New Thermocell Could Turn 'Waste Heat' Into Electricity

dryriver sends this quote from Phys.org: "Harvesting waste heat from power stations and even vehicle exhaust pipes could soon provide a valuable supply of electricity. A small team of Monash University researchers ... has developed an ionic liquid-based thermocell (abstract). Thermocell technology is based on harnessing the thermal energy from the difference in temperature between two surfaces and converting that energy into electricity. The new thermocell could be used to generate electricity from low grade steam in coal fired power stations at temperatures around 130C. This would be implemented by having the steam pass over the outer surface of the hot electrode to keep it hot while the other electrode is air or water cooled."

Comments

Re:Nuclear steam

[gewalker]

For efficient conversion of heat to you MUST have high temps. Modern pressurized water nuclear reactors run at about 150 atmospheres -- corresponding temperature of 315 C / 600 F. There is no way to avoid this with liquid water as the working fluid. Contain 150 atmosphere of pressure at all times dominates the design of the reactor. Some newer designs use different working fluid. E.g. a LFTR reactors (drawing board only) using a Brayton cycle based on helium or nitrogen gas and a 700 C temperature source -- no high pressure used in the the nuclear vessel.

Also look at the design of the power generation cycle in a power plant. There is a relatively small high-temperature turbine that generate 2/3 of the electricity and a much larger secondary turbine that generates 1/3 of the electricity. The lower-temp output of the first turbine is the input for the 2nd turbine.