What is the amount of energy spent by earth by orbiting the sun once?
The earth spends no energy in its orbit around the sun. In order to spend or lose energy, an opposing force would have to act parallel to the earth’s direction of travel. There is no such force. The earth posesses kinetic energy by virtue of its mass and speed. It also posesses potential energy due to the sun’s gravitational pull. The sum of these two energies is constant. The earth slows down and speeds up at different places in its orbit; these are fluctuations in kinetic energy which are compensated for by equal and opposite fluctuations in potential energy (varying distance from the sun). The earth loses no energy overall. The earth’s average kinetic energy due to its orbital speed is around 2.6×10^33 Joules or 1.9×10^33 ft-lbs. If you were to somehow able to use up all this energy over the course of one year (so that the earth came to a stop), it would produce about 8.2×10^19 Megawatts of power.
