Renal agenesis. Renal agenesis is a medical condition in which one (unilateral) or both (bilateral) fetal kidneys fail to develop.
Polycrystalline cells are composed of multiple silicon crystals, which is a cheaper way to manufacture solar modules. Put simply, these cells are easier for a factory to produce, so they are less expensive. Polycrystalline cells are made by several methods, but most commonly with a cast of molten silicon.
Monocrystalline vs Polycrystalline solar panels. The typical monocrystalline solar cell is a dark black colour, and the corners of cells are usually missing as a result of the production process and the physical nature of monocrystalline silicon.