RICHMOND, Va. (AP) - Dominion Energy says Virginia needs a critical upgrade of its electric grid but can't estimate how much needs to be spent.

State regulators say the company wants to pay for the upgrade in a way that makes customers pay twice for some of the costs.

The state's largest electric utility is currently scrambling to secure support for legislation that blocks its rates from being reduced, even if the company earns excessive profits.

Dominion says it needs the legislation in order to upgrade the grid and keep rates stable, but the company says even a ballpark estimate of upgrade costs is impossible to calculate right now.

Critics say the proposal lacks credibility without a price tag for the upgrades.

Lawmakers are likely to take up the legislation next week.