Wood Pellet vs Wood Chip Boilers: Which Biomass Fuel Is Right for You?
As sustainability and energy efficiency become top priorities across New Zealand’s commercial and industrial sectors, more businesses are considering biomass heating systems. Among the most common options are wood pellet and wood chip boilers both offering renewable heating solutions that can significantly reduce carbon emissions and operational costs.
But how do these two systems differ, and which one is better suited to your needs? In this article, we’ll explore the key differences between wood pellet and wood chip boilers, from fuel type and system complexity to cost and efficiency, so you can make an informed decision for your facility.
The Biomass Basics
Wood Pellet
Wood pellets are small, uniform, cylindrical pellets made from compressed sawdust or other wood waste. Because of their consistency and dryness, they are ideal for automated feed systems and provide a stable, clean burn.
Wood Chip
Wood chips are larger, irregular pieces made from forest residues or timber offcuts. While they are less refined than pellets, they are often more affordable and suitable for larger installations with space for bulk storage and handling equipment.
Key Differences – Wood Chips vs Wood Pellets
| Feature | Wood Chip | Wood Pellet |
| Processing | Minimal processing is required as the wood is chipped and dried | Highly processed, as the wood shavings and wood dust are compressed into uniform pellets |
| Moisture Content | Higher total moisture content ranging between 20% – 50% | Lower total moisture content of below 10% |
| Energy Density | The typical energy density range is between 8 and 12 MJ/kg | The typical energy density is at minimum 16.5 MJ/kg |
| Storage Requirements | Requires large bulk storage with ventilation | Compact storage, often in bags or silos. Waterproof storage required |
| Combustion Efficiency | Requires larger boilers with controlled air supply | Burns efficiently in automated biomass systems |
| Application | Used in commercial and industrial boilers, district heating, and large-scale systems | Ideal for residential heating, commercial boilers, and automated systems |
Fuel Handling & System Complexity
Pellets:
Pellet boilers typically use an auger feed system and require less manual intervention. Their uniform size and moisture content mean they’re easy to store, feed, and burn, making them a popular choice for commercial premises with limited staff or tight space.
Chips:
Wood chip systems tend to be bulkier and require more robust feed mechanisms, such as moving floors or hydraulic rakes. While they can handle larger fuel volumes, they also require more space for storage and a more involved maintenance routine.
Summary:
Fuel Handling & System Complexity
| Feature | Wood Chip | Wood Pellet |
| Storage Space | Requires larger, bulky storage with ventilation to prevent moisture buildup. | Compact storage, and must be sealed in bags or silos to prevent moisture accumulation. |
| Delivery Method | Typically delivered by tipping trucks or conveyor systems. | Typically delivered by bulk bags, tipping trucks, blown through pipes, or conveyor systems. |
| Fuel Feeding System | Automated mechanical augers or conveyors are used to transport chips to the boiler. | Compatible with automated feed systems, ensuring consistent fuel flow. |
| Handling Equipment | Requires specialised loaders, conveyors, and often a drying system. | Can be manually handled or fed into automated systems |
| Dust & Cleanliness | Generates more dust and debris. | Minimal dust, making it cleaner to store. |
Wood chips require bulk storage and mechanical handling, making them ideal for large-scale heating systems. Wood pellets, on the other hand, offer easier handling, automated feeding, and cleaner storage, making them better suited for residential and commercial applications.
Cost: Fuel & Installation
Pellets:
Because of the heavy processing requirements, pellets are generally more expensive per tonne than chips. However, their high energy density and consistent burn can offset some of the additional cost, especially in smaller operations.
Chips:
Chips are usually cheaper to produce and source, particularly in regions close to forestry operations. For large-scale users with access to cheap or on-site chip supply, this can translate to significant long-term savings.
Summary
| Feature | Wood Chip | Wood Pellet |
| Average Cost ($/ton) | Lower, typically $60-$235 per ton | Higher, around $296-$425 per ton |
| Energy Density (MJ/kg) | The typical energy density range is between 8 and 12 MJ/kg. | The typical energy density is at minimum 16.5 MJ/kg. |
| Cost per kWh | Lower, but requires more fuel volume. Typically between 3/kWh and 11c/kWh | Higher, but more efficient per unit. Typically between 9c/kWh and 13c/kWh |
Wood chips are cheaper per ton, making them ideal for large-scale heating, while wood pellets offer higher efficiency and ease of handling, making them better suited for residential and light commercial applications.
Efficiency & Emissions
Pellets:
Pellet boilers are known for their high efficiency and low emissions, due to the consistent size and low moisture of the fuel. They’re ideal for operations aiming to meet strict emissions regulations or achieve carbon reduction goals.
Chips:
Chips can vary in size and moisture, which can affect combustion quality. However, modern chip boilers with advanced combustion controls have narrowed the efficiency gap considerably. Along with secondary cyclone systems, the emissions particulates are reduced and controlled to meet strict emissions regulations.
Summary:
Feature | Wood Chips | Wood Pellets |
Combustion Efficiency | Lower combustion efficiency, ranging between 80% – 90%, depending on fuel moisture and boiler combustion system design. | Higher combustion efficiency ranging between 85% – 92% due to low moisture content and boiler combustion system design. |
CO₂ Emissions | Higher per unit of energy due to incomplete combustion, dependent of the moisture content. Wood chips emit approximately 5 kg CO2 per MWh, making them slightly lower in emissions. | Lower per unit of energy due to efficient burning. Wood pellets emit approximately 7 kg CO2 per MWh when considering the full lifecycle, including processing and combustion. |
Particulate Emissions | More ash and particulates require emissions filtration. Solid particle emissions can be reduced up to 150 mg/m³ by making use of advanced cyclone separators. | Less ash and particulates, cleaner combustion, and often require emission filtration. Solid particle emissions can be reduced up to 150 mg/m³ by making use of advanced cyclone separators. |
Wood pellets offer higher efficiency, lower emissions, making them ideal for automated residential and light commercial biomass systems. Wood chips, while cheaper, require larger boilers and better air control to optimise combustion.
Which Boiler Is Best for Your Business?
Choosing between wood chips and wood pellets depends on your heating system, budget, and fuel handling preferences. Here’s a breakdown of the best applications for each:
Needs | Best Choice | Reason |
Large-Scale Industrial Heating (Factories, District Heating Systems) | Wood Chips | Lower cost per kWh, locally available, suitable for bulk combustion systems. |
Small to Medium Commercial Heating (Hotels, Office Buildings) | Wood Pellets | Higher energy density, cleaner burning, compatible with automated systems. |
Residential Biomass Boilers | Wood Pellets | Easy to store, highly efficient, minimal ash output, consistent fuel quality. |
Cost-Sensitive Heating Operations (Schools, Public Buildings) | Wood Chips | Lower cost per ton, especially when sourced locally. |
If storage space and handling aren’t constraints, wood chips may be more cost-effective for large-scale heating, while wood pellets provide superior combustion efficiency and ease of use.
Ultimately, the best biomass fuel depends on your geographical location and biomass fuel availability. Regions with abundant forestry resources may benefit from wood chips due to lower costs, while areas with established processing facilities and automated heating systems might find wood pellets more efficient and convenient.
Let Tubman Heating Help You Decide
At Tubman Heating, we understand that every facility has unique heating requirements. Whether you’re considering a biomass boiler for environmental reasons, energy savings, or future-proofing your operations, our team can assess your needs and recommend the most cost-effective and efficient system for your business.
We supply, install, and maintain a range of biomass boilers, and can help you compare wood pellet vs wood chip options based on your site, goals, and budget.
Heizomat wood chip boilers (up to 1.5MW) offer a cost-effective, low-emission heating solution for large commercial and industrial sites. Ideal for businesses with access to wood chip fuel, these systems provide reliable, sustainable heat — helping reduce both energy costs and carbon footprint.
John Thompson steam biomass boilers (1.5MW+) deliver reliable, high-output performance using a wide range of biomass fuels — from wood pellets to grape pomace and nutshells. With no need for pre-drying (moisture <40%), they offer flexible, sustainable steam generation for industrial operations aiming to reduce fossil fuel use.
FAQs
Q1: Which is more cost-effective for biomass heating wood pellets or wood chips?
Wood chips are generally cheaper per tonne and ideal for large-scale installations with storage capacity. Wood pellets, while more expensive, offer higher efficiency and cleaner combustion, which can offset costs in smaller systems.
Q2: Are wood pellets or wood chips better for New Zealand’s commercial heating systems?
It depends on your needs. Wood pellets are ideal for automated, space-conscious systems in small to medium facilities. Wood chips suit larger operations with bulk storage capacity and access to local forestry resources.