Naysayers have rained criticism on Dutch Solaroad solar bike path system. In the first six months of operation, it reportedly overshot energy production expectations to the collective glee of engineers. However, self-described “scientists” are taking it down with numerical rhetoric, namely the cost and inferior production capacity relative to rooftop solar panels. Last year’s pilot test ate up $3.2 million in investor funding for a 230-foot stretch of concrete, and SolaRoad remains tightlipped on the cost per square foot. As electrical engineering vlogger Dave Jones pointed out in a short emission to his EEVBLOG YouTube channel, mounting solar cells in the same vicinity on a roof curved optimally towards the sun would yield twice the output. Writer Pete Danko demystifies the calculations in an article posted to Breaking Energy, writing: “If you were to put 1300 square feet of [solar panels] on rooftops in Amsterdam, it would add up to 16 kilowatts of capacity (based on 1kw per 80 square feet)." Danko then uses a PvWatt’s calculator by the National Renewable Energy Laboratory to compute solar output in the winter months from November to April in the Netherlands versus a rooftop in sunny San Jose, California during the same period. In Amsterdam, the power capacity comes to about 4,600 kwh in lackluster sunshine, while no-quit California rays churn out 10,000 kwh for the same rooftop coverage. Does all the pooh-poohing of SolaRoad get any more intellectual than Why didn’t you put these on the roof instead? The tempered glass-coated concrete modules have been known to break due to climate. In its first month of operation, a 3.3-foot patch of the 230-foot stretch was deactivated due to breakages, although the remainder of the path remained operable. Sten de Wit, a physicist involved in the development of SolaRoad, defended the idea of a solar-powered bike path in an interview with AFP. “The idea is that we have approximately 140,000 kilometers (87,000 miles) of road, which is much bigger than all the rooftops put together. We have 25,000km (15,543 miles) of bike paths in the Netherlands,” he said. The only trouble is that bicycles and solar power don’t really have a lot in common.
Posts tagged with "SolaRoad":
This solar-power generating bike lane in the Netherlands wows engineers by producing more juice than expected
Performance-wise, the Dutch power-generating bike path, SolaRoad, has overshot expectations, generating upwards of 3,000 kilowatts of power in the six months since its launch. The 230-foot concrete strip is located in Krommenie, a village northwest of Amsterdam, and is undergoing a three-year pilot test for material feasibility. The wattage generated in the first six months, according to SolaRoad, suffices to power a one-person household for a whole year. Based on this track record, the bike path is expected to generate 70 kilowatt hours per square meter per year (approximately 22,189 kilowatt hours per square meter per year), close to the upper limit predicted in lab tests. “We did not expect a yield as high as this so quickly,” Sten De Wit, spokesman for SolaRoad, said in a statement. The surprisingly inconspicuous solar panels are embedded into the concrete paving like ceramic tiling. Each panel is protected by an 0.4-inch layer of transparent, skid-resistant tempered safety glass designed to withstand the weight of passing vehicles. The pilot test itself will gauge the skid resistance of the solar panel path as compared to asphalt, and to ensure that it does not create any distracting reflections. Over 150,000 cyclists have reportedly traversed the solar-generating part of the path. According to SolaRoad, they “hardly notice it is a special path.” However, tests have shown that significant temperature fluctuations cause the glass coating to shrink, so that parts of it peel away in the winter and early spring. The coating has since been repaired, and engineers are in the “advanced stage” of developing an improved top layer. The 3-year pilot project, costing around $3.8 million, is a public-private partnership between the Dutch province of Noord Hoolland and engineering firms TNO, Ooms Civiel, and Imtech. Closer to home, Idaho inventors Scott and Julie Brusaw have their own iteration of power-generating roads, called Solar Roadways. The Brusaws are building a prototype parking lot in their headquarters featuring 108 panels to test their efficacy in the face of vehicle-imposed wear-and-tear. The hexagonal panels are designed for roads, driveways, parking lots, bike trails, and eventually, highways, and have already courted $850,000 in seed funding from the federal government and an additional $2 million from crowdfunding website Indiegogo.