I was reading this article and I thought: what if bacteria could designed with every sunlight-capturing pigments —this rare form of chlorophyll, “green” chlorophyll, beta-carotene, etc.— to capture the widest possible light spectrum? It would be able to convert an absurd proportion of sunlight energy into chemical energy. If this was coupled with an up-regulation of the fatty acid synthesis pathway, then these bacteria would be used to directly convert light energy into oil at a very high efficiency.
Unlike existing plant alternatives, the raw bacteria oil would be a transportable, near-end product that would save us from having to invest in an extensive new refining and transportation infrastructure. Even better, the bacteria could be hypothetically grown anywhere: massive hydroponic plants in the desert, miniature hydroponic tiles on buildings, even on Antarctic ice or quarantined open ocean.
Certainly, this bacteria would be far more efficient than terribly energy-inefficient, agriculturally-exhaustive corn ethanol or dangerous, difficult-to-transport hydrogen.