Background According to the European Environment Agency, energy consumption accounts for 80% of all greenhouse gas (GHG) emissions in the EU. It is one of the primary risk factors for climate change and for most forms of air pollution. The EU is committed to reducing GHG emissions to a level that will contribute to limiting the global temperature increase to 2°C above pre-industrial levels (European Commission COM(2007)1). Biofixation of CO2 by microalgae has been the subject of extensive investigations in the U.S., Japan and Europe (IEA-GHG Biofixation Network). In particular, researchers have examined its potential application in the treatment of flue gases from power plants. However, no projects have yet successfully demonstrated the feasibility of this concept at a pre-industrial scale. In previous pilot projects, the CO2 fixation efficiency - whether in open and raceway ponds or in enclosed photobioreactors - has always been quite low. Objectives The key objective of the CO2ALGAEFIX project is to demonstrate, at a one hectare surface scale, an efficient way to capture CO2 from stationary sources (in this case, a power plant that uses natural gas). It aims to demonstrate that CO2 emissions can be used as a substrate for biomass algae production. The project will use a 10 000 m2 pilot plant constructed by Algaenergy for experiments in microalgae cultivation. It aims specifically to test and demonstrate a new photobioreactor concept based on flat panels as the basis for a highly efficient large-surface culture plant. The process proposed will include novel technologies to capture and concentrate CO2, and make it available for culturing microalgae. Through ongoing evaluation and optimisation of the pilot plant’s design, and its connection to the CO2-generation plant, the project hopes to achieve increased CO2 bio-fixation and the photosynthetic efficiency of microalgal cultures. The 1 ha demonstration plant is expected to capture and fix more than 200 tonnes of CO2 per year. If successful, the technology should easily scale-up to industrial level. CO2ALGAEFIX will also evaluate possible uses of the microalgae, for example, in the production of energy, or in the production of valuable compounds for different economic sectors. Expected results: Successful operation of a demonstration plant for microalgae culture using CO2 from stack gases; Optimisation of the plant’s operation to achieve productivity in excess of 200 tonnes of algal biomass per year; Valorisation of microalgal biomass in a variety of sectors, including aquaculture and agriculture.