My Lords, I hesitate to intervene in the debate not because I have any quarrel with the principle being enunciated but because I have something to say about the effectiveness of biofuels. There is no doubt that from an agricultural point of view the introduction of biofuels—be they bioethanol from wheat or sugar beet in this country or biodiesel from oilseed rape—is highly desirable. However, we should not assume that it will solve the nation's energy problems and that aspect concerns me.
I will not bore the House with all the arithmetic, but let us put the problem in perspective. If all the land that is set aside in this country were used for the production of biodiesel, it would produce only 3 per cent of our annual consumption of diesel oil. That is all. If all the land in the country were put into the production of biodiesel, we would still have the most enormous deficit in fuel.
That is not to say that such a contribution is not worth making. To the extent that biodiesel is carbon neutral, it is better than pure consumption of mineral hydrocarbon fuel, but we have a huge problem. The difficulty is that plants are inefficient converters of solar energy. If, for instance, one put the same area of land into photoelectrics—I know that the present economics make it impossible—we would produce 10 or 15 times as much energy. We need to think carefully about what we are doing when we are in the business of green energy.
I do not oppose the policy—it is completely supportable—but we should realise that it can make only a marginal contribution to our national energy problems. I speak in order to make apparent the scale of those problems. They will not be solved by any easy measures and it is important to realise that the scale of the difficulties we face nationally and globally are far more severe than anything most people have begun to think about.