Is Over-boiling a Concern?

I've been running my electric brewery for a few months now... maybe a half dozen batches. One thing I've noticed is that I always end with with about 1 gallon short on wort volume. I'm accounting for dead-space in my tun, loss to my counter-flow chiller, etc. Regardless of the type of beer, it's always right around 1 gallon in a 5.5gal batch.

My brew kettle is running a 5500w element. The element is hard-wired to the outlet, so it's running full blast for the duration of the boil. My kettle is an uncovered 15gal SS pot, about 16" diameter and 18" tall. I used some online calculators to estimate my boil off rate and use that when planning my brew... yet I'm always short!

My theory is that my element is too strong and the surplus heat energy converting the water to vapor at a faster rate. Would ti be beneficial to lower the duty cycle of the boil element after the hot break has occurred such that you maintain a boil but don't over do it? Im not physicist, so I don't know if that's how things work, but I figure that energy has to go somewhere, right? Anyone else experience this? If that's not the problem, any other tips as to what the problem may be?

Thanks!

Your set up is way over powering the boil. You really need to dial the power back.

Some choices:
Set up a PID to control your boil power. (Do a search)
Use a 4500W (or smaller) element instead.

Lots of options but you are really over driving your boil with what you have.

What PJ said.

Most of us who use the 5500W elements only run them at around 65% once up to boil.

Yes agreed, your boiler is overpowered, you need to limit the power, or at the very least, start w/ more wort to account for the large boiloff. Best not to calculate your boiloff but rather use the real amounts you are experiencing....if you have been running a gallon short, start w/ a gallon more next time.

Awesome, thanks guys! Now that I know what the problem is, I can work on fixing it I have some SSR's and a new arduino en route, so I'll put them to good use as soon as they get here. Thanks!

The setup I'm building has a 3800w element for 5 gallons batches and it's over powered. I do have a PID, SSR, and RTD probe to remedy this though.

As a test a filled my boil kettle with 5 gallons of water at 70F. I went from that to boiling in 45 minutes.