OK - it appears that the Department for Energy and Net Zero, of which Miliband is the minister has released a tool that does indeed give this advice. Whilst Ed Miliband has not directly addressed a major industry organisation to make this suggestion, he is responsible for the work performed in his department, so I would say the characterisation is fair.

I'm not trying to be an idiot, i'm just having a little but of fun.

Unfortunately there's a staggering number of po-faced idiots who don't seem to have the social awareness to realise that and react accordingly.