I want to know the answer to the following question:
What can be used to balance out a portion of the energy used by HVAC systems?
All the background I'm provided with is that "In the United States, heating, ventilation and air conditioning (HVAC) systems account for 30% (4.65 EJ/yr) of the energy used in commercial buildings and nearly 50% (10.1 EJ/yr) of the energy used in residential buildings.". Is that enough to answer the question?