The Dept of Energy just released its quadrennial report. This chart from page 22 simply blows my mind. On the left side are the inputs from various energy sources. On the right side is the result. The dark grey is the actual energy that gets used. The rejected energy (light grey) is waste! 2/3ds of what we obtain from the planet ends up as waste! Mind boggling when one considers this is the cheapest energy source we have available and yet we have been so slow to capitalize on it.