Page 606 - Environment: The Science Behind the Stories

PV solar (Figure 2). Worst were corn The pair concluded that our needs
ethanol and cellulosic ethanol. could be met with a combination of: 1 2 Wind
Is it realistic to think we could Wind with fuel cells
power all our vehicles with wind • 490,000 tidal turbines 3 Concentrated Solar Power
• 5350 geothermal plants
power? Jacobson says yes. He cal- • 900 hydroelectric plants 4 Geothermal
culated that to power all U.S. vehicles • 3.8 million wind turbines 5 Tidal
would require between 73,000 and • 720,000 wave converters Rankings of energy sources 6 PV solar
144,000 5- megawatt wind turbines. • 1.7 billion rooftop PV systems 7 Wave
This sounds like a lot, yet it is fewer • 49,000 concentrated solar power 8 Hydropower
than the 300,000 airplanes that the plants 9 (tie) Carbon capture & storage
United States built during World War II, • 40,000 PV power plants 9 (tie) Nuclear
and fewer than the number of (mostly 11 Corn ethanol
smaller) turbines already erected These researchers judged that our 12 Cellulosic ethanol
worldwide. One reason so few turbines main potential barrier was not the scale 0 9 18 27
are needed is that battery-electric of development but rather the avail- Weighted average of rankings
vehicles make use of power much ability of a handful of rare-earth metals
more efficiently than gasoline-powered in limited supply (e.g., silver, platinum, Figure 2 Jacobson found wind power to
vehicles, so that far less energy is lithium, indium, tellurium, and neo- be the most desirable renewable energy
source overall, and ethanol to be least
required. dymium). desirable. Data from Jacobson, M., 2009.
As his research paper was being Critics of Jacobson’s work have Review of solutions to global warming, air pollution,
published, Jacobson also co-authored pointed to such articles in popular and energy security. Energy & Environmental Sci-
an article in the popular magazine Sci- magazines, and to public speaking ence 2009 (2): 148–173.
entific American with Mark Delucchi of events, to question Jacobson’s objec-
the University of California–Davis, ana- tivity and paint him as an advocate.
lyzing how the world could meet all its Critics who objected to his inclusion disaster in his comparison of energy
energy needs from renewable energy. of impacts from a nuclear weapons
sources pointed out that he has
spoken out against nuclear power in
public forums.
Geothermal Solar Any scientist who steps out of the
Wind Hydro lab, field, or office and advocates pub-
licly for particular solutions is liable to be
criticized by those who disagree with
his or her positions. Whether such criti-
cisms are fair—and whether they are in
40
Power (gigawatts) 30 society’s best interest—are complicated
questions. On one hand, remaining
objective and free of advocacy gives
science its strength and credibility. On
20
advocates to be the people who have
10 the other hand, don’t we want our
studied the issues themselves and are CHAPTER 21 • N E w R ENE wA bl E E NER gy AlTERN AT iv E s
the best informed about them?
Midnight 6 am Noon 6 pm Regardless of how one views the
Time of day recent research by Jacobson and his
colleagues, the number of such energy
Figure 1 intermittent wind and solar power can be balanced with sta-
ble and flexible geothermal and hydropower. This model for California comparisons is increasing, and policy-
shows how such a combination might reliably supply our daily energy makers today have a better and better
needs. Data from Jacobson, M., and M. Delucchi, 2009. A path to sustainable array of information to draw on to help
energy by 2030. Scientific American Nov. 2009 pp. 58–65. chart our energy future.

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