The authors review information available from Russian and internationa
l publications (including their own experimental results) wherein an e
ffect of forming an excited hydrogen species in systems with hydride-f
orming materials, as well as some evidence of the effect in physical-c
hemical processes, are considered. Some possibilities of using the eff
ect in vacuum physical-energy units and electrochemical energy convers
ion systems are shown. A connection of the said effect with a phenomen
on of ''cold fusion'' is noted and illustrated with the ''accelerating
'' model of the phenomenon as the most clear.