In this chapter the reasons for the Swedish interest in wood gasifier systems for vehicles has been explained, and the recent experiences from practical use of vehicles operated on wood gas summarized. It is believed that these experiences could be of interest for energy planning in other countries with a similar high dependence on imported fuels for the transport sector, and that the technology might be economically interesting for regular use under some of the circumstances outlined in Section 3.4.
It must, however, also be understood that use of producer gas vehicles involves certain risks. These have been described in Chapter 2, but it should be mentioned in this context that the experiences in Sweden of a rapid introduction of producer gas vehicles at the beginning of the Second World War were fairly unfavourable. There were several fatalities caused by carbon monoxide poisoning and a marked increase of the frequency of car fires. After enforcement of strict safety regulations, and strenuous efforts to educate drivers, these types of accidents became less frequent. The number of persons annually diagnosed as suffering from "chronic effects" of producer gas poisoning nevertheless increased. In total about 10000 persons in Sweden were recorded as cases of chronic poisoning during the period 1941-1945. It should be understood, however, that the symptoms do disappear after a time if a person suffering from poisoning is no longer exposed to the gas. There appears to be no permanent damage, but poisoning is still a problem because of lost working days.
It is possible that this experience was a result of the habit of bringing vehicles indoors in the winter to facilitate starting and that the risks may be less in a warm climate, but it appears to be very important to minimize the exposure to gas of drivers, passengers and persons working in garages and service workshops. The least that can be done to avoid similar unfavourable experiences is to follow the safety regulations developed in Sweden for installation of producer gas systems in vehicles. A translation is provided in (23). If vehicle gasifiers are introduced on a large scale without adequate precautions, there is a real possibility of unnecessary human suffering and economic losses. Government control of any producer gas vehicle programme therefore appears to be necessary.