Electric boiler vs Gas

[BuffaloBink]

Can anyone offer any comparison information as to the efficiency and/or the operating costs of Electric vs. Gas boilers?

The electric boiler quotes we have are substantially less, but we are wondering if the lower initial cost makes sense in the long run.

Any help is appreciated!

[Mechengineer_81]

Following.

I have not personally ran either but everything I have read leads to saying Electric is cheaper capital wise but the heat up times are a lot greater due to the heat transfer being less with a liquid to liquid convection vs using the latent heat of steams phase change to water.

What size range stills are you looking at?

 

[BuffaloBink]

We will be running a 400g double retort.

Only the main pot heated with steam and the retorts off parasitic heat from the main.

We are leasing so capital and impact to the space are always a consideration.

 

[Kindred Spirits]

Just to be clear you are talking about electric or gas steam boilers, or are you talking about the boiler on the still? 

If you are talking about heating for the boiler on the still, 400 Gallons is a lot of liquid to bring up to temperature using heating elements. What are your rated KW numbers for your heating elements? How large is your electric service?

[BuffaloBink]

Electric steam boilers vs gas steam boilers.

[Mechengineer_81]

sorry I took that as electric vs gas to heat the boiler not electric vs gas boilers to produce steam. ignore my comment on heat up time.

That question is more simple economics. what is your gas supply cost and electricity cost? then get a quote for both an electric and gas boiler of suitable size and look at the overall operating cost with the capital cost amortized across their life span. dont forget to include install costs and air permit costs for gas if applicable in your area.

 

[BuffaloBink]

Roger that! And thanks!

Easy enough to run the numbers but real life experience is sometimes a different story. Looking for first hand knowledge from anyone who’s run both. 

[Golden Beaver Distillery]

@BuffaloBinkyou also need to look at natural gas vs propane. Natural gas is a greenhouse gas, where as, propane is not. You also get more BTUs from propane vs natural gas.

We run 700g stripping pot still, 300g pot still and 400g mash tun - 2 cooks and a strip everyday and every second day we add a finishing run.  Using a 25hp boiler we generate a $900 bill for our propane each month.  

Remember, we're in CA so I assume our propane cost is higher than anywhere else in the nation...

[BuffaloBink]

Good thought Beaver but in good old NYS I think we have you by 9¢. 

[Skaalvenn]

MN here.

Have not run an electric boiler, but we used to have 2x electric stills. A ~130 gallon and a ~65 gallon.

Our electric bills dropped by about $700 per month by going to natural gas fired steam boiler.  I think our most expensive natural gas bill has been $130?  That's with a 300 gallon and 100 gallon still.

I don't know our unit cost of natural gas, because really, it's a drop in the bucket.  For electric during summer months we're about $0.14 or $0.15/KwH out the door after all taxes/fees.  I think in winter we're about $0.11?

I've said it before and I'll say it now.  The initial costs for electric were relatively inexpensive, but the UPGRADE costs for electric were $$$$$$.

 

Another plus about upgrading to steam is that I now 600 hundred amps of electrical panels with plenty of room for other equipment =D

[Southernhighlander]

Buffalobink

For a 1 hr heat up to operating temp. time you will need 400,000 btus of low pressure steam boiler output. That is a huge electrical draw.  You would need 3 phase power and plenty of it, preferably 480v.  Generally for those reasons people almost always use natural gas or propane boilers on stills as large as yours.  In fact, in some situations the power company will not connect you because the electrical draw from starting a boiler that large can cause what's called lamp flicker, meaning you will dim the lights of your neighbors when you start the boiler.    Normally nat. gas and propane cost a lot less than electric to operate.  Over the last few months propane and natural gas have been more expensive than they have been for years but projections show that could change dramatically in a year or so.  I would go with nat gas or propane.  It's just as safe and it will cost you a lot less in the long run. 

Also keep in mind that you only want to put a boiler in once.  So if you are planning to add a 400 gallon mash tun or other equipment down the road, you will need 800,000 BTUs of low pressure steam boiler output for the still and mash tun, which is way beyond the capacity of most electric boilers and you had better have industrial power if you do that with an electric boiler of that size.  Most inexpensive electric boilers do not have a capacity to run your still let alone additional equipment.

200,000 BTUs of low pressure steam boiler output will give you a 2 hour heat up time with just your 400 gallon still.  Stripping runs would take longer and you would have to add a larger boiler or an additional boiler to have enough capacity to add a mash tun etc.

 

My advice would be for you to get yourself a good nat gas or propane boiler with some extra capacity so that you can expand your operation down the road.  That's certainly what I would do if I were in your shoes.  Also, avoid cheap knock down boilers of any kind.  They come unassembled and cost a lot to have someone put them together.

[BuffaloBink]

On 1/21/2022 at 12:15 PM, Southernhighlander said:

My advice would be for you to get yourself a good nat gas or propane boiler with some extra capacity so that you can expand your operation down the road.  That's certainly what I would do if I were in your shoes.  Also, avoid cheap knock down boilers of any kind.  They come unassembled and cost a lot to have someone put them together.

Highlander,

Than you! Natural gas is it. Electric just seemed to good to be true.

[Alex_Sor]

On 1/21/2022 at 7:15 PM, Southernhighlander said:

My advice would be for you to get yourself a good nat gas or propane boiler with some extra capacity so that you can expand your operation down the road.  That's certainly what I would do if I were in your shoes.

Completely agree with you!

High power electric heating is very convenient but requires a special inclusion in the power company. And natural gas is like pouring gasoline into a car tank It's simple and fast, and does not require special reinforcement of wires for many kilometers from you to a powerful current source.

[Mechengineer_81]

also educate yourself on the difference between steam generators and steam boilers. There are many different types out there and all have pluses and minuses based on your particular setup. Most cheap "boilers" are actually steam generators and not true boilers. 

I would also add, if it is not cost prohibitive 150PSIG steam is a lot nicer  than 15PSIG as far as having a good dry steam. 15PSIG helps save costs on vessels but adds a lot of intricacies as far as condensate return systems and possibilities of flooding jackets. if you have a scenario where you have to have your boiler a decent distance from use points, lots of independent loads or a lot of elevation change, the higher pressure can really help as well. 

In my previous life I did a lot of steam utility pipe design and calculation and 15PSIG systems were always the most finicky vs the bigger 150 PSIG systems we installed.  Armstrong and Spirax Sarco have some good installation guideline books out there that have alot of good steam information if you are the type that likes to read up and learn.

I personally really like The Hook Up Book:

https://www.spiraxsarco.com/global/en-US/steam-expertise/the-hook-up-book

lots of good info in there to help understand steam.

[Southernhighlander]

On 1/24/2022 at 12:03 PM, Mechengineer_81 said:

 

I would also add, if it is not cost prohibitive 150PSIG steam is a lot nicer  than 15PSIG as far as having a good dry steam. 15PSIG helps save costs on vessels but adds a lot of intricacies as far as condensate return systems and possibilities of flooding jackets. if you have a scenario where you have to have your boiler a decent distance from use points, lots of independent loads or a lot of elevation change, the higher pressure can really help as well. 

 

Mecheenginer_81,

In many situations higher pressure boilers are the way to go for the reasons you give, however that is not the case with craft distilleries for the reasons I give below.

No distillery equipment manufacturer that I know of builds pot stills that operate on high pressure steam.  In fact everyone I know builds their jacketed pot stills to operate at less than 15psi.  We have around 500 of our stills in distilleries ranging in size up to 2,500 gallons and they all operate at less than 15 PSI.  

State and municipal requirements for high pressure steam boilers are more stringent and in many cases a full time certified boiler operator is required by law.

For these reasons and others I always steer my customers away from high pressure boilers.  Of course my pots can be ran with high pressure boilers as long as a pressure reducer is in place.

In my opinion a high pressure boiler does not gain you anything if you cannot find stills that will operate on high pressure steam.

I have sold over 80 Rite low pressure steam boilers to the distilleries that run my equipment and they all work great with no issues that I know of.

 

 

[Mechengineer_81]

Yeah if there are no stills available with jackets ASME rated for high above 15PSI steam that really negates the benefits. I figured stills would follow a similar pattern of using low pressure for smaller units then switching to higher pressures in larger units like you find in tube and shell HX and brewhouses. usually there becomes a point where the reduction of heat transfer area due to the higher pressure steam outweighs the cost of the pressure vessel certification and rating.

As for the boiler operator requirement, I have seen cases where steam generators help skirt that rule as well and don't fall under the typical "Boiler" regulations. There are also water tube steam generators that can further reduce your classification s a "Boiler" in some jurisdictions.