Cheap 500 watt PV system
I am currently working on a home photovoltaic system. Nothing fancy, it’s only 480 watts – 8 x 60watt thin-film (amorphous) Kaneka panels.
The master plan is to mount those panels on the roof of my garage, and run them to a 48-volt battery pack. I already have those batteries from my electric vehicle projects.
Feb. 19, 2010. I took a PhotoVoltaic-101 class through the MREA.
Here’s me on the way to the class.
I learned plenty, including how to use a Solar Pathfinder.
To make usable AC power, I have a 48V UPS, which I will use just the inverter section of to be able to run the electric car battery charger, some lights, and other lower power loads. The UPS was salvage. I got it from a friend who works in computer recycling. I had to wire on a new power cord, rig up some batteries, and test it. Turns out it makes better AC power than what comes out of the wall at my friend’s house.
On Feb. 26th, 2010, my Xantrex C-40 solar charge controller arrived in the mail. This is the battery charger powered by the solar PV panels. I did purchase this part new, but it can be used with 12, 24, & 48V battery systems, has a 125Voc input, and can be repurposed as a dump load controller, or an automatic load disconnect.
Right now, I am waiting for some sunny weather. My PV panels are about 3 foot square – pretty big. My current garage is almost falling down and needs to be rebuilt – this time with the roof facing the right direction for solar. Until I can get it rebuilt, maybe I can just hang one or two panels somewhere off the front of the garage.
March 4, 2010.
It was sunny today, and I had a little time, so I hooked up one panel to the Xantrex C40 through a manual disconnect switch and fuse. I ran the solar charge controller to four 12V deep cycle batteries in series. It all tested out fine, although I have no instrumentation for the system. I will need to add an ammeter, voltmeter, and for the final setup, a lightning arrestor and ground spike, and possibly ground fault interruption equipment.
As of Sept. 1, 2010, I still only have one of the 48V solar panels hooked up. Unfortunately, I don’t have as good solar access at my house as I would like. The other problem is that these solar panels use a special power connector called an MC3. Each panel has one male and one female MC3 connector. The upside of that is one panel can very easily be plugged right into the one next to it. This series connection increases the voltage. So, connecting the panels is easier, but now I would need a HIGH VOLTAGE charger/inverter to handle the nearly 400 volts I would get from it.
Alternatively, I could purchase some Y-Adapters (which aren’t that cheap either) to connect the panels in parallel. That would increase the amperage, but keep the voltage the same. That would give me a 8-amp/48-volt solar-powered battery charger.
If all eight panels were mounted together, they would be roughly 6′ by 12′.
My garage doesn’t face the sun (and a tree covers it half the day) nor does my house ridge. It looks like the best location for the solar panels would be a pole mount in the front yard. If I did that, perhaps a tracker would be in order as well. However, at that location, I would have to dig a LONG trench down the side of my driveway (and I know there are buried utilities there!) or run the cables in/under/through to the other side of the driveway.
Anyways, those are the challenges right now preventing me from setting up the full eight panels.