Wireless charging of moving electric vehicles overcomes major hurdle
news.stanford.edu
news.stanford.edu
Rail-based navigation is considerably simpler than autonomous driving. The problem is reduced to "how far am I along the track" and "if there is something in my way, it's trespassing on the railway, so make a best effort to detect the obstacle and stop, and beyond that, who cares".
I see what your point is regarding the convenience of using a car. What could be more convenient than leaving your house, getting in your car, then being dropped at your destination? But this doesn't take into account the cost of the entire infrastructure needed to make it work flawlessly. On the other hand, the train goes faster, and benefits from economies of scale. A tightly knit network of trains would beat a transport system made of autonomous cars.
I did some napkin math on this a while back[1]. It's interesting.
I think people will still want their own personal cars, because...
> some of the good parts of trains and buses, and some of the good parts of Taxis
...they won't want to get the car with the drunk vomit urine and heavily graffitied and torn up interior.
I can see how you could - via the hailing app or whatnot - send the car off as "undesired because XYZ" - and maybe it would go somewhere to get refurbed, but after a while, with so many refurbs, the companies will either give up, or they will make concessions (allowing for so much damage until it is deemed "needing repair" and cleaning it up as best as they can otherwise).
People might also want personal cars as a quicker convenience, and also as a status symbol. There's also those who might want to ride around in a personalized custom car, much like people do today.
I'm not making a case people won't have their own cars, I just think it will be less common, and extremely less common to have two or more for a family.
> ..they won't want to get the car with the drunk vomit urine and heavily graffitied and torn up interior.
It's not like you don't know who was in the car that caused the problem, and can't have the whole day recorded for proof. Charge a cleanup fee, include video as proof. If it requires immediate cleaning and must be pulled off the road, charge them for the average income for that time as well. If it's in the agreement for the ride, you can auto charge the account/card as well, since that's how they paid in the first place.
I think that's plenty of incentive to cut down on people not treating your vehicles well because there's no driver to call them out.
> People might also want personal cars as a quicker convenience, and also as a status symbol.
Sure. For the same reason people buy $100k+ cars. That's a somewhat small segment of the market.
> There's also those who might want to ride around in a personalized custom car, much like people do today.
Insurance will likely start to make that expensive. Sure, it will happen, but I think it will be less common. It's already an expensive hobby.
This is a "America v/s Europe" problem.
If you design suburbs so that houses are clustered around Train Stations, then trains are a huge asset.
If you design suburbs around the car, then no, it won't work.
It needs a lot of infrastructure in roads. That's really expensive and a huge maintenance headache.
The wireless power people need to get to a standard charging pad that Just Works, and get it widely deployed.
Is it any more expensive or more of a headache than all the externalities, costs, and dangers of the alternative? At this point in time, societies all massively subsidize the fossil fuel industry at great cost to everyone but it's so spread out its hidden from view. I'm curious, if there is ever a realignment of costs from society at large to the oil companies, would the wireless charging roads look far more viable?
On the other hand, a universal joint and a drive shaft are about as straightforward and reliable as it gets. You can still have a motor per wheel and size is not as restricted.
Long story short: in hub motors don't make sense unless you're very space constrained, like on an e-bike.
You can build a good enough demo to get press. Once the vehicles are out there as a product for a couple years the flaws will be clear.
Nice idea.
If you want to run the numbers yourself a Tesla uses 300 watt-hours per mile on the highway. California route 60 sees 337000 cars per day and is 70 miles long. And an amazing power transfer system might be 75% efficient.
337000 cars/day * 300Wh/mile/car * (1-.75) = 654W/m
So, I don't see the problem?
Along the length of the road, that is 21kWh. At 75% efficiency, that is 7kWh into the road surface per car. Roughly 2.4GWh of energy ($200k worth of electricity) per day lost as heat into the roadbed in total. Assuming 4 lanes and a 3.7m lane width, route 60 is 1.7 million square meters of asphalt and that is 1.4kWh per square meter. (8x more than your number.) Still comparable to solar irradiation though. Asphalt might get a little soft on a busy summer day when everyone is also running their AC but it wouldn't be a molten puddle. If the chargers are only embedded in a narrow strip down the middle of the lane, that section might get very soft.
So at 75% I guess it is practical. But 75% is going to be extremely hard. And the first place this should be installed is Route 1, because it would be a highway-sized snow-melter that also happens to power vehicles.
Now ask yourself why we don't have defrosted highways. Installing roadbed chargers is going to be even more difficult.
As a sanity check at highway speeds it takes ~30HP to maintain speed or a loss of 10HP or 7.5kw over ~60m (distance from one front bumper to next) x ~4m approximate width of a lane = 30w/meter which is a non issue. Lower speeds need less power, but can have more cars.
Further, not every car needs 100% power as batteries are still a thing, this is just for the subset of long distance traffic. And if you limit things to say 75% of a cars power demand that's still 4x the range.
I'm picturing future roads looking like massive Scalectrix tracks...
Taking the thought to the extreme, it could also be used as a kind of traffic shaping/control system. Have some roads "energised" at specific times to provide an incentive to go a longer way to alleviate chokes or traffic jams.
That gives many people an incentive to take a longer path (whereas current systems/methods for this are kind of driver-hostile as the drivers going the longer route don't get any direct benefit)
And then... when Road v2.0 comes out and it all has to get replaced? v3.0? Then flying cars and no one uses roads?
Also, the article is a lot more optimistic about efficiency:
"The group used an off-the-shelf, general-purpose amplifier with a relatively low efficiency of about 10 percent. They say custom-made amplifiers can improve that efficiency to more than 90 percent."
Correct me if I am wrong.
Putting solar panels flat on the ground loses 30% of their potential power.
Even ignoring all of that, covering solar panels with cars is a terrible idea.
The two problems I see with this idea are people complaining about the "view" (which is why it shouldn't be done on some really nice scenic part of a road, but in the middle of an ugly part of the city it should), and the possible problems with wind-loading, especially during storms, though surely this has been dealt with before, as there's a lot of places where they cover parking lots with elevated solar panels like this. For the view problem, they don't even have to cover the whole road with panels, they could just cover some lanes, put them in the median and extending over the inner lanes some, etc.
As a side note, you have to consider how in parking lots it is rare to have cars and trucks passing under the panels at 70 Mph, and more generally accidents are usually very low speed. Besides the "normal" resistance to wind, if you want to build a sort of half-pipe covering a highway you need to consider the pressure induced from the inside by high-speed moving objects and the possibility to resist accidents (preventing an 18 wheeler from completely crash a - say - 100 m section of the half-pipe in case of an accident needs a rather sturdy structure).
So, more or less it would be needed to build an artificial tunnel (concrete, rather thick) similar to a "snow shed":
https://en.wikipedia.org/wiki/Snow_shed
http://wsdotblog.blogspot.it/2014/03/the-i-90-snowshed-retir...
The "lighter" metal/lattice ones are only used usually for railways.
However, you bring up a great point with the "snow shed": covering all or part of a road with solar panels like this would also have the side effect of keeping bad weather off the road. How much money would that save in show-shoveling costs, and the costs to society of having roads blocked by snow (and snowplows), and having weather-induced accidents (both rain and snow)? Now, it's probably not feasible to cover every little road in a city with these things, but at least covering major arteries, while probably somewhat expensive due to the engineering challenges you raise, would have some major benefits: keeping the main roads clear even during horrible weather, and also providing a lot of energy from the solar panels.
And you have to consider how - in places where there is snow - you have to choose to either forfeit the (possibly little) energy the panels can produce in winter or anyway clean them from the snow anyway.
The good ol' rule of the thumb is that (of course it depends on the country) the cost is 10,000,000 Euro's per km of highway (plain, mainly earthworks), 20,000,000 per km on bridges/viaducts, 30,000,000 per km in tunnels. (the "base" price may of course vary, but the relative proportions remain roughly valid)
An artifical tunnel or sbow shed, besides the solar panels, would be probably 1.5 to 1.7 times the cost of the "simple" highway.
I mean, aren't these issues already basically solved? I frequently drive through miles-long tunnels under Boston at 70mph.
On the whole idea powering cars wirelessly while they drive just doesn't work on mass scales. It's going to be massively expensive to build it out.
I'm not for or against, just that coke bottle glass is not the only way
If you don't mount flat you can then do tracking too.
Like you say. Mounting flat is probably the worst way to go from a utility and return standpoint.
To have solar win against fossils you need an area that is sunny and very dry. You also need very very cheap land. Watt/square meter of land fossils will win in most places within the US.
Writing this, I recognized that it is probably short-/middle-term money, because electrical cars are quicker to develop (incl. infrastructure).
http://www.ucsusa.org/clean-vehicles/electric-vehicles/emiss...
Given that power grids everywhere are turning more towards renewable energy, this efficiency will only grow. The cleaner the grid, the cleaner the stuff that runs on the grid.
As for Hydrogen, lack of infrastructure is a major issue, on the production side as well as distribution. Producing hydrogen from natural gas produces CO2, producing it from water is slow and requires electricity, once again you're tied to the grid. There are further issues, found a good list of them here: https://cleantechnica.com/2016/06/10/hydrogen-fuel-cell-cars...
People will argue that running on the iron directly is more efficient, but on a large scale, electric wins. It already won, it's just not apparent yet.
Assuming you use electricity to split water to power your fuel cell, you've basically just made an even more complicated way to use electricity to power your car. So at that point, just simplify it and just use a battery and a motor.
"There are four main sources for the commercial production of hydrogen: natural gas, oil, coal, and electrolysis; which account for 48%, 30% 18% and 4% of the world’s hydrogen production respectively."
Cleanliness isn't really any reason one way or the other but there are other differences. Energy density of hydrogen fuel cells is higher than Lithium ion batteries so vehicles can travel further. On the other hand, physically moving hydrogen is relatively expensive and infrastructure to do so doesn't currently exist while distribution of electricity is a thoroughly solved problem and is relatively efficient.
So to beat that, you have to use less than one fuel cell to transport 19 other fuel cells. I honestly have no idea whether that's easy or not.
1) It IS inherently cleaner than conventional even without a major switchover, for two reasons:
. a) A central power station can be much more efficient than a small internal combustion engine, even using the same fuel. A good natural gas power station can get above 60% efficiency (caveat: LHV... but even using HHV value for natural gas, still above 50%), whereas internal combustion engines are around 15-25%, although can be even worse. This difference is much greater than any transmission or round-trip charging losses.
. b) Regenerative braking only (practically) works with electricity. This already makes electric cars cleaner, since they can recapture kinetic energy while braking. In conventional cars, this is all wasted as heat. A side benefit of this is electric car brakes last way longer.
2) We ARE changing over. Coal used to be >50% of our electricity, now it's on the order of 30%, and usually is dwarfed by natural gas at 33%. Natural gas per unit /thermal/ energy gives off a lot less CO2 than coal and still significantly less than gasoline or diesel. And natural gas plants are also very clean burning with almost no ash and soot (which can cause global warming in other ways, besides asthma and lung cancer, etc). And it's easier to make really thermally efficient natural gas plants than it is for coal. HOWEVER, even natural gas is now over-shadowed by clean energy (now at 36% of power) from nuclear, wind, hydro, solar, and geothermal combined (in that order). So now over a third of electricity is essentially carbon-free. This means that electricity on average is actually less carbon intensive in the US than if it were all produced from natural gas alone, which makes it even cleaner than if it were all centrally-burned petroleum, which makes it cleaner than if it were small internal combustion engines.
3) Fuel cells (let's take hydrogen for example) have major problems. The MAIN being the terrible round-trip efficiency. Electrolysis of hydrogen from water using electricity (this is basically the best case scenario, realistically) is 40-60% efficient. Fuel cells are themselves only 40-60% efficient. Then you add in the significant amount of energy needed to compress and transport the hydrogen (transportation is comparable to transmission losses from electricity, but sometimes worse), and the total efficiency is somewhere between 20-35%. Batteries are around 80-90+% efficient, and you can do even better if you're careful. That means you're ALREADY only able to travel a fourth to a third the distance in a fuel cell car for the same amount of electricity generated. That's insanely bad when you think of it. This is the main problem.
4) Fuel cells are actually much more expensive. They require high pressure storage and transfer. The fuel cells themselves are expensive, too.
5) Hydrogen itself has problems. There are material compatibility issues. A good lithium ion battery using a silicon chemistry can actually have a higher volumetric energy density (when you include the lower efficiency of fuel cells) than hydrogen, meaning you can make a more compact electric car or put a bigger battery in the same space. Hydrogen is also insanely flammable, with a very high flammability range in air. It makes explosive mixtures with air very easily. It also causes embrittlement of metals.
6) Electricity distribution is already ubiquitious due to the electric grid. Most people can charge at home (and even more if apartments just run out an outdoor outlet to parking spaces). That means people almost never need to go out to a filling station. It's only needed on long trips, and even then only after exhausting the internal battery. Many hotels/motels already have RV charging (and many allow EV charging), so on a multiday trip could start out each day with a full "tank" without any trips at all. And there's already been a lot of work installing charging stations all over the country, including very fast charging roughly equivalent to the typical hydrogen filling station. It's a lot cheaper to install a fast electric charging station than a hydrogen filling station and a lot fewer are needed.
7) Almost all hydrogen is produced by fossil fuels using steam reformation. Hydrogen is even LESS of an "inherently clean" technology than electric is, if you use today's energy mix for both!
8) Electric cars are incredibly simple. Even a conventional car already includes a battery, a starter, and an alternator. In an electric car, you combine the starter and alternator into a single larger device, get a bigger battery with cooling, and throw the entire rest of the engine (spark plugs, pistons, camshaft, exhaust, catalytic converter, fuel pump, oil pump, oil sump, oil filter, fuel filter, fuel tank, air intake, air filter, etc, etc) away. You also can DRAMATICALLY simplify the gearing. As you mention, electric cars are cheaper to develop. But they're also cheaper to make and much cheaper to maintain. Additionally, a hydrogen fuel cell car will already need everything an electric car needs, including a (smaller) lithium ion battery.
9) The ONLY thing really holding them back is battery cost. And that is rapidly being solved. A >200 mile battery gives you a practical range, very long battery life (hundreds of thousands of miles), and ability to accept a very high charge rate. And this is actually something we'll want anyway to make the grid more effective (get rid of expensive peaker plants and local grid bottlenecks at high usage) and to allow higher penetration of solar and wind. If we build out our battery production facility for electric cars to be ubiquitous, we've basically also completed enough battery production capacity to go, say, 80% solar/wind. (Although for the love of all things holy, let's keep at least our existing nuclear power plants running until we've gotten rid of coal and gas.)
https://www.eecbg.energy.gov/hydrogenandfuelcells/pdfs/28890...
Forbes had an article about it which started with a bit of skepticism about the system:
https://www.forbes.com/forbes/2003/0120/092.html
Even so - to me the idea seemed reasonable. Furthermore, there's a place in the United States almost nearly perfect to set up a production/recycling system. I have yet to find an objection to why this process (or the location - aside from possible EPA or endangered species red tape) couldn't work.
The location? Kramer Junction, California.
https://www.google.com/maps/place/Kramer+Junction,+CA+93516
If you've ever been there, you probably didn't stop (unless it was for some gas or fast food). It's a "grand intersection" - you have at least one main railroad line, two highways, and one or more high-tension power lines going thru the area.
To the east, is Barstow and Daggett - testing grounds for the Solar One array:
https://en.wikipedia.org/wiki/The_Solar_Project
So plenty of sun to power things with.
Powerballs are based on sodium hydride pellets, which are manufacturer using a complex process - part of which involves molten sodium (!) with hydrogen gas (!) bubbled thru it. Molten sodium has been used as a means for solar concentrators to move heat from the array to the heat exchangers for steam (it can even stay molten thru the night, continuing power generation with no sun input). At least, that's what I understand.
I've also heard (and maybe I've misunderstood?) that the Powerball system can also be done using sodium borohydrides - for which you would need borax. Guess what is also nearby?
Just to the west is Boron, California (famous for the "20 mule team"):
https://www.google.com/maps/place/Boron,+CA+93516
So - if borohydrides can work - you have that supply (I believe it still is mined there).
Now - hydrogen - where to get that? Well, we need water, but we're kinda in the middle of a desert here. However, not too far away is a pretty good source of water - the Colorado River (plus various lakes and reservoirs). There might also be briny ground water that couldn't be used for drinking or agriculture, but would work ok for this purpose).
So - assuming we have all of this - we can make hydrogen somewhat simply, using a couple of different methods:
1. We could use an old method to create it, using solar as part of the energy input and steam generation; this was a method used in the 1800s to create hydrogen for gas ballooning enthusiasts:
http://www.sciencedirect.com/science/article/pii/S0378775399...
I won't pretend to understand this - but the usage of coal in the process concerns me (mainly the CO production) - I'm not sure all of that is re-captured in the process of conversion.
2. We could use solar power to heat up steam enough so that it dissociates into hydrogen and oxygen:
http://oxygen.atomistry.com/dissociation_of_steam.html
A solar furnace can easily reach these temperatures.
Transport to and from the facility can be via road or railroad. Excess electrical energy can be put into the power grid.
That's the rough idea. I'm certain there are problems with it - likely big problems, which is why it hasn't been done. I'm not certain what happened to Powerball Technologies - I seem to recall hearing that they had been bought by Ballard Power Systems; I don't know if their tech was viable, or if it was a dream or money scam. Maybe it's something that works, but only on a small scale, and can't be scaled up? Or maybe its too dangerous. Or - tin foil hat time - maybe it works perfectly, and Ballard bought them to bury the tech (and anyone else who wants to try it)? Ok - I don't really believe that last one; if it did work, Ballard would try to commercialize it.
So something tells me this tech doesn't work...?
Longer range battery powered cars suffer from high weight for range and long charging time. Even the charging times of a Tesla are not truly viable in long trips; its 45+ minutes to get full. A thousand pounds, long charge, and very high capacity loss in cold weather are not the big negatives. Add in even hilly terrain hurts them too.
I think after the honey moon is over those who select an EV as their only car; a lot of those buying into the 35k-50k cars may only have one vehicle; will soon find its limitations irritating. I would not mind a Bolt,but only as a second car. 200 to 300 miles is not enough and the charge time, again even in Tesla, is not acceptable
I also own a Chevy Volt. It's my only car. The biggest improvement is the fact that I almost NEVER have to go to the gas station, and every trip I've taken has had each leg within a Model S's top range.
Going to the gas station constantly is an inconvenience that most people simply don't notice until they get an electric car.
So would I rather take a 15-40 minute lunch break on a road trip every 3 hours on the maybe one road trip beyond 200 miles I'd go on every year or have to travel to the gas station 50 times a year? Obviously the latter involves a lot more wasted time.
Oh, and charging speed is improving. No reason, fundamentally, you couldn't engineer a battery that charges, say, 100 miles in 5 minutes or 200 miles in 10 minutes. Tesla AND others (VW, etc) are planning/testing 350kW charging, which would help enable that speed.
As far as cold weather: balooney. I've lived in cold weather states for most of my life. Conventional vehicles have a huge disadvantage in that they don't even start AT ALL in some conditions whereas electrics have zero problem. And since they're already plugged in, you can pre-heat them before you leave (without burning gas, mind you).
Hilly terrain is actually much better with electrics since you have PLENTY of torque and regenerative braking means you're not going to overheat your brakes like you would in a conventional vehicle.
In a far out, sci-fi kind of world, huge solar powered blimps hover in fixed traffic patterns, collecting more solar power than they use, and relay fractional amounts of collected surplus energy down to parasite vehicles, that assume a formation for refueling laser targeting, within the blimps flight pattern.
The cars accept the laser energy in a beam collector, for energy conversion, netting a bonus as recharge, and then resume independent travel as their intended destination requires.
Predictive consumption graphs can estimate optimal routes, for different charge requirements before leaving, optimizing for fastest time, best blimp paths, least energy consumption, traffic congestion avoidance or whatever.