Ames seeks new on-site thermal generation; council asks staff to study alternative sites and negotiate engineering agreement

The Ames Electric Department told the City Council on Aug. 5 that aging local generating units and the planned end of refuse-derived fuel (RDF) burning require the city to add dispatchable thermal capacity to maintain reliability and containing price volatility in regional power markets. Staff proposed replacing Unit 7 (commissioned in 1967) and adding capacity to meet forecast growth (roughly 138 MW today projected to ~160 MW over 10+ years) with up to three large reciprocating internal-combustion engines (RICE). The utility said RICE units offer rapid start capability (minutes versus hours for older units), black-start capability for system restoration, and a way to cap extreme market-based capacity costs. Why the city is proposing on-site RICE engines Ames officials and the utility’s consultant presented multiple drivers: Unit 7 has exceeded typical life expectancy and will require either large reinvestments or replacement; Unit 8 (1982 vintage) is maintainable for now, but both units have been stressed by RDF burning and changing fuel economics. The electric…