What is Energy Efficiency?
Photo by JJ Janee Watts
Being energy efficient means doing the same amount of work while using less energy. For example, an energy efficient washing machine provides the same service, laundry, but at a lower rate of energy consumption. Similarly, a well-insulated house is more energy efficient because less heat escapes and therefore less heat needs to be used to maintain a comfortable living environment.
Energy efficiency can be achieved in a variety of ways. One way is to update or design new buildings to take advantage of natural resources and minimize energy waste. Situating a building with large windows facing south towards deciduous shade trees is an example of using passive heating and cooling to reduce energy use. In winter, the sun shines into the house through the windows, reducing the need to use electric or gas-fed heat, and the trees provide shade in the summer, preventing the sun from warming the house. Other building design practices that achieve energy efficiency include proper insulation, using double pane windows, and maximizing green space to decrease heat absorption. New technologies also help increase energy efficiency. Appliances account for an estimated 20% of the average American household’s energy bill. Replacing old appliances with newer, more efficient ones can cut back on electrical use and help lower energy bills. For example, an “Energy Star” certified refrigerator must use at least 20% less energy than current standards and 40% less energy than the standard from 2001. Visit our links page to find sites where you can calculate potential savings by switching to Energy Star appliances.
Another way to increase energy efficiency is to reduce or reuse the waste heat that is typically produced from industrial processes. About 30% of energy use in all industries is lost due to transportation and equipment inefficiencies. Annually, about 10 quadrillion BTUs of energy are emitted as waste heat and an additional 1.4 quadrillion BTUs are lost in the form of chemical emissions from industrial processes, roughly 1,960 million barrels of oil equivalent. Researching new technologies to capture the waste heat and chemical energy and turn it into electricity or other usable forms of energy could offset petroleum demand and provide cheaper, cleaner electricity to industries.
Improving fuel economy in vehicles increases energy efficiency because it reduces the need for a finite energy source without compromising the function of the vehicle. With current technology, only about 15% of the fuel used in vehicles actually serves to move the vehicle, or for other useful features such as air conditioning. The remaining 85% of fuel energy is lost to idling and mechanical inefficiencies. Internal combustion engines are very inefficient at converting the fuel’s chemical energy to mechanical energy, losing 62% of the fuel’s energy to engine friction, pumping air into and out of the engine, and wasted heat. A combination of engine and exterior redesign for commercial vehicles could save both consumers and producers money in fuel savings.
