In current California Public Utilities Commission hearings, Southern California Edison?s Mohave coal-fired plant is not only a forum for Hopi and Navajo trying to keep the plant running, but one for renewables proponents who want 1,000 MW of peaking solar generation to diminish the role of the plant?or replace it entirely. Edison, 56 percent owner of Mohave, has long been angling to shut down the plant, arguing that spending the requisite $1.2 billion on pollution controls and other upgrades is too costly. Located near Las Vegas, the 1,580 MW Mohave plant is the biggest source of sulfur dioxide in the West, emitting 41,000 tons a year. Along with co-owners Los Angeles Department of Water & Power, Salt River Project, and Nevada Power, Edison is required by federal regulations to cut sulfur dioxide emissions by 85 percent by 2006. The slurry pipeline that supplies the plant with coal is depleting the local aquifer, and the Black Mesa mine used for fuel also faces depletion (<i>Circuit<\/i>, December 5, 2003). A ?temporary (but multiyear) shutdown? appears increasingly likely in 2006, due to uncertain coal and water supplies after 2005, Edison argued in testimony. It?s ?premature? to issue a conditional certificate of convenience and necessity, said the utility, because new contracts for coal and water supplies haven?t been finalized, and critical cost-effectiveness information is missing. Edison concludes that Mohave will probably not be able to operate past 2026, given the problem of long-term replacement of water supplies. This window of operation weakens the case for installing required pollution controls and restarting Mohave after a temporary shutdown, according to Edison. However, Native Americans want the plant running. For every month Mohave is shut down, beginning in 2006, the Hopi and Navajo tribes ?will suffer $7 million to $8 million in lost revenues, taxes and wages,? they say. ?With the already staggering unemployment and poverty of the Hopi and Navajo, [we] simply cannot afford these impacts,? they warned. As for replacement coal and water supplies, preliminary results from a study on an alternative water source for the mine should be ready this fall, according to the Hopi. Available coal resources are ?significant, high quality and economical? compared to natural gas, said the tribe. Pushing a renewables alternative, Water and Energy Consulting proposes 1,000 MW of solar thermal peaking electricity, 500 MW on Hopi land and 500 MW on Navajo land, at a cost between 6 cents\/kWh and 7 cents\/kWh. The 18,000 solar dishes would be constructed by Nevada-based Stirling Energy Systems. In a twist, Stirling said it acquired from Edison the rights to the Dish Stirling System solar technology in the 1990s. The consulting firm questioned the need to approve spending $1.2 billion in ratepayer funds to refurbish 40- year-old technology at Mohave, which the company says is dirty and wastes water, without certainty about costs, the quantity of fuel available, or whether it can be transported to the plant. The CPUC has scheduled four weeks of hearings on Mohave issues.