Marcus Jentsch will take up the position from 1 February after Juwi's supervisory board unanuimously approved his appointment. He has been heading up the finance and investor relations department at MVV Energie since 2010.
Last October, municipal energy company MVV Energie agreed to take over 50.1% of the struggling wind and renewables developer.
Jentsch will be tasked with bringing the company back to financial health after it was hit hard by the collapse of the German solar market causing its revenue to fall 30% in 2013.
Juwi was forced to cut 400 jobs and reduce its operations outside its native Germany due to what it called "upcoming changes in the energy markets" in July 2014.
Earlier in January, independent renewables company Neoen acquired Juwi's French subsidiary and its 180MW of renewable energy projects in the country.