The Blog - Wind is moving gas

A group of medical students were completing a timed assignment in a library, the came across a diagram they wanted to use but did not have a scanner or cables.   The solution was to photograph the image using an iPhone, shift the image from the iPhone to Facebook and from there download it to the presentation.  There is hope for the young.  This sort of approach could be applied to conservation and renewable energy.  So often, the approach is a simple substitution, for example we try and replace coal and nuclear power stations with wind farms, we create electric cars by transplanting a petrol engine with an electric motor.  I have no idea on the merits of the fantasy decsribed here.

Occasionally whilst cycling around the leafy lanes of England, I encounter a golf buggy being driven home from the course.  Googling for he price of these things suggests that they cost something between £3,000 and £5,000 when bought new.  With some security and weather protection a buggy would work well as an urban vehicle, no direct emissions and capable of being fuelled by off-peak electricity and absorbing the output of wind and solar generators.

The economics of electric cars are attractive.  A litre of petrol costing around £1.50 yields approximately 9 kwh of energy.  Off-peak electricity costs about £0.06/kwh or in petrol terms £0.50/litre.  My thermodynamics are a bit rusty, but the conversion efficiency of a petrol driven car might be around 40%, whilst that of an electric vehicle could be 80%, thus you get more usefull stuff from electricity than you do from petrol.  This is because the conversion from coal/gas/nuclear energy is done in the power station and the price includes the cost of that conversio.  Unless the car's batteries are being charged by wind, solar or other renewable source, electric vehicles are not emission free, the emissions emerge from the power station chimney, not the vehicle's exhaust pipe.  As a percentage of our electricity is generated from nuclear sources, an electric vehicle could have a bumber sticker stating that "this vehicle is powered by nuclear energy".

Electric vehicles have an energy storage device in the form of a battery.  Whilst we call wind and solar generators renewable energy sources, they might also be called weather dependent energy sources.  One way of dealing with the vagaries of the weather is to include some form of buffer storage, when the wind blows and the sun shines, the battery charges, at other times the demand is met from energy stored the battery.

With more than a little stretch of imagination wind farms and the electric car could combine to form a sustainable technology.  Lets develop the idea to its illogical conclusion.  As the number of electric cars grows, wind farm operators start taking over city centre parking facilities and installing charging points and sell electricity directly to the motorist.  Provided the price of wind generated electricity is competitive with that of petrol, they might even charge a premium price for a package of parking and energy providing funds for future investment and maybe even tax revenues.  A similar model worked for the oil companies.

Part of the problem is the electric car itself. Range, performance and price are the main objections.  Most modern cars can be driven several hundred miles on a tank full of gas, but mostly they do a couple of long trips each year and a thousand short hops, e.g. the school run and the supermarket shopping trip.  So, for the most part a range of 100 miles is not a limitation if you can give the vehicle a daily visit to a charging point.  A car spends most of its time on a parking spot, an electric car can spend that time with a wire attached to it.  As a none-too-fit cyclist I rarely exceed 10 mph, even with this limitation, on urban journeys of less than 10 miles, I'm usually quicker than a car or the bus (to be fair, a lot of the time saved comes from not having to mess with parking).

At £25,000 an electric car does not make sense to most people, especially when you can get something reasonably environmentally friendly (emissions less than 140 gm CO2/km) for around £10,000 and still be able to drive from Lands End to John O'Groats once a year if you feel the need.  If the price drops to less than £5,000 and running costs to less than £500/year and no petrol needed, do the limitations cease to be obstacles?

There will be more on mobile phones and energy in a later blog.