Which of the following is a source of electrical energy on boats?

Batteries are a primary source of electrical energy on boats because they store and supply the necessary electrical power for various systems and equipment onboard. These systems may include navigation lights, communication devices, bilge pumps, and electronic accessories. Batteries are versatile, allowing for the flexibility of usage while under way or at anchor, and they come in different types such as lead-acid and lithium-ion, each suited for specific applications.

While wind power, solar panels, and hydroelectric generators can also be sources of electrical energy, they are not as universally applicable or fundamental as batteries on all boats. Wind power relies on consistent wind conditions, solar panels depend on sunlight, and hydroelectric generators are typically not practical on vessels. Thus, batteries represent the most straightforward and commonly used method for providing electrical energy in marine settings.