The Department of Energy states that building lighting, appliances, space conditioning, and water heating account for 36% of primary energy used in the United States. This is far greater than the total energy used in the transportation sector, and nearly equals that of the industrial sector, 2/3 of which is supplied by electricity. 40% of the total energy used in those buildings is for heating, air conditioning, and water heating. A recent study conducted by the Rockefeller Foundation and DB Climate Change Advisors supports these findings and points out that upgrading and replacing energy-consuming equipment in buildings offers an important capital investment opportunity with the potential for significant economic, climate, and employment benefits. They go on to state that “an investment in this type of initiative could yield more than $1 trillion of energy savings over 10 years, equivalent to saving approximately 30% of the annual electricity use in the U.S.”.