[pinkyand]

Of course those are factors , but qbotix has raised investment, has managed to get some commitments for solar projects, and there's even a company using their system in the UK offering to finance projects on a long term electricity purchase basis, claiming it's much cheaper than current providers:

http://castillium.co.uk/tracking-solar/tracking-250kw/

So qbotix might have good solutions for the issues you mention. And that is of course without having concentrated solar power, which makes a qbotix a more attractive offer.

[jacquesm]

Raising investment is not typically a sign of technological excellence. It could be but it's certainly not a reliable indicator. Long term reliability of such systems can only be determined in the long term. So far the score does not look good for trackers.

[pinkyand]

I'm not sure it would take the long term to determine reliability: there are engineers who specialize in that,and there are software tools to simulate the reliability of a mechanical systems.

Whether this company did this or not is unknown, if they are offering this system on a per month basis, it makes sense they did some reasonable level of analysis of costs, because it would reduce their risk greatly.