A Modest Solar Panel Setup And How Well It Performs

PARTS LIST FOR INITIAL SYSTEM

The following list isn’t quite at the level of detail you would need to replicate my initial system without a bit of your own design/thought. But it certainly fleshes out the principal components.

System 1: Running Television, DVD/VCR, stereo

  • Kyocera 130 W polycrystalline panel, 16% efficient
  • Xantrex C-35 charge controller
  • 400 W modified sine wave inverter (cheap!)
  • Trojan T-1275 golf-cart battery (12-volt, 150 amp-hour)
  • Class-T 110 Amp fuse & holder

System 2: Running Two CFL Torchier Lights

  • Unisolar 64 W multi-junction thin-film PV panel, 8% efficient
  • Phocos CML-20 charge controller
  • 400 W modified sine wave inverter
  • Trojan T-1275 golf-cart battery (12-volt, 150 amp-hour)
  • Class-T 110 Amp fuse

Shared Items

  • Current shunts for later use with system monitor
  • Extension cords for delivering power indoors
  • Lots of #6, #8, #10 stranded wire in red, white, and green
  • Quality crimper, crimp rings, heat shrink
  • Conduit, feedthroughs, terminals, ground clamp, etc.

Trojan T-105 batteries (6-volt 225 amp-hours) are more frequently seen in PV systems than are T-1275 units.  I opted for the T-1275 because I favored a single 12-volt unit for convenience.  Later, in researching battery details for the nation-sized battery post, I learned from a Trojan engineer that the T-1275 and T-105 cells use exactly the same lead plates/grids.  So they should have the same cycle performance—just packaged differently and with differing capacity.  Incidentally, a battery’s storage capacity in kilowatt-hours can be obtained simply by multiplying voltage and amp-hour capacity (then dividing by 1000).  So the T-1275 battery, at 12 V and 150 Ah, comes to 1.8 kWh, for instance.

INSTALLATION

Assembling the parts into a working system was not terribly difficult. It really comes down to lots of stripping and crimping large wires. Heat shrink (especially the kind that oozes sealant/goop as it melts/shrinks) is useful to protect the crimp joints from corrosion.

At the time, I was renting a condominium, and could not make arbitrary alterations to the place. Because I was simply running extension cords inside, I did not need to mess with the condo’s electrical system—and I found a way to get the extension cords inside without drilling any new holes. I was even able to follow existing holes in kitchen cabinet partitions made for supplying the refrigerator with water. I only needed to drill through one wall, with the landlord’s permission, to get into the living room. The panels sat on the carport, and as such (not being attached to a dwelling), I did not have to provision the system with a ground-fault protection device (GFPD). The rest of the electronics and batteries occupied a space outside in a protected alcove of our patio, safe from rain.

Big Lesson: Energy is Precious

Having such a small system, I had to be vigilant about energy use in the living room. The energy I was using had become very personal. I felt it was my energy in a way that I had not remotely felt before. I paid more attention to the weather, and to the forecast (boring as this tends to be in Southern California). Cloudy periods meant we should ration our television watching. A sunny afternoon when the batteries had reached full charge meant “free” energy that otherwise would go unused. Break out the movie!

The kind of energy awareness that accompanies personal on-site energy production—even if representing a small fraction of total use—turns out to have tremendous leverage. That’s because increased awareness and the resulting behavioral shifts transfer to all sectors. You’ll never look at energy the same way. Energy becomes personal; precious. Once you’ve experienced horror at realizing you’ve left the solar-powered lights on while out of the room (unnecessarily draining batteries and making the system’s job that much harder the next day), you’re unlikely to ever do it again, and that much less likely to perpetrate the same crime on any lights anywhere. Similarly, I have found that energy monitoring (as with a TED system) is another effective way to personalize energy use.