I thought my SSD was getting hot in my mini barebone PC so I checked with hddtemp. It's fine though at 33 Celsius. Now in the German wiki it says that hddtemp checks temps every minute which will wake up a HDD even when no data needs to be read. I'm I right to assume this is a non-issue with SSDs? Or will it impede any power saving functions?
You are correct in noting that this will not affect power performance of an SSD. Because it's your primary drive, it's going to stay powered on, and checking the temperature won't have an affect on power usage of the drive.
The case in which this would matter would be using an HDD, where the drive can be spun-down to save power, and put into sleep. Since an SSD has no power "sleep-state" it won't make a difference. On my laptop, since I have both SSDs and HDDs, I can see that the HDD is occasionally put into sleep while the SSD does not change states.
(From my experience with a Samsung 850 EVO, 1TB HDD, and a 950 NVMe Pro on an Oryx Pro)
Yes. .you are right to assume this is a non-issue with SSD's typical power draw of an active SSD is very low although it is drive dependent. All the SSD's I have draw less than an amp.
Further reading here.