Batteries..... do we need them

[Willow]

from http://www.gizmag.com/electric-power-transfer-via-car-wheel/34266/

Two issues preventing the widespread uptake of electric vehicles are recharging time and lack of range. Now, scientists have shown one potential means of negating these issues. Their demonstration of electric power transfer via the car-wheel is claimed as the world's first.

Electric vehicles can already be powered via infrastructure in the road. The South Korean city of Gumi uses a means of electromagnetic induction to power some of its buses. This newly-demonstrated method, however, uses radio frequency transmission.

The concept has been developed by Masahiro Hanazawa of Toyota Central R&D Labs and Takashi Ohira of Toyohashi University of Technology. It avoids the need for potentially dangerous contact conductivity devices by up-converting energy from power lines into radio frequency using high-speed inverters.

An electric track embedded below the road's surface transmits a radio frequency to steel s...

The radio frequency voltage is applied to a balanced metal track running under the surface of the road. The car then picks up this voltage "via electrical capacitance between the metal and a steel belt installed inside of the tires of the EV."

To test their concept, Hanazawa and Ohira created a 1/32 scale electric vehicle. Using the prototype, they were able to show that such a vehicle could be propelled at a frequency of 52 MHz with a power penetration efficiency of over 75 percent.

Hanazawa and Ohira believe that the technology has the potential to enable "a tremendous extension of the EV cruising range." Indeed, by powering electric vehicles in real-time, it would hypothetically allow them to run indefinitely on much smaller batteries than are currently required.

The electric power transfer via the car-wheel concept was demonstrated at CEATAC last week.

Source: Toyohashi University of Technology

 

[Punx0r]

It's interesting, but wireless transfer of power is inherently lossy.

The point on range and recharge times were true in the days of lead acid, but taking the Tesla Model S as a quick example you have a 300 mile range with a recharge to 80% in 20 minutes. It's also yesterday's technology, these numbers keep improving. The real issue is cost, which is also coming steadily downwards.

So I think the inductive transfer via the wheel is neat, but probably not practical.

 

[dingoEsride]

May be ok for buses or taxi's on a certain coarse in busy cities maybe but once off the power source....maybe you can still have your batteries on board and get a charge while on them

 

[Modbikemax]

My kids tell me " that's a First World Problem".
Most of the world walks or if they are lucky pedal.
Maybe a few more of us fatty first worlders should walk or pedal.
Make it cool and trendy and first worlders will think they invented walking. :?

 

[JoeBaker]

Well i guess 52Mhz would work in a lab but for sure not in the real world.

Problem with moving power vea radio waves is aside from it being quite inefficient is that your going to have the FCC or other appropriate government agency for the given country waving there finger at you. Like for the above example 52Mhz is dead center of the armature radio 6 meeter band, which is probably why the experiment was ran at that frequency (that assumes one of the persons running the experiment had a armature radio license) Something running at that frequency in the wild would completely obliterate the armature 6M band the 49Mhz military band and if we still had analog TV in the US channels 2 threw aprox 8 or 10 depending on total radiated power. Move the operating frequency up or down and you just change the list of offended parties.

Now off the cuff without looking threw the FCC rule book, in particular part 15. The only way to make something like this legal is to keep the total radiated power below a few milliwatts. Or maybe use of a junk band like where microwave ovens operate at you might be able to run a few KW if you can keep exposure limits under the legal maximum. Or you can move the operating frequency entirely out of the radio spectrum. Maybe into the near infrared perhaps? maybe not the most ideal but you wont be legally limited on the amount of power you can transmit with it. As a added benefit it would double as a road kill cooker to Maybe it would be best to shoot for a much lower frequency. Power line frequency of 50 or 60Hz is probably too low but if it could be gotten working on 400Hz it just might not offend anyone and maybe just maybe move a useful amount of power.

Its that or we wait for wireless communications to become obsolete.

 

[friendly1uk]

Power along the main roads will do. I will want a battery that can get me home when the power grid fails. Just 30 miles range would be plenty. That 30 mile battery can get me to and from the major trunk roads that have a charging facility. Very few places are over 30 miles from a trunk road.

 

[John in CR]

Charge times is the most grossly overstated issue related to EVs. Typical use means never having to stop at any filling station, because EV's can fill up almost anywhere while the vehicle isn't being used. Trying to make them long distance highway vehicles is a total misapplication of all their advantages.

I want to go wherever I want to go, and if powered roadways come into existence I'll do my best to avoid them. We'll be airborne by then anyway and leave the power roads to buses full of sheeple.

 

[JackB]

That is an interesting development, but a better idea is to have inductive charging at stop lights,
which means cars will want to stop at them, not run them. Then you can have small battery packs,
and that makes an EV very inexpensive, and much easier to install, remember they install sensors at stoplights years ago.
But ain't gonna happen.
We collectively spent $15 billion dollars
on overpriced Prius/Hybrids and have ZERO EV infrastructure to show from it.

 

[bowlofsalad]

I am really skeptical that, at least in any reasonable time frame, the idea of relying on wireless power would be an option. To illustrate my point, fiber optic cables aren't a new idea, but even today there are plenty of places that have power lines by those same places don't have fiber optic cables. I've lived in various cities over the past 10 years and never had fiber optic cable interconnectivity in my home.

This discussion can probably be likened to the idea of AC power versus DC power. AC is primarily used concerning power transmission because of the efficiency advantage when transmitting the power over any distance. If batteries and wireless power came under direct competition, it's likely batteries would win unless electricity suddenly becomes free.

Battery technology is still going to be needed and valued even if some places started really pushing for wireless power transmission.

 

[Punx0r]

Optical fibre data connections are abundant in most places (IIRC there is a huge surplus in transmission capacity due to the dot.com bubble in the early 2000's), but fibre the last mile into the home is rare. I imagine it's mostly due to the cost of the associated hardware.

Also, the efficiency of AC sucks for power transmission compared to DC. AC is afflicted by cable capacitance, skin effect, hysteresis losses and the line-to-line voltage is half that of DC.

 

[dnmun]

the people who come up with these ideas have no concept of what it is like to tear up a roadway and install cabling and then replace the roadway. that is the reason the fiber is not available on your street. cost of tearing up the street and installing the fiber makes it unrealistic. imagine all the people who have electric heat or oil heat and not connected to the gas mains. all because of the cost of installing gas pipe in the street. and there the cost benefits are $2-3k/year for each home in colder climates.

 

[friendly1uk]

the people who come up with these ideas have no concept of what it is like to tear up a roadway and install cabling and then replace the roadway. that is the reason the fiber is not available on your street. cost of tearing up the street and installing the fiber makes it unrealistic. imagine all the people who have electric heat or oil heat and not connected to the gas mains. all because of the cost of installing gas pipe in the street. and there the cost benefits are $2-3k/year for each home in colder climates.

In the UK they have just figured out that a 10mm cable does not need a 2' wide hole digging. I'm not sure how far this has got yet, but a 10mm wide digging disc can cut the hole and the cable can be right behind it so it's in before the hole collapses. I imagine that will take another 10 years to be thought of, but the narrow trench idea is already reducing costs by well over 50%

Aren't they clever


edit: charging at traffic lights gives the idea your in town, so perhaps not far from home. Long distance traveling is usually done on roads where no stops are made so a constant source of power is required. This is important when stuck in a traffic jam in the middle of winter for 4 hours wearing enough clothes to make it from car to office door. We don't want the infirm dieing while the road is cleared. Constant charging is in line with constant generation, while these 70% in 2 min chargers are quite the opposite. We won't be able to have them.

 

[dnmun]

the only solution is to have ubiquitous charging locations on every street and driveway.

it is no longer a problem to authenticate and verify the person charging and charge them directly or through sharing networks. which i think will be the format. like in southern california now.

i can see the huge need for charging already in my neighborhood as it goes totally upscale and all this big apartment buildings have no charging or parking spots. i can already see how my charging location will be critical long term in my neighborhood. not the guvment regulated charging spot.

 

[bowlofsalad]

Optical fibre data connections are abundant in most places (IIRC there is a huge surplus in transmission capacity due to the dot.com bubble in the early 2000's), but fibre the last mile into the home is rare. I imagine it's mostly due to the cost of the associated hardware.

Also, the efficiency of AC sucks for power transmission compared to DC. AC is afflicted by cable capacitance, skin effect, hysteresis losses and the line-to-line voltage is half that of DC.

To make this discussion simple, lets assume you are entirely correct and I am entirely mistaken, DC power transmission holds advantage over AC power. If there was one metric to look at that would sort out many discussions, including this one, it would be economics or cost versus benefit. The economics on batteries are likely wildly superior, much as the economics of AC power transmission seems to be superior (why else would they use it?).

I love the idea of not having to carry around a battery, I am not being biased in my perspective, but the economics are extremely likely to be wildly superior for batteries.

 

[Punx0r]

You are quite correct - breakers and transformers for AC are much cheaper than for DC. Although that hasn't stopped HVDC power transmission from being used since the 1950s.

But you said "efficient", not cheaper

 

[dnmun]

doesn't anyone know the history of the battle of Edison and Tesla over the transmission of electric power using AC versus DC power lines?

Edison actually had built a DC power system in NY to supply power and after Westinghouse bot out Tesla then he was able to show how AC was capable of carrying larger amount of current without the voltage drops of the DC system Edison developed.

Edison actually used motion pictures to record the electrocution of an elephant using Tesla's high voltage AC current to try to win public support for his impractical system.

 

[Punx0r]

Tesla's DC distribution was at the same voltage as delivered to the end-user, hence was shit.

 

[Hillhater]

that hasn't stopped HVDC power transmission from being used since the 1950s.
)

??? what are you referring to ? nearly all HV power transmission lines are 3 phase AC !
Exceptions being rail power lines and similar

 

[Punx0r]

http://en.wikipedia.org/wiki/High-voltage_direct_current

 

[JoeBaker]

??? what are you referring to ? nearly all HV power transmission lines are 3 phase AC !
Exceptions being rail power lines and similar

Well to be fair to Hillhater it looks like HVDC links are quite rare in the land down under. The closest one to his location i can find is this one.

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

HVDC links dominate submarine cable applications since conductors submerged in sea water tend to suffer massive losses from the AC charge discharge cycle. HVDC links operate steady state so they avoid that problem in that application.

The largest HVDC links are in use in countries that derive a large part of there electrical power from renewable energy sources, most often hydro electric. in situations where the generating facility is quite some distance from a population center a HVDC link is built for the bulk long haul of power to the load center. The reason this is cheaper is that with DC the same wattage can be moved with smaller conductors and insulators. I'm not going to type out a full explanation of just why that is but if you would like to know you can grab a beverage and snack then hit this link.

http://en.wikipedia.org/wiki/High-voltage_direct_current

Honestly I think use of DC links in the power grid are going to increase as the technology becomes cheaper and more developed and as renewable energy becomes more common place. With are present fossil fuel powered grid there is not much reason to build 1,000 mile plus links in the utility grid since you can locate a coal or gas fired power plant just outside of town and may only need to move the power a few hundred miles. But in the future we may see situations where you might for example have regional grid A with a large amount of hydro electric. regional grid B with a large amount of wind generation capacity. And regional grid C with a large amount of solar thermal power plants. Now with the above imaginary set of regional grids lets imagine Grid A connected to grid B and C vea DC links. One month grid A has a drought and needs some outside help but grid C has lots of sunshine. Grid C sends power to help out grid A. Next month grid B has a lack of wind grid A has enough water to hold its own but grid C still has lots of sun for its power stations. Then you would send power from grid C to A and then on to B. And so on and so forth. But honestly i think the idea of HVDC links spanning contents is a much more feasible idea than grid scale power storage large enough to hold over a long calm spell or sting of cloudy days.

 

[amberwolf]

Tesla's DC distribution was at the same voltage as delivered to the end-user, hence was shit.

Don't you mean "Edison's DC"? :?

 

[Punx0r]

Sorry, yes

I read an article today about a renewable energy company in the UK bidding for a government contract so they can build a 2GW concentrated solar array in Tunisa and pipe it directly to the UK. There are also serious proposals to run a 650 mile undersea cable from Iceland to bring in hydroelectric power. Both candidates for HVDC

 

[Modbikemax]

The answer most likely will not be millions of electric cars but millions of apartments close to work and recreation.
Just take a look at China. Apartment complexes close to work. Have a look at any Europen village built before motor cars,
A street with a few shops and a pub all within walking distance. A few miles down the road another one.
We have done it before, there is no reason to expect anything different in the future.
The real game changer for battery technology has been hand held communication devices. Remember when a mobile phone only lasted an hour or two. Removing the batteries from those is the real challenge.

 

[Punx0r]

True. Although it will require a fairly radical paradigm shift.

Then again, we're apparently starting to see a shift on emphasis away from massive out-of-town supermarkets in the UK. Apparently people's preference is moving towards food shopping in small quantities several times a week, rather than a big shop once a week. It lends itself to obtaining fresh produce close to home.