Environment – Storing Electricity a Little at a Time for Bulk Use
A sensor System that Combines Vibration Power Generation with Capacitors
The sources of energy for vibration power generation are found in the minor vibrations that occur during daily life. These include vibrations attributable to such structures and facilities as roads and factories. For this reason, the electric power generated cannot be regarded as substantial. In an initial test case, the energy generated in one second was sufficient to power only a single light bulb.
To address this concern, MEE devised a structure that is capable of utilizing at regular time intervals the small amounts of electric energy generated that have been stored in capacitors. While the amount of usable electric power remains limited, it is sufficient to power various types of energy-efficient sensors and wireless radios. Recognizing that actual conditions for use for the most part entail measuring and monitoring at such regular intervals as once every few minutes or once every few hours, considerable potential exists for the practical application of this store-and-use method.
In a second test case*, steps are being taken to measure and transmit temperature, humidity and luminance data at 10-second intervals. This frequency can be set freely in accordance with the level of vibration and the purpose of electric power use. For example, power generated is currently six times the amount used on a once-a-minute basis, and 360 times the amount used on a once-an-hour basis. This creates opportunities for increasingly energy-efficient sensors as well as more complex sensors.
- Based on vibrations of approximately 10Hz.