We propose an experimental evaluation of whether performance-based incentives for residential energy conservation remain effective when repeated. Building on our prior study with EVNHANOI, which found that both contests (rewards based on relative performance) and contracts (rewards based on absolute savings) reduced electricity use by 7–9%, with contests proving significantly more cost-effective, we aim to test whether these effects hold when households are repeatedly exposed to these incentives. Does the comparison of contests versus contracts change when households are repeatedly exposed to these? Does repeated exposure reduce energy conservation after households fail to earn a reward? To answer these questions, we will randomly assign 6,400 households in Hanoi to one of six groups. The first four groups vary by incentive type (contest or contract) and reward level (high or low). The fifth group will receive nudges without being offered explicit incentives to conserve energy, and the last group will be a pure control. Each treated household will participate in two consecutive two-week conservation periods. Using smart meter data, we will measure electricity consumption to assess both immediate effects and dynamic behavioral responses over time.