A water-miscible solvent of 1,2-dimethoxyethane was found for efficient extraction of algal oil from wet cells of Botryococcus braunii. The volumetric ratio of the extractant to water in the wet algal biomass affected the extraction efficiency at a fixed ratio of solvent to dry algal biomass, and a high algal oil recovery above 96% was achieved when a volumetric ratio of 1,2-dimethoxyethane to water in the wet algal biomass was more than 6.5:1 (v/v). An energy cost analysis indicated that the water content reduction of the wet algal biomass in the algal harvesting process had a great impact on energy saving. (c) 2012 Elsevier Ltd. All rights reserved.