The main objects of Irish electricity smart metering trials are residential and small and medium enterprises（SMEs）consumers. It delivers the results of a set of trials that were undertaken to provide robust statistical information on the impact of time of use tariffs in combination with various demand side management informational stimuli as well as some other characteristics on overall and peak electricity usage. The reason for different trial results caused by different stimulus, groups and business types is discussed, and the potential obstacle that affects the results is analyzed, so as to better excavate potential of demand response object and design relevant projects.