ZURICH (Reuters) – A Swiss government agency warned households and businesses to brace for much higher prices next year and said on Thursday it could not rule out supply bottlenecks this winter. The Federal Electricity Commission (ElCom), which oversees the electricity sector, said most of the 172 utilities that responded to a survey it conducted planned to increase tariffs by 47% on average in 2023. For a five-room household that consumes 4,500 kilowatt hours of power a year, this would mean electricity bills would rise by around 180 Swiss francs ($188) per year. Companies that use 150,000 ki…