Publication Date:
2014-10-11
Description:
Biofuels from microalgae are potentially important sources of liquid renewable energy. Algae are not yet produced on a large scale, but research shows promising results. This study assesses the blue water footprint (WF) and land use of algae-based biofuels. It combines the WF concept with an energy balance approach to determine the blue WF of net energy. The study considers open ponds and closed photobioreactors (PBRs). All systems have a positive energy balance, ranging from output-input ratios between 1.13 and 1.98. This study shows that the WF of algae-based biofuels lies between 8 and 193 m 3 per GJ net energy provided. The land use of micro-algal biofuels ranges from 20 to 200 m 2 per GJ net energy. For a scenario in which algae-based biofuels provide 3.5% of the transportation fuels in the European Union in 2030, the system with the highest land productivity needs 3,300 km 2 to produce the 850 PJ per year. Producing all algae-based biofuels through the system with the highest water productivity, would lead to a blue WF of 7 Gm 3 per year, which is equivalent to 15% of the present blue WF in the EU28. However, a complete transition to algae-based transportation fuels will cause increased competition over water and land resources.
Print ISSN:
0043-1397
Electronic ISSN:
1944-7973
Topics:
Architecture, Civil Engineering, Surveying
,
Geography
