From Greenhouse to Green House

The threats of climate change
CO2 emissions and savings


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For long journeys in the UK, we generally prefer to go by train. This is mainly because it is (normally) more relaxing and safer than driving. But the UK rail system is in such a mess that there is often a penalty in high prices, unreliable service and squalid conditions (Britain invented railways - hooray!). Trains are more fuel efficient than cars but, in the main, they are still powered by fossil fuels. At a personal level, there is not much we can do about this but we look forward to trains being run on biofuel or powered by green electricity.

One of us (GW) does not use local buses very much, mainly because of experiencing them to be somewhat infrequent and unreliable. For journeys up to three miles, we often walk.

As of late 2006, both of us have signed a no-fly pledge—no flying except in emergency. We would like to see new developments that would eliminate net emissions of greenhouse gases from this source (eg the 'Cryoplane'). Environmental taxes on air travel are badly needed, but are not optimistic.

We would like to use our bicycles more but sharing the road with motor traffic is both dangerous and unpleasant. Britain badly needs to catch up with countries like Holland and Germany in the provision of traffic-free routes for cyclists. It is a scandal that the Government is not building a national cycling network in the same way that it makes provision for cars -- it is leaving the job to a charity (Sustrans).

We don't wish to see yet more countryside torn up to make way for cars but there is no escaping the fact that for many purposes, cars are very convenient. We each run a car and use them mainly for local journeys. We are keen to find ways of running cars that eliminate CO2 emissions. For one of our cars, we now have a solution.

Electric vehicles, fuel cells and compressed air cars

Apparently, Ford have designed an electric version of their small 'Ka' that will do 120 miles on one overnight charge. But, for some reason, it is not being sold in the UK. We have not yet found an electric car for sale in the UK although we have seen references to one or two models available at rather high prices.

An electric car that could do even as little as 50 miles on one charge would be quite attractive for us. We rarely do more than that distance in a day. The car would be charged from our 'green' electricity supply so it would largely eliminate CO2 emissions from local car journeys.

We are being promised cars with fuel cells and electric motors but there is no sign of them yet in the UK. If this kind of car were run on methanol derived from plants or on hydrogen from some source that did not involve the release of 'fossil' CO2, it would be something to look at.

We are potential customers for the MDI Air Car. These run on compressed air and need to be 'pumped up' overnight using an electric motor. As with electric vehicles, we could use our 'green' electricity supply. Here is a YouTube vido about the MIDI Air Car.

Sadly, these cars are not yet available in the UK. We could go to France where they are being made but we would probably have to make do with a left-hand drive version. It sounds as if they might be quite reasonably priced when they do come up for sale in the UK.

For short local journeys, another option is G-Wiz.

Tax breaks and other incentives are needed to get this market started (but see Powershift).

Links: Electric Vehicles UK, Powershift (Energy Saving Trust), Solar electric car to shine at auto show, Project Better Place.

Hybrid vehicles and plug-in hybrid electric vehicles

A hybrid car has a Diesel or petrol engine that charges a battery that runs an electric motor. It sounds crazy but apparently it is more efficient than a conventional engine, mainly because the Diesel or petrol engine can run a constant, optimal speed. Also, the Diesel or petrol engine can be switched off in the middle of town or anywhere else where exhaust fumes need to be reduced. If a hybrid car were run on biodiesel (or SVO) it would yield zero net CO2. Hybrid cars are just beginning to appear in the UK.

One of the most interesting developments is the idea of combining the concepts of 'electric' and 'hybrid' cars (a 'hybrid-hybrid'?). 'Plug-in Hybrid Electric Vehicles' (PHEVs) are simply hybrid vehicles with batteries that are big enough to allow the car to run in purely electric mode for much of the time. During the night or at other times when the car is not being driven, it may be plugged into the mains and charged up. Then, for distances within the capacity of the battery, the car may be driven in purely electric mode. Provided the electricity is 'green', there will be zero CO2 emissions (and zero emissions of other pollutants that are produced by internal combustion engines).

One advantage of this idea is that, unlike a car that is totally electric, there is always power available for longer journeys or if the car needs to be used when the battery is flat.

PHEVs raise the fascinating possibility that they can be used to make the electricity distribution grid operate more efficiently. When they are plugged in, following the principle of 'dynamic demand',  they can be programmed to detect when the distribution grid is overloaded and avoid drawing current at those times. Even more interestingly, PHEVs can be used as a source of power to feed electricity into the grid to meet peaks of demand: at such times, the non-electric motors of plugged-in PHEVs are started and they can then feed extra power into the grid. Naturally, this would be best outside any garage or other building so that exhaust fumes do not build up.

Yet another interesting possibility is to power PHEVs at least partly by the sun. With falling prices and improved efficiencies of photovoltaic solar panels, it will become increasingly attractive to fit them to the roofs of PHEVs. At all times when the vehicle is exposed to daylight, either parked or driving and even on cloudy days, the batteries may be charged from the PV panels. 

This market needs encouragement.

Links: Powershift (Energy Saving Trust), Intelligent Energy.

Biodiesel and straight vegetable oil

Biodiesel is vegetable oil that has been processed so that it can be used in any Diesel engine. It can be made from fresh vegetable oil or from waste cooking oil from chip shops, bakeries, hotels etc. There are potential objections to biofuels but they certainly have a place as a stop-gap solution and, with certain constraints, are likely to be part of any long-term solution to the problem of climate change.

As of late August, 2002, we have traded in one our petrol-engine cars for one with a Diesel engine. We have also taken delivery of 200 litres of biodiesel from Goat Industries, with a 200 litre tank to store it in. More recently, we have been using V100 from Bio-Power. Most of the year, the car runs perfectly without any adaptation and the fuel can be mixed in any proportion with conventional diesel fuel. However, we have an electric heater for the fuel line (from Plymouth Bio-Fuels) which is sometimes needed if the weather gets very cold.

The car now carries large notices on both sides and the back advertising the fact that "This car runs on BIO-DIESEL, cutting CO2 and costs", with the address of this web site. Here is a photo of the car with Marianne and me (left and right of the group), Rick Mills (of Môn a Gwynedd Friends of the Earth), and Mr and Mrs Fitzpatrick (and baby), proprietors of one of the cafés that supplies used cooking oil to Goat Industries for conversion to biodiesel.

It is also possible to run cars on straight vegetable oil (SVO). From an environmental point of view, this is attractive because no unpleasant chemicals are needed to convert the oil to biodiesel and more of the energy in the original oil gets used for powering the car. From a personal viewpoint, it is less attractive because it is necessary to adapt the Diesel engine, and the process of starting the engine and stopping it is more fiddly (but see comments above about V100). Dr Rudolph Diesel's original designs were intended for SVO (peanut oil). It would be good if car makers would adapt their engine designs so that SVO could used in a straightforward way once again.

From July 2002, the tax on biodiesel and SVO has been reduced from 46 p / litre to about 25 p / litre. It is now slightly cheaper to run a car on biodiesel than on fossil diesel. If you would like to lobby for a further reduction in the duty on biodiesel and SVO (preferably to the preferential rate currently applied to LPG of 6 p / litre) email

Sign the petition asking the Government to reduce or remove the tax on vegetable oil when used as a roadfuel.

Costs of biofuels compared with conventional fuels.

Links: Bio-Power, Allied Biodiesel Industries (UK), Goat Industries, e-diesel,, Biofuels for Sustainable Transport, British Association for Bio Fuels and Oils, Veggiepower, Veggie Van.


Shell announced on 8th May 2002 that it has purchased an equity stake in Iogen Corporation, a bioethanol technology company. They say "Bioethanol, when blended with gasoline, is one of a range of environmentally friendly fuels Shell is exploring as it has the potential to significantly reduce greenhouse gas emissions of vehicles." An attraction of the Iogen process is that it makes ethanol from plant wastes such as straw which are otherwise burned or dumped.

Like other biofuels, bioethanol needs to be taxed at a level that encourages drivers to use it.

Links: ACOS process, Iogen.

Air travel

This is a major headache. At present, there is no clear alternative to kerosene with jet engines as the means of powering airoplanes and this technology releases large amounts of fossil CO2 into the atmosphere.

There are efforts to develop planes fuelled by liquid hydrogen (the 'Cryoplane') but this looks like a distant prospect and there are, in any case, worries about the greenhouse effect of water vapour in the exhaust gases. Of course, the hydrogen must come from renewable sources.

Until there is some effective technological fix for the damage caused by flying, there should be strict controls on the amount of flying that is allowed. In principle, many journeys can be saved by greater use of internet conferencing. It has shortcomings compared with face-to-face meetings but it also has advantages (eg saving time and money) and in many cases it will serve perfectly well.

Links: Flight Pledge Union, NoFly Travel


Apart from worries about fossil CO2 released by ships, there are growing concerns about the cost of fossil fuels for ships. Some interesting possibilities for the future are described in the sources under 'Links', next.

Links: SkySails, SolarSailor, E/S Orcelle concept vessel from Wallenius Wilhelmsen.

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