Cloud Sensor

TEG cloud sensor
Cloud Detection Part I
Gadget Freak Case #253: Peltier Thermopile Cloud Sensor
A Cloud Monitoring System for Remote Sites, Publications of the Astronomical Society of Australia, Volume 15, Issue 3 (and I think this is another presentation of this paper)
Cloud sensor instructions, with suggestion to coat pelletier in candle soot to aid absorption
Open-access cloud detection network, with good links (and a Github repo!) -- I think this is close to what I want to try
Raspberry Pi Cloud Sensor (collaborating with Steve Marpole of the Open-access cloud detection network link above)
Pelletier-based cloud sensor
Commercial version of same
Mrakomer cloud detectors
Measuring temp using a Raspberry Pi

Hardware