Energy on Earth has a finite calculable value. Of greater interest is the energy flux. Too much energy in and the Earth gets hot, like Venus. Too little energy in and the Earth cools and returns to its snowball state. If we like the current temperature then we need the same amount of energy coming in as going out so as to maintain the temperature.
The single greatest contributor to energy deposition is of course our Sun. While we see its bright yellow presence in the daytime sky, we only see its rays that are in the visible frequency spectrum. All told, its rays have an infinite number of frequencies, each with unique physical properties. The properties indicate the amount of energy that reflects from the top of the Earth’s atmosphere and the amount that arrives at its surface.
While the Sun in the sky appears the same day after day, we know that it changes. Recently, a solar storm emitted rays that acutely added 26 billion kWh of energy. The Earth, with its amazing ability, was able to reflect most of the energy back into space. Of note, the chronic energy transmission from Earth into space is at least 9.36e20J/day or 3.4e23J/a. Human technology uses over 1e20J/a most which becomes waste heat. It’s not a lot but still it’s a 0.1% increase from per-technology times. It will be interesting to see how the Earth reacts to this addition to the Sun’s regular energy deposition.