DIY 3 Phase Solar Trailer Build On A Budget

[johnshearing]

Greetings All,
I have watched most every DIY Solar Power with Will Prowse video and feel ready to build a mobile power station.
I am thinking a trailer much like the one Will built.
I do not however feel ready to design one.
Fortunately Will has done most of the design already with several examples providing equipment lists and schematics.
Thanks Will.

I will need to run 3 phase motors at 480v for off grid wood working equipment.

Can someone please direct me to an example of this with equipment list and schematics similar to those provided by Will for people on a budget.
This might also be a good subject for a video. Please consider this Will.
Much thanks,
John

 

[Supervstech]

480V equipment usually is built due to large energy requirements… large motors, etc…
You are going to need a large battery capacity to operate that load for long… think 800Ah @ 48V
Can you afford this amount of battery?

What are the Wh requirements of the equipment you want to power? How long a duration?

 

[johnshearing]

Can you afford this amount of battery?

Good point Supervstech.
I did say I wanted to do this on a budget,
But let's say yes I can afford it.

The saw mill I am looking at has an 8kW 3 phase motor.
And then it has to power the other things you would find in a house and shop including:
110 outlets, and 240 volt loads like air conditioning, washer/drier, a well pump, and welding equipment and a compressor.

What does the build look like?
How cool would it be to put this all in a trailer including space for all the solar panels?
The idea is to bring all the solar power you need to build your off grid cabin and run supporting pumps, and equipment.
Really, this subject would make for a very popular video.
Much thanks

 

[Supervstech]

Ok, you are going to need two different solar systems.
Both can draw from the same battery bank. You can start by building the unit in wills video.
Then add in the 480V setup...
An 8kW sawmill will likely need 32kW surge capability to startup and handle bog down loads.
The inverter will need about 66Amp capabilities to run the motors...

That's around 700A at 48V... a tough load to swing.

 

[Supervstech]

Aside from grid tied inverters, I haven't been able to find 480V... you might have to build a 208V setup and get step up transformer for the mill.

I know Australia uses 480V 3phase, but I don't know if they are compatible with USA 480V3Ph...

You could buy 6 of the inverters Will used in the video, set them to 120/120 and parallel two sets...
That would get you the watts you need, and output the 120V for your other loads, and supply a load to a dedicated transformer for the mill...

 

[johnshearing]

Thanks Supervstech! That sounds like a great plan.

I think you are recommending a total of 6 EG4 6500EXs?

And I think I am understanding that with communication cables between at least 3 units and with the correct parameter settings I can get 3 phase power?

Also, I think I understand that 3 pairs of paralleled units (6 units total) should give me all the three phase power I need for the saw if I transform the 3 phase 207 volts measured between one paired set and another up to 480 volts?

And the same goes for the compressor, pumps, and welder - just transform the 3 phase 207 volts to 240 volts?

Can you please confirm that I understand your solution?

Will the EG4 5 kWh LiFePO4 Server Rack Battery work for this purpose?
If so how many should I buy?
I see in this video that Will shows us how to rack 6 of them together.
Will that be enough or will I need more?

Finally, can you please recommend which solar panels to purchase and how many?
I will size the trailer according to your recommendation.
The idea is to pull the panels out of the trailer and lay them down when in use and then put them back in the trailer when traveling.

Thanks so much for your guidance.

 

[Delmar]

I did a quicky Google search and was very surprised at the number of 480V inverters available. AIMS 30kw example.

The DC input required is 200-600 volts. This is well into EV voltage which would make your self-propelled power station. Kinda what I am doing, but on steroids. If you purchase a hybrid truck or SUV that is capable of pulling the trailer, you also get an autonomous ICE generator. Could prove handy.

 

[Supervstech]

The issue there then becomes sourcing battery power for the inverter.

200+V is going to be nigh impossible for a delivery bank.

And, 30kW+ of solar to power it as well…

 

[Supervstech]

Thanks Supervstech! That sounds like a great plan.

I think you are recommending a total of 6 EG4 6500EXs?

And I think I am understanding that with communication cables between at least 3 units and with the correct parameter settings I can get 3 phase power?

Also, I think I understand that 3 pairs of paralleled units (6 units total) should give me all the three phase power I need for the saw if I transform the 3 phase 207 volts measured between one paired set and another up to 480 volts?

And the same goes for the compressor, pumps, and welder - just transform the 3 phase 207 volts to 240 volts?

Can you please confirm that I understand your solution?

Will the EG4 5 kWh LiFePO4 Server Rack Battery work for this purpose?
If so how many should I buy?
I see in this video that Will shows us how to rack 6 of them together.
Will that be enough or will I need more?

Finally, can you please recommend which solar panels to purchase and how many?
I will size the trailer according to your recommendation.
The idea is to pull the panels out of the trailer and lay them down when in use and then put them back in the trailer when traveling.

Thanks so much for your guidance.

The amount of batteries needed depends on runtime of the loads. How long must it operate for?

I napkin math it around $120K for a setup to power a sawmill… and a REALLY big trailer to fit it in.

 

[johnshearing]

I did a quicky Google search and was very surprised at the number of 480V inverters available. AIMS 30kw example.

The DC input required is 200-600 volts. This is well into EV voltage which would make your self-propelled power station. Kinda what I am doing, but on steroids. If you purchase a hybrid truck or SUV that is capable of pulling the trailer, you also get an autonomous ICE generator. Could prove handy.

Thanks for the link Delmar.
That inverter could do a lot to simplify the build.
At first I misread the number and thought it was over $100,000
I can't believe this is only around $10,000.
That's a great price!

Yes, since I will need a truck to pull it anyway, I was thinking about getting an F150 Powerboost hybrid and using that for the battery and genset, at least in the beginning. I have no idea how to tie the truck into the system yet but I figure one thing at a time.

At some point I would like to run a genset from a wood gasifier. That will take care of cloudy windless days. That will end my dependence on fossil fuels and will make it possible to trade the hybrid truck for a full electric. I am spending as much time now studying gasifiers as I am studying solar power. I already purchased property for the project.

I would like to know more about your self-propelled power station on steroids.

 

[johnshearing]

The amount of batteries needed depends on runtime of the loads. How long must it operate for?

I napkin math it around $120K for a setup to power a sawmill… and a REALLY big trailer to fit it in.

Thanks Supervstech for the dollar and trailer size estimate.

Please let's imagine that the saw needs to run for 2 hours on battery alone and that the well pump and compressor may kick on while running the saw. Please tell us what your experience suggests about the amount of batteries required?
Also, can you please talk about the napkin math so that we could do the calculations with other parameters?

Much thanks.

 

[kbeefy]

Would a gas powered mill suffice, then Batt/Solar/Inverter for the 110/220 needs?

 

[johnshearing]

Would a gas powered mill suffice, then Batt/Solar/Inverter for the 110/220 needs?

Thank you kbeefy,
Yes, absolutely it would suffice.
And this is probably the best solution for now.

But part of the game is to get rid of the need for fossil fuels
For me, fossil fuels are part of the grid.
So to me, getting off grid also means getting off fossil fuels for more independence.
The comments above show me that 3 phase off grid power is possible so I will pursue that while using a gas powered mill for now.

 

[Supervstech]

Ok, 8000W x 2 hours is only 16kWh of storage. X 4 for redundancy and overage, more runtime.
So, 64kWh battery. Each EG4 bank is 5.12kWh and you don’t want to drain below 80% so, x.80 gives 4.9kWh
64/4.9 leaves 15.6 batts, so16 of them at $1500 each is $24K
Copper cables are going to set you back around $4K with fittings, crimper, bussbars, etc.
Each inverter would be $1400 but runtime doesn’t reduce the capabilities of the inverter.
So, you still need 80kW of inverter capability… 3phase may not be as big a surge, but I would prepare for at least 5x run load… the equipment should have a LRA spec, don’t size the inverter less than 125% of the LRA number.
Likely 40kW or so… that would be an 83A draw… the 30kW inverter should be able to power it, but you’d need a dedicated bank to power it, since it requires 200V battery bank… if that is an off grid 480V inverter…
Meaning you would need to run it all the time you have a 120V load, run through a step down transformer, or
Use 208V 3phase inverters running off the bank at 48V
Now, you have 3 legs of 120V, and 208V for normal high wattage future loads, and you can feed a step up transformer to 480V
Three 6.5kW inverters would give you 19.5kW so, two sets in parallel will output the 40kW needed to start your mill…

Each of those run around $1400 so, $8400… the step up should be available for around $5K

That brings the total to 41,400 without factoring in running the 480V cabling to the equipment, or setting up the commercial 480V panel… you should be able to source some 3phase panels used, or just use 600V fused disconnect at the equipment, and at the transformer… wiring and switchgear should be around $2K if you need an electrician to set all this up, you would need an estimate.

 

[Supervstech]

I looked over the specs on the aims inverter and it has a 150% surge for 5 seconds, so it should be able to handle a 40kW startup load… maybe. But it needs 300VDC to output 30kW so, battery builds would be far outside my comfort zone… up into the EV battery voltage range… my electric truck uses a 300V LFP bank… perhaps you could source a smith electric truck and let it store the inverters and such, then use the truck BMS system to maintain the cells… idk. I haven’t gotten mine running just yet.

 

[johnshearing]

Ok, 8000W x 2 hours is only 16kWh of storage....

WOW!
Thank you Supervstech for that explanation.
Showing a man how to fish provides so much more than giving a man a fish.
Now I have a framework for thinking about this project.
I am sure now that I can do this job and make reasonable decisions during the process.
Thanks again

 

[johnshearing]

I looked over the specs on the aims inverter and it has a 150% surge for 5 seconds, so it should be able to handle a 40kW startup load… maybe. But it needs 300VDC to output 30kW so, battery builds would be far outside my comfort zone… up into the EV battery voltage range… my electric truck uses a 300V LFP bank… perhaps you could source a smith electric truck and let it store the inverters and such, then use the truck BMS system to maintain the cells… idk. I haven’t gotten mine running just yet.

Looks like that the Smith truck and the aims would make a perfect mobile power station. And plenty of room for the solar panels too.
Thanks Supervstech for the idea!

 

[Supervstech]

Get the 2012 version NOT the 2010 version... 2010 uses a bunch of 12V batteries tied together with a balance controller... 2012 uses a huge LFP bank with a inboard bms setup.
I wish I had the 2012 version truck... I only have the 2010 truck, with the 2012 battery bank... so I gotta compromise and build a huge mess to get it running...

 

[Rocketman]

As I was reading this I was wondering if using three Victron Quattro 48/10000 inverters would give enough power - then you are using a standard 48v battery?
Each leg would be 8000w or 66amps continuous with a peak surge power of twice that.

Probably the same battery bank.

(A bit outside my knowledge level ?).

 

[johnshearing]

Get the 2012 version NOT the 2010 version... 2010 uses a bunch of 12V batteries tied together with a balance controller... 2012 uses a huge LFP bank...

Thanks Supervstech for pointing out the pitfall. I am looking at the battery pack for the Smith truck here. It must be the newer one. It's part of an entire playlist about the truck. These seem perfect for mobile solar power.