What would you build?

[Moleman]

I was recently gifted 5 15w, amorphous 12v modules. I think they were bought with a harbor freight kit a few years ago. Assuming 70% efficiency from the modules, I can generate ~50w at 12v. What would you do with 50w of free panels??? I'm looking for ideas. Are they even worth messing with? I was thinking about using them to run a fan in the my shop (only during daylight of course). Do they make DC fans or will I need an inverter? It seems silly getting an inverter for 50w...

[SunEagle]

Probably the best item that came with those HF panels were the DC lamps. IMO a couple of very low wattage LED DC lamps would be the limit I would expect to work with those panels.

You can find a number of DC fans that work well with solar panels. I actually have a 12 inch roof vent fan and a 10 watt panel that works just fine together.

[littleharbor]

Those Harbor Freight panels don't last more than a couple years in continuous use.

[Sunking]

Well with five of those panels to use as frames would make a nice box or trash bin. I hope they came with the factory cardboard box because they are worth more than the panels.

[J.P.M.]

Those Harbor Freight panels don't last more than a couple years in continuous use.

And best used for target practice.

[SunEagle]

And best used for target practice.

Some of my paper targets are thicker then those panels.

[Moleman]

Good thing they were free right?

I put the multimeter on them and it looks like I'm getting about 1A (21w @ 22v) off of them. I could charge a cell phone, but I need to lower the voltage right?

[littleharbor]

That would be open circuit voltage. Under load the voltage and current will be lower. I believe those panels are rated at 15 watts

[Moleman]

That would be open circuit voltage. Under load the voltage and current will be lower. I believe those panels are rated at 15 watts

They were advertised as 15w I believe, but they are several years old. 5 in parallel are giving me those readings.

[Moleman]

This is a project to teach my kid about the basics of electricity (and to brush up on it myself). So keep in mind before bashing it, this is meant to be fun/educational.

[Sunking]

It will require a battery and charge controller, or about $75 to generate 1-cent of electricity per day. Then about 2 or 3 years time to replace the battery. How is that for fun and education?

[jflorey2]

It will require a battery and charge controller, or about $75 to generate 1-cent of electricity per day. Then about 2 or 3 years time to replace the battery. How is that for fun and education?

Because you would learn how chargers and solar panels work.

[SunEagle]

It will require a battery and charge controller, or about $75 to generate 1-cent of electricity per day. Then about 2 or 3 years time to replace the battery. How is that for fun and education?

Yeah. I think that the HF panels would be just fine for kids to learn a little something about solar. Think about all the "experiments" you did in grammar school and were they worth the cost?

[Sunking]

Yeah. I think that the HF panels would be just fine for kids to learn a little something about solar. Think about all the "experiments" you did in grammar school and were they worth the cost?

Yeah for a computer fan running 5 watts. But what is not learned or taught in schools is economics. That part is hidden from the public.

[Sunking]

So everyone tells you the box they came in is worth more then the panels and I am the bad guy for being honest?