I don't know that there are samples, but the fun of Jam themes is they are open to interpretation. "Running out of Power" could be getting tired at the end of the day, a car running out of gas, a battery that is about out of electricity. Some game concepts is your player has a light that gets weaker and weaker as the game plays and when the light runs out the game is over. Perhaps you do a city building game but the more buildings that get added you have to try and keep enough electricity to keep the city running.