An evolution to solar power
1. How Solar Power Has Evolved Through Centuries
- Solar energy has been dubbed as the perfect energy source to build the future human civilization. And considering that it promises to be a source of never-ending, renewable energy, it is easy to understand why futurists regard solar power with great hope. But unlike what many believe, humans have actually been tapping solar energy from ancient times, though in a different manner.
2. The Ancient Period
- One of the first records for solar energy utilization are by the Greeks. It is estimated that they used multiple mirrors to focus sun’s rays to light fires for religious ceremonies. This trick was also used in a battle by Archimedes who burnt down enemy ships by focusing sunlight through bronze shields. Greeks are also known to have used a special arrangement of mirrors to increase the light and heat inside their homes. And for most of history, the use of sun’s energy has largely been limited to such thermal applications.
3. The Photovoltaic Silicon Solar Cell
- In 1839, a French scientist found out that certain materials were able to conduct electricity when exposed to sunlight. This discovery led to the invention of the photovoltaic (PV) cell.
Most of the solar cells in the market today are made from silicon, primarily crystalline silicone. Unfortunately, the efficiency of silicon-based solar cells are only around 15%. This essentially means that the cell is unable to convert about 85% of the sunlight it receives into electricity. It is this drawback that has made scientists look for other solutions.
A major breakthrough has been in the development of multi-junction cells. These are similar to the existing silicon-based PV cells. But there is a big difference between the two – multi-junction solar cells have multiple layers, each of which are fine-tuned to a specific wavelength. This has increased the efficiency rate to over 40%. On the downside, the extra layers and materials used in the creation of multi-junction cells make it very expensive. This has kind of stalled any interest in such solar cells, with the market comfortable using the regular silicone PV cells.
4. Artificial Leaves
- A cutting-edge research being conducted at the University of Illinois in Chicago aims to develop ‘artificial leaves’ that use sunlight to convert the carbon-dioxide in the atmosphere into a gas. This gas can then be used directly or be further transformed into other types of fuels. If the research turns out to be a success, we could all be firing up our cars and cooking food from fuel that is generated from artificial leaves placed on the rooftop.