Some Results, Finally!

I’m happy! I got to do some *science* today! Here’s the story:

I’ve been working with various people in the ISU SPS chapter on a solar panel research project for about a year and a half now, and we finally have some data to analyze! This project has been plagued with various institutional/procedural/equipment failure hang-ups that have kept us from getting anything done for months now, so it’s nice to see some numbers finally.

The basic idea behind it is to measure the atmospheric optical thickness by analyzing a full 24-hour cycle of the current output of a solar cell. In order to normalize the data, we have to calculate the vector normal to the surface of the solar panel and the vector position of the sun relative to the earth’s surface in order to figure out the sensor acceptance at different times of the day. This involves applying some Calc III and trig techniques that I learned last semester, which is pretty exciting since a lot of the stuff I (and students in general) learn in college doesn’t get to be used right away.

In any case, the professor that has been consulting with us on the project had a meeting with me and a friend today and told us a bit about sensor acceptance and the math involved, and sketched a graph of what the relationship should probably be for our solar panel. Lo and behold, when I got through inputting all the algorithms in excel to calculate it, the graph looked markedly similar to what he had predicted! This is probably super-nerdy to anyone outside of science, but for me it’s a rather exciting thing to have semi-crap data (we’ve had problems with cloud cover interfering) to play with and actually get some good results with the data analysis.

Check it out!

This is a full day’s cycle – sunrise to sunset with each data point a minute apart. The y-axis is computed as the current (I) divided by the cosine of the angle between the normal vector of the photovoltaic and the sun’s vector position – I/cos(theta).

~ by David on 2008 March 7, Friday.