Researchers from the University of California-Davis and Stanford University have published a study that details one scenario to completely convert the world to clean, renewable energy sources – and they say it could be done in 20 to 40 years using technology available today at costs comparable to fossil fuel-based energy.
Electricity the key
The two part paper coauthored by Stanford researcher Mark Z. Jacobson and Mark Delucchi, of UC-Davis, evaluates not only the technology required, but also the costs and material requirements for converting the planet to renewable energy sources. Their plan would see the world running predominantly on electricity, with 90 percent of this sourced from wind and solar. The remainder would be made up from geothermal and hydroelectric sources, which would provide around four percent each, while wave and tidal power would contribute the remaining two percent.
For our transport energy needs, cars, trucks, motorbikes, ships and trains would be powered by electricity and hydrogen fuel cells, while aircraft would be fueled by liquid hydrogen. Commercial processes would also be powered by electricity and hydrogen, which would be produced using electricity. Meanwhile, our homes would eschew natural gas and coal in favor of electric heaters, while water would be preheated by the sun.
20 to 40 years
“We wanted to quantify what is necessary in order to replace all the current energy infrastructure – for all purposes – with a really clean and sustainable energy infrastructure within 20 to 40 years,” said Jacobson.
To that end, the plan would see all new energy generation coming from wind, water and solar by 2030, and all pre-existing energy production converted by 2050. The researchers say that the millions of lives saved by the reduction in air pollution and a 30 percent reduction in world energy demand – thanks to the conversion of combustion processes to the more efficient electrical and hydrogen fuel cell processes – would help keep the cost of such a conversion down.
“When you actually account for all the costs to society – including medical costs – of the current fuel structure, the costs of our plan are relatively similar to what we have today,” Jacobson said.
Addressing variability of solar and wind
To overcome that variability of wind and solar and ensure there is a reliable base load of energy Jacobson says wind, water and solar energy sources could be combined as a single commodity as they are generally complimentary. Solar peaks during the day, while wind generally peaks at night, and hydroelectric could be used used to fill the gaps.
The plan also envisages the connection of geographically diverse regions using long-distance transmission to overcome energy shortfalls in a given area. If the wind or solar energy generation conditions are poor in a particular area on a given day, connecting widely dispersed sites would allow electricity to be provided from a few hundred miles away where the sun is shining or the wind blowing.