When thinking about conserving energy, we normally tend to have poor judgement on what matters the most. For example, we overestimate the importance of light bulbs and TV leds, while underestimating the impact, orders of magnitude greater, of changing how we operate air conditioning and washer machines. But there is another level of potential misjudgment, which comes from narrowing our focus on residential electricity consumption, and missing the big energy picture.

A type of visualization which helps us widening our understanding of how we produce, use and waste energy, is the energy flow chart, released every year by the Lawrence Livermore National Laboratory for the US.

In the US, at the system level, to benefit one unit of energy services we waste other two potentially useful units. One part of this is inevitable, due to the physics of the energy conversions involved, but one part might be improvable, as in the past, e.g. in 1970, we were closer to a 50% rather than a 30% system efficiency.

The major driver of this drop in system efficiency seems to be related to the US increasing fraction of transportation and electricity generation in the energy balance. By opting for more efficient modes of transportation and energy sources, consumers might have the potential to significantly impact the environment, and possibly future energy flow charts.