The Crazy Genius Behind Solar Roadways | Hacker News Reader

The Crazy Genius Behind Solar Roadways

techcrunch.com

51 pointssethbannon51 comments

The creators were answering questions on Reddit here:

http://www.reddit.com/r/IAmA/comments/1042mm/solar_roadways_...

The summary seems to be "we've got this awesome idea, and lots of money, now we're going to try to see if it will work."

The engineering consensus seems to be that it won't, or at best, will have extremely limited applications. Everybody would be far better off putting high-efficiency solar panels on rooftops than low-efficiency ones on the ground where they'll get dirty and broken.

Reading their literature, there seems to be a great big gap where any kind of decent engineering analysis would be.

While I can see the appeal of the idea, unicorns and hyperspace drives would also be pretty cool. I have my doubts.

The engineering consensus or the naysayers consensus? It's all too easy to tear apart ideas on the Internet, which is a shame.

Engineering consensus. The math doesn't pass the smell test, not without some incredible materials breakthroughs.

They've got an expensive trough through which to run power, cable and fiber that I wager all by itself costs more than paving a traditional road.

Also ask yourself the question: If there was demand for putting more utility wires underground wouldn't they already be simply burying them which is much less expensive?

> I wager all by itself costs more than paving a traditional road.

Compared to a single road paving, the hi-tech road is more expensive but this road is supposed to be more durable than traditional paved roads. That means you need to compare the cost of several road pavings to get a more accurate comparison.

The hi-tech road is supposed to be installed once for several decades, where paved roads are re-paved every few years. This increases the cost of the traditional paved road.

Also, these hi-tech roads are supposed to subsidize their cost with energy creation.

> If there was demand for putting more utility wires underground wouldn't they already be simply burying them which is much less expensive?

Burying power lines is expensive. On its own, too expensive but combined with this project, it could be fiscally sound.

The key word is "supposed". If glass tiles were a good choice for road surfaces, I'd expect we'd have seen them in use by now. If it's just economics that have stopped glass tile use in roadways, I'm still dubious that the energy production from these units will come close to offsetting the additional expense.

This is what R&D is for.

The first part of R&D is research, implying "research if this is even possible". The point people are making it's far from clear that this will work, so it's silly to assume that it will work a priori given the obvious engineering challenges.

Humans have been researching and developing road surfaces for a few millennia now. It's going to be very expensive to find plausible materials that haven't already been tried.

Especially clear ones.

> If glass tiles were a good choice for road surfaces, I'd expect we'd have seen them in use by now.

These types of attitudes don't help push forward innovation.

paved roads are re-paved every few years

This is not my experience. I've lived near a secondary arterial road for nearly 9 years, and have never seen repaving done on it. It's still in fine condition.

In my limited understanding, the frequency of required maintenance depends heavily on weather conditions, and also on the size of vehicles who commonly travel on the road. Trucks cause orders of magnitude more wear on roads than cars do.

Weather conditions it is, then. It doesn't snow here, though it rains a lot. But if snow is a problem, then a solar road makes much less sense anyway.

I live in Michigan and the roads are repaved what seems like every other year. After each winter, there are potholes the size of craters on the moon. Very dangerous when everyone is swerving into incoming traffic and slamming on breaks to avoid them.

> The hi-tech road is supposed to be installed once for several decades, where paved roads are re-paved every few years.

We're comparing the cost of solar panels to the cost of pouring some shit onto the ground... I'd assume that difference is far more than tenfold?

Note: this AMA is over a year old and many of the issues they were having could be outdated by now. They might have resolved some of the concerns with the technology from a year ago.

Snake oil. Seriously. Melt snow in northern climes? Think about it. IF there were enough sunlight to melt snow, why didn't the sunlight just, you know, melt the snow? Are they THAT much more efficient at absorbing the sun's energy? I don't think so.

Cost to buy, cost to install, cost to maintain, ... the economics just don't make sense.

In Michigan there are a number of places I know of where they have used heated sidewalks. They use a ridiculous amount of electricity and rarely help much if there's more than an inch of snow. There use is limited to government and universities where they don't look at the economics often enough of what they're doing.

Especially when the snow covers the solar panels, blocking out the sun.

When it snows, the system will draw power from the grid for the heating elements.

Their snow-clearing literature says that they'll pump energy into the grid when possible, and suck it out for snow melting. Clearly a net-loss for snowmelt operations.

All the other obvious problems aside, it might be an interesting analysis to see if there would be sufficient yearly yield to offset snowmelting operations in winter. Snowfall is not constant, so "melt" operations might only need to run for a handful of days per year, depending on the location.

Lets put it this way: if you're anywhere you only have to melt snow a handful of days per year it is not worth it to have heating. Anywhere snow is seriously inconvenient this idea is silly.

Actually those areas are probably the best places to have heating. they won't have the economic need to invest in many plows and plow operators that will sit unused 95% of the time.

That being said, I think this idea is silly.

> it might be an interesting analysis to see if there would be sufficient yearly yield to offset snowmelting operations in winter

There doesn't need to be sufficient yearly yield. This isn't just trying to pay for itself by collecting electricity on clear days to melt snow. It'd still be a great solution if it uses far more electricity than it collects because it's competing with snow removal trucks. If it could be cheaper and more efficient than having trucks driving around dropping salt and plowing, it'd be amazing.

Even if it's a little more costly, the ability to keep all the roads clear, all the time, would be incredible and worth some added expense. Think about how much safer the roads would be if they could remain free of snow.

The energy costs of melting snow are huge. It's done frequently for small areas (private driveways, parking lots) where cost efficiency isn't a concern (the wealthy) or where heat energy costs are very low (geothermal sources, i.e. Iceland).

To do it on a wide scale would require ridiculous amounts of energy. I guarantee that nobody would be prepared to foot the bill for that, and these solar panels are highly unlikely to produce even a tiny fraction of the amount of energy required, unless you amortize their production over a longer period and store it somehow.

Unfortunately, it's not just a "little more costly", it's massively more costly, to the point where it's just not a good idea.

http://www.concretenetwork.com/concrete/snow_melting_systems...

I wish this idea could work. I really really do. And not living in an area with snow means I don't understand how important this factor is.

But, the grid seems to be having a pretty hard time just dealing with the influx of solar power as it is. Initially, most power grids weren't designed to be receiving power. And all it takes it a cloud moving over a suburb to mean electrical companies are shutting down and then powering up generators. Which causes more wear and tear on the generators too.

I would LOVE to hear from an electrical engineer about that aspect of this proposal.

Well I think, and I'm no thermal expert, that the 'plan' is to use energy from other parts of a grid system, where that energy is not needed. IE, use energy collected from a place with no snow, to melt the snow somewhere else.

Although, I will say it does not sound feasible, but I would love to hear an expert has to say.

Even if they have to pump energy into them to melt the snow, I'd still see it as a HUGE feature, and a big bonus to the solar roadway itself. They are not just "solar roadways". They are also "smart roadways". The changing of signs and whatnot is also a big feature, although I'm a little worried of hacking with that one.

There is no chance these are going to be more effective or cheaper than the dedicated roadway snowmelt systems that exist today.

And, is there widespread adoption of roadway snowmelt systems? No. Why? Because the energy and maintenance required is simply immense. Even when you get energy for free (geothermal), it's rarely worth the cost and upkeep.

It's a nice idea but the maths just don't work out.

If solar signs are what you want, just put up a leaderboard with a solar panel. Done.

Offtopic to 'higherpurpose': Your comments are visible, but it looks like your last several months of submissions have all been autokilled. Since they look reasonable (and the last one looks quite interesting) you might want to write to Dan at hn@ycombinator.com and see what's happening.

This is a 'feel-good' idea but it's just a waste of resources. Why not build a good road and a good solar panel separately? Combining them like this makes for a very expensive solar road that's bad at being a road and bad at being a solar panel. It's not like we're short on space to put solar panels, and maintaining roads is already expensive enough as it is.

A waste of time and money.

Not even worth trying? It seems like a smart enough idea to at least test out.

Road engineering is a pretty mature discipline. If this idea can't pass some of the basic known challenges in a thought exercise, why bother testing it? For example, they have no explanation as to how the tiles will be adhered to the surface. Silica has poor adherence to asphalt in wet conditions, and silica can react poorly with alkyds in portland cement. Both of those are big hints that it might be impossible to stick these tiles down for their claimed 20 year lifetime.

A mature discipline means highly experienced experts. And the thing about experts: they can tell you what can already be done, and tend to reject anything different than what can already be done.

It's a well-known caveat. Experts would rather focus on the flaws of the alternatives in order to "disprove" their viability, rather than try & find solutions for said flaws.

This solar panel technology may not have all the benefits of traditional roads, but it has benefits which traditional roads don't. It's not possible to really know which set of pros/cons is better for us today, before the technology is tested and iterated upon, to weed out the inevitable issues that will pop up.

Any new technology in the history of humanity has failed the "thought exercise" experiments of those deemed experts at the time. Cars, computers, airplanes, heck, even computer mice were called "impossible" at some point.

Seems like the best way to figure those issues out would be to start actively using them to discover the areas where the feature set starts to break down.

What's your plan for when they fail, because we skipped the lab testing phase? Don't forget, a failure will likely include multiple cars in a collision on a faulty road surface (10's of thousands of dollars in damages and risk of loss of life).

I expect these will show up in parking lots long before before they end up on actual roads or other paths. It's much easier to block off a section of a parking lot for installation, repair, cleaning, etc. than it is to block a section of a road. Also, parking lots tend to be privately owned.

Isn't there a weakness in that busy parking lots tend to be full during the day and empty at night when there's no sun?

Actually where it might make limited sense is in the parking lot roadways, not where the cars are actually parked.

If we're going to do anything with solar panels and parking lots, I'd much rather see something like Google's "solar trees". Paving parking lots with these tiles would mean that on the order of half of their effective area would be shaded beneath cars during the, you know, bright part of the day.

Honestly, the first thing to do is just to put up solar panel roofing over every exposed air parking lot. Everyone already wants the shade anyways.

It's honestly so weird that we're attracted to all of these 'crazy' schemes, while skipping out on the all sorts of far lower hanging, and sensible fruit.

From an energy generation point of view, this plan is pretty irresponsible. Solar installations have a relatively poor EROI as it is (for standard installations) for mid-latitude regions. Purposefully handicapping your solar infrastructure by putting on the road surface is particularly braindead in that respect. From a systemic view, it makes more sense to rip out the solar panels from the road way, and put it ontop of buildings, or really any where you won't get random occlusions, and ridiculous amounts of dirt.

I mean, I get the attraction of easily reconfigurable displays on your road surface, but honestly, the intelligence and power generation aspects of the idea should just be decoupled, and split out.

Just out of curiosity...

What are some of the sensible, low-hanging fruit you have in mind?

Solar panels on roofs of buildings

I suspect that if you took the reconfigurable displays out of the pitch, far fewer people would be keen on the idea. I think that's the bit that captures the imagination.

I think we'd get better mileage from modular roof materials like roof tiles or sheeting with in-built solar panels, or window treatments like awnings.

It would be much cheaper to just have solar panel covers over the parking spaces. And that way the cars get some shade too as a bonus.

Given how much some urban planners have denounced parking lots as being detrimental to cities, I wonder if there is potential for legislation to mandate that any new lot larger than a certain size must be equipped with some corresponding acreage of roof-mounted panels. It might force developers to think more carefully about building lots and mitigate the environmental impact of those that do get built. (Although, given the controversy that erupted when incandescent bulbs were banned, I don't see this proposal as being politically palatable.)

Are solar panels actually cost effective at this point? Any legislation forcing people to do non sensible things is bound to be met with resentment/unpalatable.

The incandescent ban I just found odd personally. If you're going to legislate bulb choice then why aren't we all being forced to buy LED bulbs? Based on the manufacturer claims they're both the more energy and cost efficient choice. (however much stock you place in those claims..)

It's an interesting idea, for sure, but I just don't see how it makes any sense at all for roadways, where the tiles will be subject to constant stress, grime/dirt (which will reduce the already-not-great efficiency of PV cells), non-constant sun exposure, and prime opportunity for theft. We have lots of not-yet-utilized solar space already that won't be subject to the downsides of this kind of technology. Frankly, it seems like a solution in search of a problem to solve. Also, they've got to be a hell of a lot more expensive than asphalt.

I can totally see this as a technology for building patios and sidewalks on privately-owned land. It would be really cool to have self-lighting pathways that also serve to generate power for my household, but in terms of sheer economics, it's going to be hard to make the argument for a lower-efficiency, higher-install-cost solar brick than to just slap a PV array on my roof.

> It's an interesting idea, for sure, but I just don't see how it makes any sense at all for roadways, where the tiles will be subject to constant stress, grime/dirt (which will reduce the already-not-great efficiency of PV cells), non-constant sun exposure, and prime opportunity for theft.

This is the part I don't understand...do people not realize how dirty roads are? How often will street cleaning need to be performed to make sure they are collecting enough power for just the LEDs? How are they planning on handling all of the leaked oil/coolant/etc.? How many cans of spilled paint (accidental or otherwise) will it take to bankrupt a city's road budget?

People are willing to risk their lives to steal copper wire...how are they planning on securing every hexagonal foot of road in america when they're each worth $1000+?

The crazy annoyance of linkbait titles.

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