Thanks for all the responses. I was so excited for this. Then the more I read the noise level would sound like a vacuum on 24/7 which my wife said would drive her crazy.  I wish there were silent mays to mine.

Thank you so much for the thorough answer. Is the USB quiet method very expensive?  Can they be run, or can any systems be run without any cooling if they sit in an air conditioned room that’s about 78°?
I read something old online that said the Goldshell KD2 is the quietest mining equipment at 55db but I don’t think it mines Bitcoin, or maybe it does.
Regarding your question about the 600kwh a month accumulation… I could let it accumulate for several months at a time and then run the equipment. Basically near the end of the year I’ll have 7,200kwh to use. I could run the mining equipment for a month straight and then turn it off for several months.
Your analysis was excellent. Thank you. If I do figure out an option and do get a setup, any chance I can tip you to help me get it?
I’d really like quiet as possible and not requiring fans and extra cooling.
Does the equipment require 220v or 110v with really high amps?
Thanks.

Is there a low power usage (like 20 kWh a day or throttleable power, or mining that can be turned on and off), not too hot, not too loud, not too expensive hardware system to slowly mine Bitcoin?
I purchased a new house with an overkill solar system. I’m also on a grandfathered net metering electric company plan where they store any power as credit I can use for up to a year at no cost.
I generate an extra 600kwh more power each month than I use. Right now I have a credit of 7,200kwh that I can use and I get another 600kwh each month (even with charging my ev). It’s use it or lose it.

Is there a slow mining, low power usage or possible one that can be turned on or off, with a timer, and not loud system, that’s not crazy expensive to slowly mine Bitcoin? I live in a very expensive power area (Hawaii 40 cents per kw) and I just let this power go to the power company for free. Even if Bitcoin mining slowly only effectively makes me 10 cents per kW then it’s still $60 a month. 
A serious thank you in advance of anyone can give guidance and opinions on this.
Aloha.

Thanks for all the answers. I think it’s too long to break even on getting a miner. I wish I could I figure out what I could do with the extra power.

Can Bitcoin mining be turned on and off and then picked back up where I left off when turned back on?
Basically, I bought a house with PV solar that generates an extra 20+ kWh a day more than I use. I’m curious if I could mine at a rate that only uses about 20kWh a day, or have it so I shut it off after about 20kWh and then it picks up where it leaves off? Or I could run it for a few weeks and then take a few weeks off. I have net metering and if I don’t use my excess the power company uses it for free. Power in my area is like 40 cents a kWh so I’d rather not go over what I generate.
Would mining make any sense?
Thanks in advance for any guidance on this.