An Economic Evaluation of Solar Roadways

Team 27 - Scott Herlihy, Jennifer Kreps, Jordan Smith, and John Steinberg

Energy and Energy Policy - Econ 26800/01

R. Stephen Berry and George S. Tolley

1

Table of Contents

An Economic Evaluation of Solar Roadways...............................................................................3

What are Solar Roadways?................................................................................................................ 3

Solar Roadways Claims........................................................................................................................ 4

History of Solar Roadways................................................................................................................ 7

Economic Implications....................................................................................................................... 8Economic Implication #1 - Snow Removal..............................................................................................8Economic Implication #2 – Accidents.................................................................................................... 11Economic Implication #3 – Fiber optic cables/ electricity underground..................................13Economic Implication #4 - More Skilled Labor...................................................................................19

Barriers to Adoption......................................................................................................................... 20Barriers to Adoption #1 - Technological Concerns...........................................................................20

Technological Concern #1 - A road made out of Glass..................................................................................21Technological Concern #2 - LED Lights issues.................................................................................................24

Barriers to Adoption #2 – Government.................................................................................................25Barriers to Adoption #3 - Competition..................................................................................................27

Cost Analysis....................................................................................................................................... 29

Conclusion............................................................................................................................................ 32

Works Cited......................................................................................................................................... 35

Appendix.............................................................................................................................................. 36

2

An Economic Evaluation of Solar Roadways

Abstract: This research paper explores the reality and implications of the proprietary technology

of the Sandpoint, Idaho company Solar Roadways. The goal is not to predict whether or not

Solar Roadways will garner widespread adoption, but rather to investigate the company’s claims

and implied effects on a level we do not believe exists elsewhere. Our belief is that at present,

there do exist alternative solutions to the carbon emissions crisis that exhibit similar benefits to

those purported by Solar Roadways, but we support the continued exploration of the technology

because it has tremendous potential for environmental impact if it overcomes many barriers to

adoption.

What are Solar Roadways?

In our analysis of solar roadways and their feasibility and economic impact, we will look

at the start up, Solar Roadways. Founded in 2006 by Julie and Scott Brusaw, the company’s goal

is to cover all concrete and asphalt surfaces with solar road panels to end America’s dependency

on fossil fuels. They aim to form a smart highway system interconnected across the country,

perpetuated by energy collected by photovoltaic (PV) cells embedded under a transparent driving

surface and alongside electronics and sensors. Solar Roadways understand the adoption and

retrofitting of solar road panels will need to be taken in stride, with small-scale implementation

through sidewalks and parking lots before larger-scale installation on local roads, highways, and

3

finally interstates. If adopted as an acceptable alternative road, Solar Roadways believes their

solar road panels can transform the American energy landscape.

While the idea, if plausible, could be revolutionary, the technology behind Solar

Roadways is not. Solar Roadways utilize and reconfigure pre-existing technologies in their solar

road panels. The solar road panels have four “layers,” the first a base layer with a mix of

recycled materials to provide stability, the next an electronic layer with large circuit boards that

house PV cells, heating element, and power transporters, an LED light layer that can be used for

signage and sensors, and finally a top layer of tempered glass that serves as a road surface. Each

four-layered solar roadway comes in a hexagonal panel that is independent, but can connect and

interplay with other panels.

Solar Roadways Claims

Solar Roadways claim various technological advancements and economic impacts they

believe solar roadways can achieve. As a preface to our more detailed assessment and analysis to

come, we begin with an initial exploration of these claims and the credence behind them.

As previously discussed, solar roadways are made up of technologically advance

hexagonal blocks.

Photo Credit: Youtube

4

Each hexagonal block is equipped with LED lights that can be programmed to create landscape

designs, e.g. driving lanes, parking lots, etc. The LED lights are capable of being controlled from

a central location to create any design necessary. A key concern surrounding the use of LED

lights is the visibility of the designs during the day. While LED provides greater visibility at

night and are paired with sensors that can send warnings if a person or animal steps onto the

road, they are unproven in daylight.

Photo Credit: Youtube

Solar roadways also include a heating element, claiming they can heat roads when

necessary simply from the energy generated from the sun. A benefit we will assess is the ability

to create safer roads by melting snow and ice. This could potentially lead to fewer accidents and

death as well as eliminate the need for snow removal and salt. Salt, especially, is extremely

harmful to the roads and results in numerous expenditures for road and vehicle repair due to

erosion of cars and asphalt.

The question now becomes, though, where does all of the melted snow and ice go? Solar

roadways hope to be equipped with two channels beneath them. One channel captures and filters

storm water and melted snow/ice. The water could be filtered onsite or moved through the

channels to a treatment facility (SolarRoadways.com). Water pollution could be greatly reduced

if this system materializes, as polluted water would runoff into the channel rather than nearby

5

soil, river, lakes, or oceans. The second channel, the cable corridor, could store and route power

lines, phone lines, cable lines, etc. We will further explore the economic vitality of the cable

corridor and undergrounding power and cable lines.

The durability of Solar Roadways is another area of claim and concern. Solar Roadways

claims that the solar road panels have a life expectancy of 20 to 30 years. It seems logical that a

road free of erosion or cracks would extend a road’s health and lifespan. However, Solar

Roadways are limited by the PV cells within them that have a maximum life expectancy of 30

years themselves. For comparison, a current asphalt road has an average life span of 25 years

with a much lower cost of repair or replacement than PV cells or an entire solar road panel. This

challenges Solar Roadways’ claim of durability and the idea that solar roadways could increase

the longevity of America’s road system.

The most important contribution and claim of solar roadways is their ability to capture

and distribute solar energy. Solar Roadways estimates that “if all roads in America were

converted to solar roadways, we would generate three times as much power as we currently use”

(SolarRoadways.com). This claim is farfetched in many ways and a vision that will take a great

deal of money and innovation to achieve. Throughout this paper, we will attempt to decompose

Solar Roadways claim of great economic and environmental impact on a cost-benefit basis. This

impact, however, needs to be addressed alongside various challenges Solar Roadways have

either yet to overcome or even consider.

History of Solar Roadways

To turn an idea into a tangible, obtainable product, Solar Roadways needed capital to

begin research and construction. In 2009, Solar Roadways secured a Small Business Innovation

6

Research grant of $100,000 from the Department of Transportation. This grant helped fund both

research and the creation of prototype I. Prototype I was finished in February of 2010 and was

largely a “proof-of-concept,” showcasing the various electrical and functional aspects of the

solar roadway but unable to incorporate PV cells or generate power. After securing additional

seed money, $50,000 from GE’s Ecomagination challenge in 2010 and an additional $750,000

grant from the Department of Transportation in 2011, Solar Roadways set out to build a more

realistic model of their vision. Solar Roadways was able to complete a 12x36 foot (108 solar

panels) fully functional parking lot, containing PV cells, generating energy, integrating a heating

element, and utilizing more durable glass. In Prototype II, only 69% of the solar road panels

contain PV cells, while it is expected that PV cells cover 100% of the road panels before

commercial production. This is an example of the progress and work that needs to be done on the

solar road panel model before it is even close to large-scale installation.

Although there have been some slight adjustments, Prototype II is the most current solar

roadway model. Solar Roadways claims their solar road panels can withstand 250,000 pounds

and a car traveling 80mph can effectively and efficiently stop. However, currently, these are just

claims and a great deal more of testing and assessment must be done before people and cars

begin to travel on these panels. In 2014, Solar Roadways secured their most recent funding

through a large online campaign through Indiegogo. They raised $2.2 million, more than 220%

of what was expected, that will be put towards testing, improvements, and further innovations.

Economic Implications

As is clear from the sections above, Solar Roadways are claiming that their creation is

capable of truly revolutionizing the world. These touted declarations of scientific invention and

7

achievement are assessed below along with other barriers to adoption. Prior to that inquiry,

though, we thought it would be best to explore some of the economic ramifications of Solar

Roadways claims if they were inevitably proven true. This investigation proves valuable because

it will be relevant to any public or private entity that chooses to employ the technology. While

this idea is still in the infancy of prototype testing and specifications regarding it are difficult to

acquire as a result, we made it a point of emphasis to ground our positions in quantifiable

statistics gathered from other sources.

Economic Implication #1 - Snow Removal

We will first evaluate Solar Roadways’s claim that they can eliminate the necessity for

snow removal through the heat plate beneath the road surface that will melt any and all snow.

Snow removal is an unassuming burden for the local and statewide economy. For example, in

December of 2010, North Carolina and Philadelphia spent $4.5 and $3.4 million dollars on snow

removal respectively (Time.com). Snowfall, although it does not affect most of the south and

southwestern parts of the Unites States, still covers about 63% of United States land each year

(Time.com). All of this snow must be removed from the roadways in a timely and effective

manner so that the safety of all travelers can be ensured. Unfortunately, though, while individual

snowstorms are relatively predictable, entire seasons are extremely difficult to forecast in

advance. As a consequence, there have been many instances of misallocation of government

funds by local and state representatives.

8

The image above highlights this discrepancy between actual and predicted spending. This issue

is paramount; there is a safety risk with accidents if the government budgets too little and a

misallocation of taxpayer’s money that can be allocated elsewhere if they budget too much

(http://ibo.nyc.ny.us). To understand this discrepancy further, we will evaluate the specific cost

of snow removal.

Naturally, the major costs of snow removal are equipment, labor, and availability and

price of road salt. While the equipment (i.e. trucks, snow plows, building infrastructure) can be

seen as fixed sunk costs —they have already purchased them and cannot factor those costs into

future decision-making processes — the cost and quantity required of both labor and salt is

highly variable. It is very tricky to decide how much labor to employ or salt to purchase before

the winter season because officials must operate off of historical averages, future predictions,

and current market rates. Neither past nor future snowfall measures ultimately resemble or mimic

what’s to come in the present. Furthermore, the mercurial nature of salt costs (for example, the

price of salt recently doubled from $30 to $60 per ton) adds another element to this already

convoluted process (NASBO.org).

As a result, local authorities unfortunately often estimate incorrectly. For example, in

2011 32 states had snowfall surpass their estimates for that year. In New York and Boston, the

estimated averages were 12 and 20.2 inches of snow and the actual snowfall was 57.7 and 70

9

inches respectively (NASBO.org). When such discrepancy between estimate and actual spending

occurs, local agencies must seek funding for local snow removal from the state transportation

departments. When the state governments run out of funds (which is more likely than one may

think) they end up seeking federal assistance. Even though snow does not affect all areas of the

U.S, a misestimate on the local level can have national ramifications (NASBO.org).

If solar roadways can sufficiently melt snow and ice, they can drastically reduce, if not

eradicate this issue. By eliminating snow on the roads, Solar Roadways can also eradicate the

government’s need to forecast future weather and predict supply levels and cost. This could not

only help reduce repercussions that come with over or under budgeting for winter storms, but

also the government’s exposure to varying costs. Money traditionally spent on snow and ice

removal can now be allocated elsewhere as well.

Solar Roadways can be advantageous for corporations as well. Looking at the larger

ramifications of a dangerous, snow lined, slippery road, an unplowed or icy road serves as a

large deterrent to going into the office. According to the Financial Forecast Center, America’s

GDP in March 2011 was in the neighborhood of $646.27 billion per day. The 17 states that hit

hardest by storms that year contained approximately 38% of the U.S. population; assuming that

20% of the population employed didn’t show up for work, we’d hit a figure of $48.8 billion in

lost productivity (Business.Time.com). We believe this estimate is on the upper bound but still

provides evidence for some loss in productivity in locations with greater snowfall. By using

Solar Roadways, this deterrent to go into the office would be resolved and the loss of

productivity due to snow and ice somewhat reduced.

While there are many positives associated with Solar Roadways snow removal, there are

also negative consequences. If Solar Roadways eliminates the need for snow removal, it also

10

eliminates the job of removing the snow and of producing equipment and products to do so. The

labor force employed injects cash into the economy. At a high level, the more laborers with

wages, the more discretionary income they have to spend. This can help contribute to growth in

other areas of the economy. With Solar Roadways’ technology, it eliminates seasonal jobs and

reduces demand for products such as snowplows and salt. This would have some negative affect

on the local employment and producing sectors. While the implementation of solar roadways

would generate a new line of specialized laborers, when speaking specifically about snow

removal and not the larger installation of solar roadways, there would be a reduction rather than

addition of jobs (especially for lower waged, less skilled laborers).

Economic Implication #2 – Accidents

When considering economic implications related to the roads, accidents and their

repercussions are common, oftentimes expensive, externality costs. Weather can contribute

greatly to the number and severity of car accidents. The costs related to accidents can be

multifaceted, from clean up crews, hospital injury coverage, and insurance. “Each year, 24

percent of weather-related vehicle crashes occur on snowy, slushy or icy pavement and 15

percent happen during snowfall or sleet. Over 1,300 people are killed and more than 116,800

people are injured in vehicle crashes on snowy, slushy or icy pavement annually. Every year,

nearly 900 people are killed and nearly 76,000 people are injured in vehicle crashes during

snowfall or sleet” (http://ops.fhwa.dot.gov).  The chart below displays additional statistics related

to weather-induced accidents.

11

Thus, it is evident that there is a relationship between snow and ice on the roads and the number

of accidents and deaths related to them. Solar Roadways has the opportunity to combat this issue

through their snow removal method. With little to no snow or ice on the road, there is a

dramatically lower chance of an accident occurring.

Car accidents are not only caused by adverse weather, but also from animal-vehicle

collisions. In many states, an accident with a deer can cause serious damage to the vehicle and

sometimes bring death to the occupant. The chance of hitting a deer in some states is as high as 1

in 44 (bankrate.com). It was estimated that the aggregate cost of deer collisions in the US

between 2011-2012 was $4 billion (wc4eb.org).  In addition to a heating element, Solar

Roadways has a sensor that could detect the weight of animals on the road ahead and

appropriately warn oncoming drivers through the use of LED lights and communicating road

panels. Many accidents occur at night or around blind corners. LEDs and their ability to

forewarn drivers of hazards to come can drastically reduce animal-car incidents.

12Snow/Sleet 211,188 crashes 4% of vehicle

crashes17% of weather-related crashes

58,011 persons injured

3% of crash injuries

13% of weather-related injuries

769 persons killed 2% of crash fatalities

13% of weather-related fatalities

Icy Pavement 154,580 crashes 3% of vehicle crashes

12% of weather-related crashes

45,133 persons injured

2% of crash injuries

10% of weather-related injuries

580 persons killed 2% of crash fatalities

10% of weather-related fatalities

Snow/Slushy Pavement

175,233 crashes 3% of vehicle crashes

14% of weather-related crashes

43,503 persons injured

2% of crash injuries

10% of weather-related injuries

572 persons killed 2% of crash fatalities

10% of weather-related fatalities

Solar Roadways’ ability to reduce the probability of an accident occurring (from both

weather and animals) reduces the expected budget for accident clean up crews and hospital bills,

among many other costs. The individual, government, and corporations will therefore save

money typically spent on car accidents and be able to allocate the money, time, and resources

somewhere else.

Economic Implication #3 – Fiber optic cables/ electricity underground

A solar roadway is multifaceted in that it can provide economic implications beyond

solar energy collection, weather-related costs, and accident prevention. Solar Roadways have

proposed moving cables and power lines into a cable corridor underground alongside the solar

roadway. While enticing, there are economic risks and rewards to this idea that need to be

explored. Cost is key when assessing the possibility of integrating cable and power lines into

Solar Roadways. A cost analysis between aerial and underground lines will extrapolate the

viability and economic liquidity of Solar Roadways as not only power generating roads, but

cable holders as well.

Aerial and underground fiber optic lines require different labor specializations, materials,

maintenance, and have fundamentally different cost structures. Aerial lines are the more

conventional method of cable, electronic, and power transportation. In the U.S, more than 82%

of transmission line miles are installed overhead (CNN.com). There is logic behind this

widespread adoption of aerial installation, driven by the lower costs associated with installation,

maintenance, labor, and materials. For a new aerial utility pole installation, it costs about

$25,000 to $50,000 per mile on average. Labor, in specific, constitutes about 50-80% of the cost

(CTCnet.us). However, both labor and quantity of fiber strands, cables, and material costs can be

13

highly variable depending on geographic conditions. The aerial installations are especially

susceptible to economies of scales; in higher density areas more people are reached per one mile

of installation and therefore greatly reduce the cost of construction. Economics of scales is just

one way to reduce the cost of overhead installation. Overlash, a process where network providers

attached lines to pre-existing utility poles, is another method that can further reduce the cost of

running aerial power and cable lines overhead by approximately $13,000 to $20,000 per mile

(CTCnet.us).

In contrast, underground power, cable, and fiber optic lines have a greater range and

often-higher cost than aerial installation. There are different methods of undergrounding fiber

optic lines, from plowing where cables are buried directly into the ground, trenching where

cables are placed into trenches, or boring where a machine is used in areas where the surface

cannot be worked on to dig a hole and pull the fiber cables directly underground. Plowing and

trenching typically cost $70,000 per mile while boring can range from $90,000 to $400,000 per

mile (CTCnet.us). The graph below shows the large difference in price between overhead and

underground fiber optic line distribution:

14

In this cost analysis, there is more to the cost structure of aerial versus underground fiber

optic lines than the direct costs and capital expenditures already discussed. Future costs must be

taken into consider as well when understanding the viability and economic rewards and risks of

embedding lines underground alongside solar roadways. Future costs capture any maintenance,

damage, or problems that could arise. Aerial lines are more vulnerable to the damages weather

can inflict. With every hurricane, windstorm, tornado, snowstorm, there is the additional repair

or rebuilding costs. For example, every 6-count cable line damaged or destroyed costs $2,000 per

mile to replace; every 864-count cable it is $50,000 per mile (CTCnet.us).

With underground fiber optic lines, there are few weather-induced future costs that need

to be taken into consideration. One of the key advantages and motivations to move cable lines

underground is to try and eliminate future costs based on unpredictable and uncontrollable

weather. New York City has had underground lines for 125 years. Throughout that time, it has

been ten times more reliable than an average American grid (ibtimes.com). This helps support

the notion that an underground fiber optic line network could prevent cost casualties associated

with power loss such as loss of business revenue, spoiled food, and power for generators.

15

However, the true question that needs to be explored when looking at a cost-benefit analysis of

undergrounding fiber optic lines is if the cost of power loss or a blackout due to poor weather

outweighs the higher cost of undergrounding.

Blackouts, brownouts, or other power outs from weather-related incidents cost Americans

an average of $18 to $33 billion per year (Energy.gov). This includes all externality costs

associated with a loss of power, and therefore shows the larger implications of a blackout and the

disruption it causes. The extent of impact and cost varies year to year, and is largely dependent

on the weather extremity and conditions of that year.  Looking narrower in scope, there was a

major storm in 2012 that contributed greatly to blackout costs in the Washington D.C metro area.

In response, many called for undergrounding of all wires to prevent future blackouts. The cost to

do so was estimated at $5.8 billion (equivalent to an additional $266 on customers’ monthly

electricity bill for the next 10 years) (WashingtonPost.com). While only a fraction of the total

costs associated with blackouts nationwide, if this was implemented not only in D.C but cities

and suburban areas across the country, it would be arguably more to underground power and

fiber optic lines. Therefore, what some deem as a flawless “solution” to electrical disruptions

have definite costs to it as well. The viability of undergrounding in response to adverse weather

would ultimately be dependent on the strength and impact of future storms as well as the specific

costs for cities and certain geographic regions.

Underground fiber optics aren’t entirely immune to weather or other disruptions as well.

Impacted less frequently than aerial lines, underground cables face complications from flooding

and technical damages. Since these problems would occur underground, they are oftentimes less

apparent, harder to identify, and harder to fix. This can lead to additional costs even when lines

sheltered from weather extremes or other catalyst of aerial destruction. It seems, therefore,

16

somewhat counteractive to underground in hopes of evading disruptions and damages to the fiber

optic lines. Many believe that it would be logical to underground a few, key lines to prevent

weather and other damages rather than attempt to underground an entire system.

Currently, it seems cost prohibitive to underground fiber optics lines. However, we are

not just assessing undergrounding in scope of the three methods commonly used to do so, but in

light of the possible transformative role solar roadways can play in cutting costs and streamlining

the process. Solar Roadways proposed cable corridor will allow fiber optic lines to share in the

benefits of the road panels (shelter from weather conditions, source of heat from the solar panels

heating element, shelter from people digging and unearthing lines, etc.). Instead of employing

machinery and laborers to bore into the ground, Solar Roadways will act as an underground

channel to harbor these fiber optic lines (SolarRoadways.com). In a 2014 study done by CTC

Technology & Energy to understand the cost of connecting a school to a larger fiber optic grid,

based on unit contractor costs for other large-scale projects it was estimated that a new

underground construction would cost a total of $85,594 per mile. Of that total $85,594 cost,

$70,985 is labor and machinery costs. In more dense urban settings like Chicago or New York

City, it would cost about $217,594 total per mile to underground lines, with labor and machinery

costs representing about $202,985 of that (CTCnet.us). Material costs per mile are fixed costs,

remaining constant regardless of population size or geographic region.

While this is just one study, it synthesizes many large-scale projects to create a

comprehensive and representative conclusion that showcase the large skew of underground costs

towards labor and machinery. Solar Roadways can help eliminate the large economic burden

undergrounding currently posses since the upfront cost needed to just install solar road panels

will already include labor and machinery. Just looking at the cost of undergrounding fiber optic

17

lines through the cable corridor and various elements of the solar road panels, Solar Roadways

can help to reduce the cost of undergrounding cables and therefore make the practice more

common and widespread. Solar Roadways even purposes future cost cuts beyond simple labor

and equipment. Solar Roadways believes in a decentralized power system, where much of the

power is used near the power source. Smaller cables would be required in this power system as

they are not only traveling a shorter distance but carrying smaller units of energy at one time.

This could then cut the cost of materials in addition to labor and machinery as well. With these

significant cost savings, Solar Roadways can make undergrounding fiber optics an economic

reality rather than an overly expensive alternative option. Returning to the 2014 CTC

Technology & Energy study, if labor and machinery costs are eliminated and material cost

slightly reduced, the total cost when utilizing solar road panels would be approximately $14,000

per mile. Undergrounding fiber optic lines in solar roadways could therefore be more

economically advantageous than installing new aerial installations and even rival techniques that

use pre-existing overhead poles such as overlashing.

While there are immense economic upsides that can reduce the cost of undergrounding,

there are still risks when integrating fiber optic cables into Solar Roadways. Regardless if the

cable lines are underground or in a concealed cable corridor, underground lines are susceptible to

insulation deterioration due to the nature of the lines lifetimes. With time, a cable’s insulation

weakens and there is an increased chance of a line fault. If or when there is a line fault, the cost

to find, cable splice, and then reintegrate can be 5 to 10 times more expensive than repairing an

aerial damage (ELP.com). It could cost even more if the entire solar roadway panel needs to be

removed and replaced to locate and fix the cable. It traditionally takes almost 60% longer to fix

an underground problem as well, leading to higher labor and machinery costs (CNN.com).

18

The extent of these variables, and therefore additional costs, are still unknown especially

when considering the lack of understanding and development of solar road panels. Take, for

example, the current time to identify and fix an underground problem. The cable corridor could

reduce the time to identify and fix the problem, but it can just as likely extend the problem or

require a more specialized labor force. While it appears Solar Roadways can reduce

undergrounding costs exponentially if the cable corridor and solar roadways themselves are

viable, the costs of maintenance, damage, and other factors related to both underground fiber

optic lines and lines embedded within solar road panels have yet to be determined. When further

information is available, a more thorough cost analysis of underground lines using solar

roadways can be determined. Until then, we can conclude that solar roadways indeed greatly

reduce the cost of underground fiber optic lines, but just how economically effective and sound

the solar roadways method is, is ultimately undecided.

Economic Implication #4 - More Skilled Labor

As we alluded to above, technologically enhanced skilled labor that is not traditionally

associated with the public works industry will be essential for Solar Roadways. There is a vast

difference in complexity between laying asphalt and rewiring and re-coding a solar panel.

Maintenance employees must be able to handle the additional responsibilities and technical

aspects of a solar road panel. Either a higher level of specialization or additional training will be

required for this profession, resulting in higher compensation for the job.

Since there is no exact labor specifications required to install and maintain the solar

roadway, we will be assessing it at a high level. Let’s umbrella the labor force required for Solar

Roadways under an electrical engineer. An electrical engineer requires rigorous education,

training, and knowledge that also demand a higher salary. The median salary for an electrical

19

engineer falls around $91,410 a year or $43.95/hour. In contrast, there is less training and skillset

required for an asphalt road paver, and therefore simply less credence behind demand for a high

salary. The median salary falls around $38,545 a year or$19/hour (Salary.com). While this is a

rough salary estimate, it demonstrates an important concept. There are more costs to Solar

Roadways than the technology and installation. Future costs, especially labor, are large and

looming. There is about a $50,000 difference between the labor currently required to maintain

the road system and the one that would be needed with a Solar Roadway system. We

acknowledge we’re taking a simplistic viewpoint, but it’s one that highlights the extraneous costs

associated with solar roadways and the unknowns that need to be addressed.

Barriers to Adoption

The previous sections explain some of the potential contributions to society as a whole

Solar Roadways are capable of if their claims prove to be true. However, in order for that to

come to fruition, there are a number of hurdles the company needs to surmount. This section

surveys some of those factors we feel have yet to be addressed. Only when these barriers to

adoption are conquered can the economic implications of Solar Roadways truly be realized.

Barriers to Adoption #1 - Technological Concerns

Solar Roadways have made a variety of claims about what their technology can do or will

eventually be able to do that many critics have expressed doubt over. Due to the number of

objections to the technology specifically, we decided to dedicate a subjection of our “Barriers to

Adoption” analysis towards the two most popular criticisms.

20

Technological Concern #1 - A road made out of Glass

Solar Roadways faces many headwinds in their efforts to materialize a solar generating

road system into a viable reality. Many barriers to adoption, such as cost and other logistical

obstacles, have prevented the quick adoption and installation of solar road panels across

America. Solar Roadways’ barriers to entry revolve largely around feasibility in implementation

and usage as an actual road and energy source. In specific, the tempered glass that serves as a

roadway and walkway is highly contested in regards to traction, weight constraints, drivability,

costs, and overall comparison to asphalt roads. As we asses the validity and economic impact of

Solar Roadways’ solar road panels, it is key to asses the barrier to adoption a glass surface

posses.

Solar Roadways uses a special tempered glass as the surface of their solar road panels.

Ribbed with grooves and rivets that provide greater traction, this transparent glass road surface

provides a very different driving experience with greater challenges and uncertainties than the

more common asphalt surface. A main uncertainty is the viability of this glass surface as an

actual roadway. Solar Roadways currently has two types of glass, one semi-smooth walking

surface they claim can stop a car traveling 40mph, and another raised hexagonal glass panel

designed for highway use that can supposedly stop a car traveling 80mph. A main issue with

these claims is that they are simply claims. Solar Roadways have yet to construct a roadway long

enough to actually test the hypothesis that a car, especially in wet conditions, can stop in the

appropriate distance when traveling 40 or 80mph. Therefore, there is no benchmark test or result

to prove the viability of tempered glass in regard to traction and drivability. Solar Roadways is

vague in quantifying what testing’s been done, simply stating that the glass surfaces have been

tested at a university civil engineering lab. They are even as imprecise as “Scott rode a bike on

21

the prototype with no problem” (SolarRoadways.com). There is such a void of scientific, exact,

specific language and evidence that it makes Solar Roadways appear more like a science fair

project rather than a credible solution to America’s dependency on fossil fuels. The lack of

transparency and lack of information creates a strong obstacle to implementation and adoption.

There is a great deal of work, of rigorous analysis, testing of their product, and acceptance by the

DOT, before a tempered glass surface can be used as a roadway.

The feasibility of a glass roadway is not limited to traction and level of drivability. It also

depends on the ability to support the weight of cars, trucks, busses, and other vehicles that drive

upon it. A roadway is not static. There is a flow of traffic that provides different weight

constraints at different times. Solar Roadways addresses the concern of weight through the

principle laid out in the Mohs Hardness Scale. Glass has a 5.5-6.0 hardness scale while asphalt

only has a 1.3 hardness scale. A solar road panel uses tempered glass that typically runs even 4-5

times stronger than non-tempered glass. Therefore, Solar Roadways argues tempered glass has a

degree of hardness that allows it to be a suitable roadway. They claim that 3D finite element

method analysis and actual load testing at civil engineering labs showed the solar road panels can

support more than 250,000 pounds of weight at one time (SoalrRoadways.com). Such analysis

and testing are processes that help assess the legitimacy of Solar Roadways’ weight claims, yet,

there is again a lack of transparency in the details and extent of the results. The viability of glass

road panel hinges on Solar Roadways’ ability to create a road complete in nature and size and to

accurately describe various testing and analysis performed on the tempered glass surface. Until

then, the inability to understand the nature of traction, drivability, and weight constraints of the

glass surface will continue to be a true barrier of entry.

22

Glass and asphalt differ in more ways than simply the driving experience they provide.

The cost of tempered glass in comparison to asphalt is essential when assessing the viability of a

glass road surface not only as a physical entity but economical one as well. Scott Brusaw

estimated in 2010 that a 12x12 foot segment of a solar roadway would cost about $10,000 (or

$70 per foot) (Extech.com). However, since then, Solar Roadways has revised this statement and

now have no current estimate of how much a solar road panel, nerveless an entire solar roadway

or system, will cost. This lack of foresight or even cost awareness is not a good sign. Relying on

third party sites like The Economist, it is estimated that it could cost anywhere between 50% and

300% more expensive to use solar tiles rather than asphalt to pave a road (Economist). Other

estimates project it could cost anywhere from $1 trillion to $56 trillion to cover all American

interstate highways with solar roadways. While these estimates include the entire solar roadways

and not just the glass surface, the cost of the glass is definitely a large contributor of cost. Since

Solar Roadways is unable to provide an accurate, or even ballpark suggestion on the cost of the

tempered glass, we will base our estimate on what material supply companies charge. Looking at

a range of supply companies, it appears a square foot piece of tempered glass can cost anywhere

between $40 and $200 (nwastainedglass.com). Solar Roadways doesn’t use simple tempered

glass, but rather ones with additional texture and strength. This would shift the cost towards

higher projections, and therefore place the cost of a unit of glass at about $200 per unit. This not

only far exceeds Solar Roadways initial cost estimates, but more importantly exceeds the cost of

asphalt roads. Asphalt roads can cost anywhere between $3 and $15 per square foot

(Extech.com). While economies of scales in large-scale production can help drive down the cost

of the glass, as of now the cost of the tempered glass road surface is exponentially higher than

23

asphalt. The cost discrepancy is so large that a glass surface is an inhibition to the adoption and

implementation of solar roadways rather than a point of excitement and innovation.

Cost is king when comparing glass and asphalt surfaces. However, there are some minute

details of simple practicality that need to be overcome as well. First, there is the simple principle

that glass shatters. While it is proven that tempered glass is extremely strong and hard, moving

vehicles and car crashes have such power and force that could break or damage the glass surface.

Tempered glass, instead of shattering, rather breaks into small circular pieces with no sharp

edges of hazardous size and shape. Therefore, if and when the road surface breaks, the use of

tempered glass reduces the hazard to people and vehicles on it. While tempered glass itself seems

relatively safe, the fact that it can break or crack at all serves as key point of concern and can not

only be costly to fix and replace, but extremely dangerous as a roadway. Solar roadways not only

can crack, but can become less transparent from dirt, mud, leaves, and other soot. A solar

roadway runs under the pretext that it can generate solar energy, but without a transparent

surface to allow light in, PV cells have no light to turn into energy. There would therefore be no

purpose to the cost or installation of solar road panels altogether.  How the glass surface will stay

clean enough to be translucent a majority of the time is a challenge that must be solved before

solar road panels are actually tried as roads and energy producers.

Technological Concern #2 - LED Lights issues

Another major concern is the Solar Roadways use of Light Emitting Diodes (LEDs) to

display road lines and other road markings. We understand it would be difficult to use the current

practice of painted road signage for solar roads. While LED lights are innovative and extremely

effective during the night, there is a question regarding the visibility of LEDs during the day.

Every photo of the solar roadway LED lights are either taken inside or after dark. In fact, the

24

founders of Solar Roadways concede that, while they believe this is a fixable issue, “for the

prototype though, we found that the LEDs we chose were not quite bright enough during the

daytime” (SolarRoadways.com). Therefore, for the LEDs to be visible during the day, Solar

Roadways need to use a higher-powered LED. These higher-powered LED bulbs require 78,000

kWh over a 60,000-hour time period to run. One of the main assets of this technology is that the

road would light itself from the power that it would gather. However, this is almost

counterintuitive. The goal of Solar Roadways is to produce energy. If the energy produced is

going towards sustaining a higher voltage of light, then the solar energy available for distribution

would be reduced. Solar Roadways must find a balance between visibility and energy usage with

their LEDs before installation and adoption.

Barriers to Adoption #2 – Government

In addition to the somewhat alarming number of legitimate technology questions, for

Solar Roadways to achieve widespread implementation there are other factors it needs to

overcome. First, amongst this list of obstacles is gaining the support of the road owners

considering the fact that these are the individuals who will ultimately have to pay the upfront

costs of transforming asphalt roads to Solar Roadways. The logical next step then is to ask, who

owns the roads?

This seemingly simple question is actually quite complicated to answer. Roads can be

divided into two categories, public and private with the public branch subdivided into “open

public road” or “government owned” (crab.wa.gov). We believe that government owned roads

are the strongest candidates to become Solar Roadways so we chose to place an emphasis on

analyzing them. We came to this conclusion because they are the most common and the

government has the greatest incentive amongst road owners to care about a public and social

25

good (crab.wa.gov). Unfortunately, however, as the quadrennial “2013 Report Card for

America’s Infrastructure” released by the American Society for Civil Engineers (ASCE)

documents, the United States roads and transit systems are currently graded at a ‘D+’ which

bodes poorly for any investment in them which requires large upfront costs. That mark indicates

“the infrastructure is in poor to fair condition and mostly below standard, with many elements

approaching the end of their service life. A large portion of the system exhibits significant

deterioration. Condition and capacity are of significant concern with strong risk of failure”

(infrastructurereportcard.org).

To take the glass-half-full view of this score, one might believe that with many of the

“elements approaching the end of their service life” this is the perfect time to invest in innovative

technology intended to improve livelihood for the long run. However, this approach is naive to

the shear amount of capital needed to restore the roadways to an appropriate level. To highlight

this reality, even though both roads and transit expenditures have increased in the past decade,

the Federal High Administration reports that $79 million more is still needed annually to

“significantly improve conditions and performance” and this is but a drop in the ocean of $3.6

trillion the ASCE calls for by 2020 to improve all areas of U.S. infrastructure

(infrastructurereportcard.org). With that being said, we feel it is doubtful that any widespread

adoption of Solar Roadways is viable in the near future; this especially true when one considers

how funds for public roads are raised.

There is a common misconception that roads pay for themselves with a “gasoline user-

fee.” Essentially, the belief is that people who use the roads the most need to buy the most

gasoline and therefore they are paying for their share of the road (frontiergroup.org).

Specifically, the amount of money a particular driver pays in gasoline taxes bears little

26

relationship to his or her use of roads funded by gas taxes – unlike other true user fees such as

admission fees for state parks or turnpike tolls. Drivers on local streets and roads, for example,

pay gasoline taxes for the miles they drive on those roads, even though those taxes are typically

used to pay for state and federal highways (frontiergroup.org).

Additionally, the amount of money raised by gasoline taxes pales in comparison to the

amount of government funds dedicated to roads and highways. Government assistance in excess

of $600 million (2005) has been used (as of 2005) since 1947 to supplement revenues from the

gas taxes (frontiergroup.org). The distinction between whether the money comes from user fees

or government subsidies may seem like a semantic distinction, but it actually proves to be quite

influential. For example, in 2011 when New York City attempted to fund a “high speed rail

system,” policy discussions were muddled by judgments that the plan wouldn’t pay for itself and

needed government assistance (governing.com). Solar Roadways, which would almost certainly

require extraordinary upfront costs and therefore necessitate financial support from the

government, would receive similar criticism and likely stifle any policy attempting to implement

them.

All of these factors individually offer difficult challenges, but together present a dramatic

uphill battle that Solar Roadways will have to fight. Based on their demonstrated support from

the Department of Transportation aforementioned in the “History of Solar Roadways” section,

Solar Roadways is on the right track, but it will take significantly more effort and lobbying for

Solar Roadways to get enough backing to get a government contract.

Barriers to Adoption #3 - Competition

When it comes to other players in the photovoltaic (PV) roadway world, Solar Roadways

faces two primary competitors: SolaRoad and Wattway. SolaRoad is a Krommenie, Netherlands

27

based company whose design is “concrete modules 2.5 by 3.5 meters featuring a translucent top

layer of tempered glass around 1 cm thick with standard silicon solar cells beneath”

(energymatters.com). This design, with exception of the square blocks (as opposed to hexagonal)

looks very similar to Solar Roadways’, whereas Wattway’s implementation is a clear departure.

They label themselves as a “photovoltaic road surfacing concept” with “[panels] comprised of

photovoltaic cells embedded in a multilayer substrate. These cells collect solar energy via a very

thin film of polycrystalline silicon that enables the production of electricity” (colas.com).

Though counterintuitive, this competition might actually be, in part, a good sign for Solar

Roadways. The economic argument is that the more exposure that consumers and investors are

to a new product the more willing they are to embrace it. This argument is currently being

realized in the electric car industry with Tesla welcoming competitors, such as, Faraday Futures

and Apple into the market. However, in the PV roadway market Solar Roadways is much more

like Faraday Futures than they are like Tesla, which is less than ideal.

Both SolaRoad and Wattway are much farther along in the development stage than Solar

Roadways is. It is likely that whichever invention becomes market ready first will take the lions’

share of business and set their competitors even further behind them. SolaRoad is arguably

closest to this mark given that they are currently in the process of installing a 100-meter bike

path in the Netherlands. When complete, the 3.5 million euro technology will provide electricity

for two to three households (energymatters.com). Wattway has not publicized any plans of

production yet, but have partnered with The Colas Group, “a world leader in the construction and

maintenance of transport infrastructure” that routinely undertakes 80,000 road projects each year

which is a phenomenal sign for the future of the company (energymatters.com,

28

wattwaybycolas.com). They additionally claim that their product is market-ready and can bear all

vehicle weight without failure (colas.com).

These two companies have demonstrated that they belong in the PV roadway market and

will continue to be worthy competitors to Solar Roadways in the years to come.

Cost Analysis

As stated in the abstract, the goal of our research was not to predict the future of Solar

Roadways. Rather, we thought that it would be interesting to do a cost analysis from an objective

standpoint and see what we found. Since Solar Roadways are still in the initial prototype stages,

there are not many facts regarding the energy production or price of their proprietary hexagonal

panels so we attempted to reach out to the founders in Sandpoint, Idaho to gain more

information. Unfortunately, the Brusaws did not respond to inquiries for a conversation so we

needed to take a step back and attempt to approach this analysis at a higher level.

(Calculations done in appendix and in Economic Implications section above)

This table explains where we view Solar Roadways’ place in the world. The technology is

attempting to simultaneously achieve the infrastructure that asphalt roads provide and the energy

generation traditional solar panels produce. However, Solar Roadways are fundamentally limited

29

to producing less energy and cost more than traditional solar panels and asphalt roads,

respectively, making them unattractive (especially in the short term). Due to the fact that the

founders are simply using the same solar panels that already exist, but are also attempting to use

the energy they generate to heat and light up the panels themselves, it is impossible for them to

produce more energy than traditional solar panels. Furthermore, if solar panels are a component

of Solar Roadways we can posit that they are bound to be at the very least as expensive, if not

much more expensive, as traditional solar panels. This naturally means that Solar Roadways are

going to be drastically pricier than traditional asphalt roads.

These two facts make one question: whether or not Solar Roadways are truly the best

option for today’s market. However, it is important to note that all “green-technology” is

generally biased against because the entire cost of their competitors is not taken into account. To

understand this point one can look at the electric car industry. Electric vehicle makers like Tesla

are competing in an imbalanced market because the incentives of their consumers are not

aligned. When one buys a typical internal combustion engine car the entire cost of that car is not

accounted for. That unaccounted cost is a negative externality and in the auto industry “CO2

emissions are that negative externality” (waitbutwhy.com). A very similar logic can be applied to

demonstrate the challenges that Solar Roadways are up against. In their case, one could explain

the negative environmental factors of asphalt roads and then show how these are unaccounted for

resulting in misaligned incentives. However, it would even be more accurate to say that the

entire value that Solar Roadways provide is what consumers are not appreciating. The extra

clean energy that Solar Roadways provide to their consumers goes unrecognized, making their

cost seem unjustly high. The breakdown below illustrates this point clearly (equations derived

from waitbutwhy.com).

30

Tesla’s problem:

Amount of Success = Value provided – Harm Caused means incentives aligned

Amount of Success = Value provided – Harm Caused means incentives misaligned

Solar Roadways’ problem:

Amount of Success = Value provided as roads + Value provided for environment means

incentives are aligned

Amount of Success = Value provided as roads + Value provided for environment means

incentives are misaligned

While the actual figures for the energy production and pricing structure remain unknown at

this time, this cost analysis is still able to emphasize the key points pertaining to Solar

Roadways. Unless the environmental impacts of the technology are taken into account, the costs

of the equipment will continuously prove to be non-economical. However, if an entity were to be

forward thinking and be concerned with the well being of all people not just the individual

consumer then, depending on the actual price, Solar Roadways could prove to be a viable choice.

The government is the ideal candidate for this job, but as addressed above, there are other

barriers to adoption that are present for the government as a consumer. Therefore, it is likely that

the relative cost of Solar Roadways will negatively impact the widespread adoption in the

immediate future.

31

Conclusion

Through our extensive research founded upon scientific discovery and economic

principles, we were able to gather more information on Solar Roadways in one place than we

think exists elsewhere. While our purpose is not to advocate for or against the company and its

technology, our inquiry has yielded a rich narrative that we think suggests a natural course of

action.

The cost analysis of solar technology illustrates that it is at present, not a viable economic

option unless externalities are accounted for. If the positive implications such as snow removal,

accident prevention, and fiber optic cables (among others) all become reality, then Solar

Roadways present an interesting argument for overseeing members of society such as state and

federal governments. Contingent on Solar Roadways claims coming to fruition, if the choice was

between asphalt roads and Solar Roadways, in a mere perfect world the latter would be the better

long-term option for the planet and as such the government should back Solar Roadways.

However, the fundamental problems with this logic are that other options exist to the government

and Solar Roadways assertions currently lack foundation.

Existing solar panel technology is proven to be both effective and successful at garnering

solar energy. As our cost analysis shows, current solar panels are guaranteed to be a cheaper

solution to Solar Roadways. One of the motivations behind Solar Roadways is that “if all the

roads in America were converted to Solar Roadways they would generate three times the amount

of energy America uses” (SolarRoadways.com), but the reality is that this is unnecessary. The

amount of surface area required for the United States to become completely self-sufficient

through solar energy from solar panels is shockingly small:

32

To further emphasize just how possible this is, current estimates state that “based on above

potential market size analysis, the current cumulative grid-connected PV installation only

represents 0.3% of total U.S. rooftop PV technical potential” and that the “technical potential of

electricity generation from rooftop PV can take over 1/3 of U.S. electricity consumption

demand” (Helixrecruiting.com). These facts illustrate a convincing argument more for the

widespread implementation of solar panels in the United States.

How does this relate to Solar Roadways? This argument is pertinent because the primary

reason that the United States government or another municipality might adopt the technology is

due to the solar energy it generates. But, when analyzed objectively, it seems obvious that the

government can more efficiently achieve the end goal of energy self-sufficiency by using the

funds it would have directed towards Solar Roadways to the adoption of a proven technology

that is superior at energy production: solar panels. Traditional panels are cheaper and have been

demonstrated to be highly effective whereas Solar Roadways are in their infancy of prototype

33

design and millions of dollars away form being market ready. With ample surface area on roofs

and the potential for more solar farms in the west (where there are heaps of space) it is apparent

that Solar Roadways are not a necessity in the United States to achieve clean energy self-

sufficiency.

This realization leaves Solar Roadways enthusiasts wanting; what is the future of the

company if it is not essential? Our opinion is that the answer lies beyond the national borders of

the United States. For countries in areas with low photovoltaic technical potential such as

northern parts of Europe, North America, and Asia or countries with high-energy consumption

and small land area, converting all surface area into solar receptors is vital. For example, in the

Netherlands, the home of Solar Roadways’ competitor SolaRoad, where the land area is a

miniscule, 41,543 square kilometers compared to the 9,831,510 square kilometers that the United

States offers, it makes sense to be making solar roads (energymatters.com). Therefore, while it

does not seem to be a great product for the United States a market does exist for Solar Roadways

technology.

Despite this unfavorable view of Solar Roadways promise in the United States, as

independent researchers we are enthusiastic about the technology and innovation of the

company. We simply do not think the government should be involved on an intimate level with

the future of the company without first prescribing to existing technology. We hope that some

day Solar Roadways become a cost effective solution because at that point their replacement of

asphalt roads will not only make environmental sense, but also economic sense. This is

something we should all hope for because any technology that encourages the advent of energy

self-sufficiency is one that fights rising carbon emissions and will help make our planet livable

for many years to come.

34

Works Cited

"American Infrastructure Report Card." 2013 Report Card for Americas Infrastructure. N.p., n.d. Web. 04 Dec. 2015.

Asdecker, Björn. "Returning Mail-order Goods: Analyzing the Relationship between the Rate of Returns and the Associated Costs." Logist. Res. Logistics Research 8.1 (2015): n. pag. Web.

"Blog." Helix Recruiting RSS. N.p., n.d. Web. 04 Dec. 2015.

"Colas Is Revolutionizing Roads with Wattway Solar Roads." Colas. N.p., 13 Oct. 2015. Web. 04 Dec. 2015.

"Do Roads Pay for Themselves? | Frontier Group." Do Roads Pay for Themselves? | Frontier Group. N.p., n.d. Web. 04 Dec. 2015.

"Elon Musk Tells Tesla Competitors to Bring It On." Entrepreneur. N.p., 28 Sept. 2015. Web. 04 Dec. 2015.

"Frequently Asked Questions." Solar Roadways. N.p., n.d. Web. 04 Dec. 2015.

"How Do Weather Events Impact Roads?" How Do Weather Events Impact Roads? N.p., n.d. Web. 04 Dec. 2015.

"How Tesla Will Change The World - Wait But Why." Wait But Why. N.p., n.d. Web. 04 Dec. 2015.

"New York City by the Numbers." New York City by the Numbers. N.p., n.d. Web. 04 Dec. 2015.

"17-2071 Electrical Engineers." U.S. Bureau of Labor Statistics. U.S. Bureau of Labor Statistics, n.d. Web. 04 Dec. 2015.

"Paving, Surfacing, and Tamping Equipment Operator Salaries." N.p., n.d. Web.

"Paving the Way to Tomorrow's Energy." Wattway by Colas. N.p., n.d. Web. 04 Dec. 2015.

"The Real Economic Cost of Snow | TIME.com." Business Money The Real Economic Cost of Snow Comments. N.p., n.d. Web. 04 Dec. 2015.

"Roads  D." 2013 Report Card for Americas Infrastructure. N.p., n.d. Web. 04 Dec. 2015.

Washington State County Engineers Article ? Number 18 Of A Series In 20. Washington State County Engineers Article ? Number 18 of a Series in 2004 Who Owns Roads? (n.d.): n. pag. Web.

35

"Wattway - Another Solar Road Solution - Energy Matters." Energy Matters. N.p., 16 Oct. 2015. Web. 04 Dec. 2015.

"What to Call the Gas Tax: Not Just Semantics." What to Call the Gas Tax: Not Just Semantics. N.p., n.d. Web. 04 Dec. 2015.

"The World's First Solar Road - Energy Matters." Energy Matters. N.p., 06 Nov. 2014. Web. 04 Dec. 2015.

Appendix

Below are some of the charts and corresponding calculations used in the paper.

36

Assuming SunPower 230-watt

1047.5 True Array PTC Watts/ 70.23 sq-ft= 14.915 True Array PTC Watts/ sq-ft

=> 100 sq-ft* 14.915 True Array PTC Watts/ sq-ft= 1,491.15 True Array PTC Watts

=> 1,491.15 True Array PTC Watts* $4.61/ per True Array PTC Watts= $6,875.94

=> Cost of 10x10 230W SunPower Panel= $6,875.94

List of Website (MLA for some reason does not actually include the URLs of the websites, however, we would imagine for fact checking purposes they are relevant so we have included them below.

http://business.time.com/2010/02/10/the-economic-cost-of-snow/

http://www.nasbo.org/sites/default/files/Analyzing%20Costs%20of%20Winter%20Storms.pdf

http://www.ops.fhwa.dot.gov/weather/q1_roadimpact.htm

37

http://ibo.nyc.ny.us/cgi-park2/?p=649

http://www.solarroadways.com/faq.shtml

http://www.bls.gov/oes/current/oes172071.htm

http://www1.salary.com/Paving-Surfacing-and-Tamping-Equipment-Operator-salary.html

http://www.crab.wa.gov/LibraryData/REPORTS/EngineerAnswers/Article18-

04WhoOwnsRoads.pdf

http://www.infrastructurereportcard.org

http://www.infrastructurereportcard.org/roads/

http://www.frontiergroup.org/reports/fg/do-roads-pay-themselves

http://www.governing.com/columns/eco-engines/Not-Just-Semantics.html

http://www.energymatters.com.au/renewable-news/solaroad-em4577/

http://www.colas.com/en/press/press-release/colas-revolutionizing-roads-wattway-solar-roads

http://www.entrepreneur.com/article/251129

http://www.wattwaybycolas.com/en/

http://www.energymatters.com.au/renewable-news/wattway-solar-road-em5133/

http://waitbutwhy.com/2015/06/how-tesla-will-change-your-life.html

http://helixrecruiting.com/helix-recruiting-solar-david-anthony).

http://www.nwastainedglass.com/Home/services-and-pricing

http://energy.gov/sites/prod/files/2013/08/f2/Grid%20Resiliency%20Report_FINAL.pdf

http://www.ibtimes.com/aging-us-power-grid-blacks-out-more-any-other-developed-nation-

1631086

38

http://www.harriswilliams.com/sites/default/files/industry_reports/

ep_td_white_paper_06_10_14_final.pdf?cm_mid=3575875

https://www.wc4eb.org/what/safety/accidents/

http://www.bankrate.com/finance/auto/top-states-most-likely-to-hit-deer-1.aspx

http://www.ctcnet.us/wp-content/uploads/2014/10/Connecting-Schools-and-Libraries-20141017.pdf

http://www.ctcnet.us/CTCCostsForAnchorInstitutions.pdf

39