The solo student pilot reported that, while practicing landings, he thought the wind was becoming "gusty," so he increased his approach speed. He added that, over the runway threshold, he reduced throttle and felt the airplane enter ground effect. The airplane landed hard, bounced, and landed hard a second time. The student pilot added full power and turned off carburetor heat, and the airplane landed hard a third time. The nose landing gear collapsed, and the airplane came to rest in the grass next to the runway. The airplane sustained substantial damage to the fuselage. The student pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The automated weather observation station located on the airport reported that, about 37 minutes before the accident, the wind was from 230° at 7 knots. The same automated station reported that, about 24 minutes after the accident, the wind was from 260° at 7 knots. The airplane landed on runway 24.