What would I put in the index?

Well, the sad fact is, despite my 'passion' for green technologies, I really don't know that much about the business world around me. Who's doing what? Of course I know a few examples that have turned up on my radar, but not enough to base an index on.

Thankfully, ASX makes it easy for you: CleanTech Fact Sheet. This was updated in June 2011, but there's no history of previous versions, so I have no idea if it'll be around for long. I've downloaded a copy and had a look.

There are 76 Companies listed, each with it's market capitalisation and a description of the market segment it is in, they break up as follows:

Name # Cap $M

Waste 13 4911

Geothermal 11 212

Efficiency 9 356

Biofuel 7 104

Water 6 59

Solar 6 685

Storage & Fuel Cells 5 679

Environment 5 124

Other 4 34

Carbon 3 64

Vehicles 3 28

Biogas 2 544

Wind 1 267

Wave 1 68

I was surprised by this list. There are around 2000 companies listed on the ASX and only 76 of those can be called clean tech. ($8B out of $1000B) And of those, by far the biggest segment is waste recycling. SIMS alone makes up nearly half the value of this group.

I'm not sure I agree with the ASX. It's a good place to start, but my green-tech index is going to have to have a tighter screen...

Now I see why there were so few companies in the other indexes.