Sahara Desert Not a Viable Source of Solar Power

Sahara Desert Not a Viable Source of Solar Power

In one of my last posts I talked about the math behind using solar power. In the end I concluded that the Sahara Desert could power the earth 211 times over. After sending out this link to a lot of family and friends the number question/objection I received back was, "But putting solar panels in the Sahara Desert is really impractical." I would first like to say that the Sahara Desert was just a comparison point to show that even with a small fraction of the available land mass (all continents have unused deserts) we can power the world.

Now it is quite true that putting a lot of solar panels in the Sahara Desert is very impractical. As my Uncle Steve said, "Who the heck are you going to get to work in the middle of the blazing hot desert?!" And as my sister said, "But how are you going to get all the power all the way back to America?"

But this brings up a very interesting and critical point: this is exactly what we are doing in Iraq, Iran, Kuwait, the UAE and Saudi Arabia this very day. There are apparently many people willing to work in the blazing hot deserts to set up oil wells, and refining stations. Furthermore we are shipping millions of barrels of the oil all the way across the ocean in giant ships. I will also point out that several ships have unfortunately crashed or been sunk in the recent past releasing their cargo onto the beaches of Spain and Alaska (to name a few) creating some of the worst ecological disasters on record.

So even though I do believe that covering the Sahara in solar panels is a bad idea, I also think it's paradoxical that most of the public would react with a similar objection, "It's just too impractical!" We are already going to greater trouble to get oil out of the ground than it would take to install panels in the Sahara and run cables across the Atlantic. Clearly, the best solution is to install high efficiency solar capturing devices on businesses and homes across the world thus eliminating the need for a large scale electrical grid and placing the "power" back in the hands of the people.

update: Since posting the original article 5 minutes ago I read the comments from my friend Ray who says that in China they have cool technology such as: electic bicycles, solar hotwater (he hasn't paid a dime for hot water since he moved there he says), and toilets that flush with the option of 1 liter (for a #2) and half a liter (for a #1). Go China!

The Mathematics of Free Energy

The Mathematics of Free Energy

Some would note that I am a bit idealist about getting off the grid and Green energy. Some might say it's impossible and rather impractical. However, I believe that the mathematics behind it really "adds up". Here's a look at the arithmetic behind it all.

First the energy usage of the world per year: from ecoworld.com we have the following estimated energy usage in 1995:

316,000,000,000,000,000 BTU = 92,614,302,461,899 KW hrs

The math: The sun pumps out 1.3 KW hrs/m^2 of energy in outer space. The actual sunlight hitting the earth's surface varies throughout the year but let's say it averages 40% of the outer space value (which is a little on the low end). The earth has a land area of about 148,939,100 km^2. If we can harness that energy at 50% efficiency (high for existing technologies), then the following tells us how much energy we can catch in one hour on average.

1.3 (kW hrs/m^2)*1000000 (m^2/km^2)*148,939,100 (km^2) * .50 (efficiency) * .4 (amount reaching earth) = 38,724,166,000,000 kW hrs

More simple math shows that in only 2 hours the earth receives enough energy to power it for the rest of the year.

However let's say that we wished to avoid covering the whole earth in solar panels (after all I do like the green grass and nice trees...the minimum land area that we would need to produce to catch the energy required in one year would be:

Lmin = 92,614,302,461,899 KW hrs/(1.3 (KW hrs/m^2)*1000000 (m^2/km^2)* .50 (efficiency) * .4 (amount reaching earth) *24 (hrs/day)*365 (days/year)) = 40663 km^2

Thus with only .02 % of the earth's available land (or presumably oceanic) surface we could generate enough energy to totally power the earth for a year. Even if you factor in an extra 50% energy usage growth since 1995 and another 50% for future usage we would still only need to cover less than .05% of the earth in solar panels.

To put this in perspective, covering the otherwise unused Sahara desert (86,000,000 km^2) with solar panels would generate enough power each year to power 211 earths.

The proof is in the numbers, there is absolutely no reason to keep paying for oil, nuclear or anything else. Let's put up some solar panels, or windmills or invent something even better!