A major challenge for next decades is development of competitive renewable energy sources, highly needed
to compensate fossil fuels reserves and reduce greenhouse gas emissions. Among different possibilities,
which are currently under investigation, there is the exploitation of unicellular algae for production of
biofuels and biodiesel in particular. Some algae species have the ability of accumulating large amount of lipids
within their cells which can be exploited as feedstock for the production of biodiesel. Strong research efforts
are however still needed to fulfill this potential and optimize cultivation systems and biomass harvesting.
Light provides the energy supporting algae growth and available radiation must be exploited with the highest
possible efficiency to optimize productivity and make microalgae large scale cultivation energetically and
economically sustainable. Investigation of the molecular bases influencing light use efficiency is thus seminal
for the success of this biotechnology. In this work factors influencing light use efficiency in algal biomass
production are reviewed, focusing on how algae genetic engineering and control of light environment within
photobioreactors can improve the productivity of large scale cultivation systems.