any ideas if there is a (cheaper) alternative for logging:
-windspeed
-rotorspeed
-stator temp
-outside temp
-date and time
Hi Daniel,
Sometimes I think you can log too much stuff that's not really useful information in the long run. For instance, I don't feel logging turbine rpm is useful except for tuning a turbine for maximum performance, and once tuned it's useless information. And also, logging instantaneous output is also pretty much useless information, again unless you're tuning a turbine to get maximum performance at a particular wind speed, or whatever.
For me, what's more useful in the long run is how many kWh the turbine makes and what the average wind speed was that it made that power at. As an example, you can have a turbine that puts out 1,000 watts for 20 minutes during a storm, then only puts out 50 watts the rest of the day vs a machine that puts out 250 watts continuous for 24 hours. The data from the machine that makes a continuous 250 watts all day is not nearly as exciting to analyze, but it made over 4x more power for the day to run your house than the one did that briefly spiked at 1,000 watts.
I've logged output data from my turbines for years using just a Doc Wattson meter with an external shunt and a recording anemometer that stores min, max and average wind speed with a date and time stamp for up to 6 months. I enter the wind speed data and the amp-hours, kWh and peak amps from the Doc Wattson into a spreadsheet, then reset the meters. The spreadsheet figures out how what the average watts/hr output of the turbine was, and the average system operating voltage, for the logging period, and graphs it.
I've used the long term output trends to tune my turbines and see what changes in adjustments make vs average wind speed, and to see what the difference is between various turbines I have flown as far as output vs wind speed. As an example, my present turbine that powers my house developed its first megawatt-hour of power for the year, last week. The 13 footer that it replaced did not make its first megawatt-hour of power until June 2 last year, and the average wind speed this year was .2 mph higher than it was last year.
It tells me all that with three simple tools - a good quality home weather station, a $59 kWh meter and a PC with Excel in it. It's a pretty rudimentary and basic data logging system. But it's pretty much maintenance free meaning I record the data when I happen to think about it, which is sometimes up to two weeks between entries in the spreadsheet.
So all I'm saying is that you can spend a lot of money on an elaborate data logger. But a year from now, going back to April 22, 2011 and seeing that your turbine was running at 225 rpm at 2:00 PM doesn't really tell you much. But seeing that it made 300 kWh for the month of April in 2011 at 12 mph average wind speed vs what you get next year at the same average wind speed after making some changes tells you a lot.
--
Chris
