What do transformers convert in a photovoltaic system?

Transformers in a photovoltaic system are primarily used to change the levels of voltage and current to optimize the transmission of electricity over distances. When solar panels generate electricity, they typically produce direct current (DC) at a low voltage. In many cases, this DC must be converted to alternating current (AC), which is usually done with inverters, rather than transformers directly.

However, once the voltage has been converted, transformers can be employed to increase voltage for efficient transmission. This process is crucial because higher voltage is preferable for reducing energy losses over long distances. Therefore, the correct understanding regarding transformers is that they convert low voltage and high current to high voltage and low current. This transformation allows for the electricity generated from solar energy to travel efficiently through power lines to consumers.

The other options present different scenarios, some of which do not accurately reflect the role of transformers in photovoltaic systems. For instance, directly converting low current to high current, like in option D, isn't the primary function of transformers as they are focused on voltage levels rather than the current alone. Thus, the functionality of transformers in the context of photovoltaic systems is best captured by the conversion from low voltage high current to high voltage low current.