At a hearing to address a challenge to the environmental impact statement for a proposed third unit at Maryland’s Calvert Cliffs nuclear plant, staff from the Nuclear Regulatory Commission said renewable power sources would likely be unable to substitute the reactor’s power generation.At the hearing before the Atomic Safety and Licensing Board last week, Platts quoted NRC project director Andy Kugler as saying an agency analysis concluded only 300 megawatts of wind and solar power generation was likely to be installed in Maryland by mid-decade. Even if 1,600 megawatts of renewable generation were built – equivalent to the proposed reactor’s power – its intermittent nature would result in an average of 400 megawatts of production, necessitating 1,200 megawatts of new gas-fired generation to ensure grid stability.His testimony contradicted a contention by environmental groups that UniStar Nuclear Operating Services didn’t adequately consider the potential of alternative energy sources when preparing its EIS for unit 3. The company, a subsidiary of EDF, has proposed building a 1,600 megawatt Areva EPR at the plant south of Annapolis, Md. Constellation Energy Nuclear Group, a partnership between Constellation and EDF, owns the other two reactors at the site.Although unit 3 received a favorable final environmental impact statement from the Nuclear Regulatory Commission last May, the project also faces legal challenges surrounding its ownership. Because EDF is a French company, the plant would need a yet-to-be-determined U.S. partner to comply with laws regarding foreign ownership of U.S. nuclear plants. Later this year the ASLB is expected to rule on a challenge related to the project’s ownership in addition to the alternative energy contention.