ENERGY, STUPID....

There is too much hysteric noise about energy&climate in the world media now that any reasonable arguments could be heard , or even better - considered.

For a seasoned power engineer , who - when closing his eyes in free time - sees a high pressure carbon-fibre tank's (type IV, as used for H2) stress areas ( where bottom joins the cylindrical part) in red under computer simulation , many things are so obvious that he can only observe these decades - long discussions with amazement of a naive child.

Journalists , politicians and general populace talk about energy needs mostly in categories of electricity. Partly ,they are right. This is the shape of the world we have built over XX-century. But deeper consideration of basic human needs show , that we need actually 2 other forms of energy more: heat (for keeping us warm in the winter and cool in the summer) and motive/mechanical energy (for moving us&our vehicles or our industrial machinery). Whereas we could easily survive without the electricity, we almost could not without heat or movement.

Telling how much exactly we need of each of these 3 is a bit difficult, as currently we co-generate (good) and co-utilize them (less good). But if we imagine the world where they are produced and consumed independently, then the proportion would be , roughly as: electricity - 10% (for lighting, computing and communication); heat and motive power ca 45% : 45%.

Now , how to produce them safely, economically and with minimal GHG-emmission?

Electricity is the easiest case: solar, wind , hydro and some storage , which - for this tiny percent - is not a big issue.

Heat (or cold, which is exchangeable term,over absorption cycle) is a bit more difficult, but not much : distributed , underground , medium-size , hermetic nuclear reactors ("thermal pills" )could solve this problem quickly for towns, villages, districts;except for very few lucky enough to have shallow geothermal nearby. Unfortunately, transporting heat over distances of more than 100 km or storage of more than 100MWth/unit becomes prohibitively expensive.

Motive/mechanical power is the hardest case. For vehicles, in particular flying vehicles - nothing beats hydrocarbons, concerning energy storage per kg/ per m3. Any repeated trials to bypass them totally will only produce more GHG than savings. Therefore following recommendations do apply:

- cargo transport per electrified rail;

- personal cars/bikes per battery EV or CH4;

- working vehicles as cranes, bulldozers ,etc - per CH4 ;

- aviation- per bio-kerosene;

- ships - per sails, CH4 or nuclear.

By the way- hydrogen (on Earth) is not a primary source , but only energy carrier , like cable - at least until we make enough solar or biological plants for massive amounts of it.

Mechanical drives (industrial machinery, motors, lifts,etc) are most difficult. There were , in the past successful trials to transmit&distribute motive energy via fluids as steam, water or air (remember one industrial town in Switzerland, wholly driven by pumped water?). But, considering that this energy would have to be generated ( from wind or water) and then distributed -via costly pipes - nothing here beats electricity. What, in turn, re-directs us back towards large-size (1GW and upwards) nuclear , possibly underground, co-generation obviously, and huge transmission network; and we can skip small "thermal pills"&windmills alike. Sorry, folks, no other way here...

Privately, and for a few years I cherished a vision where super-clean wind power is distributed via network of compressed-air piping , with energy-storage , heat&cold cycle included . No hydrocarbons, no nuclear,no electricity at all. But something kept telling me these are engineer's follies. Take only the number of windmills required...

So, unless we build our own Sun on Earth - the priorities are drawn and no need to produce foam anymore ( from saliva, as this metaphor is not directly transferable to English language). Dear journalists, politicians and general populace, sincerely Yours....