Abstracting electricity
This offence is created by section 13 of the Theft Act 1968:
This section replaces section 10 of the Larceny Act 1916. The following cases are relevant:

Visiting forces
This offence is an offence against property for the purposes of section 3 of the Visiting Forces Act 1952. Mode of trial and sentence
This offence is triable either way. A person guilty of this offence is liable, on conviction on indictment, to imprisonment for a term not exceeding five years, or on summary conviction to imprisonment for a term not exceeding six months, or to a fine not exceeding the prescribed sum, or to both. History
Section 10 of the Larceny Act 1916 provided: This offence is created by section 13 of the Theft Act (Northern Ireland) 1969, which is identical to section 13 of the Theft Act 1968. It replaces section 10 of the Larceny Act 1916. Visiting forces
This offence is an offence against property for the purposes of section 3 of the Visiting Forces Act 1952. Mode of trial
This offence is an indictable offence which may be tried summarily upon consent of the accused. See hybrid offence. Sentence
A person guilty of this offence is liable, on conviction on indictment, to imprisonment for a term not exceeding five years, or on summary conviction to imprisonment for a term not exceeding twelve months, or to a fine not exceeding the prescribed sum, or to both. This offence is created by section 15(2)(a) of the Energy (Miscellaneous Provisions) Act, 1995. That section replaces section 10 of the Larceny Act 1916, which was repealed by section 28 of, and the Schedule to, that Act.
England and Wales
it was held that electricity could not be "stolen" as it is not property within the meaning of section 4 of the Theft Act 1968.