Is there a significant power difference between 16GB and 32GB of RAM?

The power difference is negligible — only 1–3 extra watts at most, less than a typical LED lightbulb. On a desktop, you’ll never notice it on your electric bill. On a laptop, you might lose 5–10 minutes of battery life. If you need 32GB for your workflow, the performance gain from not running out of memory saves more energy than the RAM consumes.