Research

My initial research into building solar jars found several "DIY" and "HOWTO" type web sites (1, 2). These sites in turn had suggestions for how to actually assemble the thing, as well as where to source components.

The main issues are:

The electronics (battery, LED, light sensor, photovoltaic panel, etc)

• The electronics can best be sourced in one place by canabalizing a solar driveway light (or similar). A friend found Lowe's offers a 12pack for $30. I regret this purchase (more on that later, but basically.. they are too dim, too bad I didn't see this page first, as I think this jar uses the exact same guts). Second, I sourced a single "Fence Light" from Hampton Bay (a Home Depot house brand), for $9.xx. This light has 2 amber LEDs, and two 600MaH batteries. I looked at a couple other lights, and discovered the PV panel wouldn't fit in the mouth of my Slom jars, so I would recommend buying your jar(s) first and bringing to 'eyeball' the fit before buying electronics.

The jar

• I started googling to try and find a source for Mason jars, and quickly realized that the "latch top" jars that work best are not made by Mason. Mason jars have a tin lid. Searching for "hermetic jars" seemed to be the best way to find the right type of jar. Ebay and Amazon both have options, but they are slow, involve shipping costs, and generally offer just a single jar. Ultimately I went for the IKEA Slom, as it's cheap, and even though most IKEA products are a little, um, crappy, I figured it's hard to screwup glass+silicone.

The only issue with the IKEA Slom jar is that it isn't frosted. I assumed I would have to do this myself. Some web sites suggest various methods. Basically, any of the following would work:

1. Rustoleum "frosted glass" aerosol spray
2. Beer + Epsom salts
3. Glass Etching liquid/cream/etc. BE CAREFUL.
4. Sandblasting

I went with #1, because the jar didn't need to contain anything else (so the propensity of the spray to flake off or chip wouldn't be an issue). If the jar needed to contain stuff, especially anything that might eventually be eaten, I'd have gone for the glass etching liquid (which is not only dangerous, but also expensive-- although it can be reused, so the cost isn't that bad over say, 10+ jars).