Algae Could Light Up Our Cities at Night

Proper lighting at night is important for safety in cities and along highways, but all of those lamps require a lot of electricity to keep them going all night. Many places have transitioned to LED lighting, the most energy efficient lighting currently available, to cut down on the energy use of street lamps, but a renewable energy source for the lighting would be ideal.

Researchers at the Technical University of Denmark think there is an even better solution; one that requires no electricity at all but could still illuminate city streets: algae.

Bioluminescent microalgae exist throughout warm parts of the world's oceans. The source of the bioluminescence is two molecules: luciferase (an enzyme) and luciferin (a molecule produced by photosynthesis). These molecules are activated by a chemical reaction triggered by movement such as the crashing of waves upon the shore or a passing fish.

When this reaction occurs, the algae emit a blue light, but it's only for a moment.

Phil Gibbs/CC BY-NC-ND 2.0

The research team believes that the genes for bioluminescence could be isolated and then transferred to other, larger plant organisms that could be used to provide a continual source of blue light at night. An algae-based lamp would work like a solar cell and battery storage combo where solar energy during the day is converted into fuel for the organism which it stores and then uses to emit blue light at night.

If this gene transference can be done, these bio-lamps could be used to light up parking garages, buildings, shop windows and highways. The resulting light will be a bluish hue, which will change the way our cities and towns look at night but it will also be an electricity-free and carbon neutral source of light.

The researchers are trying to identify those genes that cause bioluminescence. The next step would be figuring out how the transfer those genes and then cause the plants to emit light continually during the night and without the trigger of movement.