Updated: Sep 7
April 12, 2017
CA Energy Commission awarded Pyro-E on multiple projects in solid-state waste energy recovery and renewable energy demonstration.
Americans spent 5.5 billion hours annually stuck in traffic. The extra fuel and lost hours cost ~$120 billion to the US economy annually. One solution to the problem is to recover a part of the energy spent in the all-so-prevalent traffic congestion. Along the 400,000 lane-miles of CA highways, the energy lost is equivalent to the rolling resistance of 330 billion miles driven by Californians in 2016. Consequently, the identified opportunity aims to harvest the lost energy for renewable electricity. Namely, the technology being developed uses a special class of smart materials, called piezoelectrics, to convert billions of tire compressions every day into carbon-free electricity. At scale, the power generated would feed into the grid to help offset the adverse environmental impact of gasoline vehicles. For ratepayers, this new form of energy would provide savings during peak rates that coincide with rush hour traffic (i.e., 8 am to 6 pm). Likewise, utility companies would benefit from the curtailment of conventional gas thermal plants.
Exhibit 1: Illustration of Regenerative Pavement during operation
Innovation & Benefits to CA ratepayers
The goal of the project is to demonstrate Regenerative Pavement, a roadway-embedded energy harvester, to assess its potential impact on energy sustainability through a greater utilization of untapped energy resources. The project deliverable will include hardware devices developed using smart materials. For demonstration, the devices would harvest energy from pavement deflections and vibrations under normal driving conditions. Simultaneously, energy data will be collected to demonstrate performance. One important metric is to ensure unobtrusiveness to driving and the scalability of the technology for statewide adoption. If successful, clean electricity will service local homes and business and alleviate grid demand and save energy costs.
Total units: 24 demonstrator devices
Total coverage area: 24 feet x 12 feet
Pavement material: asphalt top-layer / concrete foundation
Target performance: 300W per square-foot from passenger vehicles and light trucks.
Exhibit 2: Field Demonstration of Regenerative Pavement
Exhibit 3: Visualization of Regenerative Pavement at scale
The metrics for the demonstration project include equipment cost, the electricity produced, and renewable energy benefits. The majority of the equipment cost assumes that of the piezo-stacks, but is expected to precipitously fall with scale. Such is the case for multi-layered ceramic capacitors (MCCs), billions of which are sold in world annually. The power output of calculated from 1 millisecond of wheel impact. This contact duration corresponds to a driving speed of 25 mph.
The projects benefits are extrapolated to an annual basis. To do that, the calculation in the displaced electricity, carbon dioxide, and fresh water use assumes a capacity factor of 50-percent – about 1,100 vehicles per hour. A typical traffic congestion has a measured rate of approximately 2,200 vehicles per hour.