Two things caught my attention today on the Today programme.

First, a piece about Terry Leahy's allegation yesterday that it was not practical for Tesco to stop selling tungsten lightbulbs, since a significant number of their customers have fittings that require them.

Now, I am the last person to defend Tesco against their more obvious failings – but in this case, even a householder with a rudimentary understanding of lighting would probably defend them.

So, when some greenie was wheeled out to explain why Tesco was wrong, one might expect the interviewer (Sarah Montague) to have mugged up just for 5 minutes before questioning her. But no: just a "Why was Tesco wrong then?" and very little in the way of incisive questioning.

Point 1: low-energy bulbs are not commonly available in unusual sizes (e.g. candle, pygmy or for older spotlighters) either at all, or except at prohibitively high prices.

Point 2: At least until very recently, they couldn’t be used with dimmer switches. And the ones that can cost an arm and a leg (e.g. £12.95 vs about 35p).

Point 3: basically, despite what Ms Green said, they are not really anything like as bright as the tungsten "equivalent". 11W = 60W, and 15W = 100W – my arse, as Jim Royle would say.

We have low-energy bulbs in most fittings now, and an old house with small windows. As a result, our evenings and overcast days are spent in a dim religious light. For example, in the kitchen, we have two 60W equivalents over the table. For the first month or so they were about as bright as the old bulbs, even if they cast a ghastly pallor over all. But now, a year or two on, they are as dull as ditchwater, and not really up to the job of illuminating things brightly enough to do close work. Which is fine for those who sit slack-jawed in front of their TVs of an evening, but not for me if I need to sew a button on or do other such chores.

They touched on point number 2, but conveniently ignored the other points or skated round them.

If it's that hard to have a sensible discussion about something very easy – how hard would it be for them to discuss a complex issue? Too hard, is the answer.

The other thing I will save for tomorrow!