The world – all its industry and transportation and housing, its televisions, air conditioners, computers, wine chillers, CAT scan machines, electric foot massagers, you name it – won’t be powered entirely from renewable sources by 2030. The numbers vary, but most estimates are in the neighborhood of 14 percent or maybe 18 percent. That’s an important point to keep in mind when considering the study done by Mark Delucchi and Mark Jacobson that details a scenario for getting to 100 percent renewable energy within 20 years.
The study itself in the journal Energy Policy is behind a pay firewall, but a write-up on Physorg.com outlines what the researchers say such a transformation would involve: four million new 5-megawatt wind turbines; 1.7 billion 3-kilowatt roof mounted solar systems; and 90,000 300-MW solar power plants, for starters. (To put that last number in perspective, consider that the United States is struggling to approve and construct perhaps a dozen such large-scale solar plants in the next few years.)
What’s even more remarkable is that Delucchi and Jacobson didn’t count biomass, currently the world’s biggest source of renewable energy, as a contributor, due to its potential adverse impacts. Nuclear, as well, was not included. Instead, they focused strictly on wind power, solar power, wave power and geothermal power.
Ignoring political realities, according to the Physorg.com article, the study authors believe their scenario is possible and affordable. A big hurdle, however, would be weaving together what are highly variable sources in order to fit supply to demand. That’s where sources other than solar and wind would come into play. “The more consistent renewable sources of wave and tidal power and geothermal systems would supply less of the energy,” Physorg.com wrote, “but their consistency would make the whole system more reliable.”