I think you are confused. I never made the claim you are refuting, I merely pointed out that comparing solar roads to traditional solar panels is a moot point. Secondly, you assume that costs and technology would not decrease and become more sustainable (which if they continue to do at the same rate would take about ten years to become feasible). Current solar panels can last for over 1.1 million (or there abouts) truck tires - depending on the road that is over a year before replacement is needed. I further think you misunderstand the costs associated with ashphalt maintenance.... think pot hols.... not that hard to replace sections of a solar panel road tbh (if engineered correctly) think of a lego block or brick roads... same principal.
you are also making the same mistake as the previous person... "little gain" even if it is at 56% (which assumes no increase in technology) considering there are 3,980,817 miles of road in the USA alone that figure translates to VAST/HUGE/HUMONGOUS amounts of power.....
they also have resolved the majority of traction issues.... most of the examples you use to refute it's viability, if researched, is debunked, especially if the technology doesn't remain static (which, surprise, it doesn't).
BTW, here's the math based on current tech as of 2016:
In the 48 contiguous states
alone, pavements and other impervious surfaces cover 112,610 square
kilometers - an area nearly the size of Ohio - according to research
published in the 15 June 2004 issue of Eos, the newsletter of the
American Geophysical Union.* It is believed that continuing development
adds another quarter of a million acres each year and that typically,
two-thirds of the cover is pavements and one-third is building roofs.
Here are some conversions:
112,610 square kilometers equals 43443.54 square miles. The report used
data from 2001, so in 2016 (15 x ¼ million acres) an additional 3.75
million acres have been turned into impervious surfaces. That's an
additional 5859.38 square miles, so all told, we have 49302.92 square
miles of impervious surfaces.
Removing 1/3 for rooftops and that leaves 32,868.61 square miles of roads, parking lots, driveways, playgrounds, bike paths, sidewalks, etc., to work with.
If these impervious surfaces were replaced with Solar Road Panels, how much electricity would we produce?
In labs, solar cell efficiency has
exceeded 44-percent, but they're not cost feasible yet. For our
calculations, we use commercially available solar panels, which are cost
The efficiency of 18.5% is commonly
available, so for the calculations, the following (conservative)
assumptions have been made:
Solar cells have an 18.5% efficiency There is an average of only 4 hours of peak daylight hours per day (4 x 365 = 1460 hours per year) Sunpower offers a 230 Watt solar panel
rated at 18.5% efficiency. Its surface area is 13.4 square feet. If the
entire 32,868.61 square miles of impervious surfaces were covered with
solar collection panels, then:
((32,868.61 mi²) x (5280 ft / mi)²) / (13.4ft²/230W) =
((32,868.61 mi²) x (27,878,400 ft² / mi²)) / (13.4ft²/230W) =
(916,324,257,024 ft²) / (13.4ft²/230W) =
15,727,953,665,337 Watts or over 15.73 Billion Kilowatts
Considering only the average of 4 hours
of peak daylight hours (1460 hours per year), this gives: 15.73 Billion
Kilowatts x 1460 hours = 22,966 Billion Kilowatt-hours of electricity.
The farther north one lives, the more one
has to angle solar panels toward the equator (or more accurately, the
sun above the equator) to gain maximum efficiency.
Solar Roadways did some testing at our
location in northern Idaho, an hour south of the Canadian border at
latitude 48.19 degrees. The farthest northern point in the contiguous 48
states is 49.38 degrees near Lake of the Woods, Minnesota. That's 82
miles farther north than our location. At this northern position (48.19
degrees North), the optimal solar gain angle for solar panels is 72
degrees. By contrast, Brownsville, Texans would want to angle their
solar panels at 26 degrees. So southern roads will naturally produce
much more electricity than their northern counterparts, as solar
intensity maps show.
Unfortunately, we can't angle roads or
parking lots. Roads go up and down hills, have banks on curves (going
both left and right), and have a typical three percent "crown" (on both
sides) to allow stormwater runoff. It's a pretty safe assumption to
figure that the national average angle of roads is zero degrees.
We tested two identical solar panels. One
was mounted at the recommended 72 degrees. The other one was placed in
line with the horizon (zero degrees) to simulate an average road. We
installed a monitoring system to track the data 24/7.
Although the tilted solar panel produced
more energy as expected (an average of almost 31 percent more than its
horizontal counterpart), we discovered a phenomenon that was apparently
previously unknown: The horizontal solar panel produced more energy than
the tilted panel on certain overcast days. It appears to be similar to
getting sunburned on a cloudy day: sunlight is still present, but it is
scattered, so the horizontal solar panel is more likely to pick up the
scattered photons than the solar panel aimed at the southern horizon.
For fairness, we subtract 31 percent from our totals since we can't angle roads and parking lots:
22,966 Billion Kilowatt-hours x 0.69 = 15,847 Billion Kilowatt-hours
Another finding from our experimentation
was that our 1/2-inch textured glass surface reduced the amount of
energy produced by solar cells by 11.12-percent (we are experimenting
with some changes to improve that number). Subtracting that from the
total, we still have 14,085 Billion Kilowatt-hours. And
remember: this is the amount of power calculated for a latitude near
the Canadian border. The number would be much larger if calculated for
the southern states.
While we found no evidence that moonlight
or the light from shining stars at night produce energy in solar panels
(a common question), we found that headlights did. Although it would be
very difficult to measure accurately due to distance, speed, hi/low
beams, etc., we found that a small solar panel placed flat on the ground
about 10 feet in front of a vehicle with its high beams on produced
electricity in otherwise total darkness. So it appears that vehicles
driving on the surface at night will be providing a service as well as
reaping the benefits.
According to the Energy Information
Administration, the United States (all 50) used 3,741 Billion
Kilowatt-hours of electricity in 2009 (EIA Electricity Overview,
1949-2009). It's easy to see that Solar Roadways could produce over
three times the electricity we currently use in the United States! In
fact, just the "lower 48" could produce just about enough electricity to
supply the entire world!
Remember that these calculations are made
with very conservative numbers using north Idaho as a reference point,
which is one of the least favorable latitudes in the U.S. for solar