How much solar energy do we have?

Solar vs Fossil Fuel
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Solar on Earth

The Earth gets more solar energy in one hour than the whole world used in the year 2012. Of course, humans can’t cover the whole Earth in Solar panels and use all this energy, but the idea brings an interesting question; how many solar panels do we need to power the whole world?

Actually, one scientist says that only 1.2% of the Sahara Desert in Africa could create enough energy to power the whole world. What would be the cost of such a huge project? The scientist said just $5 trillion dollars…. which is a lot of money, but remember it’s less than the amount of money the U.S. government paid banks after 2008-2009.

$5 trillion = $5,000,000,000,000

The table below shows how much energy solar, wind, and biomass could create. Solar is the clear winner. It might surprise some people to see how much solar energy is available compared to wind. The big question is then.. why is solar energy still such a small percentage of renewable energies?

potential energies of wind and solar
Source: Wikipedia

Changing to New Technology

Biofuels create energy when they are burned. There are new biofuels for cars created from vegetable oil, but older biofuels like wood and agriculture waste are easy energy.



Hydropower and wind energy are created by turning a turbine around and around, they use force to generate electricity. These technologies developed earlier and faster than solar panels.

Notice the graph above. ”Wind” and “other renewables” can be seen as early as 1965, but started to grow around 2000. The yellow part for solar is so small it cannot even be seen until about 2010. One big reason is that in the last few years, the technology finally became cheap enough to be profitable… Notice below that the cost of solar energy dropped by about half between 2008 and 2009.

Another reason that solar is developing slowly is that over the last 100 years, huge investments went into fossil fuel energy. The entire transportation industry was built on fossil fuels. Energy companies are extremely powerful, often closely connected with the government, and will take action to make sure their investments stay profitable. For example, Warren Buffet basically stopped Solar City (a U.S. solar energy company) from profitably doing business in Nevada. The change away from fossil fuels to solar energy is a big problem and it won’t happen quickly, but the technology seems to be ready, even if the government and economy are not. Since 2015, small solar farms started by communities have increased. The picture below shows that just under 5% of solar in the world is from smaller community farms.

Solar definitely has huge potential and is growing fast, but how big will it be in the next 10-20 years? It is extremely difficult to answer this question. Every year, professionals try to guess the future of solar energy, every year their guesses change, and every year these guesses are wrong. Truthfully, guessing the future is a difficult job. Maybe using time to build the future would be easier than trying to guess it…