What are solar roads?
These are roads that are constituted of solar panels that are arranged serially and are engineered structurally to drive vehicles upon them. These are revolutionary and innovative alternatives to the roads that are made of asphalt and petroleum bi-products. Also, this is a green alternative to the use of fossil fuel in the generation of electricity. The solar roads are based on the phenomenon of being able to store the maximum amount of energy and then transform it in the form of electric energy. The energy generated can be used to light the roads as well as generate electricity for the commercial areas and the local homes. The main breakthrough of this project is the solar panel that stores energy. The Netherlands is the first country in the world to open a solar bike lane. This path joins Amsterdam with the suburban areas of Krommenie and Wormerveer. This roadway runs at a stretch of 70 metres. This is the first ever solar road which is a bike path that harvests energy and is paved. After six months of the trial period of this solar road, it is said that the solar road system is showing improved performances and better success than what was expected. The road is able to gather around 3,000 kWh electric energy, which is sufficient to illuminate a small house for more than a year. Sten de Wit, who is the spokesman for the road, says that if the annual yield of the SolaRoad is translated, it is expected to generate greater than 70 kWh meter of energy on an annual basis. The idea of constructing solar roads became very popular and there was also talk of making the entire roads of the United States of America lit with the solar panels but, the Netherlands was the first country to actually construct the solar road and is the pioneer in the innovation of solar roads (Macdonald, 2015).
The road manufacturing material and strength
These solar roads use solar panels that are placed on the path of Dutch bikes. The construction of the road is such that the solar panels are placed in between the silicon rubber, glass, and concrete. These roads are made strong and can support trucks of 12-tonne weight easily, without causing any destruction or damage to the roads. All the solar panels of the road are in turn connected to a smart meter, which causes the optimisation of the output of these roads and increases their energy output, leading to efficient street and traffic lighting or the lighting of the road grid. The durability of the system is a much-researched outcome of five years of research and development by the engineers that are involved in the project. The solar panels are made such that the damage or breakage in a particular solar panel leads to the switching off of that particular PV panel only, whereas the other panels still work efficiently. This is done in order to increase the durability of these roads (Macdonald, 2015). In the first trial of the SolaRoad there were greater than 150,000 cyclists that participated in the testing by riding their cycles over the road. The road to date is diagnosed of just one flaw; that is, the road has a small coating section for providing additional grip to the vehicles that ride over the surface of these roads. This coating gets delaminated as a result of fluctuations in the temperature. However, the SolaRoad team is working constantly to overcome this flaw of the road. According to Stan Klerks, who is a scientist at the Dutch research group in TNO, the parent company of the SolaRoad, the engineers have come up with efficient coatings that are able to deal with a load of traffic on these roads. The solar panels of these roads are designed in a manner that they let the high amount of light pass through them and have very low maintenance. They are said to last for at least a time span of 20 years (Hruska, 2014). This new solar road costs around 4.3 Million AUD $. There is a futuristic plan to extend the solar road to a 100 metres lane in the year 2016. There is a plan to use solar energy as a source of electric energy to power the traffic lights and even run electric cars and use solar panels. This project was highly appreciated by the local community, most especially school children and local commuters. An average of 2,000 cycle owners are expected to use the solar road for commuting daily. The Netherlands Organisation for Applied Scientific Research has named this innovative road as SolaRoad. The composition of this solar road is crystalline solar cells, which are layered and made of silicon. These cells are embedded in the pathways of concrete and are then covered with the use of a layer of translucent tempered glass (Hruska, 2014).
Road Surface Layer - this is a translucent layer that is of high strength and it give traction and let sunlight pass through the cells of solar collectors. The surface layer of the roads can handle heavy loads of traffic in the peak traffic hours with the heaviest congestion. The road surface layer is waterproof in nature so that the electronic layer underlying it is protected. The road surface is subjected to a treatment of a coating of the non-adhesive material coating. The construction of the road is done maintaining a slope so as slow the accumulation of dust and dirt and minimise the damage to the solar cells. As there cannot be the adjustment of these solar roads to the direction of the sun’s rays, the generation of electric energy from the solar panels of these roads is about 30% less than the solar cells that are placed on the roofs of the house for electric water heating and the power generation process (Katharine, 2014).
Electronic layer - this layer is composed of an array of cells; most of them are composed of a solar collecting cell which has LED’s paintings. These cells are composed of super caps that have the role of storing the energy of the sun for usage in future. A Solar Road Panel™ can generate energy by itself and store as well as distribute energy; these panels can heat themselves, leading to the melting of snow as well as the accumulation of ice in the northern climate. So there is no requirement of manual removal of snow and ice from the roads and no need to shut down schools as well as businesses when there are heavy snow falls. There is a communication device on every 12 feet of these panels leading to the building of an intelligent system of highways.
Layer of base plate - the electronic layer leads to the collection and the storage of energy from the sun; the function of the base plate layer is the distribution of the power that is collected by the electronic layer (as well as the signals of data that are collected from the internet and television as well as cellular devices) to homes as well as businesses that are interconnected to these Solar Roadways, for their energy as well as internet data requirements. Each base plate has four sides to which the power, as well as the data signals, is linked. The base plate layer is also waterproof in order to protect the electronic layer that lies above it. In Amsterdam, there has been laid a 70 metre stretch of cycle road that uses rugged, photovoltaic cells from textured glass. Biking is very popular in Amsterdam, so the road initiative is very popular and effective. Currently, 70 metres of the initial plan of 100 metres of the solar road is brought to completion. The path is made in a location such that there is consistent sun lighting for the most part of the day.In addition to these Solar Roads, the Netherlands is also working on inventing roads that produce power. The traction that is used in the solar roads is such that the road is textured and is also bumpy. The road is well textured to give it additional grip, so that slipping from the surface of these solar roads is not possible and is convenient and safer for the bikers. This is in consideration of the maritime climate of Amsterdam, which makes it prone to frequent rainfalls in the winter season, but in Amsterdam snowfall is not very common (Hruska, 2014).
The wear and tear and the reflectance of the solar road
These roads are more reflective in nature than the traditional concrete roads. Solar panels are installed on the road used for biking owing to the wear and tear that is expected to occur on it. Studies suggest that the road wear and tear can be indicated by the fourth-power law. This law indicates that the fourth power of the axle weight of a vehicle is proportional to the damage and wear and tear that the vehicle causes to the surface of the road. Although factors such as pressure and speed also relate to the damage that the vehicles cause to the roads, still bikes damage the roads to a much lesser extent than cars and heavy automobiles. This is why there is the construction of a biking road using solar panels, as the magnitude of stress by the bikes to the road surface is much less than that of the cars (Hruska, 2014). The benefits and potential of these roads that use solar energy is huge. They generate a huge amount of energy that is just not sustainable for the road itself, but can also be used to light local households as they generate sufficient amounts of energy, thereby giving excellent opportunities for lighting. Design lab Studio, Roosegaarde, in the Netherlands, set up a solar road in the Netherlands. This road accumulated solar energy during the night time, which was converted into electric energy and guided the cyclists by illuminating the roads at night. This road creates a beautiful illusion of starry nights by the LED lights that illuminate the road. SolaRoads, in association with the local council, is working to create technology to provide illumination in other states and localities of the Netherlands. In California, USA, it is planned to construct these solar roads there in the future (Katharine, 2014).
Solar cat-eyes and solar road studs
Luna Road lights are new, advanced cat eyes; this extraordinary technology offers customisable structures, and choice of echo friendly road safety. Solar road structure is safer as it can melt ice, and moreover, salt pollution will also be reduced. This new system is capable of gathering energy during summer, and storing it in thermal banks. This stored energy is used for cutting ice in the winter season. ICAX exhibits Solar Road Systems on the Toddington motorway; the assignment is supported by the Highway Authority. This new structure consists of two solar collector groups; these collectors are embedded in the road surface and a thermal bank. The collectors are shown in orange and thermal storage in blue below. In the first, it is shown that thermal storage can be positioned beneath the road, and the second shows that it can be located adjacent to the highway (ICAX, 2011, 2015). On the Toddington highway, energy collection is observed and in winter, the melting of snow is also demonstrated. The cold storage cooling capability is verified in summer. This whole project took around two years. It was monitored by a transport research laboratory autonomously. TRL acknowledged that heat transfers from thermal reserves during the winter season and it worked exactly as predicted in the design of this project. Interseasonal heat transfer will be used in cutting ice from roads and airport runways and public places. The following advantages are distinguished:
It keeps people safe by preventing accidents;
Due to cooling capacity in summer it maintains temperature, which increases the life of the road;
Prevents freezing in winter;
It is eco-friendly as salt pollution is reduced.