The new law allows Georgia Power to begin to collect some $1.6 billion in costs from ratepayers six years before the reactors go online.
Ratepayers would see their electric bills rise by an average of $1.30 a month in 2011. Those increases will gradually rise to an additional $9.10 a month in 2017.
Supporters say the financing scheme will lower the overall cost of the project. Critics say consumers will be forced to pay for the reactors before seeing any benefit from them.
The $14 billion expansion project at Plant Vogtle must still receive federal approval.