The algae are still not as efficient as photovoltaic. Surely farmland too marginal for crops could be converted to solar energy harvesting . It is estimated that an area the size of the Northern Territory covered in solar collectors could provide the world with all its enegy needs . We better get in first before the Africans cotton on to use the Sahara for the same purpose
. Mass production of collectors would bring the cost per kilowatt hour below current polluting coal and just think of those juicy carbon credits and slightly clearer skies
.