Monday, October 26, 2009

High Tech Red Neck

Geek, hillbilly, and redneck are generally considered terms of derision. But I've been trying to teach my children that they are badges of honor. So eight years ago, when two fellow geeks called me up and asked if I wanted to go on TV as a self professed geek, I said sure why not?! We made an audition video and sent it to the The Learning Channel's popular T.V. show Junkyard Wars. Our team was one of 8 picked from hundreds of applications, and the next thing we knew, we were in a junk yard on the outskirts of Los Angeles with cameras pointed at us, and only 10 hours to build something or look like complete fools. Talk about adrenaline!

Pirated copies of the TV show can be found for download by googling "Thomas Massie Junk Yard Wars" But if you don't want to be a pirate or have a hard time using that video format, you can go to a legitimate web site called "how stuff works" and watch our debut by streaming the video. Our task was to build a working Sand Yacht (aka Dirt Boat) in only a day, using only junk. Here's the legitimate link. I don't have true broadband, so I haven't watched the whole video online, but most of it seems to be there. Our show starts 3 minutes into that video.

We called our team "The Geeks," but I had to use more of my "hillbilly" skills than anything to bring the junk to life. No, I don't get any sort of royalty or anything from the show... like the idiots on Jerry Springer, I appeared on TV to make a fool of myself for practically nothing. It was on eof the funnest things I've ever done.

Wednesday, October 07, 2009

Finally up to 7.5 Kw of solar

In spite of wind, rain, and visiting friends, I finally finished our solar panel installation. We now have 36 panels on the roof. Each of them is rated for 208 watts, so the total production capacity of the array under ideal conditions is 7488 watts. Today, when the sun appeared between the clouds, I saw the system reach its theoretical maximum of 7.5Kw! The best number I could capture today after getting my camera out was 7.2Kw.

Speaking of clouds, it is possible (and I saw it happen when I had fewer panels on the roof), for the array to put out even more than its theoretical maximum when the sun is peeking around the edge of a cloud. I won't pretend to understand the optics, but the edge of the cloud focuses the sun on the array. The extra power is trivial since the condition only occurs for a brief period of time (clouds move!). But it is important to consider this "peaking" effect when sizing fuses, wires, and battery chargers.

Here's a picture of the cloud obstructed sun earlier today, trying to shine through the timbers and our as-yet-untrimmed windows on the south side of the house.

Saturday, October 03, 2009

moh powah

We've been operating with 5Kw of solar panels on the roof, while 2.5Kw sat in the basement... waiting for me to get up the gumption to put them on the roof. I used my 1974 Grove crane to put the first 5Kw of panels on the roof, but this time I thought I would try it w/o the crane... thereby freeing up the crane operator (my wife!) to do other tasks around the house.

My panels are attached to the standing seam roof using S5! clamps. These clamps have kept my solar panels in place for two years through high winds and adverse weather, so I decided to literally go out on a limb, and used them in conjunction with 2x4's to build a chicken ladder on my roof. After reaching the peak of my roof, I was able to attach a rope to my (almost finished) chimney, thereby providing a higher degree of safety. I attached myself to the rope using a lanyard and a rope grab with a ratcheting action, allowing me to scramble up and down the roof fairly easily.

Then I started at the peak, removing the 2x4's one at a time and attaching the solar panels as I worked my way back down the roof. These 208 watt panels are heavy, bulky, and sharp on the corners... so even though my safety was assured, I had a hard time wrangling these panels onto the roof without scratching the painted roof. (I kept a bottle of automobile touch-up paint in my pocket) There were a few times I was genuinely afraid I would drop the panels to the ground. But somehow I managed.

The wires for my solar panels pass through a hole in my roof near the eaves. From the roof surface to the breaker box under the eaves, I used solid metal conduit. Anywhere wires from roof mounted solar panels pass through a habitable structure, metal conduit should be used. (fire safety) I wired my panels so that three panels are in series. In the breaker box, four of these "sets of three" are wired in parallel. Then two wires are required for 12 panels to get power to the basement where my MPPT battery chargers reside. (I know, I know, I need a schematic to explain this.)

As of this writing, I have six new panels (approx. 1250 watts) on the roof and wired into our system! The rope remains on my chimney so I can add the other six panels this week, which will bring out solar capacity up to 7500 watts.