Final answer:
The phrase is asking about the number of people at a conference on renewable energy and wants to know if the person knows about it.
Step-by-step explanation:
The correct translation of the phrase '¿Sabes si habrá mucha gente en la conferencia sobre energía renovable?' is 'Do you know if there will be a lot of people at the conference on renewable energy?'
Learn more about conference on renewable energy