The deals, similar to fixed-term mortgages, would see users pay a tariff set by the regulator in the month their contract starts and be subject to exit fees if they leave early.
It is one of three proposed alternatives set out by Ofgem as it launches a consultation on changing the system that has left energy firms vulnerable, with many caught out by surging wholesale energy prices.
The regulator underlined the urgency of the shake-up at a time when markets are still volatile – with gas prices this week climbing close to record highs previously seen in October.
