Johannesburg - The Federation of Unions of SA (Fedusa) expressed concern on Monday about a proposed 22 percent electricity tariff increase for Johannesburg."Various suburbs in Johannesburg have experienced blackouts this week, yet the City of Johannesburg... applied to the National Energy Regulator of South Africa (Nersa) for an average electricity tariff increase of 22%," said Fedusa deputy general Krister Janse van Rensburg."This increase is above the stipulated guideline of 20.38% set by the regulator for the coming financial year."He called on South Africans to use electricity sparingly to prevent blackouts."It will be necessary for every South African to change their consumption patterns in order to save electricity this winter."The alternative is further blackouts or, even worse, that the electrical grid could collapse," said Janse van Rensburg.