Estimating steam heat utility costs

[DMcKay]

Hello everyone,

Can anyone give me a good idea on how to calculate utility cost for a 300 gallon steam jacketed still running for about 16 hrs a week on a 700,000 btu boiler? I know this will probably depend on a few things but I'm trying to figure out where to even start estimating something like this. Any help is appreciated.

[Scrounge]

Look at boiler manufacturer literature, and figure from there stated gas usage, and multiply times whatever the gas where you are costs. And then get ready for harder math than that if your going to run a distillery!!! How are you only going to run the still 16 hrs a week?

[Silk City Distillers]

Don't look at it in terms of hours, since boiler load is not fixed, it will vary based on activity. Instead, break it down by activity, and then tally up the individual activities to work into your number.

High usage periods:

Cold Boiler Startup (if you shut your boiler down)

Mash Cooker at Startup

Still at Startup

Low usage periods:

Mash temp hold

Still during run

Boiler at temp

For example, our boiler will run full out for 1 hour to startup our still, then once in a run, the steam usage is minuscule in comparison - once we dial back to 1-2 psi during the run, the boiler only cycles a few times over the course of an hour, fuel usage during the entirety of the run is probably a fraction of the startup usage. Likewise, boiler runs full out during mash cooker heatup, but once at temp, only needs to fire occasionally to maintain temp. If you calculated the 16 hours at all-out fuel consumption, you'd probably fall off your chair.

If your 700,000 BTU is boiler input, and you are running natural gas, just convert the 700,000 btus to therms, and go off your gas bill. Use the activity totals above and multiply it out.

For example, if your gas costs $1.50 a therm delivered with taxes and surcharges (I just made this up), and your still startup takes 1 hour time with the boiler running full out, it will cost you $10.5 in gas to heat up your still, if you plan to heat up your still twice a week, put $21 in that row. This is a completely fabricated example with made up numbers, but this would be the easiest approach.

[DMcKay]

16 hours a week is just a starting point for me to try and figure out utilities cost. The idea was to produce about 60 gal of spirits a week through my 300 gal still. I still need to figure out exactly how long a run will take. Thanks for the information James!

[DistillateurQc]

Hi all, I am not sure I understand very well the calculation.

Let say we have a 350 000 BTU/h boiler input.

We have a 1200 Liters mash tun.

We have a 600 Liters vodka still.

We will run the mash tun once a week and the still twice a week.

Propane gas cost 0.64$/liters.

How can I evaluate the gas cost?

 

Thanks to all!

 

 

[HedgeBird]

Not what your asking for, but if your just looking for some numbers to plug into a budget this may help.

I am paying about $225 a month to UGI Natural Gas to run our 150 gallon still 5x a week and our mash tun 4x a week, the neighboring breweries 300 gallon kettle about 1x per week and the heater in the tasting room when its gets below freezing out. We are using our recovered hot condenser water for mashing.  It looks like my UGI rate is $4.32160 / MCF.  Thats our 150 gallon setup pretty much maxed out (at least with a single shift) so if I was budgeting for a 300 gallon setup maxed out I would just plug in $450 per month.  

Just getting actual numbers from operating distilleries is probably easier (and more accurate) than trying to do a theoretical cost calculation that needs to take into account way too many variables.

[Huffy2k]

I have a 300 gallon setup, natural gas boiler (1 million btu) with basically the same production scheduler hedgebird described. His $450 estimate is pretty accurate. Some months higher, some lower but on average, that's a pretty good budgeting number

[AC-DC]

Great to get real world examples!  Thanks for sharing.   Another good resource for understanding and calculating has been the book (on amazon)

Distillery Operations:how to run a small distillery by Payton Fireman.

 

Its a dense read, but covers a whole host of calculations and corrections for efficeincy and losses (many you will have to guess at )

Distillery Operations: How to Run a Small Distillery

 

by Peyton Fireman( I think)

 

It breaks down a phenomenal number of calculations and explains how to get there.  A VERY DENSE READ.  Make sure you account for efficiency ratings and losses.

 

Edited December 31, 2016 by AC-DC
Dropped text

[Silk City Distillers]

Big difference between propane and natural gas.

At $5 an MCF and $0.64 per liter of propane, the cost to run on propane is about 6x higher.  So that $450 month on nat gas would be $2,700 on propane (at the prices above).

Maybe my math is wrong.

 

[3d0g]

Typically, NG < Propane < Electric

Since Propane is refined and therefore tied to crude prices, it has in the past exceeded the cost of Electric.