Understanding the load pattern created by compact fluorescent lamps is key to evaluating the impact on the utility's system peak demand and calculating energy savings. A household survey was distributed to consumers involved in a Danish CFL programme. The primary goal was to map the daily patterns of CFL and incandescent lamp use in the residential sector throughout the year. A secondary aim was to evaluate consumers' acceptance of the CFLs. Two CFLs were offered free of charge to each of the utility's 240,000 residential customers. The participation rate was 90% (1.8 CFLs per home). Although this represents only 7% of the total number of lamps per home, the CFL's long burning hours accounted for nearly 20% of the total burning time of all lamps. Total annual household electricity savings consumption for lighting due to the CFLs is approximately 15%, or 125 kWh per home. During afternoon peak hours on winter days, up to 80% of the CFLs are in use. During the morning peak hours, however, only 30% of the CFLs are in use.