Two years since its conception, my "modular solar" project is now up-and-running. Here's how I did it and how I'd do it differently if I started today.

As a renter, dropping thousands of dollars to renovate my roof into a field of solar panels wasn't an option for me. A couple years ago I was inspired to attempt a more modular solution, buying a panel at a time and spreading room to room throughout the house. While easy as DIY projects go (no sawing, soldering, or even sewing), it was not without a few snags.

The first problem was parts. The initial list that I put together was lacking in some very important ones, namely all the cables that let energy flow from one component to the next. Here's the grand list of what I ended up buying (with suggested replacements for products that have since been discontinued).

1. Photovoltaic (PV) panel. I bought a Uni-Solar US-64 (which I love) but it's since been discontinued. I still think the wattage and price was about right for this system, so I'd replace it with a Kyocera KC65T 65-Watter for just over $300.
2. Output cables. These emerge from the panel's junction box (or J-box) and travel to the charge controller. They're "two strand" with both positive and negative wiring inside a single weatherproof shielding (#10 AWG). Ten feet (10') is about $25.
3. Output terminals. You can't connect bare wire to the J-box or charge controller, so you need terminals. Luckily, they're super-cheap. An assorted 75-piece package is less than $5. Fitting the terminals to the cable will require a stripper/crimper.
4. Charge controller. The charge controller keeps your battery from overcharging once it's full. The Morningstar SunSaver (20-Amp) is great and still available for $80 but the ProStar (15-Amp) is tempting with its battery indicator and covered terminals for only $20 more.
5. Charge cable. This cable connects the controller to the battery and often comes with its own terminals and a built-in fuse (so your battery doesn't explode if your solar panel is hit by lightning). Depending on how far apart your components are, a three-footer for $20 should work.
6. Battery terminals. You might not need them, but I used some ring terminals from the assorted package above.
7. Battery. Absorptive Glass Mat (AGM) is a lot safer than gel or sealed and maintains okay health under deep-cycling. I'd stick with my choice in the 92 Amp hour MK 8A27 for $180.
8. Inverter cables. See, lots of cables! Since these are thicker and thus more expensive than the others (#4 AWG), I'd recommend keeping them short. $30 for 3 feet isn't bad, but you could probably pick up #4 wire and add your own battery clamp terminals for cheaper.
9. Inverter. The Aims 1000W is a little bit loud and possibly overkill, but still a great catch at $75.
10. This space intentionally left blank. You really should plug something into your inverter. That's sort of the point.

The above system was, more or less, what debuted at last year's Burning Man camp and powered our hanging lights all week. After that, it tried to move to the roof of our apartment but was soon discovered by our landlord who followed the cable into our bedroom window (and accused us of throwing "graffiti parties" up there as well).

Now it finally has a (semi-) permanent home in our new apartment. Attached with wire (more wire!) to the back deck, the output cables run into our laundry room and the charge controller. The battery is currently in a cardboard box until it gets a more secure container.