The electric power industry is the generation, transmission, distribution and sale of electric power to the general public.
Once an expensive novelty limited to the most densely populated areas, reliable and economical electric power has become a requirement for normal operation of all elements of developed economies. By the middle of the 20th century, electric power was seen as a "natural monopoly", only efficient if a restricted number of organizations participated in the market; in some areas, vertically-integrated companies provides all stages from generation to retail, and only governmental supervision regulated the rate of return and cost structure. Since the 1990s, many regions have opened up the generation and distribution of electric power to provide a more competitive electricity market.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.
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.
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.