This workshop was held in conjunction with ExCo64 in Liege, Belgium on 1 October 2009. At the workshop presentations were given by 8 invited speakers and consisted of four sessions as follows: Session 1: What's the overall state-of-the-art for the different feedstocks and technology options? Session 2: Marine macro-algae Session 3: Micro-algae in open ponds Session 4: Micro-algae in closed systems