Solar Road Energy Recovery

This project is to advance the use of free energy. The solar piezoelectric system is collecting two energy sources. The solar panel is connected on top of the piezoelectric. The energy is taken from the sun's rays through the solar panel and from the compression through the piezoelectric. Then the free energy is stored in a battery.

Background
The purpose of this project is to establish the feasibility of a roadside hybrid energy collection/recovery system that can then be used for running nearby street utilities such as lights/signals. The hybrid sources are solar energy (harvested by a commercially available solar cell located next to roadway) and piezoelectric energy (harvested by an array of piezoelectric elements in the roadway). Each of these systems will have its own component level controller. A practical ratio of cost-effective energy recovery from these two sources will be sought in the design of the supervisor controller. It should be possible to monitor system performance via a wireless display located a safe distance from the energy harvesting equipment.

Solar Panel
Solar panels are devices that convert light into electricity. They are called "solar" panels because most of the time, the most powerful source of light available is the Sun, called Sol by astronomers. Some scientists call them photovoltaics which means, basically, "light-electricity."

A solar panel is a collection of solar cells. Lots of small solar cells spread over a large area can work together to provide enough power to be useful. The more light that hits a cell, the more electricity it produces, so spacecraft are usually designed with solar panels that can always be pointed at the Sun even as the rest of the body of the spacecraft moves around, much as a tank turret can be aimed independently of where the tank is going.

Specifications Related power: 10W Voc: 20.6V Vop: 17.3V Short circuit current (Isc): 0.69A Working current (Iop): 0.58A Output Tolerance: ±3% Temperate coefficient of Isc: (010+/- 0.01)%/ ℃ Temperate coefficient of Voc: - (0.38 +/-0.01)%/ ℃ Temperate coefficient of power Voc: -0.47%/℃ Temperature range: -40℃to +80℃ Frame: Heavy duty aluminum Kind of connection: waterproof junction box, can be customized Guarantee of power: 90% within 10 years 80 within 25 years Kind of glass and its thickness: Low Iron, high transparency tempered glass of 3.2mm SLA Battery Voltage: 12V

Piezoelectric
Piezoelectricity, also called the piezoelectric effect, is the ability of certain materials to generate an AC (alternating current) voltage when subjected to mechanical stress or vibration, or to vibrate when subjected to an AC voltage, or both. The most common piezoelectric material is quartz. Certain ceramics, Rochelle salts, and various other solids also exhibit this effect.

A piezoelectric transducer comprises a "crystal" sandwiched between two metal plates. When a sound wave strikes one or both of the plates, the plates vibrate. The crystal picks up this vibration, which it translates into a weak AC voltage. Therefore, an AC voltage arises between the two metal plates, with a waveform similar to that of the sound waves. Conversely, if an AC signal is applied to the plates, it causes the crystal to vibrate in sync with the signal voltage. As a result, the metal plates vibrate also, producing an acoustic disturbance.

Piezoelectric System
The piezoelectric elements produce alternating current (AC) which need to be converted to direct current using a diode to make the current flow in one direction. Then store the voltage in a small capacitor. After that, transfer the voltage to the battery.

Switching between sources
The switch is controlled by a microcontroller where the switch will be temporary on the solar source. The switch is on the solar side until the time difference between the battery charge and the capacitor discharge reaches the ideal time range and then it switches to the piezoelectric source.

Document Archive
[[Media: All_Meeting_Minutes1.pdf|All Meeting Minutes]]