Building a Solar Panel
Monday February 5, 2007 // Share on Facebook
Yesterday, it was cold… like single-digits. But the sun was shining really brightly.
I’ve been looking into adding a solar panel to the back (south-facing side) of my house, to try to capture some of the suns’ rays and converting it into heat for the house. I found numerous products that do the job, but they all have two problems:
- Too expensive
- Missing features
How expensive? About $1100 per panel. What does $1100 get you? An insulated, wooden box that’s painted black, glass on one side and an AC fan. That’s right… the fan plugs in. Um… if it’s a solar heater, why not add a solar panel to power a fan, too? When I asked, a DC fan could be added for nearly $200. Hmm… did you know a case fan on your desktop computer is 12v DC-powered, and you can get them for $4? And you can get a 12V solar power supply off eBay for about $20 ($30 with S/H).
OK… so after a lot of research, I’ve drawn up my preliminary specs, and have some notes for additional things to consider. I’ve ordered the 12v, DC solar power unit, and the thermostat (so the unit will automatically turn the blower on when the air has heated up). In addition to this, there’ll be a switch on the inside of the house to turn the unit off.
I’m still trying to figure out how to put the entire panel on a hinge, so I can swing the bottom out (up), lock it in place but not disturb the ductwork. An accordion-style, flexible duct may work… I’ll have to buy some & try it out.
So Laura’s not too crazy about the idea of me drilling big holes in the house, but if we can heat the back bathroom (for free!), she’ll enjoy it.
This entry was posted on Monday, February 5th, 2007 at 7:08 am and is filed under Energy. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.
Brian said...
Before you drill the hole in your house you can mock it up and send the hot air back through the exhaust fan (fart fan) duct work, I think it will probably vent off the side of the house, just have to disable the one way flap.
I assume the maze of baffles is to stop the air from circulating too much so that you end up mixing it?
Not quite visualizing why the unit needs to be on a hinge…
I would suggest hitting up an HVAC supplier for insulated duct, they have it in a variety of sizes.
~B
February 7th, 2007
Eric said...
B -
The 2 holes came from a fan-less design… cold air enters the bottom, warms & rises, and exits the top. I’m not sure how a 1-hole system would work.
The baffles is to allow the air time to warm before coming back into the house… again, from the fan-less design. Do I need them with a fan? Who knows.
However, as I think about it, the baffles should not be parallel to the ground - they should angle up a bit, to allow the hot air to rise vertically and move horizontally at the same time. Think of the opposite… dropping a golf ball down a series of planks, going back & forth until it hits the bottom. If the planks are parallel to the ground, the ball stops. If the planks are too vertical, the ball picks up speed. I want the air to slowly move up, so it heats up. But again, with the fan, I may not need this.
The hinge will push the bottom of the unit away from the house, causing the suns rays to hit the entire unit more directly. Ideally, the angle between the sun and the unit should be 90*. I’ve read this is best done by angling the unit 10* + your latitude. Therefore, the farther North you are, the less the angle. Folks in Alaska will have a slight angle - Miami has a large angle. Picture the sun as it moves across the Alaskan winter sky - it doesn’t go very far above the horizon. In Miami, it’s high up.
So now, I have to think if I need the baffles if I have a fan, since the air will only re-enter the house if the fan is activated, and the fan will only activate if the thermostat is triggered.
February 7th, 2007
Putting it Together - Nagel Family Website said...
[...] UPS and the mailman have been delivering package after package to my house as the parts to my solar heater come in. I made a trip to Radio Shack today and picked up the fan, some wire, a 12V battery and a [...]
February 9th, 2007