There is a dream that natural flows of solar and wind energy can replace and transition from fossil fuels — transition to an equivalent lifestyle. A dream so strong, it is as a religion for some — a dream that hits the wall of reality.
If a source of energy costs as much energy to produce as we get from it, it is a dead end. This is called “energy return on energy invested” (ERoEI). ERoEI is one important measure. Solar hot air, photovoltaics and ethanol are all marginal or even negative. They hardly replace the energy they take to manufacture, transport and maintain the equipment. Wind is a better option using this measure.
A second piece of the hard wall of reality is that all the devices needed to capture the wind or sun are extensions of the fossil fuel supply system. It takes an industrial infrastructure to mine, refine, process, manufacture, transport, install, maintain and replace the devices needed to capture the sun or wind.
These devices do not make enough energy to reproduce themselves. In essence these devices are not renewable. Even if they could squeak out enough energy to reproduce themselves, they couldn’t go on to reproduce the goods needed by society.
The hard wall of truth is that the fossil fuel/industrial infrastructure is simply not green, so considering this approach, green is an illusion. The whole system, from the mining to the various toxic chemicals to transportation, is simply “business as usual.”
And it is critical that the process be considered as a system and not the isolated component on the wall or roof.
Unfortunately, this is a 20th century dream in the hard financial and environmental reality of the 21st century.