evnow wrote:Every time a we changed the energy source in history - we have always gone from lower energy density to higher.
But when we try to move from oil - we would be doing it the otherway. From a very high energy density to a low density energy store (battery) and a very diffuse source of energy (wind/solar etc).
I'm not sure I agree with the comparison between oil and battery. I'll have to think about that a bit more.
Ok... Oil is only an energy carrier, not an energy source - just as hydrogen and batteries are carriers. From that viewpoint, I think looking at energy density with regards to fuel transition is just a distraction. It does apply to range between fillups, though! But even that paradigm can be broken by installing coils in roads to inductively charge EVs while they drive down the interstate - or by using electric trains that carry us long distances while recharging the EV.
We absolutely need energy - and that need will keep growing. But we already know that we can get more than we need from PV and solar/thermal. We can get more from wind, tidal, biomass, and other means. We can store the energy in batteries, underground compressed air storage, by pumping water uphill, and by electrolyzing water to make hydrogen. Other methods will be invented, and current methods will be made more efficient. We can use these today to provide the energy we need even if we stick to our current level of energy use.
We've had class-8 trucks on the road since the late 1970s that cut fuel use 20% thru aerodynamics alone
. We have home building methods that cut energy use by over 40%. Our land fills generate millions of cubic feet of methane each year but most of that goes into the atmosphere - that's basically free hydrocarbon energy that we're not only not using, but by allowing it to escape we're adding a green house gas. That methane can be used directly and can be converted to liquid fuel.
edit... Just found this...Really Encouraging!
"Over the past few decades, the U.S. and many other countries have shown that the supposedly iron link between energy growth and economic growth can be not just reduced but reversed. In 2006, America’s absolute use of total energy, oil, gas, and coal even went down, because energy intensity fell more (3.32 percent) than the economy grew (2.78 percent).
Today America enjoys more than doubled GDP, but consumes one-half less energy and oil, two-thirds less water and directly used natural gas, and 18 percent less electricity to make a dollar of GDP than in 1975.
While directionally correct, this trend is not yet strong enough. The U.S. is still an incredibly energy-intensive society.
Denmark just grew its economy 56 percent without using more energy. Japan wrings 2–3 times more work from its energy than the U.S. does, yet has shown how to triple energy productivity again.
Reinventing Fire requires unlocking the full potential of energy efficiency."