Wood Fuels Guide: Biomass Pellets, Briquettes & Logs Compared
For their sustainability, clean burn, cost effectiveness and convenience, wood fuels have soared in popularity recently — both for households and businesses!
But you might have a few burning questions about these relatively newfangled sources of energy.
How are wood pellets and briquettes made? What can they be used for? How much do they cost? How do they compare to each other and traditional types of wood fuel, like firewood logs?
As leading BSL-authorised suppliers of ENPlus A1-certified wood pellets and quality briquettes, allow our team of wood fuel experts to answer all.
What are wood fuels?
‘Wood fuel’ is a catch-all term that can refer to wood burned for energy and heating purposes. Examples include logs, firewood, charcoal, wood chips, sawdust, pellets and briquettes.
There are direct and indirect fuels: direct wood fuels come straight from the forest or are extracted from wooded areas for energy purposes; indirect wood fuels are created from waste streams from wood processing activities.
Classed as a ‘biofuel’, wood fuels differ from fossil fuels in that they are made from biomass that renews itself over a relatively short period of time, rather than the far longer processes involved with the creation of fuels like crude oil. As long as we harvest and consume them responsibly, they will never run out.
Whilst the use of wood fuels is thousands of years old, it’s only relatively recently that its use as a biomass fuel alternative has soared. Recent advancements in the wood energy sector has allowed the development of innovative new products (such as pellets and briquettes) that have higher performance than traditional types of wood fuel.
In fact, wood fuels have been a mainstay of the energy mix of many Scandinavian countries since the 1980s, particularly in Sweden. Now, they’re gaining traction across the world as an efficient, cost effective, renewable and environmentally-friendly alternative to fossil fuels.
Wood fuels advantages and disadvantages
As households, businesses and governments seek to reduce their reliance on nonrenewable fossil fuels (and reduce their energy prices!), bioenergy sources like wood fuel are in.
- Sustainability: Trees can be replanted, which means when the parent material is sourced from a sustainably managed forest, wood fuels are the ultimate environmentally friendly, low carbon, renewable energy source.
- Cost: Wood fuels have favourable setup and ongoing costs, especially compared to fossil fuels — particularly with the recent increases in gas and electric prices for households and businesses in the UK.
- Accessibility: Whether that’s firewood or the pellets and briquettes, wood fuels are increasingly available to buy.
Possible downsides to wood fuels can relate to the convenience and, depending on practices, environmental impact.
- Convenience: With systems requiring refilling, wood fuel can represent a slight inconvenience. Some types of firewood can also vary in size, making storage awkward. Proper storage can be important, particularly with briquettes that are very sensitive to moisture.
- Environment: If the wood fuel is sourced from woodland that isn’t managed sustainably, the use of wood fuels can contribute to deforestation. Be sure to buy your wood fuels from a merchant with a clear environmental commitment (like us!).
Biomass wood pellets
- Popular uses for wood pellets: Home pellet stoves, automated pellet central heating systems, industrial boilers, fireplaces (with basket), power plants and even as cat litter and horse bedding.
- Calorific value: 4.85kWh/kg
- Moisture content: 5–10%
Wood pellets are small, cylindrical objects made from compacted leftover timber, sawdust and other lumber-related byproduct waste. This timber biomass is compressed to provide a low-carbon, green source of energy — a great alternative to fossil fuels.
As well as coming from 100% renewable sources, wood pellets are 100% natural, containing no chemicals or additives.
One of the most traditional forms of wood fuel, the pellets’ small, uniform shape and size means they pack in some real density. They also have a very ‘predictable’ size, making them simple to handle — excellent for transportation and storage.
Wood pellets have a very consistent ‘calorific value’ of around 4.85kWh/kg, meaning that a kilo delivers 4.85 kilowatt hours of heat energy. This compares favourably with firewood, whose calorific value is typically lower and more inconsistent.
The waste materials used to create wood pellets are heavily dried and compressed during manufacture, providing a product with very low moisture content, typically in the 5–10% region. Compared to the parent material, this is around 50% lower. Kiln-dried firewood logs usually have an average moisture content of 20%.
High moisture content in wood fuel is bad news; when moist wood is burned, not only does it provide less heat, but it creates a heavy smoke that condensates causing a build up of tar and leaving acidic residues.
Whether for domestic or commercial premises, a biomass wood pellet boiler can be a cost-effective alternative to the increasingly eye-watering costs associated with traditional gas systems. Did you know that our entire offices are heated with biomass fuel?
Although they require electricity, occasional maintenance and can sometimes come with a bit of extra noise, these systems have everything associated with a traditional heating system, including temperature controls.
Did you know that wood pellets can be used on an open fireplace as long as you use a specially-designed basket or tray?
Biomass wood briquettes
- Popular uses for wood briquettes: A firewood alternative for wood burning stoves, open fireplaces and chimineas.
- Calorific value: 4.85kWh/kg
- Moisture content: 6–10%
Briquettes, like pellets, are a type of indirect wood fuel, made up of compressed waste from timber machining and sawmill operations. These byproducts are compacted using an industrial pressing rod — much in the same way as pellets.
Whereas pellets are bullet-sized, briquettes are slightly larger — around 25cm x 7.5cm — and weigh around 1–2 kg each. They are exceptionally energy dense compared to firewood, offering a hotter, longer and cleaner burn. They also boast a more consistent, convenient shape and size.
High quality briquettes are dried and compacted to a moisture content of around 6–10%, with a typical calorific value in the region of 4.9kWh/kg, so essentially identical to pellets (and certainly superior and more consistent than ordinary firewood). All of this means they burn hotter, cleaner and for longer.
That said, briquettes can be very sensitive to moisture in the surrounding environment and should ideally be kept in their packaging until being used. If taken out, ensure the environment is exceptionally dry and well ventilated.
Wood pellets and briquettes vs. logs: how do they compare?
Kiln-dried firewood logs are the least processed form of wood fuel. As a result, they are often more widely available and can be cheaper; they can also be less fussy to store. They’re generally more intuitive than pellets.
But choosing logs based on face value cost can be a false economy.
Pellets and briquettes are typically drier and more energy dense than regular logs, packing in higher calorific value. They burn hotter and for longer: the energy equivalent of logs in briquettes and pellets will take up much less space. Because of the more convenient and predictable shape and size of wood pellets and briquettes compared to regular firewood, they can be easier to transport and store.
A lack of consistency when it comes to size, species and moisture content makes it difficult to draw clear, concrete comparisons between the performance of firewood, pellets and briquettes. A quality kiln-dried log will usually have a moisture content of 20–25% on the outside, with 10–15% on the inside (providing an average of around 20%). On the other hand, pellets and briquettes sit in the sub-10% region.
As mentioned earlier, higher moisture levels result in heavy smoke when burned, causing a build up of chimney and flue-damaging residues. Woods that are dried to a low moisture level burn more cleanly.
Of course, logs or briquettes are not suitable for wood pellet heating systems, so this section is mainly to compare the merits of these wood fuels when used in a stove, fireplace or log burner.
Wood pellets and briquettes prices
When you’re buying your wood fuel, look out for the ENplus A1 quality assurance certification, ideally from a Biomass Suppliers List (BSL) accredited supplier — like ourselves! Just get in touch to begin your enquiry.
- Pellets: 65 x 15kg bags — £560.00 inc VAT
- Briquettes: 1 pallet of 98 packs (6 briquettes per pack; 588 per pallet) — £425.00 inc VAT
ENplus is ‘a world-leading, transparent and independent certification scheme for wood pellets’ that aims to combat fraud and guarantee quality in the supply chain. Their A1 certification is the best guarantee and assurance of premium-quality pellets that you can get.
Our products are compliant with the Clean Air Act and carry ‘Ready to Burn’ approval. You can buy and collect from us (we’re based near Ripon, North Yorkshire), or we can deliver them directly to you, wherever you are in the UK!
Didn’t get the answer you needed from this article?
As a leading BSL-authorised supplier of ENplus A1-certified wood fuels, our team should be able to help with any other questions!
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