After the hubbub that Solar Freakin Roadways caused last year (ranging in tone from hopeful to critical) all seemed to have gone quiet on the potentially revolutionary road surface front. I don’t think anyone expected us to be laying these things down en-masse once the Indiegogo campaign finished but I’ve been surprise that I hadn’t heard more about them in the year that’s gone by. Whilst Solar Roadways might not have been announcing their progress from the rooftops there has been some definitive movement in this space, coming to us from a Dutch company called SolaRoads. Their test track, which was installed some 6 months ago, has proven to be wildly successful which gives a lot of credibility to an idea that some saw as just an elaborate marketing campaign.
The road was constructed alongside a bike path totalling about 70m in length. Over the last 6 months the road has generated some 3,000kWh, a considerable amount of energy given the less than ideal conditions that these panels have found themselves in. Translating this figure into an annual number gives them around 70kWh per square meter per year which might not sound like much, indeed it’s inline with my “worst case” scenario when I first blogged about this last year (putting the payback time at ~15 years or so), but that’s energy that a regular road doesn’t create to offset its own cost of installation.
Like Solar Roadways the SolaRoad’s design is essentially a thick layer of protective glass above the solar panels which are then backed by a layer of rubber and concrete. Instead of the hexagonal tile design they’ve instead gone for flat panels which would appear to be more congruent road design although I’ll be the first to admit I’m not an expert in this field. By all accounts their design has stood the test of time, at least with the light load of cycling (although they claim it could handle a fire truck). The next stage for them would be to do a full scale replica on a road that sees a decent amount of traffic as whilst a cycleway is a good indication of how it will perform there’s nothing better than throwing the challenges of daily traffic volumes at it.
Unfortunately SolaRoad isn’t yet ready to release a potential price per kilometer installed however the entire program, including the research to design the coatings and the road itself, has come up to some $3.7 million euros. Considering that my original estimates pegged a competitive cost at around $1 million per kilometer I’d say that the trial has been a pretty good investment (unless you’d really want 4km worth of road somewhere instead…). That will ultimately be what determines if something like this can become a feasible alternative to our current asphalt road surfaces as the idea won’t get any traction if it’s noticeably more expensive than its traditional counterpart.
It’s good to see progress like this as it shows that the idea has some merit and definitely warrants further investigation. Whilst the power generation numbers might not be revolutionary there’s something to be said for a road that pays itself off over time, especially when that comes in the form of renewable energy. With further advances in grid technology and energy storage these roadways, in conjunction with other renewables, could form the basis of a fossil fuel free future. There’s a long way to go between today and that idyllic future but projects like this ensure that we keep making progress towards it.
The problem that most renewables face is that they don’t generate power constantly, requiring some kind of energy storage medium to provide power when its not generating. Batteries are the first thing that comes to everyone’s mind when looking for such a device however the ones used for most home power applications aren’t anymore advanced than your typical car battery. Other methods of storing power, like pumped hydro or compressed air, are woefully inefficient shedding much of the generated power away in waste heat or in the process of converting it back to electricity when its needed. Many have tried to revolutionize this industry but few have made meaningful progress, that was until Tesla announced the Powerwall.
The Powerwall is an interesting device, essentially a 7KW (or 10KW, depending on your application) battery that mounts to your wall that can provide power to your house. Unlike traditional systems which were required to be constructed outside, due to the batteries producing hydrogen gas, the Powerwall can be mounted anywhere on your house. In a grid-connected scenario the Powerwall can store power during off-peak times and then release it during peak usage thereby reducing the cost of your energy consumption. The ideal scenario for it however is to be connected to a solar array on the roof, storing that energy for use later. All of this comes at the incredibly low price point of $3,000 for the 7KW model with the larger variant a mere $500 more. Suffice to say this product has the potential for some really revolutionary applications, not least of which is reducing our reliance on fossil fuel generated power.
The solar incentives that many countries have brought in over the last few years has seen an explosion in the number of houses with domestic solar arrays. This, in turn, has brought down the cost of getting solar installed to ridiculously low levels, even less than $1/watt installed in some cases. However with the end of the feed-in tariffs these panels are usually not economical with the feed-in rates usually below that of the retail rate. Using a Tesla Powerwall however would mean that this energy, which would otherwise be sold at a comparative loss, could be used when its needed. This would reduce the load on the grid whilst also improve the ROI of the panels and the Powerwall system, a win-win in anyone’s books.
It would be one thing if Tesla was just making another product however it seems that Elon Musk has a vision that extends far beyond just ripping the battery out of its cars and selling them as grid connected devices. The keynote speech he gave a few days ago is evidence of that and is worth the watch if you have the time:
In its current incarnation the Tesla Powerwall is a great device, one that will make energy storage feasible to a much wider consumer base. However I can’t help but feel that this is just Tesla’s beachhead into a much larger vision and that future revisions of the Powerwall product will likely bring even larger capacities for similar or lower prices. Indeed this is all coming to us before Tesla has completed their Gigafactory-1 which is predicted to reduce the cost of the batteries by some 30% with further iterations driving it down even more. Suffice to say I’m excited about this as it makes a fully renewable future not only inevitable, but tantalizingly close to reality.