Students learn how to build simple piezoelectric generators to power LEDs. To do this, they incorporate into a circuit a piezoelectric element that converts movements they make (mechanical energy) into electrical energy, which is stored in a capacitor (short-term battery). Once enough energy is stored, they flip a switch to light up an LED. Students also learn how much (surprisingly little) energy can be converted using the current state of technology for piezoelectric materials. This engineering curriculum meets Next Generation Science Standards (NGSS).