Hubble was originally launched with two large solar panels, which were sufficient to power its instruments and systems. These solar panels remain in operation today, providing the necessary energy for the telescope.

However, Hubble has undergone several servicing missions, where astronauts have replaced and upgraded components, including the solar panels themselves. For example, during the Space Shuttle mission STS-109 in 2002, the original solar arrays were replaced with new, more efficient ones. These new panels generated more power, allowing Hubble to run its instruments for longer periods and perform more demanding observations.

So, while Hubble did receive new solar panels, it was not due to a necessity for an additional panel, but rather an upgrade for improved performance.