Road to the Future

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Adam's Weekly Blog

Road to the Future

Road to the Future

The Dutch are the tallest people in the world. I’ve no idea why but...
The Dutch are the tallest people in the world. I’ve no idea why but you can see the evidence of it in this programme in which we travelled to the Netherlands to see how they are developing novel ways of using solar power. Watch out for the shots of me on a bike next to the Dutch head of a company making solar panels.

We have done a lot about energy generation in Horizons but this is something very different because these are no ordinary solar cells. The company we are visiting in the Netherlands has created the world's first solar road - an energy-harvesting bike path paved with glass-coated solar panels.

The solar panels are sandwiched between glass, silicon rubber and concrete, and are strong enough to support 12-tonne fire trucks without any damage. Each individual panel connects to smart meters, which optimize their output and feed their electricity straight into street lighting, or the grid.

Up close, the road looks like it is covered in the kind of stuff that all roads are covered in - it doesn’t look any different but it is.

What’s more, like so many interesting ideas – the concept of a solar covered road feels obvious once you think about it.

The world is covered with roads – it’s the defining icon of modern life. If we could only cover all those roads with solar cells that could be driven on – then we’d have access to huge amounts of electricity. Not only could we generate a huge amount of electricity, we could do it right at the centre of the urban communities which need the power. At the same time we would be generating electricity and getting rid of a lot of transmission costs and efficiency loss which comes with trying to send power around large networks.

The researchers design the panels to not only let in as much light as possible, but also to last at least 20 years.

The solar road consists of concrete modules of 2.5m by 3.5m with a translucent top layer of tempered glass, which is about 1cm thick. Underneath the glass are silicon solar cells.

The idea is appealingly simple; making it work is actually more complex. That’s because the road surface has to be translucent so the sunlight can get through. However, it also has to repel dirt as much as possible and be skid resistant.

Because the solar cells in the path cannot be adjusted to the position of the sun, the panels will generate approximately 30% less energy than traditional cells placed on roofs. However, the road is tilted slightly to aid water run-off and achieve a better angle to the sun. Its creators expect to generate more energy as the path is extended to 100m in 2016.

The company behind the solar road say they started with a type of coating that they use on steel bridge decks. But of course that type of coating is not transparent, “so we developed a transparent version which is a tough problem to crack from a scientific point of view.”

In the test they have 70m of solar road installed and that produces enough electricity for three Dutch households over a whole year – that’s approximately 10,000KW hours

They told me the following to help me get a sense of the potential: “If you paved one third of the Dutch road network with this type of technology, you would generate enough electricity to power eight million electric cars. That’s the same amount of cars that we have today.

In an hour and a quarter, the amount of sunlight that threads through the clouds to the Earth’s surface could power all the world’s electricity, vehicles, boilers, furnaces and cooking stoves for a year. Yet solar power produces less than 1% of the world’s commercial energy.

Innovations like the one we are featuring from the Netherlands could well start us on a path to catch more of those valuable rays in the future.
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