Energy demand-side management becomes a well-established approach in the Smart Power Grid. Aggregation of consumption information is a critical operation performed by most demand-side energy management mechanisms as it provides information about the required adjustment of power demand. However, a centralized demand-side energy management approach controlled exclusively by utility companies is not always scalable, robust and aligned to the privacy requirements of consumers. A large amount of end-user consumption information is aggregated continuously in centralized approaches. This paper introduces an alternative demand-side energy management scheme: ALMA, the Adaptive Load Management by Aggregation. In ALMA, consumers adjust their demand by selecting between different incentivized demand-options based on aggregate consumption information provided by peer-to-peer aggregation mechanisms. The feasibility of dynamic adjustment in power demand is evaluated and confirmed analytically using data from the current reality and practice of Smart Power Grids.