right? Well hold on. That is at 24 volts. Let's separate the 6 panels into groups of 3, then let's wire each of those 3 panels in series giving us 72 volts at 8 amps! Now we will wire both sets of 3 panels in parallel which gives us an output of 72 volts @ 16 amps which is in the specifications of the charge controller. Not only that, but you can use smaler gauge wire without power loss since the voltage is now higher(72 volts vs. 24 volts), but the amperage is now MUCH lower (16 amps vs. 48 amps).

$1267.20 for the charge controller.




Cables;


Don't skimp here. Poor quality cables can decrease total power available to charge the batteries. Poor quality battery terminals are also a fire hazard as they will heat to the point of melting plastic and catching fire when asked to provide a lot of power. In general, about a 20% or so of what you spend on everything else should be spent on cables.

Let's say $600 for cables.



Batteries;


I prefer AGM batteries for the simple fact you can install them inside in an enclosed area and you don't have to worry about venting of gases. They are also absolutely zero maintenance. If properly maintained, they also last a LONG time. Brazos Hunter has 2 batteries he got from me that are Hawker 50 amp/hr. They were made in the year 2000 and I bought them in 2009 used from a guy. 15 years after their manufacture date, they are still in great condition. Now this is not typical as a typical AGM battery is designed to last 10 years.

Here is a guy in Dallas that sells AGM batteries and for a good price. I have bought some other batteries from him before and have been happy.

http://dallas.craigslist.org/dal/mad/5155364635.html

These are 6 volt 250 amp/hr batteries that are 2 years old and are $90 each. For a modest system with the above panels, I would say to have 6 of these batteries. Wired at 12 volts, that would yield a 750 amp/hr battery bank. That means you could use 37 amps constantly for 20 hours straight before the battery bank would need to be recharged.

$540 for batteries.



You are looking at around $3300 or so just for the basic system. This would allow you to use any 12 volt DC device directly off of the battery bank and you could also use a 12 volt DC power inverter for any small to medium size 120 volt items you may want to run. Add a good size generator and a good size 120 volt battery charger and you could recharge the batteries if, for example, snow covered the panels and power output dropped.

[91cavgt]

For a lot of your appliances you can use 12 volt RV replacement ones. Like an RV fridge. You can use 120 volt appliances, but if you do you will loose a lot of power just through the conversion process of converting the 12 volt battery power over to 120 volt. You can buy coffee pots, electric frying pans, heaters, vacuums, refrigerators, hair dryers, and fans amongst other things that are all ran off of 12 volt DC power.

Personally, I would add a big 250 gallon propane tank outside of the cabin to run a stove and a Dearborn heater off of. I put this in a 600 square foot cabin that I lived in for a while and could run for 3 weeks off of one bar-b-que size propane tank in the winter time so imagine how long a 250 gallon tank would last!!!


If you were to install a metal roof, you could also install a rain gutter setup and run those rain gutters into a couple of 250 gallon water tanks! Add a 12 volt Surflow RV water pump and now you would have pressurized water for the entire cabin. You would just need to filter it before using it for drinking water.

[91cavgt]

I almost forgot. If you have a family living in an off grid cabin, you will NEED a water heater. Straight electric water heaters are out since they pull too much power. Tankless water heaters are great at not wasting electricity or gas, but you would need one, preferably, that does not use electricity.

http://www.grainger.com/product/BOSC...AS01?$smthumb$


For $612.50 you can have a tankless water heater that has a pilot light on it! So there is no need to run electricity to it, just a propane gas line! And, it can supply 1.3 gallons per minute with a 90 degree rise in water temp. So if it is winter and your water storage tanks are outside, let's say the water temp is 40 degrees. You could potentially scald yourself with 130 degree hot water in the winter time! Super hot shower anyone? At a lower temp rise of 45 degrees it flow 2.6 gallons per minute, or enough for someone to hand wash dishes while someone else is taking a shower, in the winter time, with 85 degree water!

[Backwoods101]

Printing now . Thank you for taking the time out to spell it out for me. I have never been able to grasp the whole electrical thing, for some reason it sounds like a foreign language to me lol.

[Backwoods101]

This is a thread I started about a cabin we are going to put on our land outside of Fredericksburg. I will be checking back in quite frequently during the build and I want to thank y'all in advance for sharing y'all's wisdom for those of us that have no clue, what y'all are talking about ;-)
http://discussions.texasbowhunter.co...d.php?t=534285

[Brazos Hunter]

Originally Posted by Backwoods101

This is a thread I started about a cabin we are going to put on our land outside of Fredericksburg. I will be checking back in quite frequently during the build and I want to thank y'all in advance for sharing y'all's wisdom for those of us that have no clue, what y'all are talking about ;-)
http://discussions.texasbowhunter.co...d.php?t=534285

I dig that and can't wait until we pull the trigger and purchase our "homestead"! Jellous!

[Brazos Hunter]

I got the motor in for my wind turbine build today! I'm sick though...two hours after this pic my son called, he was broke down. So, I grab a couple tools and my Fluke to go get his car going. I work on it an hour, get it going but, let the Fluke on my bed rail. My son called and told me it fell off the truck! I turned around and made it back to it just in time to see a guy in a new white Chevy quad-cab pick it up out of the street and leave

[Backwoods101]

Cool, looking forward to seeing it up and running

[CountryTexan]

subscribed

[91cavgt]

I just realized I had not talked that much about what good cables actually means. So, here we go;


So what makes one cable good and another one bad?

There can be multiple things that differentiates a good cable from a bad cable. But first, here is a list of the parts on a cable. If ANY one of these parts are not good quality, then it makes the entire cable bad.

1. The conductor. This is the actual wire inside the cable. Pay close attention here because not all wire is copper. Here lately, it is very easy to find aluminum wire and copper coated aluminum. The difference here is that copper has a lower internal resistance than aluminum and thus, you won't loose as much power when using a copper wire vs. the same size aluminum wire. The conductor strand count also comes into play. This is how many wires make up the conductor. Wire for home use typically only has one single strand of wire inside the wire. While this is fine for A/C high voltage and low amperage home use, it is not good for D/C low voltage high amperage use. Not to mention that single strand wire is not very flexible. Multiple strand wire is better for D/C low voltage high amperage use, and with it being very flexible it makes it easy to use. Typically, the more strands of wire inside a conductor, the more flexible and the higher the quality of wire.

2. The insulation jacket. Yes, this is important. But why? It's not like the wires are going to be moving around like they can in a car. Here's why. Specifically with power inverter wiring, but also if you have a lot of solar panels, there is going to be a LOT of current running through the wire. If you have an inferior wire with a very thin insulation jacket around the conductor, then the chances of that insulation jacket cracking over time and exposing the conductor increases. Not only that, but if you are running a lot of amperage through a wire, it is going to heat up. A thin insulation jacket won't be able to withstand the heat as well as a thick jacket wire.

3. The cable ends. This is one area that gets neglected very frequently. You can buy the best wire money can buy, but if you cheap out and buy the cheap twist on wire ends, it makes the entire cable a poor cable, AND it can lead to a fire too. Here is why. If the cable ends are not properly coming into contact with the wire, that is going to increase the resistance of the entire wire. When you increase the resistance, you also increase the temperature. Eventually, you can actually have the cable ends melt and catch fire from the heat. I prefer a VERY heavy duty crimp. I bought one of these just for my modest solar panel setup and have used it many times since;

http://www.grainger.com/product/QUIC...AS01?$smthumb$



So ANY part of the cable that is not of good quality can lead to a premature failure at best of your solar panel setup, and at worst it can lead to a fire. Here is a couple of pictures of the wires that I made for my solar panel setup;

4 gauge positive (orange) and 4 gauge negative (black) wire with custom crimped ends, heat shrink tubing to protect the cable ends (as well as for identification of polarity), and custom cut to length.


1/0 gauge wire for my power inverter. This is a bit overkill, but in the event my power inverter pulled 200 amps from the battery bank (which is within the specifications of the power inverter) it will be able to supply the power without the cable getting hot. There are 4704 strands of wire inside this cable making it VERY flexible as shown in the picture. I was easily able to bend this cable around in a tight circle, and when I let go it went back to being straight.

[Brazos Hunter]

Nice writeup David!!!

[Brazos Hunter]

Okay, I am sold on a company and a brand. Missouri Wind and Solar ( http://store.mwands.com/index.php? ) and MidNite Solar Classic charge controllers are awesome! If you want a large or small off-grid system, a hybrid system, or you are just thinking about getting started in alternate energy, give Missouri Wind a call! They are awesome and will answer and all questions you may have and they will help you in designing your system!

[Brazos Hunter]

I'm stoked! My MidNite Solar Classic 150 charge controller came in! Time to have fun now

[Brazos Hunter]

Man, one needs an electrical engineering degree to program this thing! I skimmed through the manual jumping to the "quick" start guide following the directions. I had to pull up a YouTube video to help me out a bit. Half way through it now.

[Brazos Hunter]

Okay, after a couple weeks of calling the manufacturer I received a replacement control board and got it going! We have decided to go a different route on the solar end so I'm going to part with all 30 of my large panels at a crazy price, $5 each! Buy all for $150 and I will include a charge controller!

[Brazos Hunter]

I sold all the project panels and, for the moment, went with four of these. Will order more later this month. Found a great deal and couldn't pass them up.