School project

[Living Large]

Great discussion here. I didn't think my resistor suggestion was necessarily a good one, but I threw it out there as a starting point. I like the ammeter suggestion, and the other ideas are novel.

[milkymj]

Okay, great ideas. What I think I'm going to do is a combination of them. Get 2 small dc pumps and run each one on the hour for 5 minutes and see how much water each pumps. Do that over the course of the day and plot it out.

What do you think? Accurate enough for this project?

[sdold]

Sounds good, if the pump is small (or the orifice is restricted) and you use big buckets or bottles, maybe you could leave it running all day.

[foo1bar]

What do you think? Accurate enough for this project?

The first thing I came across in a quick search was that trackers add 22-30% in efficiency.
So if your pumps (or other measurement apparatus) are within 2% or even 5% of each other, it should be good enough.
But can you find a pump to run off a small solar panel?

As for sourcing - I'd suggest finding who makes solar trackers, and contact them to see if they'd be willing to lend you the tracking hardware. Quite possibly they have something that's the right size for this, and they use it for sales/marketing.

[milkymj]

The first thing I came across in a quick search was that trackers add 22-30% in efficiency.
So if your pumps (or other measurement apparatus) are within 2% or even 5% of each other, it should be good enough.
But can you find a pump to run off a small solar panel?

As for sourcing - I'd suggest finding who makes solar trackers, and contact them to see if they'd be willing to lend you the tracking hardware. Quite possibly they have something that's the right size for this, and they use it for sales/marketing.

I've found some fountain/aquarium pumps that will work. I will need a slightly larger panel though. I did find a small tracker. Not sure if it's ok to post links, if not please remove:

http://www.amazon.com/gp/product/B00997KGMC/

[Wy_White_Wolf]

May be a little out of your project price range but they do make DC watthour meters.

http://www.rc-electronics-usa.com/ammeters/rv-battery-monitor.html

Hook one up to each panel and have them charge a battery for the day. Make sure the battery has a load on it or is discharged enough that it won't get fully charged by the end of the day.

WWW

[ericf1]

I've found some fountain/aquarium pumps that will work. I will need a slightly larger panel though. I did find a small tracker. Not sure if it's ok to post links, if not please remove:

http://www.amazon.com/gp/product/B00997KGMC/

If you know anyone who is into amateur astronomy, talk to them about borrowing a telescope mount. Even a cheap equatorial mount would track the sun for you, as would a computerized alt/az mount. Your science teacher, school, or a local astronomy club might be willing to help you out.

You could also just mount the cell on a camera tripod, print out a table of the azimuth and elevation of the sun throughout the day and make manual adjustments every half hour or so.

[Living Large]

If you know anyone who is into amateur astronomy, talk to them about borrowing a telescope mount. Even a cheap equatorial mount would track the sun for you, as would a computerized alt/az mount. Your science teacher, school, or a local astronomy club might be willing to help you out.

You could also just mount the cell on a camera tripod, print out a table of the azimuth and elevation of the sun throughout the day and make manual adjustments every half hour or so.

Ya know, those are two good ideas. I had an equitorial I just sold. The only small challenge is attaching the array to the mount, but since it is so small and lightweight, it shouldn't be a problem.

I have an old school surveying transit that would work for your second idea, with scales for both elevation and azimuth. I just used it to check the shading at a potential off grid sight. If he is going to use a measurement technique that involves visiting every 15 minutes or whatever, then he could adjust the angles as you suggest.