Thoughts on Solar

In parts 1 and 2 of this series, we documented what went into securing the rebate reservation and the process by which we secured our permits.  Now the actual work could begin - and that work starts on the ground.  So in this Part 3, we will look at the staging that was required for this production and take a close-up look at some of the heavy lifting that was needed far below the array itself.

A project the size of what we were going to install at Westridge - 52.3kW - involves thousands of parts, all of which not only must go together properly for the system to work and be safe, but they must arrive in a timely fashion!  For example, here’s just a sample of the parts that were needed for this job: hundreds of FastFoot plates, thousands of screws, hundreds of flashings, standoffs, and flange connectors, dozens of rail sections, mid-clamps, end-clamps, ground lugs and splices, to say nothing of 209 micro-inverters and solar panels!  Collectively these products came from five different distributors in four different states.

Needless to say, not everything goes as smoothly as you might like when you are pulling together all of these pieces.  UPS likes to brag about Logistics, but we found some of their logistics to be highly illogical.  Such as their sending two shipments that were sitting in an LA warehouse on a frolic and detour down to San Diego for the weekend, instead of driving them the twelve miles up the road to our job site!

Equally baffling were the folks who delivered our boom lift to the job site late on a Friday evening without even a phone call and just parked it out on the street - in front of a No Parking sign!

Seriously…

Would you leave this…

Here?  Right - neither would we!  (And yes, the keys were in it!) The unscripted appearance of our boom lift prompted a puzzled call from the facilies director at Westridge:

Brian: “Were you folks expecting a boom lift to be delivered?”

RoS: “Yes, they are delivering it tomorrow morning.”

Brian: “Well, it’s here - and they left it on the street next to a No Parking sign.”

RoS: (Eek!) - “Really?  We’ll be right there!”

Like I said, not everything can go exactly as planned, but soon enough, everything arrived and in good condition.

Our staging area was set with:

LG Solar Panels

Enphase Micro-inverters

Unirac Solarmount (Evolution) racking parts

And lots of wire!

Transformation

Our first main task on the ground, now that everything was at hand, was to install our transformer.  This project required a transformer to step-down the voltage from the utility service (480 volts, three-phase) to the voltage that would be used by our micro-inverters (208 volts, three-phase).

Setting the Stage

Our transformer was a 700 lb beast that had to be installed on a concrete pad (that we had to pour) in the equipment storage area on the East side of the building.  To secure the transformer to the pad, we would imbed bolts into the pad and then maneurver the transformer on top of the bolts and anchor it with washers and nuts.  Two key challenges there - first was to guarantee that our bolts were precisely positioned in the pad since the transformer gave us very little margin for error.  Second was to get the transformer in place on top of the bolts without damaging them.

We solved the first problem by drilling into the existing concrete and securing our bolts into the ground with heavy duty anchors - as you see here with the framework for the pad surrounding them.

Then, when we were ready to fill in the form with concrete, we added some framing at the top to try and keep the bolts as plumb as possible, as you see here:

The Big (Not So) Easy

That took care of problem number one, but what to do about problem number two? Now that the pad was dry, the challenge became getting our transformer into place.

Our solution would make any student of ancient cultures proud - we crafted a wooden platform over the pad and slid the transformer from its pallet onto the platform.  Then we lifted each edge, one at a time, and placed blocks of wood under each corner.  That allowed us to remove the platform and then begin lowering the transformer over the bolts by carefully removing a block at each corner.

As we removed each block, the transformer came closer to the bolts protruding from the pad.  We could push the transformer - gently - so that it aligned with the bolts.  Ultimately, the last block was removed and the result was a complete success with just the right amount of angst along the way!

But as you can see, we really didn’t have much margin for error!

The Art of Conduit

In addition to our transformer, there were several other pieces of gear that had to be mounted on the ground including a 200 Amp sub-panel, two disconnect switches and a performance meter.  Linking them all together is the conduit through which our conductors would be pulled.

Pasadena requires rigid metal conduit (instead of EMT) to be used for solar power systems wherever it is accessible on the outside of a building.  That offers some additional safety, but it comes at a cost - especially given that we were using 1.25″ conduit for most of our runs.  Rigid conduit of that dimension is heavy and cannot be bent by hand.  Instead, a motorized pipe bender was the order of the day - and it took some really skilled craftsman named Don and Josh to get our conduit in place and looking good.

It really is an art, as much as a science, and when done with care and precision, the result is quite appealing!

Pulling it Together

Our final ground-based task was to pull the conductors through the conduits.  Our longest pull was 245′ - not quite a football field, but close!  Moreover, that longest pull had multiple bends as we routed the conduit to make it as invisible from the ground as possible.  (To complete the task of making the conduit “disappear” to the greatest extent possible, the client painted the conduit to match the walls and the trim!)

At the end of a very long, drizzly Saturday, we were rewarded with having our conductors fully in place from the utility disconnect switch and performance meter socket:

… to our disconnect switch adjacent to the transformer:

Our penultimate installment will take you to the roof where the real action takes place.  So buckle in, the next chapter isn’t for the faint of heart!