The announcement today by American Electric Power and Duke Energy to build a $1 billion, 240-mile transmission line in Indiana points out the challenges to link new supplies of renewable energy with utility customer load.

The 765-kilovolt line proposed by AEP and Duke would connect AEP's Rockport Station east of Evansville, Ind., with Duke's Greentown Station near Kokomo, Ind. The line could tap more than 3,000 megawatts of wind power planned in central Indiana.

The proposed joint venture project faces a number of state and federal regulatory hurdles and would be completed at the earliest in 2014. Approvals would have to come from the Midwestern Independent System Operator and the PJM Interconnection. The JV also must file in Indiana to operate as a transmission utility and seek rate approval from the Federal Energy Regulatory Commission. Utility customers would pay for the project in rates.

Overcoming regulatory hurdles for siting and developing new transmission lines for solar and wind energy in remote areas in the Midwest, California, desert Southwest, Texas and other states is critical for the development renewable enrgy supplies. We'll keep an eye on this latest proposal in the Hoosier State.

It's a busy day on the transmission front in California for Southern California Edison and San Diego Gas & Electric.

Reuters reports that SCE launched construction of its big Tehachapi Renewal Transmission Project to deliver 4,500 megawatts of mostly wind power to customers in Kern and Los Angeles Counties. Phase 1 is to be finished in 2009. Tehachapi is part of SCE's proposed $5 billon expansion for its high-voltage grid.

To the south, the North County Times says SDG&E's delayed Sunrise Powerlink may get a boost from a decision by the federal Department of Energy affirming "designated energy corridors" on the East and West coasts. The decision means that SDG&E could ask the Federal Energy Regulatory Commission to approve the contested transmission plan if it can't win a go-ahead from the California Public Utilities Commission.

The Sunrise line would carry power from the Imperial Valley to San Diego customers but it has drawn fire from environmentalists because the route would run through the Anza-Borrego Desert State Park, the largest state park in California.

Take a look at a story in Energy Daily today (requires login) updating the transmission flap between Southern California Edison and Arizona utility regulators. It appears that SCE is talking with the Federal Energy Regulatory Commission to authorize the Arizona Corporation Commission to approve a new transmission line to carry power from Arizona to southern California. You will recall that last year the Arizona panel rejected Edison's proposal, calling the project an "extension cord" to siphon off needed Arizona generation to help out SCE. Energy Daily notes that the Edison case could affect controversial transmission plans in other states.