144 kWh per day off grid system

[MartyByrde]

Hello!

I am new to solar and have been learning a ton over the past two weeks. I am looking into building an off-grid system that can provide 6000 watts per hour (144kWh per day) 24/7. I’ve been looking at combining some wind to compliment the solar. Maybe one or two 1000w turbines. The average sunlight in my area (west Texas) is about 12 hours per day.

It seems like there are a lot of options to build a DIY system. It gets a little overwhelming with the inverters and voltages. The complete kits I’ve looked at online also seem to greatly increase the costs however so I’d prefer to do DIY if feasible.

Is it feasible to build this type of system? What do you think it would cost if I did do DIY?

 

[sunshine_eggo]

Hello!

I am new to solar and have been learning a ton over the past two weeks. I am looking into building an off-grid system that can provide 6000 watts per hour (144kWh per day) 24/7.

MASSIVE system.

I’ve been looking at combining some wind to compliment the solar. Maybe one or two 1000w turbines.

Wind Resources

Rule 1: The power rating of a wind turbine has NOTHING to do with the amount of power you'll get. The amount of power you get depends on the size and efficiency of your wind turbine, and your wind. The power rating of a wind turbine is just its...

diysolarforum.com

The average sunlight in my area (west Texas) is about 12 hours per day.

Simulate an array at https://pvwatts.nrel.gov/

It seems like there are a lot of options to build a DIY system. It gets a little overwhelming with the inverters and voltages. The complete kits I’ve looked at online also seem to greatly increase the costs however so I’d prefer to do DIY if feasible.

Is it feasible to build this type of system?

Yep.

What do you think it would cost if I did do DIY?

30kW array - $15K
144kWh battery - $30K DIY LFP
12kW Growatt Inverter - $2500 (also provides 7kW solar input)
Additional 4 Growatt SC48120 120A MPPT - $2000

Total: $49,500

+ several other thousands for mounting, wiring, breakers, etc.

Also note that this is all low-ish end Chinese stuff. If you want to go with name brand U.S. stuff, probably add about $8-10K

 

[robby]

If you have Zero DIY Solar experience this is going to be a massive undertaking that will no doubt take nearly a year to complete. @sunshine_eggo left out the Wind Turbines which are going to add several thousand dollars more. I would suggest skipping the Turbines as most people find them to be problematic.
Is this for Bitcoin Mining? I only ask because you mention a constant power consumption of 6KW.

 

[sunshine_eggo]

If you have Zero DIY Solar experience this is going to be a massive undertaking that will no doubt take nearly a year to complete. @sunshine_eggo left out the Wind Turbines which are going to add several thousand dollars more. I would suggest skipping the Turbines as most people find them to be problematic.
Is this for Bitcoin Mining? I only ask because you mention a constant power consumption of 6KW.

I was counting on the Wind Resources discouraging him from pursuing it...

 

[toms]

This is a good example of a DIY setup for larger systems. Each layer is 560ah@48V.

For your system finish the 3rd layer, then make another cabinet the same.

The DC Bus can be ridden by whatever Inverters/Chargers you require.

Plenty of people have done what you are trying to do - reach out to those that have built systems like the one pictured. Beware of taking advice from those that haven’t actually been involved in big builds - there are a lot of details.

 

[RV10flyer]

I would plan on $100,000 minimum! Everything has gone up 10-30% in the last year.

With my 20.6kW pv in Kentucky, two 12K, 132kWh battery, I use about 40-70kWh/day. I had one day of 130kWh at the end of March.

I did almost everything myself. Three months after work and on weekends. Very familiar with construction, built one home/two garages, building and working on aircraft/automotive dc systems, installing/servicing residential HVAC daily. It was a still a steep learning curve.

 

[Nickatnyt]

144kWh is the anti-thesis of an entry level DIY project.

 

[AntronX]

If you want to try DIY route first try 300x smaller system as proof of performance. One 100w Renogy solar panel, 12v 100ah LiFePO4 battery with bluetooth BMS to monitor state of charge, Victron smart solar 75/15 mppt controller and 8.7 ohm 50w resistor as 20w constant load. About $500 worth of parts that you can sell later. This will essentially be a mini test version of your offgrid system. With it you will learn the limits of trying to supply constant load with variable solar. You could even make it where your load is 20w 12Vdc LED light. More utility than a resistor and provides visual status of your system uptime.

 

[toms]

I don’t see how it is any more complex to make a battery system like the one i pictured vs a 12V 50ah system. The only difference is time and money.

 

[sunshine_eggo]

I don’t see how it is any more complex to make a battery system like the one i pictured vs a 12V 50ah system. The only difference is time and money.

AND POWA!!!!

 

[MartyByrde]

Would something like this be scalable to achieve this system?

It seems like his solar array is too small for the battery capacity?

 

[AntronX]

Are you able to vary your load power depending on solar conditions? That would save you a lot on batteries.

 

[time2roll]

Start with 15 kWh to keep a few lights on. Then scale up. Every big journey starts with a small step.

 

[Bluedog225]

First, welcome to the forum.

Second, I think you may have made some assumptions about west texas sun that may not be entirely true.

If you price out about $10,000 in panels from some place like signature solar or santan solar, you can find out how many watts of solar you get. Then go to the excellent pv watts website mentioned above and play around with it. Use default values for most stuff but include your watts from the panels.

Then play around with some south east and west facing panels to see how many watts you can generate in a day. You need enough solar to carry your loads all day, and charge your batteries for the 14 hours when you are not producing (Probably longer than 14 hours).

Then figure out how many batteries to carry you through one night.

The wind stuff is tough. Unless you have a really big turbine.

Good luck. Ask questions.

 

[robby]

Would something like this be scalable to achieve this system?

It seems like his solar array is too small for the battery capacity?

Maybe, but you could not do it with closed loop communication as I think the limit is 16 batteries and you would need 28 of them. The second issue is price, even if I only add on $100 shipping per battery and exclude the taxes your looking at $45,000 just for those batteries. Your basic system price is now probably way over $70,000 with just the basic Misc stuff included. That's a lot of money to be DIYing around with.

How much money are you willing to spend?

 

[Usangira]

I would plan on $100,000 minimum! Everything has gone up 10-30% in the last year.

With my 20.6kW pv in Kentucky, two 12K, 132kWh battery, I use about 40-70kWh/day. I had one day of 130kWh at the end of March.

I did almost everything myself. Three months after work and on weekends. Very familiar with construction, built one home/two garages, building and working on aircraft/automotive dc systems, installing/servicing residential HVAC daily. It was a still a steep learning curve.

What are you running for you to consume 100+kWh per day ?

 

[MartyByrde]

Running gpu miners. 100 miners around under 70watts each. My current warehouse rent and electricity bill is around $800 per month. So my thinking is that I could build out a solar system perhaps through a solar loan that would get that cost down to less than half. I saw a 50k solar loan for $250/mo for 20 years. So excluding the mining hardware and thinking in terms of my ongoing rent and electricity bill - it seems this will save me money over the long term. Then I’d build out the solar system on my land.

Gpu mining may end up not being successful but that’s another topic. I’d at least have a good system for another business or build an off grid home.

I want to keep costs as low as possible and I am a DIY guy. I taught myself how to mine and I have faith I can build a good solar system. Just getting stuck on the following:

It seems most things I’ve read recommend to think with my end goal system in mind. I keep getting stuck with how can I further add on to scale the system, if I did start small, without increasing the overall cost of the total project. Like having to swap out inverters and batteries and do-overs. It would be good and wise if I could just scale up as long as the sum of the scales equals the sum of the end goal system. Is it possible to start smaller with lets say a quarter of capacity on solar for my system specs?

 

[MartyByrde]

First, welcome to the forum.

Second, I think you may have made some assumptions about west texas sun that may not be entirely true.

If you price out about $10,000 in panels from some place like signature solar or santan solar, you can find out how many watts of solar you get. Then go to the excellent pv watts website mentioned above and play around with it. Use default values for most stuff but include your watts from the panels.

Then play around with some south east and west facing panels to see how many watts you can generate in a day. You need enough solar to carry your loads all day, and charge your batteries for the 14 hours when you are not producing (Probably longer than 14 hours).

Then figure out how many batteries to carry you through one night.

The wind stuff is tough. Unless you have a really big turbine.

Good luck. Ask questions.

It seems like west texas has some of the highest PV in the country, right? When I ran it it said I had enough but maybe I did it wrong.

 

[MartyByrde]

Are you able to vary your load power depending on solar conditions? That would save you a lot on batteries.

Yes I can turn off equipment if I needed but that drops income. I can also transition equipment over to off grid if I add more batteries over time. I get caught up with what type of battery setup would work best in this route. Should I just add on to one large battery pack building out the capacity? Or is it safer to have several battery packs feeding into the system? Thanks

 

[Usangira]

Running gpu miners. 100 miners around under 70watts each. My current warehouse rent and electricity bill is around $800 per month. So my thinking is that I could build out a solar system perhaps through a solar loan that would get that cost down to less than half. I saw a 50k solar loan for $250/mo for 20 years. So excluding the mining hardware and thinking in terms of my ongoing rent and electricity bill - it seems this will save me money over the long term. Then I’d build out the solar system on my land.

Gpu mining may end up not being successful but that’s another topic. I’d at least have a good system for another business or build an off grid home.

I want to keep costs as low as possible and I am a DIY guy. I taught myself how to mine and I have faith I can build a good solar system. Just getting stuck on the following:

It seems most things I’ve read recommend to think with my end goal system in mind. I keep getting stuck with how can I further add on to scale the system, if I did start small, without increasing the overall cost of the total project. Like having to swap out inverters and batteries and do-overs. It would be good and wise if I could just scale up as long as the sum of the scales equals the sum of the end goal system. Is it possible to start smaller with lets say a quarter of capacity on solar for my system specs?

Great stuff.... congratulations.
If there's no other limitations.
I believe you can do it. Just make sure everything is genuine. Due to financial constraints I chose Chinese stuff. Never go for Chinese solar chargers....I learnt it in a hard way. Batteries and panels can be relied