For example, over many years requirements for energy efficiency of refrigerators have steadily become more rigorous, successfully driving new technological innovations, yet the resulting products are also cheaper as well as being more energy efficient. The amount of energy saved in this one area alone is more than the total of all renewable energy generated in the US today!
像是歷年來冰箱能源效率標準的提升，就成功帶動科技創新，也研發出價格更低、省能效率更高的產品，省下的能源甚至比目前全美所有再生能源加總起來還要多！