You learned from the last blog post about how much electricity you are using. This post is about generating that electricity yourself rather than relying on the power system. There are two ways to go about doing this:
Grid-Tied System
In a grid tied system, you only need to buy solar panels and a grid tie inverter. The solar panels connect to the grid tie inverter, which then connects to your house. Any excess energy that you generate actually gets sent back into the electric system, and you can potentially be paid by the electric company instead of the other way around.
This is not as interesting to me though because you need a professional electrician to connect the grid tie inverter to your house. Also, if the electric company's power goes out, your house goes dark, even if your solar panels are generating electricity. You need to add batteries if you want to use it as a backup solution as well.
Off Grid System
In an off grid system, you are generating your own electricity and storing it in batteries. This is good for a cabin in the woods. It was also good for me in my case to just learn what solar stuff is all about.
Parts to the Off Grid System
Solar Panels: These will be rated by how many watts they'll generate with direct sunlight shining on them. There are 3 types of solar panels:
- Polycrystalline: Your basic panel
- Monocrystalline: Your basic panel, but more efficient (and more expensive). So a 100W monocrystalline panel will most likely be smaller than a 100W polycrystalline panel.
- Amorphous: Whereas the two types above are rigid, this is more pliable. I believe some companies pretty much just print this stuff out. It is less efficient (so a 100W amorphous panel is comparatively HUGE), but it also does better in indirect sunlight (like a cloudy day) than the other two do.
- PWM (Pulse Width Modulation): Your basic charge controller. Any voltage over the limit is simply dropped. Unfortunately this can be inefficient (say 80% efficient).
- MPPT (Maximum Power Point Tracking): Newer, fancier charge controllers (also far more expensive). Instead of simply dropping any voltage, it'll convert the extra volts to amps instead (I'll talk about the math of this later), radically increasing the efficiency of your system (like 97%).
Batteries: You pretty much want to charge your basic 12V car battery. Except apparently 12V marine batteries (specifically deep cycle batteries) and 6V golf cart batteries are actually better suited for the task. Car batteries are meant to have a big pull right at the beginning (starting your car), and then not much else. Apparently boats and golf carts are more likely to drain a battery all the way down, and then charge it all the way up again, just like a solar panel system would.- Modified Sine Wave Inverter: Your basic DC/AC inverter. It'll give a bit of a choppy AC signal, which will work fine for most of your appliances, but not all. For example, laser printers won't work, fans and fluorescent lights may buzz, and generators/motors may run hot.
- Pure Sine Wave Inverter: This gives you the same type of signal at your wall outlet. Much more expensive.
- Solar panel: I bought a small 5W panel to test with for $25. I'm looking to get some cheaper, larger panels off craigslist now that I have a better idea of what I'm doing. I'd like to stick them on my shed in the backyard, and they'll provide power for parties out back.
- Charge controller: I got a small 3 amp / 12 V charge controller to test with for $11.
- Battery: I got a deep cycle marine battery from Walmart with 100 amp hours for $75.
- Power Inverter: I got a 200W Whistler power inverter years and years ago for Christmas that I just kept in my car.
- Misc
- $6 for some 14 gauge copper wire at home depot
- $10 for an add-on cable to connect my power inverter directly to the battery ($10 was a huge rip-off, like everything else at radio shack)
- A battery trickle charger, wire strippers, and a multimeter all came in handy at different points that I already owned as well.





























