Economy of a producer gas truck
The difference in annual cost between a diesel truck and a wood gas truck will be evaluated for the same economic situations as considered for the tractor. The initial cost of the truck is assumed to be US$ 28000, with ten percent added for freight costs to a third world country.
The difference in cost is shown in Table 3.21 for three utilization levels, i. e. 60000, 120000 and 240000 tons and kilometers per year.
The average velocity is assumed to be ten percent Less for producer gas operation, mainly because of stops for fuel charging. In European conditions the average velocity is assumed to be 60 km/in for the diesel vehicle. In the other cases, where road conditions are less favourable, the average velocity is assumed to be 25 km/h.
As can be expected, the results of the comparison are qualitatively similar to those presented for a farm tractor. Wood gas operation in Sweden will not be economic until the diesel price has increased considerably — by more than 200 percent.
Under intermediate conditions where wages and the price of fuel wood are lower, wood gas operation does not appear economic either. This is a different conclusion from the tractor case, and can be explained by the differences in use pattern. If it had not been necessary to drive the wood gas vehicle a longer distance to carry the same load, the wood gas truck would have been marginally economic for the case of 240000 ton km/year. The increase in diesel fuel price required for wood gas to be economic is between 100 percent and 25 percent. For long distances driven annually, it may be economic at the present oil price if the wood is extremely cheap.
For the extreme case of low wages, low fuel wood price and high price of diesel fuel, the wood gas truck appears extremely profitable with a pay-back time of two years or less for the gasification equipment.