Category Archives: Electric Vehicles

The ‘power’ of the Press…

sizewellYou shouldn’t, of course, believe what you read in the papers. This is a good general rule, but recently we had a rather striking example. On Feb 11th, The Times ran an article entitled, “Electric cars mean UK could need 20 new nuclear plants”.

Here’s an extract, talking about a Transport for London report:

The analysis, seen by The Times, says that moving to an electric or hydrogen vehicle fleet “has implications for London’s energy supply system”. At the maximum level of uptake in the city green cars would demand between seven and eight gigawatt-hours per year. Experts said this was equivalent to the output of more than two nuclear power stations similar to that being built at Hinkley Point in Somerset. Extrapolated nationally, it would require the equivalent of 20 new nuclear power stations nationwide.

That’s a pretty memorable number – 20 new nuclear power stations! – and indeed, a family member who had seen it asked me about it, knowing my interest in the topic.

The trouble is, it’s just plain wrong. It was repeated in The Daily Mail, too, and Mail readers, bless them, are even less likely to have the critical faculties to question the headline…

I did some back-of-the-envelope calculations and things looked fishy, and it turns out that the original article is full of mathematical errors and lack of understanding. The first, and biggest, is that seven gigawatt-hours-per-year is not the same as seven gigawatts! Two Hinkley Points would indeed produce about 7 GW, but that is 7 gigawatt-hours-per-hour, not -per-year! So they were out by a factor of about 6000 immediately. However, many of the other figures quoted were also incorrect (some of them in the other direction).

If you’re interested in the real numbers, David Pellow’s letter to the Editor gives a much better analysis, but a quick summary is that yes, of course, we will need some more power generation when all of the UK’s 31M cars are electric, but if those cars are mostly charged overnight during off-peak periods, we could handle about 20M of them already just using the current power network.

This whole area is rather a fun topic, actually, and takes us into the realms of smart grids, home solar, grid-scale storage made from recycled batteries, and so forth. Cars are remarkably flexible about when, and how fast, they are charged, making them ideal for absorbing excess power and smoothing out the fluctuations of demand and of renewable generation. One day last year, Germany’s renewable sources of electricity produced so much power that they actually paid people to use it, and the problem of dealing with the peaks and troughs of demand is something that the power grids have had to struggle with for decades. Cars can actually help with this.

But I digress. What I actually wanted to talk about were a few other things that struck me about this story:

  • The Times has since published a brief retraction in the small print. I doubt this will remove the ’20 power stations’ idea from many people’s minds, though. Wasn’t there a proposal once that such corrections should be given the same font sizes and number of column inches as the original article? When I’m an MP, I’ll propose a bill to that effect…

  • The online version of the article has been edited to remove the dramatic claims, though the URL still reveals the original embarrassing headline. I can’t decide whether this is an admirable admission of error, or an attempt to rewrite history and pretend it never happened. What do you think?

  • The Daily Mail’s version of the story is still online, and I don’t believe they’ve published a correction at all. Should they be required to do so, when they were repeating another paper’s story which has since been retracted?

Electrons by the gallon

Rumours emerged last year that Shell were thinking of installing electric-vehicle charging stations in their forecourts, and they have now confirmed that the first ones will be rolled out in the next few months.

This is great news, though I’ve complained before that having an electric vehicle means you tend to spend more time in motorway service stations, and, frankly, if there’s one place worse than a motorway service station, it’s a petrol station forecourt. I’ll be much more enthusiastic when, say, the National Trust expands its laudable if rather meagre network of charging points, so I can charge my car while strolling through Capability Brown landscapes.

Still, a more ready availability of charging points anywhere is excellent news, and in-city petrol stations will certainly help those who want to own an EV but don’t have their own off-street parking — currently a significant barrier to electric adoption in cities.

I can’t help wondering, though, how petrol stations that still tell you it’s dangerous to use your phone in the vicinity of petrol fumes will cope with the 50-kilowatt 400-volt circuitry of rapid chargers… 🙂

Sending satnav locations from your iPhone/iPad to a BMW navigation system

One of those ‘in case you’re Googling for it’ posts! This will probably be of little interest to anyone who doesn’t own both an iOS device and a BMW, but might be useful if you own both.

Also available on Vimeo if preferred.

The Hybrid Tipping Point

One of the questions I often get asked about my car is, “Is it all-electric, or is it a hybrid?” For most EV owners, the answer to that is easy, but for the BMW i3, it’s a bit more complex. You see, it is a hybrid in the sense that it does have a petrol engine, but it’s also completely different from most of the Toyotas, Mitsubishis, Hyundais, etc. out there.

The i3 has a ‘Range Extender’ option (known as the REX), which is a little 650cc scooter engine, not much bigger than a melon, and a two-gallon petrol tank. The engine never drives the wheels directly, and in fact, it doesn’t even really recharge the battery, but it can keep the battery at a constant level of charge while you’re buzzing along. So if I have a battery range of 70 miles and I need to go, say, 120 miles with no charging points en route, here’s what I normally do: I put my destination into the satnav, and then glide silently out of town and onto the motorway. When my battery has depleted to about 50%, I turn on the REX, and use a bit of petrol until the remaining satnav distance is less than my remaining battery range, at which point I turn it off again. This means I only get the (small amount of) extra noise on the highway, where there’s plenty of other noise anyway, I keep pollution away from the populated areas, and I arrive silently at my destination, having used the minimal amount of petrol.

For me, it’s the perfect combination. I’ve now done about 12,000 miles in this car, and I’ve used less than 12 gallons to do so, which means my average MPG is still in four digits. In 5-10 years’ time, we’ll have much bigger electric ranges, without having to pay Tesla prices, and charging points will be sufficiently common that the petrol bit will be unnecessary. (Unless I move to a remote part of Colorado or Australia, I think I have probably purchased my last fossil-fuel-burning car.) At some point between now and then, one of the major petrol companies is going to install rapid chargers on all their forecourts. There’s a rumour that it might be Shell. This will be a brave thing to do, because it will instantly make EVs massively more attractive to the ordinary driver and will make a dent in the revenues of all the oil companies. On the other hand, this process is inevitable, so you want to be the company that does it first. I watch with interest…

But let’s get back to the hybrid discussion.

The challenge that plug-in hybrid designers face is how wholeheartedly to embrace the battery. You see, there’s a tipping point: you can’t sit on the fence. For most hybrids, you are building a normal car, and adding all the cost, weight and complexity of batteries and an extra motor. You don’t get enough electric range to use it as a real EV, though you might get some pretty impressive MPGs if, say, you charge each night and have a short commute. But when you’re running on the battery, you’re dragging around a lot of unnecessary metal and liquids. When on petrol, you’re carrying a lot of heavy battery. You need to keep a big enough engine to do everything people expect of a traditional car as well as fitting in a big enough electrical system to make the battery bit worthwhile. Minimalism it ain’t.

The beauty of pure electric vehicles, in contrast, is just how simple they are: no gearbox, exhaust, piston rings, tappets, crankshafts, oil sumps, filters, radiators, fuel-injectors, spark plugs, catalytic converters… all that messy stuff just goes away. I had originally planned to get a plug-in hybrid; the Golf GTE caught my eye when it came out, and I enjoyed test-driving one of the first ones in the UK, but I’d been spoiled by that point, because I’d also driven a couple of proper EVs, and I realised that they had to be the future. I often tell people that if you have (a) another car and (b) a driveway on which to charge, there’s no real reason now, when choosing a second car, for it not to be all-electric. The Nissan Leaf or Kia Soul EV are great vehicles, and I started to think I could get something like that for my normal day-to-day use and park my old Golf out of town somewhere, to be fetched when needed for long treks.

But for us, it would be silly to have two cars, which is why the i3 was the perfect solution. All the benefits of an EV, with no ‘range anxiety’ and very little extra complexity. Unfortunately, in Europe at least, BMW are currently the only company making this combination, which means that to get it, you have to pay BMW prices: quite a change for someone like me who spent much of their life crawling under elderly Minis or Beetles. I hope some other manufacturers catch on soon, but in the meantime, I do at least get the satisfaction of driving what Munro Associates described, a couple of years ago, for a whole range of reasons, as “the most revolutionary car in terms of creative engineering and manufacturing since Henry Ford’s Model T”.

Altruistic Autonomous Vehicles

One of my shortest recent posts generated quite a lot of discussion, both here and on Facebook. I wrote:

When we have proper and affordable self-driving vehicles, will that be the end of the railways?

Clearly there are some things that railways will do better for the foreseeable future, like long-range high-speed links, or carrying heavy freight. And don’t get me wrong: I like train journeys. But it seemed to me that the key reasons people currently take trains for normal day-to-day journeys — wanting to read en route, a lack of parking at their destination, avoiding congestion — could very soon be overcome when, for example, your car can go and valet-park itself after dropping you off at the office.

And the disadvantages of train travel: the fact that instead of going from point A to point B, you have to go at least from point A to point B to point C to point D, possibly waiting on a cold platform at point B for an indeterminate period, and not being sure whether you’ll get a seat from point C to B on the return journey. Will it be worth the hassle?

One of my assumptions is that traffic congestion will become less of an issue when cars are smarter, of course, which may not be a valid one, especially if lots of train travellers take to their cars instead.

There’s an interesting question as to whether lots of small independent agents trying to meet their own goals are going to result in an optimal solution for road congestion as a whole. We may start off with vehicles that are pretty autonomous initially, but become less so in due course, as the road infrastructure starts to adapt to them. Network packets on the internet know their destination, but it’s the routers (the junctions) that tell them which exit from the roundabout to take.

Will the Department of Transport manage overall use of the network better than each individual car? Well, that depends on who has the better computer scientists, of course! But it also depends on the amount of knowledge each vehicle can get about the overall road network, and, of course, on how selfish your car is: will it decide that the needs of the many outweigh the needs of the one (or the few)?

Perhaps we need Altruistic Autonomous Vehicles? (You heard it here first!) There could be financial incentives to encourage this. You get lower road tax if your car agrees to obey centrally-prescribed rules at times of high congestion. Perhaps you get to use the high-speed autonomous-only lanes if you’re willing to hand over to the cloud-based algorithms. Of course, this could open up all sorts of wonderful opportunities for hackers, too. Remember the movie?

Anyway, perhaps congestion will be less of an issue, but for a completely different reason. If you can be having a coffee, working on your laptop and taking Skype calls while you slip quietly along in your electric car, you may be more productive than if you’d got to the office on time.

Car Talk

The Amazon Echo arrived in the UK a couple of days ago, and by combining some of my earlier work with John Wheeler’s excellent Flask-Ask framework I was able to make it talk to my electric car.

Also available on Vimeo here if preferred.

Counting the cars on the new electric turnpike

IMG_2598In the last couple of months there’s been a lot of discussion amongst electric vehicle owners in the UK about Ecotricity’s decision to start charging for its ‘Electric Highway’: the network of rapid charging points at motorway service stations and similar locations. Some think it’s outrageous that, if you’re charging away from home, it can cost as much per mile as petrol. Others point out that these charging points cost many tens of thousands to install and run, and the cost is therefore very modest. Personally, I think they have the pricing about right, but I wish they’d chosen a 15-minute granularity instead of going for 30-minute slots. But no doubt this will be tweaked over time.

One benefit of these chargers no longer being free is that there are fewer ‘casual’ users, or people hogging them for extended periods of time. If you turn up at a charging point now you’re very likely to find that it’s available, something that is, in fact, exceedingly important. (The ideal charging network is one that nobody else seems to use except you! It’s quite a contrast to petrol pumps, where the owners want them to be in use almost constantly.) However, this change is so apparent that some have speculated that almost nobody is using the pumps, and the whole idea is a disaster. The real numbers were, however, pure speculation for anybody outside Ecotricity.

Well, with some devilishly cunning technical tricks, I came up with a way to monitor a few charging points and see how they’re actually being used. I tried to pick a mix of some popular pumps, some I was just personally interested in, and some in more out-of-the-way places, so I settled on the charging points at:

  • Cambridge Services (A14)
  • Baldock Services (A1M)
  • Heston (M4 near Heathrow)
  • IKEA Wembley
  • South Mimms (A1M/M25)
  • Leicester Forest East (M1)
  • Kettering (A14/A43)

And I checked them every 5 minutes for 4 days – a Fri, Sat, Sun and Mon – to see whether they reported their status as ‘Available’ or ‘In Use’.

Kettering, sadly, appears to have been out of action for all this time, as does one of the pumps at Baldock. And one of the Leicester Forest pumps was reporting ‘Swipe card only’. So for this (small and completely unscientific) trial, I effectively had 6 locations and a total of 12 charging stations. And here’s what I found:


Click for a higher-resolution image, or download the PDF here

Each dotted horizontal line represents a normally ‘Available’ pump and the vertical marks indicate when it is ‘In use’. The five minute period of my checks mean that a standard half-hour charge is shown by roughly six little vertical lines.

A few points to note:

  • Some of the sessions are less than half an hour, and some appear to be noticeably longer, though my system wouldn’t detect one car finishing and another immediately taking its place as two separate events.
  • Drivers who get their home electricity supply from Ecotricity do not pay for charging, so they have no particular incentive to work in half-hour units. The majority of sessions, however, are multiples of half an hour.

Here are some numbers derived from the data:

Approx pump statistics

ID Location Samples in use/total Avail% 24hr Avail% >7am 30min sess/day 30min sess.p.a.
1037 Leicester Forest East Services 102/2292 95% 93% 2.1 780
1038 Leicester Forest East Services CCS 94/2286 95% 94% 2.0 720
1068 South Mimms Services 0/2294 100% 100% 0.0 0
1069 South Mimms Services CCS 141/2291 93% 91% 3.0 1078
1080 IKEA Wembley 462/2263 79% 73% 9.8 3577
1081 IKEA Wembley CCS 219/2291 90% 86% 4.6 1675
1132 Heston Services 292/2291 87% 85% 6.1 2233
1133 Heston Services CCS 54/2294 97% 97% 1.1 412
1134 Heston Services CCS 30/2294 98% 98% 0.6 229
1235 Baldock Services 253/2294 88% 85% 5.3 1932
1236 Baldock Services CCS 0/0312 100% 100% 0.0 0
1241 Cambridge Services 0/2294 100% 100% 0.0 0
1242 Cambridge Services CCS 246/3433 92% 89% 3.4 1255

Assume electricity cost per session of £1.44
Annual profit from these pumps approx £63348
From a network of 300 pumps, if these are representative: £1461881

With the exception of the Wembley IKEA points, you can turn up between 7am and midnight and have at least an 85% chance of finding one of these free.

Now, these pumps may not be representative, being generally rather London-focussed, especially since a couple of my more rural ones didn’t yield useful data. I’ve included one which was offline and excluded a couple of others. And all of my figures are very approximate, so should all be taken with a big pinch of salt. But my estimate is that Ecotricity are making £1-2M per year from the network at this rate.

In their announcement about the introduction of the charges they talked about having provided £2.5 million pounds worth of free travel in the first five years of the network. It grew from nothing to its present size over that period, so we might assume that the annual costs of about £0.5M represent the half-way stage and that they were getting close to £1M p.a. at the end of the free period. I don’t believe these numbers include the substantial installation costs of the pumps, which are apparently around £30-50K each. Nor, I think, do they include the salaries of support staff, etc.

But overall, my analysis, for what it’s worth, would suggest that the current charges are not too wide of the mark for what they need to run a sustainable network. It won’t make much profit nor allow much further development, but nor will it run at a huge loss, as it has up to now. Fortunately Ecotricity have a variety of motivations for this work, and not all of them are profit-based.

I could attempt a more substantial analysis, but the APIs I was using are probably not meant to be public and I didn’t want to trespass on their good will. If anybody from Ecotricity would like to authorise me to capture more data (or offer me a job to keep me quiet!) I’d be delighted to talk!

The network will need further investment, since the number of electric vehicles on the road is growing fast. This is offset somewhat by the fact that their electric range is also increasing, so charging points are needed less frequently. But analysts are predicting surprisingly short timescales for us to reach the point where the majority of our cars are electric, so it’s a fascinating space to watch…

Software security and the new app platform

As regular readers will know, my car has a programming interface which, sadly, is not officially supported by BMW. Still, it lets me create some little apps to improve the daily experience of car ownership; not something I’ve really been able to do with any previous cars. We’ve come a long way from some of my earliest ones, where I spent most of my time straightening bent carburettor needles and replacing leaf springs!

car_lock_checkMy latest hack is a little script which runs periodically on one of my servers and checks whether the car has been stationary for more than 15 mins. If so, and the windows, sun roof or doors are open or unlocked, it sends a notification to my phone. This is partly for security reasons, but mostly because the British weather has been sending us hourly alternate bursts of sunroof-opening heat and torrential downpours! Of course, if I’m not near the car at the time, I can lock it remotely.

One of the many things I find appealing about the move to electric cars is that the actual mechanics become so much simpler. I no longer have an exhaust pipe, a clutch or gearbox, an oil sump or filter, head gaskets or piston rings. The motor isn’t much larger than a melon, and the batteries can be made in various shapes and sizes to fit the layout of the vehicle. In my case, I have a flat floor, with no propshaft tunnel or gear lever to get in the way. Reconfiguring such a design to be a van, a campervan, a flatbed truck, or whatever, is much less of a challenge now.

As the complexity of the mechanics goes down and the flexibility goes up, I think software, both inside and outside the car, is going to play an ever more important role in our experience of it.

The automotive industry has become interesting again, for the first time in many decades.

Archers 2.0?

If I had a farm, I’d want one of these. Actually, I don’t have a farm, but I still want one of these.

Petrol? Where we’re going, we don’t need petrol…


As regular readers will know, a couple of weeks ago I took my electric car to the Lake District with my friend Hap. I go there fairly regularly, but this was the first time since I got the i3, and I was wondering how it would cope. Charging points are fairly scarce there, and the gradients very different from its normal home in East Anglia. Would we get stranded somewhere on the Whinlatter Pass?

In fact, I needn’t have worried. Our charming B&B in Grasmere let us plug in each night, and even though we did a fair bit of driving around, we always came back at the end of the day with more than 50% charge left. In truth, though you can spend a lot of time driving there, the distances are usually fairly small because so much of it is below 30mph (something which also helps the efficiency!) The steep uphill slopes swallow battery but this is offset somewhat by the regenerative braking on the steep downhill ones.

What I hadn’t expected was just what a delight the car was to drive there! This was partly because creeping down valleys and winding over mountain passes is much more pleasing in an almost-silent vehicle (though you do need to watch out for walkers in the middle of the road who haven’t heard you coming). It was partly because it loves the corners, as a BMW should. And it was partly because the big windows and high driving position gave such a good view of the landscape.

But it was mostly because of what i3 owners call the ‘single-pedal driving’: the fact that the regenerative braking kicks in as you lift your foot off the accelerator, meaning that under normal circumstances you very rarely need to use the brakes. If you know the Lakes, you’ll know there are many roads where, in a normal car, you need to move your foot from accelerator to brake on every corner. You need to change gear around every second bend. I, on the other hand, was just gliding around the corners and up and down the hills with my foot on the one pedal. No gear changes (I don’t have a gearbox, even an automatic one). No sound of straining engines, because it doesn’t make any sounds. No need to engage low gear for engine braking on the steep slopes, because engine braking is what I do all the time. I even enjoyed the long descents, because they recharged my battery.

No, all in all, I spent a lot of time grinning as we drove from Grasmere to Borrowdale, from Great Langdale to Coniston, from Tilberthwaite to Ambleside. It’s the best place to drive this car, and it is certainly the best car I’ve ever driven there.

In Arcadia ego

My friend Hap and I drove from Cambridge to Grasmere today — 280 miles — using about a pint of petrol. It should have been all-electric, but we got lost trying to find one of the charging points!

You may or may not think that having to visit rather more M6 service stations on the way than one might otherwise do makes such a form of transport worthwhile. But I think you’d agree that paying about £1 each, to cross the whole country to a place where you can do this walk before dinner, is pretty good value:



Hiking into the future

Today I realised there was yet another reason why I want a self-driving car.

It’s for when I’m walking.

The challenge with going for a good long walk in the country is often finding a nice circular route that will bring you back to where you parked the car.

But imagine you didn’t have to do that. Imagine that you could just walk from point A to point B and the car would be waiting for you when you arrived. You could then ride home in comfort, or, perhaps, enjoy lunch from the picnic hamper in the boot before setting off for the next reunion at point C. You could do this for days.

What’s even better is that you wouldn’t need to know your destination in advance! You could wander lonely as a cloud, floating o’er hill and dale, until you spied a welcoming tavern. While enjoying a pint of their finest ale, you would summon the car, and it would be parked outside by the time you wanted to leave. (And take you home, of course, if the ale had been particularly fine…)

© Copyright Quentin Stafford-Fraser