DRAMs consume a large portion of total system energy consumption. Thus, reducing DRAM energy consumption is able to prolong the lifetime of battery-operated embedded/portable systems. To this end, we propose DRAM energy-aware data prefetching scheme to lengthen DRAM idle periods by clustering DRAM accesses. Low-power modes of DRAMs can better exploit longer idle times. We performed experiments with a cycle-accurate simulator with built-in DRAM power model. The experimental results show that our proposed DRAM-aware prefetching is effective in reducing DRAM energy consumption. Up to 77% and average 59% of DRAM energy consumption is saved.