phrase1: fixed rate
phrase2: consistent speed
sentence1: In addition, on July 30, 2010, Google Energy agreed to purchase 114 MW of Iowa wind energy from NextEra Energy at a fixed rate for 20 years.
sentence2: In addition, on July 30, 2010, Google Energy agreed to purchase 114 MW of Iowa wind energy from NextEra Energy at a consistent speed for 20 years.