Our energy dilemma The hydrocarbon economy is faltering as oil reserves dwindle worldwide (Hirsch, 2008). Commodity prices have begun to fluctuate drastically due to the uncertain cost of petroleum, which resulted in food riots around the world in 2008. With a steadily decreasing energy supply and the demands on energy systems continually growing, the planet is in dire economic, geopolitical, and environmental straits. In order to halt the advance of climate change, prevent ecological collapse, rescue the global economy, and ensure our energy security, humanity must find a way to harness currently available (non-fossilized) energy. The largest source of energy on Earth, excluding the future potential for thermonuclear fusion reactors, is the sun. Human civilization consumes 15 TW annually while approximately 80,000 TW of solar energy fall on the Earth’s surface each year (Makarieva et al., 2008). For hundreds of millions of years, this solar flux has been the driving force for life on Earth. It is estimated that photosynthesis absorbs and distributes seven times more energy to the biosphere (~100 TW) than is consumed anthropogenically each year (Makarieva et al., 2008). There are many promising technologies in development that will cheaply harness solar output, like next generation photovoltaics, advanced wind turbines, tidal power systems, wave energy generators, solar thermal collectors, biofuels, solar fuels, electrofuels, etc. In the end, some combination of these solutions, coupled with improved energy and transportation infrastructure, will be needed to resolve our energy dilemma. In this article, I focus on cyanobacteria and their potential for hydrogen production, which, if properly developed, could provide sustainable fuel for transportation and industry in a post-petroleum world.