DIY Wood Pellets – Is It Worth the Effort?

You’ve probably seen YouTube videos on pellet mill machines and people making their own wood pellets. It sounds like a great idea, especially with inflation driving up the price on everything up, including wood pellets. Who wouldn’t want to make their own wood pellets and save a bunch of money, right? Sadly, making your own pellets is much harder than it looks. It’s not impossible and some people really do make their own pellets but it’s definitely not as easy and cost effective as you may think and what pellet mill sellers want you to believe.

The short version is don’t try and make your own wood pellets. It’s much easier and I think cheaper to buy wood pellets. Making your own pellets requires thousands of dollars in equipment and it’s not as simple as it looks. You don’t just tip sawdust into a machine and wood pellets pop out the otherwise like magic. Also, it is a lot more labour intensive and if you value your time then there’s very little reward using it to try and make pellets yourself.

Overview of Making Wood Pellets

It sounds and looks easy on YouTube videos. However, here’s the lowdown on all the steps required if you want to make your own wood pellets for heating:

  1. Get some raw wood material, usually sawdust, and get a lot of it, at least a few tonnes.
  2. Screen the wood material removing rocks, metal and any other objects which won’t burn.
  3. Crush the filtered wood material down so it is small enough to go through a pellet mill.
  4. Dry the wood material to remove excessive moisture content.
  5. Feed the wood material through the pellet mill to make pellets.
  6. Cool the freshly made wood pellets as they are super hot after being made.
  7. Store the wood pellets somewhere or bag them for future use.

Raw Wood Material

First, you’ll need wood material to turn into wood pellets. Most people use sawdust of from a timber mill or something similar. Whatever you use, you’ll need several tonnes of it. We’re talking cubic metre upon cubic metre of sawdust here. Most people burn 60 to 100 bags of wood pellets a year in Tasmania, and considering you’ll probably waste some material in the process of making pellets, I think it is safe to say you’d need at least 2 tonne of wood waste. If you want to make more than a year’s supply, then you are going to need even more sawdust.

How are you going to get so much of that wood material back home or to where you are making the pellets? How are you going to transport it? You may have to pay for delivery if you don’t have a suitable vehicle. You could do it with a ute and trailer but that would require several trips. Also, how much is the wood material going to cost you? If you can get it for free, that’s great but many saw mills now understand sawdust can be turned into pellets and understand the value of it. They no longer just give it away for free. So you’ve got the cost of the sawdust and then possibly cost of transport.

Once you get the sawdust or waste wood material home you will need a place to store it. If you leave sawdust out in the rain, it will become saturated with water and have an even higher moisture content. That extra moisture content will require even more time heating and drying when you turn it into pellets, so wet sawdust will cost you extra money later in heating costs when drying it. If you can store the sawdust in a shed or somewhere dry, you will still need considerable space to store potentially several tonnes of the material before you process it.

Screening the Wood Material

Before you can turn sawdust or any other wood waste material into wood pellets you need to screen it. There’s probably going to be rocks and other foreign objects, like nails, in the sawdust that will jam up the pellet mill or cause problems when burning in a pellet heater. This is an important step because rocks in sawdust going through a pellet mill machine will potentially cost you thousands of dollars in damage or hours spent trying to repair it. Burning wood pellets that contain rocks or other junk in any type of pellet heater, including expensive European heaters like Piazzetta pellet heaters, will cause problems just like it would in Chinese made heaters sold by Pellet Fires Tasmania.

Now it’s possible the sawdust you have is clean, especially if it’s come from a saw mill, but not screening the material opens up potential problems, as mentioned above. So you’ll probably have to buy some kind of screening setup which could cost thousands of dollars or you could make your own but it would require hours upon hours to screen sawdust by hand. Again, this adds to the cost of making pellets yourself, in addition to the cost of transporting the sawdust back home and storing it somewhere.

Crushing the Wood Material

In addition to screen wood waste you may also need to crush it down in size. Even sawdust could have pieces of wood in it that are too large to go through a pellet mill. Pellet mills usually press pellets that are 6mm in diameter. This means any wood material that you feed into the pellet mill needs to be smaller than 6mm in size. The finer you crush the material, the better, but again this means you’ll have to spend money on to crush the material down to size.

Hammer mills, which are used to break material such as wood waste down to the right size, can cost hundreds to thousands of dollars. The more you spend the bigger, better and faster they’ll be at processing and crushing waste material down. Don’t forget you’ll need to feed the sawdust or other wood waste in as it is being crushed, so that means either by hand or a conveyor belt. Potentially an added cost for a conveyor belt if you don’t already have one. Obviously hammer mills with conveyor belts cost much more and take up more space but do make the process much easier.

Drying the Wood Material

Once screened and crushed you’ll need to dry the wood material. Wood waste used to make wood pellets needs to be around 10% to 14% moisture content. Sawdust can be anywhere from 50% to 60% in moisture content. It may be higher if it has been sitting outside in the rain for an extended period of time. The higher the moisture content in sawdust, the more you will have to dry it. Drying is not free and you’ll spend more time and money drying sawdust that is higher in moisture content.

Again, this adds to the cost of making pellets because you’ll need some kind of rotary dryer or something that slowly dries the sawdust or other wood material and brings the moisture content down. So you’ll need to pay for the rotary dryer and then pay for the heat. Most pellet mills burn wood pellets but it’s still a cost because those wood pellets could have been used for heating your house instead. Also, you have to be careful and not over dry sawdust. If it is too dry, then the pellets won’t “stick” together when being made and they’ll just crumble. Drying sawdust is both time intensive and costly.

Making the Wood Pellets

Finally, you are ready to make pellets. There are many different types of pellet mills, and most likely you have been looking at the smaller ones that go up to about 7kw in power. They come in three kinds: electric, diesel and PTO drive such as by a tractor. No matter which type you pick, they all need to be powered by something and that means you’ll be paying for diesel or electricity. If you get a PTO model then you’ll need a tractor to drive it, another added cost if you don’t already have one.

Next, you’ll have to feed the wood material in while making pellets. This means either by hand or another conveyor belt, more cost. However, you can’t just switch a pellet mill on and start making pellets straight away. Pellet mill dies need to be “warmed up” so the die or metal press in them is hot enough to make pellets. This usually takes half an hour or so. Once warmed up and ready to go you’ll then need to feed the sawdust in. You can do this yourself but that means instead of paying with money you are paying with “time”.

Finally, maintenance. Pellet mills need to be looked after and maintained. After you have finished running sawdust through a pellet mill you’ll need to run some material through that is oily/greased up to keep the holes in the die from blocking up. Just switching off a pellet mill and not “cleaning” it means the die holes will block up as waste wood material left inside hardens. As the mills are mechanical you’ll also need to replace parts and just look after and troubleshoot them if you have problems. Hopefully you can see pellet mills aren’t switch on, make some pellets, switch off and wait until next time. There’s a lot of prep and ongoing maintenance required.

Cooling Freshly Made Pellets

Conragulations! You finally made some wood pellets. All good right? Wrong. Wood pellets that come out of a pellet mill are burning hot. They’ve just been compressed down and thus are still very warm. These freshly made pellets need to cool down and if you put them straight into a plastic bag or some other container they’d burn holes through it. This means you’ll need to store them somewhere. You could store them on the floor or somewhere similar but if you are making a lot of pellets you’ll need some kind of cooling racks or similar setup.

So, this means more cost. You’ll probably need to buy or make some drying racks. Even if you do have material that you could use to make the racks, it’s still going to cost you time. Also, you need to get the pellets from the pellet mill to the racks. Most factories do this using conveyor belts but if you don’t have one and don’t want to buy one then it’ll mean dumping them on the ground or in some container that won’t burn and then doing it by hand. Again, more money, time or possibly both.

Storing Wood Pellets

Once cooled down you’ll need to store the pellets somewhere. This could be in drums, containers, plastic bags or bulka bags. Whatever or however you store them will mean you’ll need to move the pellets around. So another conveyor belt or more labour. There are automatic bagging machines that put wood pellets into bags but they are VERY expensive and most people couldn’t afford them. However, it’s something else to keep in mind if you are thinking of making your own wood pellets.

Summary of Making Your Own Wood Pellets

Don’t get me wrong. I love the idea of making and burning my own wood pellets. I think it would be fun. I love tinkering with stuff and learning how to do new things. However, there’s a lot more to making your own wood pellets than retailers want you to believe. You’ll need a lot of machinery which will cost at least $10,000 and up if you want to get everything you need. You’ll need a lot of space to store the sawdust or other material. You’ll need a lot of time and manual labour to run everything.

Hopefully you can see I don’t recommend you try and make your own wood pellets, unless you already have the machinery or are happy to spend the money and have the space and can get or have free sawdust. Also, there’s nothing wrong with making your own wood pellets if you don’t care what it costs and just want to do it for fun. The truth is if I had deep enough pockets I’d buy all the machinery and try to make my own but I don’t 🙂 Happy heating!