Edison Revisited: Should we use DC circuits for lighting in commercial buildings?

► We model a 48,000 ft2 commercial building lighting system with AC and DC circuits. ► At 2012 efficacies and costs, LEDs are lowest levelized annual cost (LAC) option. ► DC LEDs can lead from an LAC increase of 5% to a decrease of 15% (vs. AC LEDs). ► Grid-connected DC LEDs with PV can lower LACs by 2-21% (vs. PV-AC LEDs). ► PV-DC LEDs may match the LAC of grid-powered AC fluorescents by ∼2013.