"Practical thermionic generators have reached efficiencies of about 10 percent. The theoretical predictions for our thermoelectronic generators reach about 40 percent, although this is theory only," noted Mannhart.[/size]
http://revolution-green.com/new-highly-efficient-thermoelectronic-generator/ (http://revolution-green.com/new-highly-efficient-thermoelectronic-generator/)
Some weekend reading
Kind Regards
Mark