I've just looked at it Steveg and it looks interesting. Might have a go at it later today, thanks

Me too, seems logical, just need to get fork handles ;o)

I would like to try it in my shed but I don't know where to get tee lights that last that long. All the ones I've used in the past only last an hour or two. Not long enough to keep going all night.
Does anyone know where I could get the appropriate tee lights please ?

These glo wax that I have burn for 10 hours my wife uses them around the house

http://www.ebay.co.uk/itm/GLO-WAX-EXTRA-LARGE-10hr-LONG-BURN-TEA-LIGHTS-TEALIGHTS-/140734776097?var=440054865021&_trksid=p2054897.l4276

Thank you. I'll get some :o)

Those are £5 for 20 (+£4 p&p), rather more than 4p per day.
I wonder why he needs the extra plant pots etc. "Energy can neither be created nor destroyed" (mr Einstein) so the greenhouse only receives the energy, heat, stored in the candles initially.
It all sounds a little bit 'Urban Myth' to me but I might try it with a fat church candle for the next heavy frost.
For 8 or ten hour 'T' lights have a look at Amazon.

I tried this in our small conservatory. It did work....but just took the edge off the cold rather than warming the place up. Might be better in March. You can get T lights for peanuts in Ikea.

I agree Bulba, this doesn't sound an efficient way of using energy. It's probably more efficient and cost effective to use an oil burner such as a paraffin heater. He probably uses the plant pots to retain the heat and slowly release it into the greenhouse, but the same thing can be achieved by heating fire bricks up on an open fire and putting them in the greenhouse.

I also doubt the cost of the tea lights... 100 for £1? And I've never come across ones that burn for 24 hours.

I've watched the demo. Impressed, but where on earth do you get tealights at 1 or 2 p each. Best I've found is 20p each from an address given above by Steveg himself. Couldn't find any in Ikea's listings.