Woolly Perspectives

Posted on September 19, 2012 by Alison Kidd

My favourite role as a research psychologist is recording and analysing the language people use when they are discussing something which I’m studying.

Our friend the artist, Pip Woolf is running a fascinating project attempting to mend a badly eroded peat bog on a local mountain top using local wool and local people. Over time, she is drawing lines of wool which look spectacular and are slowly halting the ongoing erosion.

On the last trip up the mountain, I took my digital recorder to try to capture how different volunteers  understood or related to the project. Here is the result.

I like the fact that some people talked about the ecological and artistic aspects of the project. Others compared it with other much more “high-tech” projects elsewhere. But for others, it was simply enjoying the horses or hammering in the pegs to hold the wool, the stunning scenery or the chance to meet new people.

People won’t necessarily engage in sustainability projects for sustainability reasons – they may simply do so because it’s fun or different or sociable. I like it.

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Twizyology 2 – when is a car not a car

Posted on September 7, 2012 by Alison Kidd

As previously, noted, we think the Renault Twizy’s greatest strength is in the fact that it’s not a car – it offers something completely different and fun for travellers who just want to get short distances cheaply and using very little energy. Perfect, for example, for the hilly rural area where we live and work where many people’s journeys are less than 5 miles but up and down very steep hills to the nearest village or town.

We also think that the Twizy’s “not-carness” gives it a chance of disrupting the car market in a way that more conventional electric cars are struggling to do (because they automatically get compared unfavourably with the existing market products).

The most obvious symbol of the Twizy’s not-carness (or so we thought) was that it didn’t bother at all with doors thus making a statement about the kind of short journeys it expected to make. It appeals, for example, to people who might cycle but don’t want the physical effort (especially on our hills) or people who might use a motor scooter but are nervous of driving a two-wheeler and don’t want to get soaked in the rain. The fact that the basic Twizy is completely open-sided makes a statement – this is not trying to be your average car. Think differently! You won’t expect to go far in this, you will need warm clothes and a hat in winter and it’s obviously not intended to be your main car or carry you long distances. Of course, on sunny summer days, it’s delightful to drive along open to the elements especially on our country lanes and open hillsides. But come winter, don your warm coat and hat (which you will need anyway when you get out of any car) and whizz along the few miles to work or the shops. The good news is that you don’t get wet even in our open-sided version – well not until you stop!

But, we discover that most people are choosing the Twizy with doors option. And then unfortunately, psychology cuts in. If you have doors, it feels odd (when it rains) not to have windows which you can close. I have driven both kinds of Twizy in the pouring rain and it certainly feels odder in the doored version not to have windows – I almost found myself reaching out to close them. In our own, open-sided version, it might be pouring with rain just beyond elbow reach but the concept of windows doesn’t cross your mind – how could it when you don’t have any doors?!.

So, maybe inevitably, just months after the Twizy is released, there’s already an add-on accessory of windows and now as autumn approaches, the Twizy owners with doors and windows have started discussing heaters!! Again, the advantage, if you will, of our open-sided version, is you can’t really discuss heaters!

A few Twizy owners are thus turning their vehicles step by step into ‘proper’ cars and the risk is death, effectively, by focus-group-think of a winningly different concept for local, low-energy travel. I hope I’m not right and I also hope those Twizy owners who seemingly really want a car realise that and buy themselves a small, conventional electric car instead.

Once people think of Twizys as proper cars, they lose their challenge to our car-centric mindset. They will start to be compared with small “proper” cars and may risk being written off as somewhat inferior – unless of course padded seats are introduced, proper doors and windows and a greater speed and range. Then, hey presto, you have small quite pricey electric car just like the other small electric cars on the market. We have one such as a community electric car – it’s functional but it offers nothing new or different and is certainly unlikely to challenge the existing market.

The Twizy, as envisaged by Renault, is a challengingly different travelling concept for short journeys. It says something different and offers different values and thereby disrupts our assumptions about car travel and energy. I hope that Renault has the courage to stick with their original idea.

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Solar miles

Posted on September 3, 2012 by Alison Kidd

As you may have spotted, The Prospectory has a strong interest in the relationship between energy and travel – from both a technical and psychological perspective.

We are interested in how we can all move around using a lot less energy than we currently do and where the energy we require to move us comes from.

Here in the Brecon Beacons, we are lucky to be able to generate a lot of our energy from natural, local sources – mostly rain, some sun and (outside the National Park at least) wind.

The Prospectory itself has a 4kW domestic PV installation and we run a Renault Twizy, “Thierry”, as our own domestic vehicle and in our capacity as Directors and promoters of the Eco Travel Network scheme.  Although Thierry can only sometimes charge directly from our PV panels (he tends to recharge a bit too fast), we were curious to know what percentage of the miles he has transported us over the past 2 months (July and August) was effectively generated by our own PV – i.e. pure solar miles.

In those 2 months, our PV panels have generated 722 kWh and according to the stats on our energy use per Twizy run, Thierry averages 8 miles per kWh so, in total, the PV panels have generated 5776 potential Twizy miles. And Thierry, in that time period, has actually travelled 1022 miles. His daily average is 21 miles. (Interesting to note that the national UK average is 23 miles car miles per day – so much for range anxiety!!).

And, rather intriguingly, this is what it looks like on a daily basis over July and August (which were certainly not the sunniest months on record) but each day, there were plenty more solar miles we could have done! And the sunnier it is, the more enjoyable it is driving in an open car.

Travelling green is OK but travelling yellow is a lot more fun!

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Twizics 3

Posted on August 29, 2012 by Alison Kidd

Twizics 2 identified air resistance as a major energy drain at high speed, but changing speed also uses energy.  If there were no air, drive train or tyre drag, we could maintain a constant speed with little or no energy input, but accelerating and changing direction always takes energy.

Acceleration increases kinetic energy, so you can work out how much energy you need for a given change of speed of a given mass. What’s not so easy to work out is how much we accelerate in the course of a given trip.  Driving at high speed usually involves more acceleration and braking, but it’s hard to quantify.

The lower your top speed, the less energy it takes to achieve it, and you also lose less energy when you brake.  But should you accelerate gently to your top speed or is it best to accelerate hard?  The energy to accelerate a given mass between two given speeds is the same no matter how long it takes you to do it.  But the harder you accelerate, the higher your average speed will be over the course of your trip, and that increases the energy used to combat air resistance.  So although you will spend less time combating that air resistance if you accelerate quickly, you will use proportionately more energy.  So to maximise your range it is best to accelerate gently to your chosen speed and then try to maintain it.

Braking reduces kinetic energy. In a Twizy you get some of this energy back if you slow down using the regenerative braking of the motor rather than the friction pads of the brakes.   Friction just converts the kinetic energy into (wasted) heat, while regenerative braking converts some of it back into chemical energy in the battery.  But unless we’re going to stay still, we have to accelerate and decelerate to get anywhere, and you can’t really work out theoretically how much energy you would use on an average trip.

The other big consumer of energy around here is hill climbing.  Once again, the physics is straightforward: it takes a given amount of energy to raise a given mass against the force of gravity, regardless of how long it takes.  But again, the faster you climb the more energy you consume overcoming air resistance.  Also, you will need more power even though you need it for less time, so if a hill is very steep, the Twizy’s motor may not be powerful enough to climb it at full speed.

The bottom line is that it is difficult to predict how much energy a Twizy will use on a given trip unless you know the terrain and the speed at all points of the journey.

In an attempt to construct an empirical model, I used a log of a trip I did last year in a fully instrumented electric vehicle. The log records the position (longitude, latitude and altitude) every 5 seconds of a vehicle being driven conservatively along a gently undulating 10 mile route at a maximum speed of 25mph and an average of 16.  I did the same trip rather more quickly (maximum speed 35mph average 21) in a Twizy and I know how many Watt-hours of energy that took.

Using this data set I can calculate the overall power consumption by applying the various parameters (drag coefficient, cross-sectional area, rolling resistance, drive train drag, vehicle and occupant mass, gradient).  I do not know the true parameter values in all cases, so have made credible estimates.  There are several combinations that will produce a “right” answer – i.e. one that corresponds to the actual recorded power consumption on this trip in a Twizy – but the tuning process enabled me to establish which ones are most sensitive.

I then used this “model” to calculate the expected energy consumption for the same trip conducted at a range of “maximum” speeds.  The graph below shows the (very simplified) result.  Here’s (roughly) where I think the energy goes on a typical ten mile Twizy trip in gently undulating terrain in mid-Wales.

This fits our actual consumption of about 125 Watt-hours per mile at the sedate speeds at which we drive, and the more exciting 170 to 190 Watt-hours per mile that we get when we’re showing off, and all our friends seem to get most of the time!

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Twizics 2

Posted on August 22, 2012 by Alison Kidd

Most Twizy drivers will struggle to achieve 125 [wall] Watt-hours per mile and a range of 50 miles in a hilly area like ours.  There are two important numbers governing the range and speed of a Twizy – 30 and 50.  If you drive a Twizy at 50 mph (its maximum speed) whenever you can, and otherwise as fast as conditions allow, you might get 30 miles.  If you drive at 30mph on flat roads whenever you can, and at whatever speed the same power can maintain at other times, you can manage well over 50 miles unless the terrain is against you.

To understand why speed has such an impact on energy consumption, we need to know where the energy goes:  some is lost as heat in the conversion from electrical to mechanical energy; a fair bit to the tyres; a fair bit to the drive-train, gears, bearings and brakes; and some to the control systems and (at night) the lights.  Most of the large power drains increase roughly linearly with speed, so although you use twice as much to go twice as fast, it shouldn’t affect how far you can go because you take half the time. But above about 10mph you are also subject to air resistance, whose force increases with the cube of the speed, which means that the power to overcome it goes up with the square.  So by about 50mph pushing the air aside is accounting for at least half the power expended while at 25mph it accounts for less than a quarter.

The (purely illustrative) figure below models a typical “power budget” you might expect to maintain a Twizy at a constant speed on a flat road.

The graph above is of course over-simplified, and certainly not taken from any official Renault figures! But as a model of Twizy performance it does roughly coincide with what we achieve in practice, and the same model produces the following graph of expected range at a given speed on a flat road.

But of course, our roads are not flat, and we do not drive at a constant speed.  We accelerate and we brake, and we climb hills and come back down again.  I’ll have a look at the power cost of these in the next article.

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Twizics 1 – the Physics of the Renault Twizy

Posted on August 17, 2012 by Alison Kidd

The goal of the Eco Travel Network is to offer people in sparsely populated rural areas more sustainable personal transport.  Country people can live as sustainably as city folk in most respects, but the low energy of city public transport systems cannot be matched in sparsely populated rural areas.

Professor David MacKay, in his book “Sustainable Energy without the Hot Air“, measures the energy used by various modes of transport in “kWh per 100 passenger kilometres”.  So, for example, he calculates that an average UK car with one person in it uses about 80kWh of energy to travel 100 km: 80kWh/100p-km. An inter-city coach doing 65mph with 50 people aboard manages 6kWh/100-pkm.  A rush hour London Underground train manages 4.4kWh/100-pkm.  Most rural commuting trips are, by necessity, car trips, so country people are typically using more than 10 times more energy to get around than their city cousins.

Vehicles like the Renault Twizy can change that if they can match the energy per person of urban mass public transport systems.  Our Twizy needs 125 watt-hours of mains electricity for each mile we travel with both of us aboard.  100km is 62.14 miles, and 125 watt-hours per mile works out at 7.77 kWh of mains electricity for 100km.  This means that a Twizy with only one person in it(at 7.7 kWh/100-pkm) is as energy efficient as a city bus, and with 2 up uses less energy (3.9 kWh/100-pkm) than a rush hour tube train.

The battery charging process on a Twizy isn’t 100% efficient, so 1kWh of mains electricity doesn’t put 1kWh of power into the batteries.  Nor is the electrical power in the battery converted completely into mechanical power.  Renault hasn’t published either of these efficiency factors to my knowledge, but Tesla claim an impressive 88% “wall to wheel” efficiency for their latest Model ‘S’ Sedan.  Let us assume that the Twizy manages a more modest 80%.

That would mean that every kWh of mains electricity translates to 800 Watt-hours of mechanical energy, and our figure of 125 mains Watt-hours per mile translates (somewhat suspiciously!) to exactly 100 Watt hours of mechanical energy for each mile.  To see if these figures makes sense, we can note that a 6kWh battery would take you about 60 miles, and require about 7.5 wall kWh of mains electricity.  The Twizy charger requires 2.2 kW at full power, and it should therefore take around 3.4 hours to replenish a completely empty battery.  Renault’s published figures for the Twizy are about 60 miles maximum range, and 3.5 hours maximum charge time, so we can be reasonably confident that our assumption of 80% “wall-to-wheel” efficiency is not far off.

So what we have in the Twizy is a personal transport system with better energy efficiency than a regular bus, and when carrying two people better energy efficiency than the tube.  Interestingly, it is also good for about the same journey length one would typically make for a commuter trip, so vehicles like the Twizy can make rural personal transport as “green” as urban mass transit while offering many of the same conveniences as the most popular form of private transport, the car.

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Twizyology 1 – the Psychology of the Renault Twizy

Posted on August 14, 2012 by Alison Kidd

We haven’t blogged much recently as we’ve been busy launching a new, not-for-profit company, The Eco Travel Network Ltd which grew out of our b-bug project which The Prospectory ran last year.

The aim of the Eco Travel Network (ETN) is to enable visitors and residents of the Brecon Beacons National Park to travel around in lightweight, low energy vehicles – powered by electricity generated by local solar, hydro and wind.

With the support of the Sustainable Development Fund  and Renault UK, the ETN has purchased a fleet of 7 Renault Twizys which it is leasing to accommodation providers in the National Park for them to use themselves and rent to their visiting guests to replace journeys they would otherwise make by car.

Now, the scheme is launched, we are starting to refocus on The Prospectory’s original research interests in the ETN project.

Here are our behavioural research interests:-

1. The Renault Twizy as a ‘not-car’

From a Prospectory perspective, the most interesting thing about the Twizy is that it’s not trying to be a car.  It offers something different– a small, lightweight, open-sided, low energy runabout. We think the Twizy’s “not-car-ness” might give it a better chance than other electric vehicles of disrupting the existing car market. Why? Because conventional electric vehicles are having to compete with petrol and diesel cars on speed, comfort, range and all the well-established values of the existing car market which auto journalists use to evaluate new offerings and customers expect when they buy a car.  That is difficult for electric vehicles to achieve at the moment and impossible in the same price bracket.

Established technologies tend to be disrupted and eventually replaced by new technologies which, at their outset don’t perform as well along existing dimensions of value but offer customers new and different values. Digital cameras are an example. The first digital cameras were heavy, more expensive and delivered much poorer image quality but people found they could do different things with them. Digital cameras have now caught up on image quality and price and almost completely replaced traditional film but they have also radically changed the way we do photography.

The Twizy makes a statement that it is NOT a “proper car” – it is open-sided, unheated, tandem-seated and ridiculous for travelling long distances in but, at the same time, it’s nippy, cheap, handy and fun for the 85% of journeys which are under 5 miles.

So, from a research perspective, we are interested to gather feedback from our Twizy users to see if people do think about the Twizy differently, travel differently with it and whether it helps disrupt the established dimensions of the car market.

Or do people think it’s an under-specified car and start to demand it has doors, windows, heaters, more comfortable seating and a greater speed and range. We have noticed that auto-journalists are the first to view it that way and, sadly, the industry is already offering Twizy windows as an accessory. The jury is out.

2. Changing attitudes by changing behaviour

We could attempt to educate people that they don’t need a car with a performance spec (speed, power, comfort, range) to take them 400 miles to Scotland simply to nip 2 miles down the road to buy some milk or drop the kids at school – especially when most of the energy is taken up moving the car rather than the people in it.

However, along with the neuroscientists, we believe that people’s attitudes (in this case to car travel) follow their behaviour, rather than the reverse.  So, our goal is to give people a chance to experience doing short journeys in a different kind of vehicle which clearly doesn’t have the performance characteristics necessary to take them to Scotland but which, as a result, uses a fraction of the energy to transport them 2 miles down the road.  We will then explore how that experience (however brief) impacts their thinking and attitudes to car travel.

We originally focussed our experiments on tourists because people on holiday are away from their normal context, time constraints and habitual behaviours and they tend to be more open to doing things differently.

But will these experiments work? We don’t know but we are confident that we and the Twizy drivers will have a lot of fun finding out. Watch this space.

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Hybrid pedal and electric – the “Henry Hollick” experiment

Posted on March 20, 2012 by Alison Kidd

The Prospectory is experimenting with “not-cars” – i.e. ultra low energy. lightweight alternatives to cars which are efficient, cheap AND fun to drive short local distances in a hilly, rural area. Can we entice people into having some fun discovering different ways to get around?

Cars are designed to travel hundreds of miles in great comfort at 70mph but we mostly use them to travel a few miles to the nearest shops or work. We don’t consider this strange even though it’s costly, uses a lot of energy and carbon and most of that is to move the vehicle rather than the people in it! We are interested in whether we can change this entrenched behaviour and perception.

Our b-bug project with electric road legal buggies is an ongoing ‘not-car’ experiment and we are currently seeking ways to establish b-bugs as rentable vehicles for visitors to the Brecon Beacons National Park. People love driving them as an alternative to their car and at 30mph with a 25 mile range, they are fine for many of people’s local car journeys (at least in dry weather).

But, we are intrigued by whether an even lighter weight electric vehicle is possible because the lighter the vehicle, the less energy required to move it – especially if you don’t mind travelling a bit more slowly and taking a few more minutes to reach your destination.

We recently discovered that my Great Grandfather, Henry Hollick designed the body for the first ever J.K. Starley electric tri-car built in the UK in 1888. Here it is:-

Intrigued, we wondered if we could experiment with something along those lines. It would also allow us to reintroduce the option of harnessing some human energy in the form of pedal power. Pedal power is so amazingly efficient, it seems a shame to waste its potential (and it keeps us healthy) but we have found that many people simply aren’t happy riding a 2 wheel bicycle. So, can we combine some of the comfortable, sitting down, side by side aspects of a car with the electric assist pedalling power of an electric bike?

As an experimental project, The Prospectory has just taken delivery of a Ricksycle from Canada – the nearest model we can find for an electric tri-car along the lines of the one designed by Henry Hollick himself. Here we are in our first “Hollick” outing – a working run to the Post Office 2 miles away.

Freewheeling downhill to Talybont certainly gave us an enjoyable feel for what riding in the first electric tri-car in 1888 might have been like. Pedalling back up the hill reminded us that electric assistance on the ‘Hollick’ would make a big difference to its everyday utility and enjoyment and take it a step closer to its 1888 fore-runner.

Experiments will continue. Watch this space.

 

 

 

 

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Light Green Transport for Rural Wales

Posted on February 27, 2012 by Alison Kidd

The Prospectors are interested in introducing funky, lightweight, low energy vehicles to replace short car journeys here in rural Wales – the kind of journeys we do every day to get to work, drop the kids at school, nip to the local shops or get to the railway station. 63% of our journeys are in this category (less than 5 miles).

The b-bug is an early, opportunistic example of the kind of vehicle we have in mind as is the soon-to-be-released Renault Twizy. We are also interested in hybrid pedal and electric combinations. We want to keep them lightweight so the electricity they require can be satisfied to a large extent by our natural elements – sun, wind and water. Currently a single set of domestic PV panels can support 3-5 b-bugs and the Talybont community hydro could keep 150 such lightweight vehicles  on the road.

We want the vehicles to be practical and cheap for local residents so they can replace the 2nd car. But we also want them to be a novel and fun attraction for our many holiday visitors. Our dream is for the Brecon Beacons National Park to be the first UK destination where visitors don’t need or want a car to get around. Instead they enjoy moving around powered only by our natural elements..

You can read more about our strategy for ultra light green vehicles here.

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One-eyed Turks? – it’s all in the brain

Posted on February 1, 2012 by Alison Kidd

OK, so I admit it, The Prospectors (when not busy Prospecting) are avid supporters of the Llanelli Scarlets  – or “one-eyed Turks” as we are known to supporters of other Welsh rugby sides. And, like most supporters, we are inclined to think that “our side” play better (and certainly more interesting) rugby than any other side.

It transpires that this well known bias amongst supporters may have a neuropsychological basis rather than simply(?) a cognitive one.

New Scientist reports this week on a study by Pascal Molenberghs at the University of Queensland in Brisbane, Australia.  He divided 24 volunteers into two teams and then asked them to judge the speed of hand actions performed by one member of each team.

Even when the hand actions were performed at exactly the same speed, the volunteers judged the actions of their own group member as faster than the other group’s member.

Brain scans showed that the brain activity (of those making the judgement) was different in the two cases – suggesting the bias arises at the perceptual stage rather than the decision-making one.

So, who knows, the moniker “one-eyed”, when referring to opposition supporters, may actually hold a grain of truth in that we may indeed perceive physical actions differently depending on which team’s actions we are watching at any moment in time.

Disappointing if the study included no control – i.e the brain scans of neutral observers who didn’t belong to either side a.k.a. “the ref”!

The Study is due to be published in Human Brain Mapping.

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