A solar power milestone was reached last week when First Solar Inc brought its manufacturing costs for cadmium telluride (CdTe) solar panels down to $1 per watt, eclipsing silicon panels, which are still in the $3 range.

The company estimates that it needs to get manufacturing costs down to $0.65 to $0.70 per watt and other installation costs down to $1 a watt to reach grid parity — goals First Solar plans to reach by 2012.