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Energy Efficient Design

Humans use energy to enhance life in important ways. Yet commonly used energy sources like coal, oil and gas are finite in supply and release greenhouse gases. To continue to improve quality of life while maintaining the planet’s ability to support us, we need to both move towards renewable energy and design for energy efficiency.

Beyond Efficiency, to Energy Effectiveness

Energy efficiency is only part of the story. Being energy effective means both designing for efficiency and choosing the right technologies and energy sources.  For example, the Carnot cycle dictates that the most efficient internal combustion engines will only be 40% efficient with today's materials. Also, most use fossil fuels. Instead, it's more effective to use an electric motor with energy sources generated from the sun and wind.

Engineers and designers have a big role to play. By understanding energy, how it is converted to useful forms, and where it is lost, engineers and designers can rethink the way we make things and use energy more wisely.

Forms of Energy

Energy is the ability to do work. It is measured in joules or kilowatt-hours. Power is the rate at which we use energy, and it is measured in watts. To get the energy when and where we want it, we need to convert energy from one form to another.

There are many different forms of energy. For example, the spinning wheel of your bicycle has mechanical energy and the battery in your phone stores chemical energy. Your toaster converts electrical energy to heat energy.

Minimizing Energy Loss

Whenever energy is converted, some useful energy is lost. Energy is also lost if designers aren’t careful about using it efficiently. Today’s engineers and designers have an incredible opportunity to help society use energy more effectively.

You can minimize common forms of energy loss like mechanical friction, fluid drag, and unwanted heat transfer, by doing things like improving the layout and insulation of a refrigerator or designing lighter vehicles that are more aerodynamic and have lower rolling resistance.