The use of renewable energy is a topic on everyone’s lips at the moment. How can we meet the demand and produce a supply of clean and renewable energy that will be sufficient for this and coming generations? Imtech, has developed the world’s first solar road and it is located in Krommwnie, Holland. The firm, in conjunction with the Province of Noord-Holland and Ooms Civiel, have constructed this ingenious piece of engineering.
The solar cycle path will be attached to the national grid in order to meet the ever-increasing demands of energy and also to advance renewable energy use in Holland.
The cost of the pilot scheme is €3m ($3.7m) and was funded by the local authority. The “SolaRoad” pilot cycle path is made up of two lanes, one of the lanes is made of prefabricated concrete slabs that are connected to the national grid. One of the lanes is constructed from 2.5 by 3.5 meter slabs of concrete that has an integrated layer of crystalline silicon solar cells and has a top layer of 1cm thick, translucent, tempered safety-glass. The second lane is constructed without solar cells and will be used for testing various top surfaces.
The Crystalline solar cells are made with two ‘doped’ semi-conductors (n-type and p-type). The phrase ‘doping’ is the adding of an impurity to the silicone. Impurities in the silicone of the n-type semiconductor will create mobile free electrons and in the p-type semiconductor, the impurities create holes. Where the n and p-type layer meet together is called the junction. This is where electrons cross the junction and join with a hole, thereby cancelling each other out. This leaves a positive charge in the n-type. The holes also move across the junction from the p-type region to the n-type and this leaves a negative charge. The movement of electrons across the p-n junction creates a built-in electric field, which is always present across the cell. When photons from the sun strike the solar cell, there is a release of electrons from the junction back to the n-type semiconductor and holes back to the p-type semiconductor. The resulting separation and resulting fluctuation of positive and negative charges across the junction creates a voltage.
The testing period is three-years and during this time, the team is aiming to collect data and research numerous factors which could influence the project going forward. Additionally to the lab-based experiments, a variety of aspects of the road will be researched and calibrated. Although the single-lane path is capable of producing less than 30% less energy than rooftop solar panels, the researchers are hoping that the SolaRoad will make use of up to 20% of the 140,000km roadway for renewable energy generation. Initially, the small stretch of highway is expected to produce enough electricity to be able power approximately 2 or 3 average homes per year.
Interestingly, there are future projects in the pipeline, which are aiming to develop road surfaces that will be combined with a Road Energy Systems product, (also developed by Ooms Civiel), that has been designed to extract heat from asphalt surfaces.
Who knows what types of renewable energy projects will produce the most beneficial amounts of clean energy in the future? With projects such as this though, I think that we are on the way to helping the future generations figure out what to do when fossil fuels run out. The solar road will be open to the public on Wednesday the 12th November 2014.
[Image via revolution-green]