New sawmill - electric or diesel?

[stanmillnc]

Like so many others, I ordered a new sawmill in April - WM LT50 with all the bells and whistles. I ordered the diesel engine, but have since been doing a lot of thinking about this, as it's an expensive $11K upgrade, plus the Sales tax. I've got 3-phase power at my sawmill site, so I'm thinking about changing my order to the electric motor. Not only will it save $, but it would probably be quieter and less maintenance long-term? 

A couple questions for those who have experience with electric mills: it appears the only option from WM is 25hp - is this enough? I mill mostly hardwood and a lot of wide slabs, so I don't want to be underpowered with big hardwood logs.  I currently have the 38hp Kohler on my LT40 and it does just fine with everything I throw at it, but I wouldn't want to take a step back. I am considering sticking with this motor option as well, as I really only ordered the diesel because it seems that's what all the big boys have!

Obviously I won't ever be portable with an electric motor; but that hasn't been my business model, so no concern there, except for the flexibility of having this option in the future. What other pros / cons are there with the electric motor? HP is my main concern, but maybe there are other things I haven't considered? Thanks

[longtime lurker]

If the plan is to stay stationary in a shed with 3 phase power and you don't go electric you've got rocks in your head. 

But resale might be harder, and if you need to go portable you'd need to drag a generator along.

Rule of thumb is 1 electric HP  = 2.25  diesel HP.

[Southside]

I ran a Super 40 with the 25HP electric on it for a guy - was no slouch.

[moodnacreek]

3 phase 25 hp will surprise you if you have been using internal combustion.

[muggs]

I think you will be money ahead with fuel costs alone if you go electric. The diesel costs $25000 more.Wow

[muggs]

I meant to say $11000. Have not had my coffee yet. But still wow.

[stavebuyer]

I had both a 55HP Yanmar and 25hp 3 phase LT70s.

You could push the diesel a little more. As mentioned, re-sale is limited on 3 phase equipment.

Your electric company and how they bill is a huge factor. In our case just to have the 3 phase drop active was about 1k per month. If your sawing M-F 40 hours no problem to justify, part time might outweigh buying the diesel fuel.

3 Phase and part time often means 3 phase converter set-up, them your only downside is portability and resale.

[sealark37]

Before you commit to electric, you need to get a quote from Duke Energy for the 3-phase connection.  Their charge for hook-up and monthly minimum is exorbitant.

[PC-Urban-Sawyer]

OP said he already had 3PH electric at the site where mill will be set up, so should not have setup/connect charges from electric utility.

[ladylake]

 
  
If you dont saw a lot the monthly minimum could be a killer, if your running 8 hours a day no big deal.  Steve

[esteadle]

A lot of electric utilities will give you a break when you start using larger amounts of power. If you are a commercial or industrial customer, you get put into a demand bucket or a "schedule", and the utility can use your usage patterns to pre-purchase and schedule power from the suppliers, which makes their job easier. My utility did this and I thought they were pulling something funny when they informed and then switched me over to this, but it ended up costing me less, and saving me money.

Diesel is not getting cheaper. Electricity can be supplied by the sun and the wind these days. Free energy is a lot cheaper than any fossil fuel. We installed a 4.5kw solar w/ 9kw battery backup on the house this summer. I laughed at my electric bills each time they came. $25.26; $43.55, and 35.02 for the 3 hottest months of the year running AC at full blast. Those would have been $150-$180 if not more. That's in Pittsburgh, PA, not Athens GA or anywhere south. When I can get an electric car, I will drive for free. And when I get an electric sawmill, I will saw for free too.

[muggs]

A 25 hp 1750 rpm electric motor will put out 75 ft. lb of torque. You can compare that to an IC engine.

[stanmillnc]

Thanks for all the responses. For clarification, I just had 3-phase power run to my shop by the power company and it's cost me nothing thus-far. I was under the impression that there wouldn't be a monthly service charge, beyond the usage (I did email Duke Power to confirm this). I gave them my 3-phase equipment list to size the service line appropriately and they told me that they would evaluate my usage over the next 2-3 years and adjust my rate accordingly after that. Sounds great thus-far and hoping for no surprises, but now you guys have got me somewhat concerned. 

Anyway, it seems like I've got rocks in my head  if I don't go electric, but then again I have to weigh not ever being able to go mobile in the future. And the resale value is another consideration; not that I think I'd want to sell anytime soon, but then again this will be my fourth sawmill!

[customsawyer]

I don't have a electric mill but sure wish that I did. You are not just talking about fuel cost savings. You are also talking about much less in maintenance cost. I switched my edger from diesel to electric back in 2012. My electric bill went up about $60.00/month. Or about two days worth of diesel for the previous edger. I never had to change the oil, filters, starter, battery, or check the antifreeze. In the 10 years there was 2 times that we lost power and I had to shut down.
I have looked into putting an electric motor on my mills and the only reason I haven't is they don't have a auto clutch for the LT70s with electric motors. When you are production sawing that would be fine. When you are doing some quarter sawing or some such as that, where you are going up and measuring the log or something similar, you would either have to turn the motor off or be loosing band life. Check with WM and see if there is a clutch on the electric mill you are getting.

[muggs]

Out of curiosity Custom sawyer. What was the hp of the diesel and what was the size of the electric motor? How did the two compare, powerwise?

[CCCLLC]

Added  benefit of just hearing the saws in the cut working. Tells a lot foreseeing changes and cutting straight. Wish I could hear something other than 35 hp diesel while cutting. 

[longtime lurker]

Another point that favours electric is integration, and it's maybe the biggest benefit of all. Want to put in an edger, there's plenty out there with electric motors driving them. Docking saws, transfers, waste belts, resaws, moulders, compressors, chippers, debarkers, auto stackers if you're that keen... all available as reasonably priced good second hand units but always three phase.

A few gallons of diesel a day for one lil saw should be neither here nor there in your business although it is a cumulative saving. But a decent 3 phase power connection is a prerequisite to efficient sawmill operation and until you get it it's like one hand being tied behind your back, you can operate without it but going forward is twice as hard as it could be.

[customsawyer]

The one edger had a 34hp Perkins. The replacement had a 20hp electric. It was considerably  stronger than the diesel. When you start maxing out a diesel things start to slow down a little. When you start maxing out an electric it just draws more amps. The WM edger I had came with a 15hp electric and it did fine. It was only rated for up to 2" material. Where the Cooks with the 20hp electric was rated up to 3" material, thus the extra hp. I now have a Baker with a 20hp electric. 

[muggs]

Thanks for the info. Customsawyer.

[Dave Shepard]

The 25hp electric motor Wood-Mizer uses is specially built for them. It has a heavy flywheel under that end cover. I was told that you can pull 70 horse from it for short periods, which is why they want a 55kva genset for an 18.6 kw rated motor. 

[longtime lurker]

That's actually a really interesting way of getting there and I wonder how effective it is.

My resaw runs a 45 Hp motor but the wheels probably weigh close on a half ton each so there's a lot of stored momentum in them. It's really only there to give time to slow the feed/for the motor to pull more power. I've heard of circle saws set up with a flywheel on the shaft too, but never seen one; guess that went out with lineshaft power.

I love those old fashioned engineering solutions like flywheels, seems way more sensible than a huge motor with whopping great soft starts just to handle the occasional peak loading.