The ABC is breathlessly reporting that London busses may soon be powered by waste coffee grounds. This is a relief to those who also bought the story about global warming, if unchecked, could reduce the area suitable for coffee cultivation.

So here’s the plan. You go to all those coffee shops around London, scrounge their bin for a litre or two of waste, take it to the factory, refine it and there you have it- “bio-diesel” for your bus fleet.

Here is the problem. You have a choice of a product that is low and variable quality and distributed in small quantities over a large area which then  has to be refined in a small scale facility and then sent to the bus fuel station. Or you could use a product of known and standardised quality, produced in huge quantities through known processes and with already established distribution facilities.

It’s not hard to work out which is going to win hands down.

I started to try to work out a rough estimate of costs but there isn’t enough information to go on. I suspect that residents of London will end up paying more in the name of saving the planet, with no real guarantee that they are reducing CO2 emissions which is given as the aim of the process.