First and second clocks are applied to first and second capacitors, respectively. One example method comprises, during engine non-fueling conditions, where at least one intake valve and at least one exhaust valve of the engine are operating, generating an ambient humidity from the exhaust gas sensor and, under selected engine combusting conditions, adjusting an engine operating parameter based on the ambient humidity. The decentralized construction may have many mutually independent fuel cell systems, permitting a high-efficiency power supply. In another embodiment, the nanoshells are tuned to extinguish energy from other parts of the energy spectrum.