When we think of solar energy, we tend to picture shiny, bluish-silver photovoltaic cells, lined up in intricate patterns over enormous surfaces, all laid out in the heat of beating sunlight. These solar arrays may look cool, but the technology they employ is quite expensive and, in the end, not very efficient.
Mother Nature herself, as it turns out, does a much better job dealing with the energy available in sunlight. So what if we could employ sunlight the way nature does? What if we could use photosynthesis to create a better, more efficient and more versatile type of solar energy than current technology allows?
Researchers have recently found a way to alter the photosynthetic process so that its chemical reactions produce liquid hydrogen, which can be used in turn to create energy — and ultimately the electricity that powers all our stuff.
Using hydrogen as a fuel isn’t a new idea; it’s a proven energy source. The problem is making enough liquid hydrogen for it to be viable on a large scale. Producing pure hydrogen, which is extremely rare on Earth, is now energy- and time-intensive. Photosynthesis produces hydrogen naturally by using sunlight to break water molecules (H2O) into hydrogen and oxygen. If we could harness this natural process, we could produce hydrogen cleanly and abundantly.
England’s Daily Mail recently reported that a team at Australian National University created a protein that, when exposed to light, displayed a process similar to that of a plant’s leaves. It replicates “the primary capture of energy from sunlight” needed to break down H2O. The great thing about this protein is that, unlike hydrogen, it is naturally occurring, so doesn’t require lots of expensive raw materials to create.
The resources needed to produce hydrogen this way are the same as those in photosynthesis: water and sunlight. This opens the technology to possible widespread use in developing nations, where exotic raw materials and expensive technology aren’t easy to come by.
Moreover, photosynthesis doesn’t produce carbon, which makes it much better for the environment than current fossil fuels. The already available technology for turning hydrogen into electricity is also carbon neutral. So, overall, photosynthesis-aided hydrogen power would be a great breakthrough for the environment.
Despite the recent advances, the technology isn’t quite where it needs to be — not yet, anyway. As with all solar-based energy, making efficient use of the photons available in sunlight is a challenge. Stability is another issue in this process, which requires some sort of catalyst to get the sunlight to break down the water molecules. These catalysts can be either organic, like the naturally occurring protein used by the Australian team, or inorganic, like various metal oxides.
The problem with organic catalysts is that they tend to wear out over time. What’s more, they often wind up damaging photosynthetic cells through secondary effects they generate. Metal oxides, on the other hand, seem less efficient than organic catalysts, and they aren’t as wonderfully abundant as sunlight and water.
Given these and other difficulties, an efficient, widely available and carbon-neutral photosynthetic technology isn’t just around the corner. But it is a real possibility — sometime in the next decade.
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