(Reuters) – Britain’s energy regulator Ofgem on Friday opened a consultation on a proposal to switch from half-yearly to quarterly price cap updates and reducing the advance notice for new tariffs to take effect. “We are consulting on a number of changes to the price cap methodology in response to the recent unprecedented rise in wholesale market prices and volatility,” Ofgem said. The consultation will end on March 4. The move comes a day after the regulator announced a 54% increase in the cap applied to the most widely used tariffs. Energy prices for millions of British households are set to…