London Part II – South Kensington, Imperial College London


My first week in London was spent buying the necessities, and I was busy being deathly sick for most of the second week, so it wasn’t until now that I had a chance to actually explore London a bit.

Sorry for the lack of blogging!

London is a very old city with some very interesting stories – Knights Templar, Freemasons, kings, queens, dragons, William Shakespeare, churches, etc, but that’s for another time.

This post is about a fairly new area called South Kensington. It’s fairly new by English standards – most of the iconic buildings in this region were built in the latter half of the 1800s.

Why South Kensington? Because that’s where Imperial College is, and I had a chance to walk around it this afternoon and snap a few pictures, thanks to the generosity of the people in Department of Computing responsible for arranging schedules.

It’s quite an interesting area, with various museums, one the most famous concert halls in the world, various embassies, various colleges, and quite a few billionaires.


Beit Quadrangle, our student union building that’s apparently also a hall for undergrads?


Right across the street from the college (and Royal College of Music) is Royal Albert Hall, one of the most famous concert halls in the world, where the Queen goes to watch performances.


Royal College of Music, sharing the same block with Imperial College


Imperial College geoscience building (I think?)


National History Museum, just south of the college.


The other side of Royal Albert Hall, from Hyde Park. Not pictured, but to the right is Royal College of Art – according to Wikipedia “the world’s most influential art and design institution”.


Albert Memorial in Hyde Park, across the street from Royal Albert Hall.



Hyde Park.

Hyde Park is the site of The Great Exhibition in 1851, where inventors from many nations were brought together to showcase their inventions. Surplus from the exhibition funded all 3 museums in this area – Victoria and Albert Museum, the Science Museum, and the National History Museum (according to Wikipedia). The Exhibition essentially kickstarted the development of this area.

Nowadays it’s a lot more humble. It’s just a very big open space with a big pond for the most part, which is actually quite nice, in the most expensive area of London where every square metre of land probably cost more than any house I have lived in.

It’s pretty cool that Imperial College is in such a cultured area, and my daily commutes take me through all these sights people come all the way to London to see, though the school kids in long lines do get annoying sometimes… and it’s a little inconvenient that we don’t really have any off-campus dining options, since anything in this neighbourhood is probably £20+ per meal.  Maybe I just haven’t looked hard enough?

London Part I – You Are Poorer Than You Think


That’s the view out of my room in London. Isn’t it amazing?!


People say London weather is bad, but I’ve actually found it quite agreeable, compared to other places I’ve lived in.

OK, that’s not saying much. I’ve lived in Taiwan and Vancouver, and after living in those 2 places, one would probably find the weather in northern Russia agreeable, too.

It’s end of September, and we still get quite a bit of sunlight. Temperature has been fairly steady at 15-20C, which is quite a bit warmer than I had expected. I still go out in a tshirt, though I do seem to be a little out of place at times. I blame that on being Canadian :).

A new Welsh friend told me London has its own little weather system, and is usually a few degrees warmer than the surrounding areas. That’s pretty cool. I haven’t had a chance to verify it, yet. It’s actually pretty difficult to get out of London from the centre, just because how big it is.

It has been 1 week since I moved here, and I haven’t had a chance to see London much, since I have mostly just been shopping for the essentials, and food.


Like this £9.15 (~$15) meal from IKEA. I am pretty sure in the US this would have been less than $9.15.



I found that to be the general pattern here – a $5 thing in the US would be £5 here. Even after taking out the 20% VAT that’s usually included in prices, that’s still a good 40% more. I guess that’s the price to pay for living in the most expensive area of London!

After a while, you just learn to mentally replace the £ sign with $ instead of actually doing a conversion to evaluate the prices. Because if you do the conversion, you’ll starve.

The place I’m living in is just north of Shepard’s Bush, which is reasonably close to Kensington (where Royal Albert Hall, Hyde Park, and all the interesting museums and all the billionaires are), hence £££.

That’s pretty much by necessity, because some genius decided to build Imperial College in the middle of South Kensington, right across from Royal Albert Hall – quite possibly the most expensive land in all of the UK.

Well, it’s nice that I can go check out a museum or watch a musical between lectures at the most famous concert hall in the UK, but I think I’d be willing to give up that privilege for £300 per month lower rent.


It did take a bit of adaptation to get used to not having a car.

While I did walk a fair bit in Canada, I’ve always had access to a car, and always drove if I had to buy a lot of things, etc.

Here, it’s all buses and tube. I had to make 3 separate trips to IKEA just because I can’t physically carry that much stuff in 1 or 2 trips. I have never had to do that before.

It’s also slightly mind-bogging how big London is. In Vancouver, I can run from one end of the city to the other in about 2 hours. In London, 2 hours would move you by a few pixels on Google Maps, if you zoomed out to see all of London.

I have visited quite a few huge cities, but this is the first one I have lived in, and having to tube and bus everywhere really puts the size of the city into perspective.

If you are ever bored in London, you can just hop on the tube in some random direction and  sleep for 2 hours. When you wake up, you would still be in London. You’d be in a middle-of-nowhere borough you’ve never heard of, but still London.

For comparison, the population of London is about 8 million. Vancouver has about 500K, San Francisco has about 800K, and LA has about 4 million.

Compared to a similar sized city like New York, I quite like it.

It does have the usual problems with all metropoles – congestion, high prices, crime, pollution, etc, but overall, I like it a lot better than New York.

The streets are not nearly as clean as Vancouver, but also not nearly as bad as New York. Public transportation is much better – this one probably doesn’t really need an explanation if you have tried public transit in New York (subway drivers can randomly skip stations, take random detours, etc, and some lines still run at about 20km/h). London’s tube system has its quirks, but it’s pretty good on the whole, and very extensive. It is a little confusing at first with something like 8 lines and 250 stations, but that’s not really a problem if you have Google Maps. If you just follow their directions, the tube will take you to pretty much anywhere in London, relatively fast, especially in times of congestion. I like it over Vancouver’s system because Vancouver relies on busses too much, and busses do get stuck in traffic. Obviously also like it over Bay Area’s lack of a system at all.

Trains are reasonably fast. They aren’t as new and high tech as in Vancouver or Washington DC (their stations are absolutely gorgeous btw), but they do work, and are reasonably clean.


Also, their rhinovirus strands are amazing! At least the one I am sampling at the moment. Give it a try?

Technology Progression in Harddrives

I recently had to destroy a few hard drives before throwing them away, since they contain confidential information.

I could have used dd (or any secure erase program), but some of the drives have the older PATA (IDE) interface, and I no longer have a computer with a PATA interface. Which means, it’s time to get…


20140820 001734

In this picture I have taken out all the PCBs from the drives, as well as all the platters (the metal disks that actually store data).

  • 80 GB Seagate Barracuda ATA IV, date code says it’s from November, 2002.
  • 200 GB Maxtor DiamondMax 21, PATA, from October, 2006.
  • 2x1TB Western Digital Green SATA, from 2009.

The oldest of the drives are about 12 years old, and the newest about 4, and I thought it would be interesting to see exactly how technology has changed over the years, through these drives.

Obviously the biggest difference is in the platters. All 4 drives happen to have 2 platters – 40GB per platter on the 2002 drive, and 500GB per platter on the 2009 drive.

However, they looked exactly the same under naked eyes (exactly the same diameter!), and I don’t have a microscope, so I am going to focus on the PCBs, and look at how electronics design has changed, and how we are now doing the exact same thing differently from how we were doing it back in 2002.

Turned out we can learn quite a bit just looking at the PCBs!

All these PCBs do pretty much the same thing – power supply conversion, a main controller that interfaces PATA/SATA to the platter sensors, and a spindle controller to drive the motor, and some kind of memory for buffer. But their designs are quite different.

The first board we are looking at is the oldest one – the Seagate 80GB from 2002 –

20140820 004314

The central processor is ST branded, but I cannot find any information on it, probably because it’s a custom OEM chip.

– On the right is a Hynix HY57V161610DTC-6 – 3.3V 166 MHz, 16Mbits synchronous DRAM.

– On top of that is a ST M29W102BB – 1 MBit parallel flash memory with a boot block and 2 main blocks.

– Above that is a MSC LX8815-33 – dual channel 3.3V 1A low dropout linear regulator… with pretty crappy specs (1.1V dropout, up to 5mA quiescent current).

– On top of the main controller to the left is a chip labeled SH6950. I can’t find a data sheet for it, but according to some random site, it’s a TI spindle motor + voice coil motor driver.

– The chip on the left of the main controller is an agree MS455. No idea what it is.


Next up is the PCB from the 200GB Maxtor drive –

20140820 004319

– The main chip this time is an agere chip. They seem to be making a lot of hard drive stuff. No information can be found for this chip unfortunately.

– On the right is a Hynix HY57V641620ETP-6 – 3.3V 166 MHz, 64 MBits synchronous DRAM.

– The tiny chip on the bottom left is an Atmel chip, but the part number doesn’t return any results. I am guessing it’s EEPROM for the main controller.

– On the top left, the big TQFP chip is a Smooth 100369972, which I believe is a spindle motor driver

– The small chip above the main controller is a Fairchild chip. I am also not sure what it is, but since it’s connected to a big inductor and a big resistive divider, I am going to assume it’s some kind of switching regulator.

– On the top right there is another switching regulator, in QFN package. The printing on the chip is too small to read.


The last board we have here is from the 2009 Western Digital Green 1TB –

20140820 004324

– The main chip this time is a Marvell 88i9045-TFJ2 micro controller with external EEPROM (the Winbond chip just below)

– On the left is Hynix HY50U121622DTP-D43 – 2.5V 133 MHz 512 MBit DDR synchronous SDRAM (note that even though the clock frequency here is lower, data is transferred on both edges of the clock, so it’s equivalent to 266 MHz data rate SDR).

– The only other chip is a Smooth L7251 spindle motor controller.


It’s interesting to see how many electronics trends can be seen in just these 3 PCBs.

First of all, there is a clear trend in reducing number of ICs. The first board had 8 chips each doing very specific things, and the 1TB drive only has 4 chips, with most things integrated into the bigger chips. This is mostly to save cost. Many more chips are custom designed for single products now than how it used to be – IC manufacturers making small chips to do very specific things, and circuit designers putting them together to do what they want (like in the first hard drive).

Looking at the PCBs, I am surprised most ICs are still TQFP instead of BGA. Most electronic designs have moved on to BGAs now for space saving and better signal integrity at higher speeds. Interestingly, the only BGA chip here is the main controller on the oldest board. However, looking from the side, it seems to be about 1.2mm pitch (distance between balls), which is huge by today’s standards. Most modern chips are going 0.5mm or lower, and require more precise placement using optical alignment.

The oldest PCB has almost all 0805 (0.08” by 0.05”) and 1206 passive components. That’s pretty huge. On the 200GB board, we are mostly down to 0805 and 0604. On the 2009 board it’s almost all 0402.

The routing on the oldest PCB definitely looks less dense than the other 2. It looks like it’s roughly 8 mil traces and 8 mil spacing, whereas the newer boards use 6/6.

The old board also seems to have a HASL (hot air solder levelling) finish (or some kind of organic finish? though I don’t think they existed back then), whereas both the new boards use immersion gold (ENIG). Immersion gold offers better planarity (good for BGA chips that require pads to be perfectly flat) and oxidation resistance (so boards have longer shelf life before soldering).

Since the new board also doesn’t have any BGA chip, there is really no need for ENIG. It’s possible that the cost is not much higher in recent years, so they are just doing it with all boards now. Maybe ENIG wasn’t popular back then? Maybe it didn’t exist back then? It was already popular when I started doing electronics about 5 years ago.

Cool eh?

Technology in the (Small Airplane) Cockpit

When I learned to fly 2 summers ago in San Jose, California, I flew this beauty –


A 1960s Bellanca Citabria 7ECA.

It’s about as simple as airplanes get – no flaps, constant pitch propeller, tailwheel, center stick, front and back seating, and a 115 HP Lycoming engine with a gravity fed fuel system.

And the cockpit looks something like this (I don’t have a photo of the instrument panel for that plane, so this is a random Google image for a plane of the same type) –


There is no attitude indicator. No heading indicator. No any kind of navigation equipment. Basic 4-dials Mode-C transponder (required because we were under SFO Class B). 90 kt cruise.

Simulated instrument flying was very interesting. I did all my PPL hood flying with a partial panel!

On the plus side, on the PPL written exam there are always a few questions on minimum equipment lists – is this instrument legally required for day VFR? Is that instrument required for night VFR? etc. Those questions were very easy for me, since all I had to do was to think about the cockpit – if it’s on my airplane, it’s legally required to be there, otherwise it’s not.

I did OK. Flew some cross-countries using my Android tablet for navigation, and passed my checkride.

1 day after I passed the checkride, before I had a chance to exercise the privileges of my FAA license even once, I had to move back to Vancouver… and with that a 1 month wait for the highly efficient organization Transport Canada to issue me a license validation so I can fly in Canada.

As soon as I got the validation (and medical), I took a virtual Google-stroll to the airport to find an airplane to rent… there were a lot of 30 years old Cessna 172s as I have expected, but then I also found out that I can also fly an almost fully loaded Diamond DA40 with G1000 avionics for only about $20/hr more… sounds like a deal to me.

I had never flown a technologically advanced aircraft before, but I decided to give it a try, and I was immediately hooked.

This is the airplane I have been flying –



2005 Diamond DA40. All composite. G1000 avionics. Way more navigation instruments than I need or know how to use. 2 axis autopilot with altitude hold and preselect. A database of the entire world’s airports and airspaces. Live weather and TFRs from satellite link. Secondary surveillance radar with active interrogation. Fuel-injected 180hp Lycoming engine with variable pitch propeller. 145 kt cruise.

I pretty much just time-traveled about 40 years forward, from a fabric Citabria with barebone instruments to a Diamond Star.

And I don’t think I will ever turn back, if I have a choice. I really like all the additional safety technology provides.

There is a lot of debate in the aviation community about the merit of these glass airplanes, which is what prompted me to write this post.

How has technology made flying safer?


It is more tiring to fly the DA40 by hand in cruise than other aircraft of the same class, just because it cruises at 145 kt.

On a C172 if your attitude is 1-2 degrees off in cruise, you’ll probably end up climbing or descending at 100 fpm or so.

On the DA40, if your attitude is 1-2 degrees off, you’ll be off the assigned altitude by couple hundred feet in no time (though autopilot will say “leaving altitude” in that case to warn the pilot, if properly set up, even when not engaged).

Yes, hand flying the DA40 is definitely doable, and I have done it a few times, but nowadays I almost always use autopilot in cruise (when I don’t have a passenger to use as autopilot).

That way I don’t have to spend 50% of my mental capacity on flying the airplane, and can focus on other things like navigation, traffic scans, and keeping up with building a mental map of where everyone else is by listening in on the radio, etc.

Computers are good at mundane tasks like keeping an airplane straight and level. Why have a human do it?

Has my piloting skill gotten rusty due to my use of autopilot? I don’t think so.

I still do most of climbs and descents by hand, and those are more difficult than cruising anyways.

Crew fatigue is a common contributing cause of accidents, and autopilots make flying much less tiring.

As an aside, unintentional flight into IMC is another major VFR-pilot-killer, and having autopilot (and knowing how to use it) makes those situations much more survivable. In fact, the new FAA recommendation for people getting into those sticky situations is to use autopilot to get out, if one is available and the pilot is familiar with it.

Situational Awareness

If I have a gradual loss of oil pressure or alternator failure in flight, how long would it take me to notice it?

I try to glance at engine instruments every 10-20 seconds, but I know I have gone for couple minutes without glancing at them in very high stress situations – eg. flying a long final into busy airspace, being 5th in sequence and looking for 4 planes in front, while trying to maintain 60 kt (stall warning constantly blaring) in strong crosswind because the airplane in front is a C152 flying a 50 kt approach, taking care to not stall, all while configuring the airplane for landing and looking for a VFR checkpoint I am not familiar with.

I am a creature of probabilities, and in those situations, my chance of dying from a mid-air collision is much higher than my chance of dying from a loss of oil pressure, so I prioritize accordingly.

But wouldn’t it be nice if there is a computer that is constantly checking those things for you, and will give you a nice audible warning if anything is wrong?

G1000 does that.

It also monitors the integrity of input sensor data (presumably by cross-checking), and will put big red crosses over instruments if there is any doubt, just so the pilot won’t use wrong information.

Sure, it’s slightly annoying that it always warns about loss of oil pressure while idling the engine on the ground, but I would still rather have it than without.

Could something like that have saved Air France Flight 447?

There is also real time weather available (METARs, TAFs, satellite overlay, position of recent lightning strikes, etc), with obvious benefits.


Every pilot in Vancouver has a story or two.

Not fun stories. Stories of close calls.

Every year, 1 or 2 pilots die in Vancouver from mid-air collisions.

It doesn’t matter how good the traffic scan is – every pilot will get a few close calls if they fly enough (a few hours is usually enough).

It’s a scary place to fly, especially since unlike in the states, Vancouver Terminal doesn’t offer flight following, and everyone is on their own.

A series of mid-air collisions and close calls starting from the 1956 accident over the Grand Canyon led to regulations that made collision avoidance equipment (TCAS) mandatory on commercial flights, but for another few decades those equipment were too expensive to be installed on small airplanes.

That started to change couple years ago, as more and more small airplanes are now equipped with traffic avoidance systems, including the DA40 I fly, and I am very thankful of that, as a Vancouver-based pilot.

It’s an active secondary surveillance radar, which basically means it can see all transponder-equipped aircraft. Integrated into G1000, it can display all those traffic on the moving map tagged by their relative altitude, and issue audible warnings (in ATC traffic advisory format) when another airplane gets too close.

Obviously it doesn’t relieve the pilot of the duty to see and avoid, but it’s still very nice to have.

It has already helped me see a few airplanes that I probably would have never seen, including one time when another faster airplane was coming up from behind, and ATC didn’t give us a warning until they were way too close.

There is no way we would have seen that guy.

You could say my traffic scan is not good enough, but I’d rather be alive than dead even if that’s true.

Mid-air collisions are one of the leading ways to die in an airplane, so I always use everything I have at my disposal to stop it – that includes my eyes, my passengers’ eyes, ATC, and now TAS.

In the future, hopefully TASs won’t be necessary once US NextGen ATC services become widely available (traffic maps are much cheaper to implement using ADS-B). Hopefully we will see much wider adoption then.

But until then (and in Canada, which apparently has no plans to implement ADS-B), TASs are very nice to have.


Virtually all airplanes being made today have glass cockpits, so technology is taking over the GA world whether we like it or not, and rent on glass airplanes is already getting pretty close to rent on older airplanes.

In places like SF bay area, there are so many G1000 (and Avidyne) airplanes that they don’t really cost much more than 1970 spam cans to rent (though they are still quite a bit more expensive to buy).

You could say we don’t need technology as long as we keep our eyes open at all times, but that’s much easier said than done, and flying for couple hours in one of the practice areas in Vancouver on a sunny Saturday afternoon may change your mind.

Everyone makes mistakes sometimes, and technology makes mistakes less deadly, on average.

New small airplanes now have almost as much technology as Boeing 747s from just a few years ago, and for some reason some people are saying that’s a bad thing and is totally unnecessary. I beg to differ.

Sure, they tempt some people into doing things they would not otherwise have done, like flying into IMC without proper training, but the same can be said for almost all safety features, and history has proven again and again that we cannot stop Darwin.

If cars don’t have seat belts, I probably would drive much more conservatively than I do now. Why isn’t anyone arguing for the removal of seat belts?

Solar “Freakin” Bullshit

If you are on Facebook, Twitter, or any other social media network, chances are you have already heard of this project – (I obviously do not endorse it). 20140429030846-LEDs_-_white If you haven’t heard of it – it’s a project that wants to replace the surface of all roadways, sidewalks, parking lots, airport aprons, runways, etc, all with these 7″ hexagons that contain about 50 high powered RGB LEDs to be able to make configurable patterns, photovoltaic cells (solar panels) to power them, heating elements to melt snow, and about 1″ thick of specially textured glass on top. The panels can also communicate with each other wirelessly, presumably as well as with a base station of some sort, through the mesh network.

Sounds cool. Looks cool (*1). Is definitely technically plausible. What’s not to like about it?  

*1: Though if you look at illustrations on that page, you’ll find something strange – those tiles seem to have much higher resolutions than would be possible using just 50 LEDs per panel.

If you actually read through the Indiegogo page, you’ll find that it has no mentioning of cost at all, except that it supposedly “pays for itself” by generating electricity using those solar panels.

Yeah well, if that’s the case, why aren’t all our roofs covered by solar panels already? Solar panels do not pay for themselves at the present time, in most cases (only in places with extremely high sunlight, and very high electricity prices). That’s why.

If you look at the FAQ, there is a question “How much will your panels cost?”, and the answer essentially boils down to “we are not going to tell you”.

They already have working prototypes, and they can’t even give us an estimate of production price? That’s something all engineers are trained to do from very early on. How can you go as far as having working prototypes, and not having even an estimate of production cost? Or maybe they are hiding something?

But fear not, there is enough details on that page that, with the power of back-of-the-envelope calculations and Wolfram Alpha, we can come up with an estimate that should at least be within an order of magnitude of the actual cost –

How much does one panel cost?

A 7″ hexagon has an area of 0.082 m^2


Judging by the picture, and by the fact that they need to be able to support large trucks, the glass should be at least 3/4″ thick. How much does 3/4″ thick glass cost? I checked a few places, like this one, and they are pretty consistent. $21 per sqft, or $226 per sqm. I’m assuming margins are not very high in the glass material business, so let’s say the cost is $150 per sqm? The glass on a panel would cost $12.30, assuming post-processing is free.


Judging by the picture above, there are about 50 LEDs on one panel. Since they need to be able to change colors, they need to be RGB LEDs. Since they need to be visible under direct sunlight, through 3/4″ thick of textured glass, they need to be at least 1W, possibly much higher.

1W RGB LEDs cost about $8 each at 5k qty. Let’s say $5 at practically infinite qty? That’s $250 per panel.

Solar Panel

How much do solar panels cost?

The best solar panels available right now are about 20% efficient, and 1 m^2 gets about 1KW of sunlight on average, when the sun is directly above, with no clouds.

So with a 7″ hexagonal tile, we’d be looking at about 16.4W per tile.

Actual average power output will be 5W or so since it won’t be noon 24/7, but we still need to get 16.4W panels to get 16.4W when it is noon.

Before we go into price… did you notice something doesn’t add up? How the @#$@#% are we going to power 50W worth of LEDs with just 5W average?

Ignoring that for a second, the current cost of solar panels is about $0.70/W. That’s $11.48 per tile. Not quite as bad as I had imagined!


This is harder to estimate, but the wireless module will cost at least $5 at qty, and the CPU $2, and there will also need to be at least 3 MOSFETs per LED at maybe 3 cents each, for a total of ~$5.

I’m going to estimate $20 in electronics per tile. Unfortunately I cannot really justify this estimate further, but I believe it’s a very conservative estimate.

I am not going to include the cost of a 50W power supply… because we still don’t know where that power is coming from.

Total cost

Taking into account those components above, we are looking at a total of $294 per tile, most of which is from the high powered LEDs. The cost of the solar panels turned out to be almost negligible.

How many panels do we need?

First of all, what’s the total length of roads in the US?

6.5 million km in 2007.

Or just over 2 million km if we only count motorways (freeways), highways, and secondary roads (secondary roads are main roads in cities that feed into the highways). Let’s use this number, since it’s smaller.

How wide are the roads? According to the US Standards for Interstate Highways, the minimum lane width for a highway is 3.7m. Or 7.4m both ways. That’s the absolute minimum, and doesn’t include sidewalks. So let’s say the average width of roads is 10m, as a conservative estimate.

How much road surface is that?

2e10 FREAKIN m^2

How many tiles do we need?

2.44e11 FREAKIN tiles


But how much will that cost?

71 trillion dollars.

Note that the cost is almost entirely proportional to area, so changing the tile size won’t change that number significantly.

Since we usually have trouble taking astronomical numbers like that in perspective, let’s compare it to a few other astronomical numbers –

The entire annual US military budget is 0.683 trillion (it’s already the highest of the entire world), which is about 4% of the US annual GDP of 16 trillion.

That means, if we increase taxes to 100%, and shut down education, medicare, the military, and all the other government services, we will be able to make all our roads (well, just the big roads) shiny in 4.5 years… assuming we can still maintain a $16T GDP in those conditions.

Cost of labour, transportation, and disposal not included. They say they are aiming for 20 years life time for those tiles. That’s funding-seeking-speak, so let’s say 15 years as a more realistic estimate.

That’s still $4.7T/year, or almost 7x the military budget.

Even if I am off by an order of magnitude, that’s still 470B/year.

What else is wrong about this project?

Many things, in fact.

I’m not going to get into all of them, since I don’t have all day, but here are few of the best –

Charging EVs with solar panels

Inductive charging is 60% efficient over a gap of 12 cm, and decreases rapidly as the gap increases. Most EVs sit more than 12 cm from the ground. Even if one EV can draw power from 50 tiles, that’s 250W total, and about 125W after inductive loss.

A Tesla Model S base model has a 60kWh battery. That’s almost 21 days to charge at 125W. In those 21 days you can drive 230 miles.

More realistically, if you use it as an extra/bonus thing, if you drive for 4 hours on those tiles, you would have charged your battery 0.7%.

It will cost the same as paving


Sure, you can sell the electricity, if you don’t even need 5W to run a tile. How much can you sell it for?

Assuming a 17c/kWh buyback price (that’s the current solar buyback price in Georgia, and will likely decrease significantly if supply increases significantly), over 15 years, you would be able to sell 5W for $111, likely much much less if all the roads suddenly start selling back power, and government can no longer afford to heavily subsidize selling back solar power (or if the government own those tiles).

Why include solar panels on those tiles?

Why not just put them aside, or get rid of them completely since most of the power is going to have to come from the grid anyways?

The problem with solar power is not space, otherwise all our roofs will be covered by solar panels already.

Putting them in road tiles is solving the wrong problem.

Why not just build solar power plants elsewhere (in a desert), centrally? That would be much more efficient, and with HV power transmission, there is actually not much losses.

We don’t have many solar power plants in use today, mostly because they are still cost prohibitive.

Putting them in road tiles below 3/4″ of glass won’t magically make them any more efficient… quite the opposite in fact.

Of course, the real reason they are doing this is because people have warm and fuzzy feeling about solar power, and we WANT to be convinced that there is a way to use it cost effectively, and we are willing to turn off our common sense for a little while to get that feeling.

How do I identify nonsense like this in the future?

When you see a Kickstarter or Indiegogo campaign that is as technical as this one, yet doesn’t mention any numbers, and gives you everything in qualitative terms, you should be wary.

Just because the tiles cost money and you can sell electricity for money, doesn’t mean the amounts are equal, or even comparable in order of magnitude.

Just because you can theoretically charge EVs through induction, doesn’t mean you’ll actually be able to charge them at a non-negligible rate, and be worth the added cost.

It’s all in the numbers.

Just because 500 media outlets reported on it, doesn’t mean they have actually gone through it with common sense and a little bit of scientific literacy.

I suspect even the scientifically literate among the journalists actually intentionally turned a blind eye to the obvious infeasibility of this idea just so they can write an article and get viewers excited.