Assembling the core of the solar array

My Hive buddy and PAL streamer of The Tinker Tribe @makinstuff came out to my farm along with his friend to help me set up the innards of the solar array. The battery bank, inverters, transfer switches and wiring was the work I needed help with. His friend is an EE (electrical engineer) and @makinstuff is well versed in the solar arrays as he has one himself. My farm hand and I did the work of burying the wire, setting up the panels and anything else that is not electrical related.

The day started with unpacking the batteries, lots of tape to remove on the terminals, and with 48 of them it took a few hours. As the tape came out, buss bars were used to run multiple sets of series of batteries in parallel. We used disconnect switches on the inverter to the array and for the solar to make it more safe working on it.

Buss bars are thick pieces of copper that transfer electrical current better than strands of wire.

We got a picture together before getting to work, I was already all sweaty working outside. He had the nice cool basement to work in.. haha We joked every other time we have met the weather was awful and quite wild, with crazy thunderstorms and all day rain and the next day we got snow. Next time I camped out at his place the wind was very strong but at least no snow and freezing rain. The weather was quite nice during their stay in Virginia. Worked out the third time we hung out the weather was finally good. Glad it could finally come out to my farm and check it out a little during their short stay here.

These batteries are lithium iron phosphate, with an expected life of over twenty years!

Banks of batteries is the best way to store energy produced by the solar panels. With over 10,000 watts of power my panels are producing we need lots of storage.

Transfer switches are used to switch from grid power to solar when needed. We ended up installing two in this basement so we can cover all the breakers and not have to exclude some from the solar array.

Next was to install the solar panel combiner box, this is where the rows of panels all combine together. We use blocks mount it to one of the panel poles.

This bow allows of to series up panels, and then run them in parallel.

Eventhough the cables are designed for direct bury, we sleeved them up so they do not get damaged when trimming the grass around them. I did not want to put them in the ground. Figured if I could see them good its better than not knowing where they are while digging.

Running power into my workshop, we drilled a hole through the sheet metal.

Then using an electrical box we can run wire through and it goes all the way to the ground outside to protect the wire.

I had ordered more panels before their arrival, but the ETA of the shippers showed they would arrive after they left. Leaving some spots open in my array.

Though luckily the panels showed up early, and we had a chance to put up a few before they had to leave back home. My farm hand and I can put up the rest.

I come back to the basement where its all wired up and lots has been done.

We added more supports to the table to make sure it can handle the weight.

We used some 2x6's and my miter saw to cut them at angles to put up.

That should help the table handle the weight well.

Helping get conduit into wire I thought the pros made it easy but seems everyone struggles getting that wire into the sleeves.

Unfortunately we could not get everything set up on their first attempt. I will need to run more wire to buildings to support 240v and that is something I will need in my workshops. I thought only two wires needed to buried, which is fine for 120v but not 240v. So now we are planning on setting up a second battery bank and split the PV between the two battery banks. So I will need to order more batteries and inverters. So long runs of trenching does not need to be redone, just to add two more wires. Having two battery banks will add reliability and that way we will have more capacity. And in a pinch I could run 120v to other buildings using the wire already in the ground.

So what's next?

We need to get another battery bank ordered, and they come from China so it could be a month or longer to get it.

Buy an inverter for the home with the new battery bank. We are thinking of going with a single 12,000w inverter instead of two 6500w in parallel.

I need to run two more wires to my workshop. So it can have 240v. The other homes will have their own battery banks and inverters so they will have 240v as well.

Put in the last row of solar panels, bringing me up to 13kw (13,350w)

Wait for @makinstuff and his friend to return to finish wiring up the farm.

Posted with STEMGeeks