So much noise surrounds the promotion of various green energy technologies that it's great to see independent assessments of these alternatives.
Now, two of our top minds tackle this task with mountains of data and calculations that tend to confirm what we already know.
Jacobson's purpose is to "review and rank major proposed energy-related solutions”, while McKay guides us around the “claptrap” to actions that really make a difference and to policies that add up.
Jacobson looks at twelve combinations of energy sources and vehicle type, in order to "place electricity and liquid fuel options on an equal footing"through a thorough assessment that looks at global warming, air pollution, and energy security while considering impacts on water supply, land use, wildlife, resource availability, reliability, thermal pollution, water pollution, nuclear proliferation, and undernutrition.
In Jacobson's overall rankings of the combinations, wind-powered battery-electric vehicles (BEVs) came out so far ahead that other options like corn ethanol (E85) vehicles are forgettable...down near the bottom of the list, along with cellulosic ethanol and coal with carbon capture.
"The results suggest that the diversion to less-efficient (nuclear, coal with carbon capture) or non-efficient (corn- and cellulosic E85) options represents an opportunity cost that will delay solutions to global warming and air pollution mortality."
McKay stacks up the UK's energy consumption of 195 kWh per day per person against its potential green energy production of 180 kWh/d/p.
A close race, you might say, except McKay admits his production estimates throw all economic, social, and environmental constraints to the wind. For example, McKay has both PV and solar hot water competing for British rooftops.
"Realistically, I don’t think Britain can live on its own renewables – at least not the way we currently live. I am partly driven to this conclusion by the chorus of opposition that greets any major renewable energy proposal. People love renewable energy, unless it is bigger than a figleaf."
McKay worries that "we won’t actually get off fossil fuels when we need to. Instead, we’ll settle for half-measures."
Jacobson likes wind, yet McKay doesn't think there's enough of it for America (considering NIMBYism). Go figure!
So, the good news is: we can see a way out. The bad news is: we're standing in the way.
According to McKay, America should "go immediately for a technology that adds up: concentrating solar power." McKay estimates that all of North America could be powered by CSP on an area the size of Arizona (a square roughly 370 miles on a side).
Oh, and, McKay gets cute when considering America's challenge:
"The average American uses 250 kWh/d per day. Can we hit that target with renewables? What if we imagine imposing shocking efficiency measures (such as efficient cars and high-speed electric trains) such that Americans were reduced to the misery of living on the mere 125 kWh/d of an average European or Japanese citizen?"
Still, both scholars' perspectives are vital to our decision-making on energy technology and policy:
Says McKay: "Make sure your policies include a plan that adds up!"
Says Jacobson: "Don't divert your energy policy on technologies that won't get you there."