New hi-tech meters should be installed in customers' homes to help them cut gas and electricity bills, according to an energy watchdog.
Current meters display the amount of energy used but not the cost
Energywatch said the "smart" meters could calculate consumption costs, allowing consumers to check at a glance how much they were spending.
It said the government should ask the industry to adopt the new technology.
The call came on the day British Gas and Scottish Gas price rises of 14.2% came into effect.
Graham Kerr, of Energywatch Scotland, said smart meters could help consumers reduce their costs, promote energy-efficient behaviour, and help prevent vulnerable households getting into debt.
"The paucity of information given to consumers makes it difficult for them to monitor and manage energy costs," he said.
"Smart meters giving half-hourly readings would change this dramatically.
"What more incentive would you need to leave bad habits behind if you had to sit and watch your energy bills go up every 30 minutes?"
Energywatch says the changeover would cost suppliers about £85m a year. The meters would lead to more accurate billing, leading to fewer complaints and lower costs.
It says suppliers would also save money by being able to read the meters remotely, rather than having to send someone to do so.
Increases to British Gas and Scottish Gas prices were announced on 9 September and take effect on Monday.
The company, which is owned by Centrica, said increases were necessary due to soaring oil prices and declining North Sea reserves.