Energy roads

[malikofscience]

I was thinking about roads being the energy supplier to a new-type of vehicle.

If the streets can be made to absorb solar energy and transmit that energy to a new-type of vehicle, then a city can be energy efficient. A rode model to show a country how to be energy smart and clean.

 

 

Any thoughts?

[Baub]

An interesting idea. Think of all the surface area out there in road ways, soaking up and storing solar energy. Not only enough to power autos but also power the cities. I have wondered about something along the same line of thinking....only my roadways contained super cooled magnets which then interacted with magnets in the vehicles.

[Klaynos]

The cost and energy consumption of converting the roads would make it infeasible. Something similar is done with electric trains, but the generation is not local.

[Mokele]

It might just be easier to put a roof over the road, with solar panels on it. It could harness energy, and simultaneously would make driving easier by deflecting rain and snow.

[Mr Skeptic]

A bad idea, the expensive solar panels will be covered in mud and terribly damaged by tons of cars and trucks passing over it. Mokele has the better idea here, solar roofs over the road would be nice.

[malikofscience]

It might just be easier to put a roof over the road, with solar panels on it. It could harness energy, and simultaneously would make driving easier by deflecting rain and snow.

 

Mokele that's a great idea. The roads can be covered with a thin surface made up of solar cells.

[CaptainPanic]

Why not put the solar panels next to the road? The world ins't that full yet that we have to optimize things that much.

 

How would you transfer the electricity to the cars? With a system like the bumper cars, or overhead cables?

 

Perhaps it's a good idea to cover existing overhead cables of trains with solar panels. The steel structures are already in place, and maintenance is easier because of train schedules (often tracks are hardly used at night - making it accessible for maintenance). But again, it might be easier to place the solar panels next to the tracks.

 

I'd be worried about short-circuiting. Do you know how often the overhead cables of trains are broken (lightning, trees falling)? The traffic problems would be unimaginable. Not one car that stops, but the whole traffic system can come to a halt in a thunderstorm

When trains stop running, the train company can use buses... but with cars, even if you can arrange another form of transportation, people might be reluctant to leave their cars behind.

[npts2020]

I have read in Scientific American that it will take about 40,000 square miles of solar panels to provide half of all of America's energy needs in 2050. By coincidence there are about 40,000 square miles of roadway in America according to USDoT. I would like to see the entire road/rail system automated, enclosed, and powered with wind and solar energy. I don't think that it will be practical to put solar panels anywhere on the road, they will have to be elevated above or beside, as pointed out by others. You would have to figure out places where it would be a waste to put a solar panel because of lack of direct sunlight, though (between tall buildings in a city, behind a mountain, etc.). All of the technology required is in existence today and only needs to be refined for this specific application. I haven't written much in the past couple of months but if you are interested here is much of what I have written about automated transportation, if you are interested. I recommend starting with the oldest posts first.

[Mokele]

Why not put the solar panels next to the road? The world ins't that full yet that we have to optimize things that much.

 

Next to the road is often people's property, or is otherwise in use. Plus, by using the space above the road, it has the auxiliary benefits of shade and shelter for the road, reducing the need for A/C on hot days, and most likely reducing accidents on snowy or rainy ones.

 

 

As far as power, I was actually thinking more in terms of just wiring it to intermittent power stations along the road, much like modern gas stations. The difficulties of tethered power, especially with lane-changing etc, are just not worth it.

[iNow]

It would be interesting if the power could be transmitted via something like wi-fi directly from the panel roof to the battery of the cars driving below it. This way, you'd only need to stop at the service station to take a leak and grab a drink, since the batteries would be continuously regenerated as you drive.

[SH3RL0CK]

I'm not meaning to be negative as I think the idea has merit. But I'd like to play devils advocate and point out some potential problems.

 

One problem would be that the entire USA (and all of Europe as well) will be in the dark approximately 12 h a day. What do you propose will power the cars at night and/or where will the electricity be stored during the day?

 

Another problem compounding this issue would be during the winter months, there is darkness for considerably more than 12h per day. And during the day, it is often overcast and/or perhaps snow covering a significant portion of the solar panels.

 

In addition, I wonder how much of this area corresponds to the traffic density? There are lots of roads which are very rarely used and far away from the major cities where the roads are heavily used.

 

And would the public accept driving in a dark tunnel most of the time if the panels were placed above the road?

[swansont]

It would be interesting if the power could be transmitted via something like wi-fi directly from the panel roof to the battery of the cars driving below it. This way, you'd only need to stop at the service station to take a leak and grab a drink, since the batteries would be continuously regenerated as you drive.

 

Any folks who think cellphones cause cancer are going to love that idea.

[Mokele]

It would be interesting if the power could be transmitted via something like wi-fi directly from the panel roof to the battery of the cars driving below it. This way, you'd only need to stop at the service station to take a leak and grab a drink, since the batteries would be continuously regenerated as you drive.

 

The way I figure it, you have to eat and piss anyway, so if the car can go for much longer on battery power alone, it's not a big deal to plug the car in at the station while you take a leak and eat a burger.

 

One problem would be that the entire USA (and all of Europe as well) will be in the dark approximately 12 h a day. What do you propose will power the cars at night and/or where will the electricity be stored during the day?

 

Batteries.

 

Another problem compounding this issue would be during the winter months, there is darkness for considerably more than 12h per day. And during the day, it is often overcast and/or perhaps snow covering a significant portion of the solar panels.

 

I suspect that solar will almost always be a sort of backup or surplus power, to be used to supplement existing power sources and reduce demand.

 

In addition, I wonder how much of this area corresponds to the traffic density? There are lots of roads which are very rarely used and far away from the major cities where the roads are heavily used.

 

Could just be routed to the nearest town for their power needs.

 

And would the public accept driving in a dark tunnel most of the time if the panels were placed above the road?

 

Depends, if it meant free power during the day, probably. Besides, in most places there isn't exactly much to look at anyway.

[malikofscience]

I'm not meaning to be negative as I think the idea has merit. But I'd like to play devils advocate and point out some potential problems.

 

One problem would be that the entire USA (and all of Europe as well) will be in the dark approximately 12 h a day. What do you propose will power the cars at night and/or where will the electricity be stored during the day?

 

Another problem compounding this issue would be during the winter months, there is darkness for considerably more than 12h per day. And during the day, it is often overcast and/or perhaps snow covering a significant portion of the solar panels.

 

In addition, I wonder how much of this area corresponds to the traffic density? There are lots of roads which are very rarely used and far away from the major cities where the roads are heavily used.

 

And would the public accept driving in a dark tunnel most of the time if the panels were placed above the road?

 

I was thinking about the vehicle being a hybrid, using solar for the day and use another energy supplier at night. That should be 1/2 of the energy a city can supply to the hybrid.

 

 

For extreme weather like snow, this smart road should have an integrated heating system that will melt the snow. And it should have a system that is water resistance.

 

 

Someone will make a more sophisticated capacitor that will store the energy.

[swansont]

The way I figure it, you have to eat and piss anyway, so if the car can go for much longer on battery power alone, it's not a big deal to plug the car in at the station while you take a leak and eat a burger.

 

Well, we've been over this ground before. The problem is that while filling your tank, you are effectively transferring energy at a rate of around 10 MW. At 1 MW, you have your "stop for a burger" fill-up time. Who has that kind of delivery capability for electricity?

[SH3RL0CK]

I was thinking about the vehicle being a hybrid, using solar for the day and use another energy supplier at night. That should be 1/2 of the energy a city can supply to the hybrid.

 

 

For extreme weather like snow, this smart road should have an integrated heating system that will melt the snow. And it should have a system that is water resistance.

 

 

Someone will make a more sophisticated capacitor that will store the energy.

 

 

Well, I am not sure that anyone would be more than willing to spend Billions (or Trillions) of dollars for power plants which will only be used half the time - not even the US government. Most power companies expect their main power generators to operate 24/7 and very infrequently shut down for operation maintenance...offhand I'd expect downtime of less than 5%. Granted there are (and must be) ways to adapt for peak demands, but additional power generators are kept to a minimum, some utility companies will actually pay industrial users to shut down during times of peak demand. Now these could potentially help provide this peak demand power, but thats not what we are discussing here...

 

To melt snow on top of the solar panels could require more energy than they generate. It might be better to leave the snow.

 

Regarding this energy storage; its very easy to transport electricity efficiently. It is very difficult to store it efficiently. There will be considerable losses with either batteries or capacitors; assuming of course they could be scaled up appropriately.

 

And swansont has probably the best argument against this idea, how to pump 10MW into your car in a few minutes via electricity?

 

Despite the problems noted above, I think this plan is actually a good idea for two reasons:

 

1) The solar panels could be used to provide electricity in a clean manner. But only for select locations where it could make economic sense (i.e. in warm, sunny climates near major cities). And in a manner which makes sense (i.e. for peak or industrial demand; maybe for energy storage if there were a good way to do so available).

 

2) The covered roads would be safer than uncovered roads by keeping the rain/snow/sunglare away.

[Mr Skeptic]

As to the "dark tunnel" problem, just cover the roads with a translucent roof and use only half for solar panels. This would protect from many bad weather effects and glare, and yet be fairly bright.

 

Hm, I think there is actually a problem with this idea. I understand that the hot sun is supposed to soften the asphalt and allow cracks that have accumulated to close. On the other hand, I think much of the problem is damage from freeze/thaw of ice in those cracks, and snowplough damage. Dunno if a roof would be a net plus or not. The roads would actually have to be fairly enclosed to keep out all the bad weather.

[Sedit]

I would think that some sort of heat transfer device and something to convert this to electricity would be the most feesible way of using the road power.

If you consider that roads need to be repaved all the time anyway this systems could be put in place next time its due for repairs.

 

Also there will be a conservation of the energy expended as heat as the cars wheels meet the road.

 

At first thought I would believe that this could be done with a blanket of fluid filled pipes but Im sure there are many other ways that one could use this thermal energy to convert it to electric.

[CaptainPanic]

I think it's cheaper to put a solar panel on a roof than over a road. That's because buildings on which the solar panels are placed generally will not move at 100 km/h.

 

I once compared the area in the Netherlands with buildings with the area needed to replace all Dutch electricity consumption. Conclusion: filling up 65% the roofs of houses is enough to replace 100% of the electricity consumption. If you use all buildings then this is even less than 50%. Calculation follows below with references (links).

 

Calculation:

The total energy consumption of the Netherlands (2006) was 120 TWh, or almost 14 GW [2].

 

solar panels are assumed to convert 10% of the sun's energy into electricity (new panels can do 15% I believe, but let's be a bit conservative).

 

Source [3] shows the average insolation (radiation from the sun) in Europe. Amsterdam gets 2.27 kWh/m2/day. That is an average (24 hrs average) of 95W.

 

The panels convert 10% into electricity, so that is 9.5 W/m2.

 

To generate 14 GW with 9.5 W/m2 means we need about 1400 square kilometers (km2).

 

The total surface in the country for housing is 2218 km2. The total built environment is even 3096 km2. And the total surface of the country is about 44000 km2 (so, yes, our country is quite full).

 

[1] http://www.milieuennatuurcompendium.nl/indicatoren/nl0201-Stroomdiagram-energie-voor-Nederland.html?i=6-40

[2] http://www.energie.nl/

[3] http://www.apricus.com/html/insolation_levels_europe.htm

[4] http://www.cbs.nl/nl-NL/menu/themas/natuur-milieu/publicaties/artikelen/archief/2003/bodemgebruik-in-nederland-geharmoniseerd-met-top10vector.htm - click the Excel sheet at the bottom (all in Dutch)

[5] http://www.herbergpv.nl/kosten.htm

 

Note that electricity consumption will go up with the use of electric cars... which is obviously not yet included here.

[npts2020]

SH3RLOCK; Solar power may require backup but once installed requires little maintainence. Also, peak use is almost always during daylight hours, meaning it may be most useful as a power supplement rather than the main source. For more than that, a storage system of some kind is necessary but the problem is not intractable as there are many proven ways of doing it.

According to Scientific American, if a wind grid is well designed and large enough (size of Australia, U.S. or E.U.), it will not require backup, since there is always wind somewhere.

Other notes; If the transportation system is automated, enclosure will be necessary to enable high-speed travel. IMO speeds are too high to be safe on current roads mostly because of mixing vehicular and non-vehicular traffic and incompetent human drivers. Some people will object to not being able to look out the window of their vehicle to see scenery but I think most will "get over it" in a short time and accept the utility of the system as being better. If it is desired, an image of the surroundings can be projected on the inside of the vehicle.

In automating the system, it may turn out that rubber on asphalt is not our best option. The reason this is used now is mainly for ability to change direction quickly (i.e. friction) and smoother, quieter rides. It may be that something more similar to steel on steel like railroads will be better.

IMO the only way to build quickly is to prefab sections of roadway and connect sections like Hot Wheels or model railroad tracks. This should enable construction crews to measure progress in miles per day instead of days or weeks per mile.

[SH3RL0CK]

SH3RLOCK; Solar power may require backup but once installed requires little maintainence. Also, peak use is almost always during daylight hours, meaning it may be most useful as a power supplement rather than the main source. For more than that, a storage system of some kind is necessary but the problem is not intractable as there are many proven ways of doing it.

According to Scientific American, if a wind grid is well designed and large enough (size of Australia, U.S. or E.U.), it will not require backup, since there is always wind somewhere.

 

True, peak demand tends to be around 5:00 PM.

 

http://en.wikipedia.org/wiki/Peaking_power_plant

 

However, note that the demand is normally still very high as late as 8:00 PM, long after the sun would have set in the winter.

 

http://en.wikipedia.org/wiki/File:Tagesgang_engl.png

 

So it will be necessary to maintain and expand the current back-up systems and/or develop a storage system(s). I'm not fundamentally opposed to this, however it seems to me that this will result in additional costs. At some point, these additional costs would make the idea not feasible, but without a careful cost analysis we don't know exactly where.

[CaptainPanic]

True, peak demand tends to be around 5:00 PM.

 

http://en.wikipedia.org/wiki/Peaking_power_plant

 

However, note that the demand is normally still very high as late as 8:00 PM, long after the sun would have set in the winter.

 

http://en.wikipedia.org/wiki/File:Tagesgang_engl.png

 

So it will be necessary to maintain and expand the current back-up systems and/or develop a storage system(s). I'm not fundamentally opposed to this, however it seems to me that this will result in additional costs. At some point, these additional costs would make the idea not feasible, but without a careful cost analysis we don't know exactly where.

 

"Feasible" in this case means "competitive with fossil energy" I guess?

Because some people also look at "feasibility" from the perspective of "affordable". They see that sustainable energy has an added value compared to fossil energy (like "saving the planet and humanity" and stuff), and are realizing that this added value has to be compensated by a higher price. (And now, the only compensation is in the form of carbon-credits, which is not a lot of money).

 

I believe that transforming to a completely sustainable economy is feasible. I also did a calculation on that once for the Netherlands... if about 9% of the gross national product until 2020 is spent on sustainable energy, then we're done - completely 100% sustainable forever.

 

Is that feasible?

Edited March 4, 2009 by CaptainPanic
linking to new post with complete calculation for wind power costs (feasible or not)

[SH3RL0CK]

"Feasible" in this case means "competitive with fossil energy" I guess?

Because some people also look at "feasibility" from the perspective of "affordable". They see that sustainable energy has an added value compared to fossil energy (like "saving the planet and humanity" and stuff), and are realizing that this added value has to be compensated by a higher price. (And now, the only compensation is in the form of carbon-credits, which is not a lot of money).

 

I believe that transforming to a completely sustainable economy is feasible. I also did a calculation on that once for the Netherlands... if about 9% of the gross national product until 2020 is spent on sustainable energy, then we're done - completely 100% sustainable forever.

 

Is that feasible?

 

 

By feasible, I mean compared to all the alternatives (including, but not limited to fossil fuels). If plan B was clearly a better alternative than plan A, in terms of cost, user-friendliness, and in terms of the environment, then clearly plan A is not feasible.

 

There should be clear data and studies regarding the costs of alternative fuels (I'm sure these already exist) so that legislators, utilities, the public, etc. can make the best decisions. However, there is still going to be differences of opinion regarding these matters. For example, 9% of GDP for the next 11 years might seem ok with some people, but might be unacceptable to others in the Netherlands. Do you think the Netherlands would be willing to spend this much?

[CaptainPanic]

By feasible, I mean compared to all the alternatives (including, but not limited to fossil fuels). If plan B was clearly a better alternative than plan A, in terms of cost, user-friendliness, and in terms of the environment, then clearly plan A is not feasible.

 

There should be clear data and studies regarding the costs of alternative fuels (I'm sure these already exist) so that legislators, utilities, the public, etc. can make the best decisions. However, there is still going to be differences of opinion regarding these matters. For example, 9% of GDP for the next 11 years might seem ok with some people, but might be unacceptable to others in the Netherlands. Do you think the Netherlands would be willing to spend this much?

 

Such studies exist. They always include the "status of technology". The technology which is not yet ready for large scale application is always the better one (whether that's because it's really better or because the researchers aren't objective about the potential, I don't know).

 

I do not think that anyone is willing to spend this much, because there is always somebody who says: why start now when alternatives are cheaper? Ok, they're not yet completely developed... so let's just wait.

 

And that's an important issue to realize... because technology progresses anything will always become cheaper (except oil). But waiting also means you postpone the pay-back time.

 

Additionally, the carbon balance is included. This is always something to debate... because how this is calculated is quite complex and dependent on a large number of assumptions.

 

In short: it's actually surprisingly hard to compare alternatives...