Solar Roads: Is The Future Of Energy Under Our Feet?

Follow Antony

Utah highway

Utah highway

Enlarge Photo

Whatever the future energy mix, it's becoming apparent that coal and gas are both hugely consumptive and not entirely great for the environment--even if they provide large swathes of the world with their energy.

Renewable energies like solar, wind and hydro on the other hand supply only a small proportion of the world's population, yet they're vastly cleaner. The challenge is scaling them up to such an extent they can be truly useful.

But how do you make use of nature's own energy? One option is solar roads--using heat from the criss-cross of asphalt in every nation to generate electricity.

The theory is this: In hotter climates particularly, roads and parking lots get really hot. Oppressively, uncomfortably so if you're unlucky enough to be walking along one on a hot day, with extra heat radiating from the black ribbon of asphalt under your feet.

According to Oilprice, scientists at Worcester Polytechnic in Massachusetts propose burying water pipes an inch or so beneath the road surface.

Heat absorbed by the dark road surface then heat the water, which in turn can be used to generate electricity. As a side-benefit, the transfer of heat from road to water also helps cool the road surface, extending its potential life.

Water heating is used in many current solar generation applications. The difference here is that it's visually no more intrusive than the existing road already is. No fields would be filled with solar collectors, for example.

Rajib Mallick, the associate professor leading the team of researchers, says the team's "preliminary results provide a promising proof of concept for what could be a very important future source of renewable energy."

Don't get too excited though--there are a few hurdles to overcome.

The first is finding investors for a system with untried, unknown potential returns. Some scientists speculate that the heated water simply wouldn't be hot enough to generate high levels of energy, making return on investment too low.

And it'd be quite some investment - not just installation costs for the water piping and electricity generators, but the cost of fully re-surfacing any road where the system is installed. To ensure that return on investment, you'd be talking significant stretches of highway.

It could, potentially, be a technology worth pursuing on private land, but it seems like there are too many hurdles to see widespread adoption of solar road technology.


Follow GreenCarReports on Facebook and Twitter.

Posted in:
Follow Us

Comments (6)
  1. What a joke. The roads in this country are deteriorating rapidly. Imagine if they had water lines in them. They would be wet all the time with leaks. A traffic hazard. Then the lawsuits....

    The answer to our energy problems is there - just look up at that yellow thing in the sky.

  2. We should tie in this to the discussion.
    They have been working on solar roads for many years now.

    I particularly like this video.
    where they show how they can put lighted signage on the road surface.

    It seems really impractical, but who knows. At least they have prototypes.

  3. I started on this in the 80s with a more holistic approach, you are correct that many designs and systems bear an impractical accounting, design or expectation of the infrastructure. This makes for issues when the real world integration begins.....and a lot of headaches.

  4. I saw a video where they were using this kind of thing in the UK in an asphalt parking lot to heat a small school and it works well. Boosting ambient tap water up to 150F before adding a little more gas fired heat could be viable. (Can't say I'm a big fan of the natural gas industry though.)

  5. I say make roads white to reflect the heat of the sun. Paint all roofs white as well. We have to replace the reflective polar ice caps that are melting into the seas.

  6. I came up with much of this and more, including a way to build and repair roadways faster in the 1980s. Our funding was caught in the storm in fall of 1987. I have a better and more complete system than anything I have seen to date, including this. I also am the holder of much of the intellectual property and have overcome many real world obstacles they have yet to see. I also have the better materials for building the system. If they want to really make it work they need to see what I quietly built for decades.

Commenting is closed for old articles.

Get FREE Dealer Quotes

From dealers near you

Find Green Cars


© 2015 Green Car Reports. All Rights Reserved. Green Car Reports is published by High Gear Media. Send us feedback. Stock photography by izmo, Inc.