Coming soon: 100% renewable power

By Chris Nelder | December 12, 2012

One day in the not-too-distant future — probably sooner than many expect — some parts of the world will have power grids that are completely powered by renewables. Eventually, the entire world could be powered by renewables.

These are not green pie-in-the-sky fantasies, but the conclusions of recent research.

There is no doubt that renewable resources are positively vast. Solar alone could power the world: The solar energy that falls on the Earth every minute is more than the amount of fossil fuel the world uses every year. Wind alone could provide about 15 times the world’s energy demand. The recoverable geothermal heat under the U.S. is about 140,000 times its annual energy consumption. Wave power alone could supply twice as much electricity as the world consumes.

Capturing that energy, and being able to use it to power everything, is the hard part.

Probably the most ambitious attempt to quantify that challenge to date has been done by Mark Jacobson and Mark Delucchi of Stanford University, who have published a series of papers over the past several years outlining how it could be done. In 2010, they published two papers (Part Iand Part II) estimating how the world’s energy demand for all purposes — including electric power, transportation, heating and cooling — could be met with renewables by 2030, and replace the existing energy generation mix by 2050:

• 3,800,000 5-MW wind turbines
• 49,000 300-MW concentrated solar plants
• 40,000 300-MW solar PV power plants
• 1.7 billion 3-kW rooftop PV systems
• 5,350 100-MW geothermal power plants
• 270 new 1300-MW hydroelectric power plants
• 720,000 0.75-MW wave devices
• 490,000 1-MW tidal turbines
• Storage in grid-connected electric and hybrid-electric vehicles
• Increased grid transmission capability

(A quick word on units: A kilowatt, or kW, is 1000 watts. A megawatt, or MW, is 1000 kW. A gigawatt, or GW, is 1000 MW.)