I like questions. I remember in the 4th grade school science class, my teacher, a very dignified and self-composed middle-aged woman with very limited eyesight and patience taught us about food chains and energy transfer. I listened, fascinated, about how plants rely on energy that they receive from the sun in order to make their food, and then the primary consumers such as cows eat the plants and finally we, the secondary consumers eat the cows. One thing she said struck a chord in me. She mentioned that as we went down the chain from plants to humans, there was a significant loss of energy. Why, I asked, could we not simply use the solar energy to make our own food like the plants and save the energy from being wasted? This was only the 4th grade, and words like photosynthesis and chlorophyll weren’t part of my vocabulary as yet. Apparently they didn’t exist for my science teacher either, because instead of explaining respiration versus photosynthesis, I was asked to stand up and hold my hands in the air for asking such a rude and insolent question to which there was no apparent answer.
But the question of solar energy being harnessed, although asked in the wrong context by my 4th grade self, is now being asked on a daily basis, and billions of dollars, yuans, rupees and dirhams are being spent in answering it. Instead of food, solar energy can be utilized to produce power and electricity. But is this a green myth or a green miracle?
It is a bit of both, with the line in between not clearly visible. Most articles will rant about how the Earth receives enough solar radiation to meet all of our current energy needs hence we should ‘shift immediately’ to solar power and stop burning fossil fuels which are non-renewable and detrimental to the environment. While it may be true that the earth receives enough solar energy in a couple of hours to meet the current annual power consumption of the entire planet, we do not however currently possess the technology to extract and convert this energy efficiently enough to make the ‘immediate shift’ feasible.
The key word here is ‘currently.’ Harnessing solar energy from photovoltaic cells is a reality, and the 14 MW (Megawatts) Nellis Solar Power Plant in Nevada, USA and the 10 MW plant in Abu Dhabi, UAE are proof that this is happening all around the world. India recently announced that it is working towards adding 20 GW or Gigawatts (For those of you who missed physics class, Giga is 109 watts while Mega is 106 watts) of solar power within a decade’s time. So some people will enjoy this clean energy, but it is still not going possible for all everyone just as yet.
This has to do with the efficiency of the process itself and the technology to do the conversion of solar energy into usable electricity. This is currently priced between 20-25 US cents per KWh (approx. 73-91 fils per KWh) compared to the 2011 UAE electricity prices of 5 – 38 fils per KWh (disparity is due to different rates for commercial/residential/industrial and consumption thresholds etc). At the moment, the cost does not seem worthwhile as getting power from solar energy is way more expensive than the current system of electricity production from burning fossil fuels.
However, in a conference in late November 2010, a director from BP Solar commented that the cost of generating power from solar energy will fall by around 10% every year until in a decade’s time, it will equal the cost of fossil fuel based power generation.
Now that is when the line between myth and miracle will be clear, and the choice to depend on a cleaner means of producing electrical power will be ours.
by: Razib Khan