Originally Posted by killian
So How long would it take to heat 5 gallons of water to 170°F @ 1920 watts? I know you have to account for heat loss so just say there is no loss.
Assuming your starting groundwater is 55F, it will take ~46mins to heat 5 gals of water to 170F. These calculations assume the best conditions.
Speaking from experience, I was able to maintain a VERY WEAK boil with a 2000W heatstick with 5gals of wort. I found this out after my propane tank ran out at the last 10mins of my brewsession.
Here's some more food for thought, I brew 6 or 12gal batches currently. For 6gal batches I can use 2X 1500W elements each plugged in to a 15A 120V GFCI (3000W total for those that don't like math). And that gives me a great boil with no external control needed. With a 12gal batch I need to supplement with propane.
Edit: Obviously this would require you to have access to 2X 15A or larger circuits in your brewing area.