Saturday, October 29, 2005

Solar Power: Step 78

Step-by-step, one small piece at a time the system comes together. The special quick connects came in, but one wire ended up too short, and so I have another on order. Nonetheless, the panels all were producing 70 volts per series pair. They are now wired into the DC breaker panel.

The panels covered for safety. There is no way to turn them off, so
when the sun shines they are "hot" and can potentially cause a shock.

I needed help to raise the panels and put the legs on. In theory, they will not have to be touched for 20 or more years. Panels are quite inefficient converting only about 10% of the power that hits the panel. In 20 years I'll bet 2 panels of this size will replace the 10 I have now.

The panels up and working.

Inside the electrical shed work continues. The inverter weight 66 pounds. I had to build a shelf to place it on while I bolted it to the wall. All that remains, I think, is one solar panel connector, two battery cables and wiring it into the AC side.

The inverter (left) installed, and awaiting twocables coming from
Apache Junction, Arizona.

Wednesday, October 19, 2005

Final Failure & the Simpsons

I told the inspectors I wouldn't be back until Wednesday afternoon, but when I arrived I found 3 yellow sheets of paper stuffed in my front door jamb. I failed my final inspection on 3 counts.
  1. The inspector couldn't enter the building.
  2. There needs to be 3' of flat runnout at the bottom of the stairs, and some of the gravel had sunk down a bit.
  3. Lack of adequate hold-down on the porch roof.
Items 1 and 2 could have been handled had I been there. In fact there is nothing left to approve inside, but the inspectors have every right and are naturally welcome to make sure they caught everything. The reason I know that there is nothing left inside is that I had a final inspection 3 months ago in order to get occupancy and at that time there was a list of items to complete: front and back handrails, porch lights, finish siding, and a couple of little nits. Nothing about the porch roof structure, which was finished at that time.

Frankly, I've worked hard keep from using Simpson Strong-Ties in visible locations. The reason being that most of them are as ugly as sin, and meant to be used inside walls and covered over. On an exposed structure like a porch they really can detract from the look. Their popularity stems from the combination of increasing code requirements and cheaper construction methods and materials. Use a Simpson Strong-Tie and everyone is happy because the burden of failure falls on them. It's a CYA sort of thing.

I was delighted when my first final list made no mention of additional hold-downs on the downhill side of the porch roof. The engineer had made much of the uphill connection at the house, but was silent on the lower portion. In the absence of direction my builders had fastened them with a single #10, 4-inch, stainless steel deck screw. My real frustration at not being there for the latest final inspection was that I might have been able to distract him or at least point to the last inspection report and kept the focus on those few items.

When I described the whole situation to my octogenarian neighbor, Roxy Nelson, he laughed. He had commented to me long ago that he thought the roof was liable to blow off in a stiff wind. As a machinist he had used plenty of metal in his place, and he was skeptical about my solution.

I did finally look up some data and the likely uplift on each rafter is 350 pounds. Trying to find the pull-out resistance of the screw was more difficult, but it seemed clear that 350 pounds was a stretch. Moreover, it seemed clear that the real point of failure would be the screw pulling through the cedar. So, in the end the house may be uglier, but safer.

Monday, October 17, 2005

Solar Panels (photos)

Today I finally got to put the panels up...or rather down. The rack system I bought from Uni-rac, "the leaders in the industry," but it had some issues. The panels have legs to raise them to the requisite angle, but it's not really possible to install the panels on the raised rack. Here's why:

  • The panels themselves provide the third arm of the triangle. Without the panels in place there is no real frame. A catch-22. Can't install the panels on the floppy rack. Can't make the rack stiff without installing the panels.
  • The panels clamp from the top using special clips. The panels must be held in place to install the clamps.
  • The clamps between panels hold both panels and thus two panels must be done at one time.
After trying to do this at an angle, I gave up, layed the whole mess down and installed them easily in minutes.

A rack of solar.

Every time I turn around I find I need another specialty part. Most recently I opened up to find the panels have specialty, quick-connect electrical cable pre-wired. Quick if one has this kind of cable around. I don't. It's now on order.

The panels look diminutive because the electrical shed is 10' tall at
the face. The panels are 3' x 5' each and the two racks together is
about 30'. The panels weigh perhaps 30 lbs. each, so I'll need help
raising them.

Friday, October 14, 2005

Adding DC (photo)

I've started working on the solar system. It's not really a good time of year to be doing solar, but I've had the panels for over 2 years now, and I'm interested to put it all together. Besides, it does add a battery backup component, which is a good thing to have during winter storms.

On the left (gray boxes) is the AC side. On the right is the start of the
DC (solar) side.

Monday, October 10, 2005

Exterior is Finished (photos)

There was a bit of a delay waiting for new cedar planks to cover the back wall. We ran out of salvaged, cedar barn planks, but it was amazing that we got 3 sides done in old wood.

Jordon (top) and Jason put the final plank in place.

The back (north) wall gives a sense of what the house would have looked
like if it had all been done in new wood. Dull, uniform, and lacking in

The final house with its back to the north wind. It was a conscious
choice to have no windows (only skylights) on the north side.

Saturday, October 01, 2005

First Bread (photo)

It finally got cool enough to try baking bread. The results were quite good, but the house got quite warm.

It takes a small inferno to get the oven to 450 F (Photo: Alice Brawley-Chesworth)