Energy Informative, By Mathias Aarre Maehlum, June 7, 2013
1. Solar has Incredible Potential
If we add the amount of solar energy that is absorbed by the Earth’s atmosphere, land and oceans every year, we end up with approximately 3,850,000 EJ (exajoules or 10^18 joules).
To put it in more understandable terms, this amount of energy is equivalent to:
- 2.7 million earthquakes of the same size as the Tohoku earthquake in Japan (2011).
- 40 000 times the total energy consumption in the United States
- 8 000 times the total consumption in the whole world.
- About 40% of the energy that is required to heat the entire volume of water we have on Earth by 1°Celsius
Unfortunately, harnessing all this energy is not achievable. Here’s an overview that illustrates the potential of solar power more realistically:
The sum of the tiny squares you see on the world-map is the area that is required to cover the entire energy consumption with solar power.
2. Is Solar Power Green?
Let me get one thing clear: Solar power is certainly greener than conventional ways of harnessing energy sources such as fossil fuels and coal.
On the other hand, there are issues regarding manufacturing of the solar panels, as well as disposal and recycling of byproducts. Where does the solar panel end up when it is no longer usable? (Most solar panels for home only have a warranty of 25 years).
Emissions of greenhouse gases do take place during the manufacturing. Dangerous climate gases such as nitrogen trifluoride and sulfur hexafluoride are both on the list. These literally have many thousand times the impact on global warming as an equal amount of carbon dioxide would.
3. Solar Powered Aircrafts!
Yes, it’s true. NASA has been working on a series of solar powered unmanned aircraft since the 1980’s. Pathfinder, Pathfinder Plus and Helios Prototype, is the result of NASA’s efforts to use solar power for long duration high altitude flights.
The Helios Prototype (above) reached a record altitude of 96 863 feet in late 2001, which is the highest altitude reached by an aircraft that is not powered by rockets for sustained horizontal flight.
4. Solar Energy is Nuclear Fusion
Nuclear power is a term we use to describe ways to harness energy through nuclear fission and fusion processes. Conventional nuclear reactors rely on the fission of uranium atoms to produce heat, which we use to generate electricity. Nuclear fission processes releases vast amounts of heat, but is still far from the potential of fusion, the exact same phenomena that powers the Sun (as well as other stars).
Scientists are now working on what can be described as “the holy energy grail of energy”, or how to harness nuclear fusion, and they have been doing so for the last 70 years.
If we are able to tame this power before we reach a century of scientific efforts is uncertain. What is certain is that once we reach this milestone, the way we harness energy will be revolutionized. We are no longer dependent on resources when it comes to energy. Terms like renewable and sustainability will become meaningless. We will move into a new paradigm where knowledge = energy.
5. The Sun is Dying
You probably know that solar energy is considered a renewable energy source. The reason for this is that the electromagnetic radiation emitted from the Sun (also known as sunlight) will be around for us to harness, and will not disappear anytime soon:
According to astrophysics, the Sun was born about 4.57 billion years ago and has another 6-7 billion years before it becomes a white dwarf (a planetary stage where nuclear fuel in the star is exhausted).
Fortunately you don’t have to worry about this. When the hydrogen reserves on the Sun are depleted, it will expand into a red giant, and will likely swallowing the Earth. Luckily we have another 5 billion years before this will happen!