BWE president Hermann Albers said the renewable industry currently employs 370,000 people, which could rise to half a million by 2020. The wind sector alone employs 170,000 people in Germany, he added.
However, Albers said that increase would only happen if the right policies were implemented in Germany and across Europe.
"What we need is an intelligent European industry strategy for renewable energy, and we need a strategy to make trade fair all over the world," Albers said.
He said the industry "will be faster growing and bigger than the German car industry is today".
Albers blamed German policy for the collapse of the photovoltaic industry in Germany over the past two years.
"In the wind industry, [Germany] has five or six companies in the top ten but in PV two years ago it was the same and we lost this position. Today, no German PV company is in the top ten of the world. That is what is going wrong with the policy of the German government."