How's the return/turnout so far? I am guessing you are already using a computer and graphic cards that you already bought before (no additional investment) but does running the node increase your electricity consumption?
When I first started, I installed the Edge Node on my internet browsing/email computer that generally runs 24/7 anyway. This computer did not have a high end graphics card and I had not staked TFUEL to upgrade the Edge Node to an Elite Edge Node. It earned roughly 5 TFUEL and a negligible amount of LAVITA over the course of a month. I was not going to get rich with this set-up, but something is more than nothing for a computer that was always on anyway.
I later found a refurbished computer with a CUDA enabled NVIDIA graphics card for sale for about the same price as buying the graphics card alone would have cost me. I replaced my old internet/email machine with the new one, configured the CUDA stuff and ran the Edge Node on it. I also bought and staked 10k TFUEL on this machine (upgrading it to an Elite Edge Node). Over the course of one month, this machine earned around 120 TFUEL (from completing jobs and from staking rewards) and 240 LAVITA. It's on pace to return greater than 10% of my TFUEL stake over the course of a year.
I have not done an analysis on my electric bill, but what I can tell you is that the Elite Edge Node is processing jobs on average about once an hour (sometimes more, sometimes less). Jobs generally take less than a minute to process. While processing, the GPU card's fan will activate. Since I'm running the EEN in the background while I'm doing other things, that's often what alerts me to when the EEN is processing a job. In other words, the GPU is very active for about 20-30 seconds once an hour or so. I don't think it's generating that much heat or using too much excess power.