The symbol "kWh" is commonly used in commercial, educational, scientific and media publications,4 and is the usual practice in electrical power engineering. Other abbreviations and symbols may be encountered: "kW h" is less commonly used.
It is consistent with SI standards (but note that the kilowatt-hour is a non-SI unit).The international standard for SI states that in forming a compound unit symbol, "Multiplication must be indicated by a space or a half-high (centered) dot (?), since otherwise some prefixes could be misinterpreted as a unit symbol" (i.e., kW h or kW?h).
This is supported by a voluntary standard6 issued jointly by an international (IEEE) and national (ASTM) organization.
However, at least one major usage guide and the IEEE/ASTM standard allow "kWh" (but do not mention other multiples of the watt hour).One guide published by NIST specifically recommends avoiding "kWh" "to avoid possible confusion". The US official fuel-economy window sticker for electric vehicles uses the abbreviation "kW-hrs". Variations in capitalization are sometimes seen: KWh, KWH, kwh etc. "kW?h" is, like "kW h", preferred with SI standards, but it is very rarely used in practice. The notation "kW/h", as a symbol for kilowatt-hour, is not correct. Źródło: https://en.wikipedia.org/wiki/Kilowatt_hour
The electric power industry is the generation, transmission, distribution and sale of electric power to the general public.The electrical industry started with introduction of electric lighting in 1882.
Throughout the 1880s and 1890s, growing economic and safety concerns lead to the regulation of the industry.
While such markets can be abusively manipulated with consequent adverse price and reliability impact to consumers, generally competitive production of electrical energy leads to worthwhile improvements in efficiency.
However, transmission and distribution are harder problems since returns on investment are not as easy to find.Źródło: https://en.wikipedia.org/wiki/Electric_power_industry