Why have algae generated excitement and attracted research investment in recent years? Like all green plants, algae contain chloroplasts in their cells. These tiny structures are charged with chlorophyll, a molecule that uses light energy to combine carbon and water into a simple sugar. The cells further transform some of these sugars into proteins and lipids or oil.
But if algae are doing the same thing as corn, wheat and apple trees, why bother raising them? After all, corn on the cob, sweet rolls and apple pie taste better than seaweed to most of us. Here are some of the things algae have going for them:
- Productivity: Algae are super fast-growing. Land plants take months or years to reach maturity. Algae can complete their entire life cycle in a single day. Some algae can double their biomass in just an hour [source: Jha].
- Efficiency: When it comes to converting solar energy to biomass, algae are all business. Because they're supported by and take their nutrients directly from water, they need no roots, stems or flowers. Land plants use as much as 95 percent of their energy building the structures they need for support, feeding and breeding [source: Edwards].
- Concentration: Because of their efficiency, algae can be grown in a very concentrated space. They produce up to 100 times more oil per acre than land plants [source: Edwards].
- Versatility: It's estimated that there are more than 70,000 species of algae, many of them not yet classified [source: Guiry]. Growers can pick ones suited to conditions and goals, selecting varieties for a specific temperature range or water salinity, for example.
- Non-competition: Algae don't compete with current crops for land or fresh water. They can be grown in ponds in locations, like deserts, that don't sustain land plants. Some varieties prefer saline or polluted water.
Attracted by all these advantages, algae cultivators have been working diligently to come up with efficient and economical ways to grow and harvest the plants. The cost factor is currently the great challenge that must be overcome to make algae commercially viable.