174 petawatts (PW) of energy comes in form of solar radiation (or insolation) hits our atmosphere. Almost one third of this is reflected back into space. The rest, 3 850 000 exajoules (EJ) every year, is absorbed by the atmosphere, clouds, oceans and land – one hour of insolation is the equivalent to more than the world’s energy consumption for an entire year.Solar energy is by far the largest energy resource on the Earth.
Here are some other interesting comparisons to help make you grasp the massive potential of solar energy:
- One year’s worth of solar energy reaching the surface of the Earth would be twice the amount of all non-renewable resources, including fossil fuels and nuclear uranium.
- The solar energy that hits the Earth every second is equivalent to 4 trillion 100-watt light bulbs.
- The solar energy that hits one square mile in a year is equivalent to 4 million barrels of oil.
In comparison, only 1% of the electricity consumption in the U.S. can be sourced back to the United States. This number is steadily growing and is expected to help replacing fossil fuels in the long run.
Intermittent Energy Source
Unfortunately, far from the entire solar energy potential is exploitable. Solar is an intermittent energy source, which means that it is not available all the time – sunlight always hits the surface of the Earth, but due to the fact that the Earth rotates around the Earth, solar energy is not available on one single location day and night.
You are probably wondering how big the potential of solar power is (converting solar energy into electricity). Estimating this potential largely depends on what factors are taken into account. It is important to realize that solar power isn’t feasible in many areas of the World due to low cost-competitiveness. Luckily, by the help of government and state incentive, costs are decreasing.
Here’s an overview over how much area has to be covered in photovoltaics (solar cells) to cover the entire World’s energy consumption (based on an assumption of an electricity conversion rate of 8%):
Image credit: Wikimedia Commons
Read more about the potential of solar energy in Solar Energy Pros and Cons.