reaction of hydrogen with oxygen

thermionic action

combustion of fuel in absence of oxygen

any of the above

oxygen

ammonia

hydrogen

carbon monoxide

2.5 kW/sq. m

1.0 kW/sq. m

500 W/sq. m

200 W/sq. m

molten salts

liquid metals

water steam

any of the above

Coastal areas

Hot arid zones

Mountain tops

High rainfall zones