First Solar Roadway Built – And Worse Than You Would Have Thought

A few years ago, I touched on the subject of solar roadways.  The concept has gotten quite a bit of attention from the general public, mostly due to slick marketing.   It’s actually a terrible idea.  There’s really no more expensive way to pave a road, and, if you are going to have solar cells, you won’t find a much worse place for them than on the ground, potentially shaded and not tilted toward the sun.  Beyond that, the solar cells are exposed to moisture, dirt, grime, vibration and pressure.   The surface needs to be covered with some kind of super-durable transparent material, but aside from possibly synthetic diamond, all potential transparent substances will scratch and scuff with time.
Despite all these issues, one has finally been built.  Technically, it’s not a road but a bike path.  It is however, a start.  A start to what, I’m not sure.

Via the BBC:

Netherlands unveils world’s first solar bike lane

The world’s first cycle lane made from solar cells produces enough energy to power three households.

Installed in Krommenie, 25 kilometres from Amsterdam, the pilot project is 70 metres long, and will be extended to 100 metres by 2016.

The bike path is made from rectangular concrete modules that contain solar cells, and is encased in a one-inch thick layer of glass strong enough to withstand a truck.

It is capable of producing enough energy to power three homes, though is 30% less efficient than roof-mounted solar panels, as these can be aligned to the sun.

Due to be officially launched on 12 November, the project has so far cost €1.5 million euros, though will ultimately cost up to €3 million once finalised.

Dr Sten de Wit from SolaRoad, the consortium behind the project, envisages that solar roads could eventually be used to power the electric vehicles that use them.

“Electric vehicles are on the rise, but are not really a substitute until the electricity they use is generated in a sustainable way. Roads can generate power right where it is needed,” de Wit explains in a publication for the contract research organisation TNO.

“Sensors gathering information about traffic circulation can help improve traffic management, or even allow automatic vehicle guidance,” de Wit added.

A couple in the United States is currently raising funds for a solar-powered road project. Julie and Scott Brusaw predict that if every US highway incorporated solar technology, the country would generate three times as much electricity as it currently consumes.

The catch? The technology is also three times more expensive to install.

Only there times the cost? Standard solar power may be expensive, but it is not *that* expensive.

The article states that the path can power three households. That’s a terrible way of benchmarking power output, because a “household” can consume anywhere from almost zero watts to several kilowatts, depending on what is being operated. From what I have seen, however, it is often used to mean kilowatts, where one kilowatt is presumed to be the approximate electricity consumption of a household.

If that is the case, this has a peak output of three kilowatts. That, of course, would be nameplate capacity, and almost never reached. The path might come close to three kilowatts, but it will often be much less and at night will be approximately zero kilowatts. For comparison, this is about the power output of the engine on a riding lawnmower. It’s enough to operate a singe laundromat dryer.

Yahoo News Provides some more details about the energy output:

The path has been working for 16 days, during which it generated 140 kilowatt hours of electricity, equivalent to around 140 washing machine cycles, said SolaRoad spokeswoman Jannemieke van Dieren.

Note that when they say “enough to power 140 washing machine cycles, they mean washing machines running for about one hour. in 16 days, it produced enough power to run 140 washing machines for one hour or one washing machine for 140 hours.

There are 384 hours in a 16 day period. So by diving it out, we can see that the average power output from the path is about 365 watts. In other words, it produces as much energy as a generator that is running all the time and has an output of 365 watts. That is just barely enough to run a desktop computer. It’s less than a person can produce on an exercise bike.

And the total cost is reported to be 3 million Euro. That’s about 3.74 million US Dollars, 4.25 million Canadian Dollars, 4.29 million Australian Dollars or 2.38 million British Pounds. It’s a lot of money.

As for how much this costs compared to standard solar panels, a major home supply retailer in the US sells a one kilowatt grid-tied solar power kit for just over $3,200 dollars. That does not include installation, and there might be some other expenses. Yet clearly, even buying solar panels at retail price (and a large customer would get a much better deal), it’s not hard to get a lot more bang for your buck than this 3 Million euro project.

Much as promoters will talk about the potential to pave all the paths or roads in the Netherlands or anywhere else, I’m sure it won’t happen. There may be some other small-scale projects, but the money to mass deploy this simply does not exist. It’s not likely that any kind of research and development will drastically reduce the inherently high cost by much. Even if the cost could be cut in half, it’s still unmanageably expensive!