Residents have until Monday to sign up to a scheme to cut the cost of gas and electricity bills.
More than 1,300 have so far signed up to the Essex Energy Switch, run by the county council.
It brings together residents who want to switch providers and pay less for their energy.
Independent provider iChoosr, which specialises in collective energy switching, will carry out an energy auction on Tuesday where the major energy companies will offer the lowest energy tariff to everyone who has signed up.
The company offering the lowest price wins.
Everyone registered will then receive a personal offer of the new tariff from iChoosr, based on their existing energy usage.
Residents can then decide whether or not to accept their offer. There is no obligation to switch.