It was said here on hotcopper, by a previous holder in conversation with Mega I believe. If you look at the last page or two of posts on the old CWE stock code you should find it. The poster mentioned specifically that he had heard that performance was poor, particularly in light conditions, and as a result he no longer held.
My own determination that Ceto 5 did not perform well was based on Carnegie's behaviour over about 18 months starting part way through the deployment. Specifically; not mentioning performance numbers, not releasing data in any announcement (including income from the power generated during the trial), Carnegie delaying Ceto 6 by years after saying (in late 2014) that it would be deployed in 2016, Carnegie buying EMC using money rasied for Ceto 6 and getting involved in all types of projects unrelated to Ceto, etc. This was born out when Carnegie admitted that Ceto 6 was delayed due to the need for more development work and them eventually coming out with the 3 legged version.
CCE Price at posting:
1.7¢ Sentiment: None Disclosure: Not Held