April 25 , 2004
On Track with the Rack
The first of the two large racks was completed this week. It was quite a laborious project, but doing the labor myself has kept the cost quite a bit lower compared to building the rack from a prepackaged kit. It took a good five hours to line up the posts in the hole to make certain that the rack was plumb and square. Hopefully, with the experience that I have gained the next rack will go a bit faster. I think that next week, I'll take a break from building racks and put up the first set of solar panels. Mixing cement, even with a mixer is hard work and my body could use a rest from shoveling sand and gravel.
Before mounting the solar panels, I hope to find a sunny period in which to test the electric output of the panels. The specifications state that the panel's output is 158 watts, but there will always be some variation to the specification.
This can reduce the entire system performance if panels with a lower output are matched with panels of a higher output. The system output will default to the lowest common denominator when the panels are strung together in series. For example, if you had 3 panels in series and two of the panels produce 158 watts while the third panel only produce 150 watts, the entire string would produce approximately 450 watts instead of 468 watts. This doesn't seem like a big deal, but with multiple strings of panels operating this way, it could have a sizeable impact on the entire performance of the system.
By taking a little bit of extra time and rating all the panels ahead of time, the panels can be matched in strings of 3, to increase performance.
This may seem trivial, but there are a number of other factors that plague total system performance: Wire lengths, wire gauge, wire connections, ambient temperature and inverter efficiency. Some of the factors can be controlled while others cannot. By the time all things are said and done, the total system performance can be as low as 75% (or less) of the original power output of the panels. A bit of tweaking here and there should get the system functioning to about 85% of the stated output. I plan on doing my best to keep the efficiency as high as possible.
The Dancing Woodcock of Houston, Minnesota
A neighbor stopped by the other day and besides trading mouse damage stories we talked a bit about bird watching. He told me that I should go see the "dance" of the American Woodcock. The American Woodcock is a rather unique bird that spends the summer here and through most parts of North America. It's unique from a number of standpoints: It's considered a shore bird, yet it spends its time on forest floors. The female nests on the ground and their beaks are rather long in order to feed on its main diet of tasty earthworms.
He told me of a park not too far away where I might see this marvel of marvels. He said to go there about 8 O'clock in the evening and keep an eye out on any movement by the trail head and listen for a strange buzzing sound.
So I went there with great anticipation. About five minutes after I got there, a car pulled up from Wisconsin. They were a retired couple and since they had a pair of binoculars with them, I took my chances and asked them if they were there to see the Woodcock too. Sure enough, word was getting around about this Woodcock and it had now reached as far away as Wisconsin. (This sounds impressive, but in reality Wisconsin is only 20 miles away.)
The three of us waited and waited. No strange sounds. No sign of the Woodcock. It was now getting rather dark. Our attention was diverted to other things such as a grouse roosting in a tree and other evening bird calls. All at once, there was this "buzz". The sound was similar to a Night Hawk. Then there was dead silence. About a minute or so past and there was another buzz. And then about a half minute later there was another buzz. The sound was coming over by the trail, but it was getting hard to see the ground since it was getting dark. Then there was another buzz. They seemed to be coming more rapidly now. Eventually, the buzzes were getting really close together and all at once the bird took off to the sky, circling higher and higher, making a series of chirps and tweaks as it ascended. The bird went up so high we lost sight of it, but you could still here it's bizarre mating call. Then it made a different series of chirps and tweaks and nose dived for the ground. Just before you were beginning to think it was going to impale its beak into the ground, it softly fluttered back to earth and landed dead center on the trail.
Now that we knew where it was located, I grabbed my camera and tripod and tried my best to take some time exposures of the bird. (All the photo's came out blurred...not worthy of the Internet...sorry...I may try this again.) The Woodcock started buzzing again and as the buzzes got closer together, it took off for the sky again. After its "routine", it landed back on the trail. I looked in my camera and was startled to see that the bird landed exactly in the same spot as before.
The bird kept up this dance over and over again. After about 15 minutes, it was still doing its dance but it was dark by now, so we packed up our gear and headed home. It was a very entertaining show and I may go back this week for an encore presentation. According to the park's naturalist, the bird has been returning for three years now. Who needs a TV when you've got the dancing Woodcock of Houston, Minnesota?
(If you would like to learn more about this bird and listen to its strange call, click here.)