A nonplanar solar cell having a water vapor transmission rate of 10−4 g/m2 day or less is provided. The nonplanar solar cell unit comprises a nonplanar substrate, a back-electrode disposed on the substrate, a semiconductor junction layer disposed on the back-electrode, and a transparent conductive layer disposed on the semiconductor junction. A transparent nonplanar tubular casing is disposed onto the nonplanar solar cell. A first sealant cap is hermetically sealed to a first end of the nonplanar tubular casing. A second sealant cap is hermetically sealed to a second end of the nonplanar tubular casing. In some instances, the solar cell unit is a monolithically integrated arrangement of solar cells. In some instances, the solar cell unit is a solar cell.