Modelling a future fuelled by sustainable energy

3 Comments on "Modelling a future fuelled by sustainable energy"

Davy on Tue, 30th Oct 2018 12:33 pm 



“transition from fossil fuels to alternative energy is dependent on their relative productivity”
Yea, but isn’t that a no-brainer?

“Sustainable energy sources such as solar and wind power are potentially limitless, but supply is inconsistent, and they require large amounts of capital investment to make them a viable source”
Well, potentially limitless theoretically but not limitless when one reality tests.

“However, alternative energy substitution can alleviate the negative implications on growth”
I would say to a point alternative energy substitution can allow adaptation to a world of declining net energy. Alternative energy can assist mitigation of a decline that is likely inevitable. This is why it is critical we move in this direction quickly before economic constraints kick in.

“If alternative energy remains less productive than oil, we will suffer falling growth, possibly for a prolonged period, as we are forced to switch to the less efficient alternative.”
In my opinion it is not “if” because alternative energy is not as efficient as fossil fuels in the macro sense. You can cherry pick the situation and data and leave out all those difficult variables and say it is. I would also say “when” we will suffer falling growth. It will not be a “possible” “prolonged period” it will be the end of growth as we know it. As long as our society is structure as an on demand growth driven one without adapting to seasonality and intermittency then alternative energy will be less efficient. It will not replace fossil fuels at the 100% mark. In some locations we may go over the 50% primary energy mark which is exceptional in my opinion. If we were to localize and practice consumption management and population control then maybe alternatives could be incorporated into this adapted way of life and be more efficient than fossil fuels. This is because the waste product and environmental damage would be lower. The question is can our modern civilization change to a less energy intensive and lower population world? I would say no but maybe some locations can.

“If society can improve the productivity of alternative energy in the long run to a level comparable to oil, then the future will be at least as bright as it was at the peak of the economy’s oil dependence.”
I would say in a physical consumption sense humans will never again experience the consumption bonanza of the last half century…never. Yet, it is possible we could actually have a better life with less but this requires different social narratives and mythology. The current paradigm is not conducive to an awakening of the human spirit. The current paradigm is about crushing the human spirit in the blind pursuit of any and all knowledge good or bad at any cost in the name of power, affluence, and stimulation.

makati1 on Tue, 30th Oct 2018 11:51 pm 



Chicken guts readers…er…economists are now experts on techie dreams…er…’renewable’ energy. LMAO!

Antius on Wed, 31st Oct 2018 8:29 am 



Iron powder as a fuel?

https://www.newscientist.com/article/mg18825221-100-powdered-metal-the-fuel-of-the-future/

https://www.mcgill.ca/newsroom/channels/news/could-metal-particles-be-clean-fuel-future-257172

According to wiki, the energy density of iron powder burned to Iron II oxide is 4.9MJ/kg. That is about one eighth the energy density of diesel, but compares well with the energy density of lithium batteries (0.8MJ/kg). On a volumetric energy density basis, iron has about the same energy density as diesel.

Iron powder would be produced by mixing iron oxide with reduced iron in an electric furnace and passing hydrogen through it at 800-1200C. The advantages of using iron as fuel are the ease with which FeO can be recycled back to metal (compared to other metals) using excess renewable electricity; its easy storability compared to hydrogen and it’s reasonably good energy density. Some disadvantages: Having to burn a powder in a boiler to release the energy; relatively poor whole cycle energy efficiency: ~25-40%; the need for mechanical processing – grinding, sorting and mechanical feeds; metal powders can be explosive in air.

The process is unlikely to be used to fuel road vehicles, because of these difficulties. However, its long-term easy storability and density make it a contender for powering large ships and maybe power stations. If iron can be burned within a boiler in a way analogous to a coal burning plant, then it can be used as a topping cycle in thermal energy storage systems. It is possible that the electric furnace and boiler can be integrated on the same site, such that waste heat from the furnace is converted back into electricity within the boiler, with minimal wastage of energy at the production side. The oxygen produced from electrolysis feeding the reduction process can be liquefied or stored in gasometer and used to burn the iron at much higher temperatures. A hybrid plant generating electricity from stored heat and iron combustion, could have an overall efficiency of 50%. Not as efficient as pumped storage, but much more energy-dense and independent of topographic considerations.