Which component most closely compares to the output of a solar cell?

The output of a solar cell is typically characterized as a direct current (DC) voltage that is produced from sunlight exposure. Among the options provided, the NiCad (Nickel-Cadmium) battery most closely compares to this output.

NiCad batteries are rechargeable and known for their ability to deliver a consistent voltage output over their discharge cycle, similar to how solar cells produce a relatively stable voltage output when exposed to light. They can also be charged with various power sources, including the output from solar cells.

In contrast, lead-acid batteries, lithium-ion batteries, and supercapacitors have different discharge characteristics, efficiencies, and charging requirements that do not align as closely with the output nature of a solar cell. Lead-acid batteries are heavier and are primarily used for higher capacity applications, while lithium-ion batteries offer higher energy density and charge/discharge efficiencies. Supercapacitors are designed for rapid discharge and charge cycles, providing short bursts of power rather than a steady voltage output, making them less similar to a solar cell in this context.

Thus, the similarities in functionality and application make the NiCad battery the best comparison to the output of a solar cell.