Topic: Crazydane's 32 kw solar array build feeding 16 kw worth of miners - page 5. (Read 6474 times)

Wow, thats a lot of work. Your area looks very similar to mine in the Appalachians.

Very nice.

I have a couple of different methods to monitor my energy production and consumption.  Each array cluster has what is known as a solar gateway that collects data from all the micro-inverters to provide stats on how my energy each panel produces in real-time.  Each micro-inverter is equipped with a low power Blu-tooth transmitter to communicate with the solar gateway.  The solar gateway has an Ethernet connection to my LAN.

Here's a view of the initial 24 panel ground mount array, showing the power being generated by the individual panels:



So drilling down to this level of detail is great for trouble shooting performance issues with individual panels and/or inverters.

For my location and with my current setup with 128 panels rated at between 260W and 290W, my monthly production should be something like this:



Here's a look at my actual power usage and cost over the last several years:



My first array came online in December 2016, and you can see from the above chart that by March, 2017, I had reached a point where I was producing more power than I used.  So the only thing I had to pay for was the monthly service charge of $31.73.

Then in July 2017, I started mining and it quickly got to the point where my miners were sucking down way more power than I was able to produce.

I recently installed a system that allows me to track both usage and production.  Here's a look at the summary dashboard from this application:



From here I can drill down into various graphs to look at individual stats.

Here's a view of my solar power graph from yesterday:



Some clouds rolled in during the afternoon as you can see from the drop in power levels starting around 2pm.

Here's another view showing my actual kWh production yesterday:



So just under 120 kWh.

Here's a view of all my power consumption yesterday:



So a little under 15 kW plus whatever household appliances happens to be running.

A view of the net power consumption yesterday with the power produced from the solar arrays subtracted:



Since I have a current transformer connected to each circuits that carries miner related loads, I'm able to track consumption down to that level.

Here's a view of the miner dashboard I created.  It shows daily power, in kWh, consumed by each rig (or rigs connected to a given breaker circuits), and well as the power level usage throughout the day:



In order to track power at the circuit level, I had to install energy monitors at each breaker panel.  Here are the monitors installed at the 2 main panels:



I have similar energy monitors installed at the network/server sub-panel, as well as the shop sub-panel where the solar panels are located.

The original shop roof mount array and the ground mount array installed at the same time, provided an 80 panel system capable of producing 20 kW.  For my latitude, that works out to around 2,200 kWh month averaged out over a year.

This was more than enough to cover all my energy needs, which was pretty high to begin with.  But once I started mining mid summer last year, I quickly found my consumption outstripped my production, so I decided to add another 48 panels via a pair of 24 panel arrays.

The panels have arrived.  These are rated at 280w where the previous ones were 260W.  Not a huge difference, but I'm curious how many kWh they will produce in the real world compared to the older panels.



I got the tube framing in place and the rails on the 1st array:



And about 50% done mounting panels:



All done:



For the power back feed, I decided to get a single exterior rated 200A panel, and consolidate all 128 panels to this one location.  I tapped the 400A shop sub-panel meter base as follows.  Note that ground and neutral are kept separate since this is a sub-panel off the main service entrance at the house:



And the 200A tap runs to the right towards the 200A solar sub-panel:



And here's where the 3/0 Cu cable terminate in the solar sub-panel.  The pic was taken before the ground wire was run.

And shot of the dedicated solar sub-panel with the roof and initial ground mount strings being connected to the grid:

The 24 panel ground array consist of panels identical to what is on the roof array.  Being that the array was located on recent back-fill, I decided to play it safe and do a full footer pour.



With the core frame in place, it was time to add the aluminum rails the panel were to rest on:



Panels all in place:



Backside showing the micro inverters at each panel"



You can see this is just before the end-run connectors were wired in.

This 24 panel ground array was broken into 2 12 panel strings, with each string returning to a 240V 20A breaker.

I figured I'd start a thread detailing my 3 stage (so far) built out to what is currently a 128 panel, 32 kw solar array to assist with offloading the cost of my mining operation.

It all started during the summer of 2016, before I got into mining.  I just wanted to generate my own power, but still be connected to the grid via an arrangement known as net metering.  In a nutshell, that means that when I generate more power than I use, my meter runs backwards, and I'm credited at the same rate I'm billed, for any power I put back into the grid.

I have 2 buildings on my property, the main dwelling with a 400A service, and my shop building with a separate 400A service.  When I inquired about going solar and wanting to connect all the panels to the shop building, I was told that was a no no since the shop building used very little power on an annual basis compared to the main dwelling.  So I had to disconnect the service at the shop, and instead, have the house be the single service entrance, which would then have to feed the shop and have the solar farm connected to it.

So in order to accomplish that, I had to first have the power to the shop building terminated.  POCO come out and drop the lines feeding the service to the shop:



I then dug up the 500 MCM Al cables between the pole and the shop, and dug a new trench from the house to the shop, to drop them back into:



What a mess that was...  500 MCM cable is pretty damn stout, btw:



So in order to meet code, I had to get a 400A safety disconnect and since I wanted to have a whole house backup generator, a 400A transfer switch.  The POCO was kind enough to drop off a new 320A meter base (transient rating is 400A), so that I could do all my prep work prior to the cut over.  So here are all 3 pieces prior to installation:



Here's the new meter base and safety disconnect mounted with the existing service just "flapping in the air":



Called the POCO back out, and it took me about 45 minutes from when the cut the power at the pole, to pull the old meter base and replace it with the 400A transfer switch and get everything wired to the point they could restore power:



After the "ground work" inspection, I was then able to back fill the trenches and seed:



So now I could finally prep for installing the first solar array, which consisted of 56 panels mounted on my shop building roof.

Here are the panels and assorted hardware:





I started by installing all the mounting brackets on the roof and then the bottom skirts:



After a few days, I was about half way there (I'm doing all this solo, btw):



6 days later I was down to the last panel:





Now it was time to do the electrical work.  The 56 panels on the roof consists of 4 strings with 14 panel in each.  I use micro inverters that are rated for 250W, so each string can generate up to 3,500 watts @ 240V.  Here's what each panel looks like before mounting on the roof:



So the DC voltage from the panel if fed into the inverter, which in turn puts out 240A AC which is then connected in series with the other panels in each string:

At the end of each string, there is what is know as an "end-run connector".  It simply terminates the AC voltage to 10 gauge wire, which is feed down to a 20A breaker:



All 4 end run connectors are then combined into a single run down into the breaker panel:



And here are the 4 solar panel strings terminated into 20A breakers in the sub-panel: