Can you get Speed {L} Energy with Volkner?
No, you cannot. Speed {L} Energy only counts as Lightning Energy when it is attached to a Pokemon.
Source: TPCi Rules Team (2020-05-07)

Relevant cards

Note: All applicable cards may not be listed below.
SM5_135
SM5_135A
SM5_135A
SM5_156
SWSH2_173
SWSH2_173