A decision on a proposed high-voltage power transmission line that would run through several Illinois counties is now heading to the state Supreme Court after an energy company decided to appeal a ruling against construction.

The high court agreed last week to review an appellate court's decision on the Rock Island Clean Line, a 500-mile electric project transmitting wind energy from Iowa turbines. The appellate court reversed a 2014 decision from the state Commerce Commission, which approved construction of the line.

Evidence presented by Rock Island in the case suggests the project would reduce electricity costs by hundreds of millions of dollars. The construction of the project would also create construction jobs.

Rock Island also would pay each county through which the transmission line passes $7,000 per year for each mile for 20 years.

The company has faced four years of legal opposition by the Illinois Landowners Alliance, the Illinois Farm Bureau and ComEd. The groups argue that the project doesn't meet Illinois Public Utilities Act requirements.