Buildings and Cities
The building sector worldwide uses approximately 32 percent of all energy generated; more than one-third of that is for heating and cooling. Maximum efficiency in heating and cooling could cut energy use by 30 to 40 percent.
The means to increase efficiency are at hand, and one technology stands out from the rest: heat pumps. Like a refrigerator, a heat pump has a compressor, condenser, expansion valve, and evaporator, and transfers heat from a cold space to a hot one. In winter, that means pulling heat from outside and sending it into a building. In summer, heat is pulled from inside and sent out. The source or sink of heat can be the ground, air, or water.
While cost can be high and efficiency fluctuates depending on local climate, heat pumps are easy to adopt, well understood, and already in use around the world. They can supply indoor heating, cooling, and hot water—all from one integrated unit. When paired with renewable energy sources and building structures designed for efficiency, heat pumps could eliminate almost all emissions from heating and cooling.
Technical summaries for each solution will be available May 1, 2017.