阅读理解
Scientists are looking for ways that we can effectively use the light and heat from the sun. One idea that has caught their imagination is solar roads. They are expected to produce clean and renewable energy.
With solar panels on the surfaces, solar roads cost more than traditional roads. However, besides the functions of traditional roods, they have the panels to receive sunlight and change it into the energy to supply power to homes, factories and street lighting. There are four layers in a solar panel:
•Base layer: It is made of insulation material and forms a good grip with the road below this layer.
•Middle layer: This is the most important layer. It holds all kinds of power lines connecting all the solar parts in the panel, like LED lights and the heating system.
•Top layer: This layer is super-strong glass. It allows the panel to hold the weight of the heaviest vehicles.
•Capping: This is the topmost layer used to offer extra protection to the solar parts in the panel. The layer must be rough enough to provide the traction for the safety of vehicles.
With the smart design, solar roads can successfully charge the vehicles on them. And the roads have inbuilt LED lights to replace the traditional rood signs and lines, which are usually painted and harmful to humans. What's more, the heating systems in the solar roads can take care of the snow and ice on the roads for drivers.
Test solar roads have been built in several countries (France, China, USA, etc.) since 2014. The first word solar road project, Metrics of Watt Way in France, was set up by a French company called Construction Colas. It was an example of low effectiveness. In the first year, it had been expected to produce around 767 kWh of energy a day, but it only produced 409 kWh. Even so, the production could increase with design improvements. Of course, more time is needed before this technology is put into use.
Solar roads may not be widely used in the near future, but they are indeed great for an environment-friendly and energy-saving world.