Every home in Wales could have new "smart" meters checking how much energy they use minute by minute, Assembly Members have been told.
Smart meters would bring about the end of estimated bills
Firms gave evidence to AMs to argue that the meters could revolutionise the way energy is used, leading to cuts in bills and carbon emissions.
But firms say they will not invest in the meters without a clear lead from the UK government and a rule change.
The assembly sustainability committee aims to produce a report in the summer.
"We need a mandate from government before industry invests," said Russell Hamblin-Boone, of the Energy Retail Association, which represents energy companies.
But if the government gave the green light, the meters would be installed over 10 years, he said, proving a bigger task than the change to North Sea gas in the 1960s and '70s.
Trials have already begun in parts of the UK, including Newport.
Smart meters display accurate real-time information on energy use in the home and transmit the information back to the energy supplier.
It would mean the end of estimated bills, give customers the chance to cut back on their energy, and even sell energy back to the supplier if homes were equipped with wind turbines or solar panels.
"Smart meters provide the opportunity to revolutionise the way we use energy," said Mr Hamblin-Boone.
"They are a two-way communication device between household and energy supplier, offering real-time information on gas and electricity use."
Mr Hamblin-Boone was speaking to the assembly's sustainability committee, which is examining how to reduce the use of carbon fuels.
But he said the UK government would have to change competition laws to allow energy companies to develop standard meters, and companies needed a decision on how they should be introduced into homes across the UK.