An Illinois utility said customers who refuse to have an electricity meter installed will see an additional $20 monthly fee on their bills.

According to reports, Ameren Illinois says the so-called smart meters, which transmit details about power usage, enable the utility to pinpoint outage problems and fix them faster. They add the meters can be read remotely and the $20 fee covers the cost of sending out a person to read the older analog meter.

The company is set to install 780,000 of the new electricity meters in central Illinois and 468,000 upgraded gas meters, which offer similar capabilities.

The Illinois Commerce Commission, the state's utility regulators, approved the extra charge and says the company should be compensated for meters that require a person to visit them.

It also approved a $70 onetime "exchange fee" for customers who accept a smart meter but then change their minds.

Some opposition groups in Decatur and other cities claim the meters pose a health risk through their communication signals, but Ameren rejects the health risk argument.

Other critics have said the meters' transmission of power usage is a breach of privacy. Ameren said the meters' information is too general to be seen as an invasion of privacy.