To ask the Minister of Agriculture, Fisheries and Food (1) what is the average yield of diesel per acre from oilseed rape;(2) how many gallons of diesel are used to produce 15 gallons of diesel from oilseed rape, taking into account that used by machinery, pesticides and fertilisers.
Diesel fuel from rapeseed oil is not in production in the United Kingdom, so only theoretical estimates can be given. Taking a five-year average (1987 to 1991) of rapeseed yields in the United Kingdom, very approximately 520 litres of diesel might be produced from an acre of rapeseed. Diesel derived from rapeseed could cost around three times as much to produce as diesel derived from inorganic sources. Calculating the ratio between the energy expended on the production of diesel from rapeseed and the energy released when that diesel is consumed is complex. In particular, the inputs are difficult to quantify comprehensively. The best assessment currently made by my Department is that the ratio of energy expended to energy obtained is possibly in the range 1:1 to 1:1·5.