Saturday, August 29, 2009

Powering The World With Solar Panels

CLICK HERE to link to a very interesting graphic showing how much of the world's total surface area would have to be covered in solar cells in order to supply all of Earth's current energy needs.

I don't know the map's ultimate source, but it looks legitimate enough. And even if not completely accurate, it does provide plenty of food for thought. I'm guessing the chart is assuming present-day efficiency with solar cells (the best current commercial models are about 42% efficient); future versions of the technology could greatly improve on efficiency, and require less surface area to produce the same amount of power.

The problem with all of this, though, is cost. Look at the figures; 495,805 square kilometers = 496,805,000,000 square meters. The cost of commercial solar cells today is about $1000 per square meter, so putting up enough solar cells to meet projected 2030 demands would cost $496 trillion--over 30 times the current yearly output of the entire United States economy. Assuming very optimistic cost reductions from mass production in quantity and more advanced, lighter, and cheaper-to-produce solar cells that could reduce costs 100 fold, the total would still hover around $5 trillion dollars. Spread out over 20 years, that's $250 billion a year.

That might seem to some to be a small price to pay for powering the entire world CO2 free, but try convincing any current politician or economist of that, especially with so many more pressing economic issues today.

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