I am designing a 12kw off grid solar power system for my home. There is a lot of companies out there to buy components from and I need help finding a good quality company to buy a DIU Kit. So I am asking if anyone can make some recommendations as far as possible mistakes I can avoid and good quality panels, inverters, battery management systems and rack building panel angles and so forth. Thanks

 

...make some recommendations as far as possible mistakes I can avoid...

I think a DIY approach is a big mistake when there are plenty of off-the-shelf solutions designed by professionals, with guarantees, safety ratings, user reviews, etc. I'm not even sure you'd be eligible for various tax incentive programs if you do it yourself. Don't reinvent the wheel.

 

If you talk to local solar installers, they might have deals on used stuff, like "end of life" panels that are still perfectly usable. You should definitely study the safety requirements; it only takes about 22V to sustain an arc, and you'll be dealing with much higher voltages.

 

There are a lot of suppliers that sell complete kits for a full install. You should define your needs and talk to the salespeople at some of these suppliers. You will get a sense of what the market is like by talking to different sales people and you should soon find out what is available, what is preferred and what fits your budget.

I put my own grid-tied system together. I researched several different ground mounting systems, a whole slew of different panels and inverters, and just about everything else that goes into it. I looked at many online suppliers, but ultimately, I found a local electrical supply house that gave me the best deal on panels and an inverter.

When I installed my system, the State of Maryland allowed anyone to design the system. Since then, Maryland has tightened their restrictions to require that the system designer be NABCEP ( North American Board of Certified Energy Practitioners®) certified. In talking to the electrical supply house that I used, they keep a NABCEP certified designer on staff so that someone like me can still install their own system, but still have it designed by a certified designer. So it's definitely worth it to talk to suppliers, especially local ones.

Lastly, do heed bassbindevil's warning about safety.

 

Check Youtube channels, there's plenty of sources for solar systems, components and assembly. Then you can decide better is it something for you. There could be even books for DIY solar builders.
Know how of basics is essential, that you know what youre doing and what you are dealing with else you end up causing lot of damage. 12kW is a lot of power for someone who hasn't done anything like that before. Start from small system and upgrade it, or ask a ready made packet, just do the assembly yourself, this saves $$ too.

 

I am designing a 12kw off grid solar power system for my home.

What country are you in?
A lot of us will have potentially useful information for you, which will be completely irrelevant (if it refers to regulations and tax incentives) if you don’t live in the same country.

 

Check Youtube channels, there's plenty of sources for solar systems, components and assembly. Then you can decide better is it something for you. There could be even books for DIY solar builders.
Know how of basics is essential, that you know what youre doing and what you are dealing with else you end up causing lot of damage. 12kW is a lot of power for someone who hasn't done anything like that before. Start from small system and upgrade it, or ask a ready made packet, just do the assembly yourself, this saves $$ too.

here is a link to Adi Pfeifers' book. He is the Geru of Solar installation.
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https://www.thriftbooks.com/w/the-e...eper-adi/568196/#edition=3152245&idiq=7527048
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here is a more affordable option:
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https://www.thriftbooks.com/w/the-e...KTkaAgmcEALw_wcB#idiq=7255783&edition=2300054
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and No - I am not selling nor am I receiving any compensation for this post (I happen to have the Blue Copy of his book. And he covers everything in simple down to earth language so anyone can understand).

 

I am designing a 12kw off grid solar power system for my home. There is a lot of companies out there to buy components from and I need help finding a good quality company to buy a DIU Kit. So I am asking if anyone can make some recommendations as far as possible mistakes I can avoid and good quality panels, inverters, battery management systems and rack building panel angles and so forth. Thanks

Hello there,

It is a good idea to read up on this with some books written on the subject. That should give you a better all around idea what all this entails.
Also, are you intending to go all DC or tie into the line to get power company pay back on electrical energy costs?

I worked with several kilowatt systems in the 1980's when i worked in the industry. These were line tied systems that provided AC for homes or other. The solar panel i used was probably 50 feet long and 15 feet high on an angle toward the south and the cost about a million dollars. I dont believe the efficiency was as good as today however. Right now i work with s much smaller panel but it's interesting to see how much energy you get for free just by collecting some energy from the sun. It is truly free energy, except on cloudy days.

One think i have learned that is kind of important is that some of the companies that sell solar panels will literally lie about the performance on cloudy days. Some quote 80 percent of what you get with full sun. That's an outright lie. You are lucky if you get 10 percent. That means with a 1000 watt panel you dont get 800 watts on cloudy days, you get about 100 watts if you are lucky. The proof is if you look at some of the measured insolation levels in your area, measured by sensors around the state. If the normal insulation level in the area is 100 percent (compared to the theoretical max of 1000 watts per square meter) when there are clouds you may get 10 percent, and since insolation level correlates to output power directly that means you only get 10 percent of the max of your panel multiplied by the max percent in the area.
You do get plenty of power at full sunlight however, which is quite amazing. I can see why there is so much interest in this type of energy collection. It's just too bad the clouds block some of that and even a lot of that over weeks.

It's also interesting to look at the numbers that show the total power output of the sun. It's a huge number. If you could collect all of the energy of the sun from all 3d angles you could power several Earths.

I've read the panels last 10 years but don't have any real data myself on that. The newer panels are not too bad on efficiency either, around 20 percent for monocrystalline.