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Standards are required to describe biomass equipment, and biomass fuels. They are vital if forms of biomass are to become commodity fuel that users can buy with confidence of trouble free operation. They are there to ensure reliable, efficient, trouble free operation.
The need for standards

There is a wide range of biomass potentially suitable for energy use, however most types of conversion equipment works effectively with a very few types and forms of biomass fuel.

Even with a specific form of fuel, such as wood chips, there can be major differences in characteristics and properties between different batches chipped using different chippers, from different material, with different moisture content.

This means that while it is all eminently usable, one batch will allow a particular piece of equipment to operate according to specification, but another may cause blockages in the fuel feed line, inefficient operation, emissions, condensation in the flue, or automatic shut down of the equipment as it moves outside its design operating regime.  In different equipment, however, the second batch of fuel may be perfectly acceptable.

Sustainability standards too are required, and gradually being developed to ensure that biomass is only derived from sustainable, legal sources. CPET, the Central Point of Expertise on Timber Procurement, provides detailed information and advice on how public sector buyers and their suppliers can meet the UK Government’s timber procurement policy requirements in practice, and demonstrate that timber supplied is legal and sustainable.

Executive Summary of UK Government Timber Procurement Advice Note April 2010Executive Summary of UK Government Timber Procurement Advice Note April 2010
Guidance from CPET on government timber procurement to ensure legality and sustainability (PDF - 228 kB)
CEN/TC 335

This is the technical committee developing the draft standard to describe all forms of solid biofuels within Europe, including wood chips, wood pellets and briquettes, logs, sawdust and straw bales.

CEN/TC 335 allows all relevant properties of the fuel to be described, and includes both normative information that must be provided about the fuel, and informative information that can be included but is not required.  As well as the physical and chemical characteristics of the fuel as it is, CEN/TC 335 also provides information on the source of the material.

More about CEN/TC 335 specifications and technical standards

Woodsure is an accreditation scheme for assuring the quality and suitability of wood chip, pellets, briquettes, logs and hog fuel (shred).

Woodsure Accreditation of a woodfuel supplier means that these products have been tested to ensure they meet the BS EN or Önorm woodfuel standards that have become the established measure in the European biomass industry.

Woodsure accredited woodfuel assures customers that the fuel they are purchasing fulfils the appropriate specification for their equipment. It helps to guarantee a high standard and reliability in the supply chain.

More about Woodsure
While the CEN/TC 335 suite of standards are intended to be the universal standards for solid biofuels across Europe, prior to these many countries developed their own standards. The Austrian Standards Institute is ÖNORM. While ÖNORM is now adopting its own implementations of the CEN/TC 335 standards, many Austian boilers have been installed in the UK and specify fuel according to ÖNORM M7 133 for wood chips (Woodchips for energy generation: quality and testing requirements) and ÖNORM M7 135 for pellets.
More information on ÖNORM M7 133
The German Standards Institute (Deutsches Institut fur Normung) also developed its own biomass fuel standards DIN 66 165, and these too are sometimes encountered.
BS EN 303-5:1999

In addition to specifications for biomass fuels, there are also specifications for biomass combustion equipment.  BS EN 303-5:1999 applies to heating boilers for solid fuels, hand and automatically fired, nominal heat output of up to 300kW.  It is the local UK implementation by the BSI of EN 303-5.

BS EN 303-5:1999 covers properties such as performance, efficiency, emissions, thermal output, pressure testing, safety measures and testing.

Related pages
Types of biomass fuels
Biomass conversion technologies
Standards testing
Companies accredited by the UK Accreditation Service for the testing of biomass fuels
Documents about standards
Woodheat Solutions Summary of woodfuel standardsWoodheat Solutions Summary of woodfuel standards
A user friendly introduction to the EN woodfuel standards from the Woodheat Solutions project (PDF - 1.1 MB)
Roadmap for implementing standardsRoadmap for implementing standards
A translation of an Austrian document discussing the importance of standards in woodfuel. (PDF - 3.2 MB)
Documents from CPET
Documents from CPET (the Central Point of Expertise on Timber Procurement) giving advice about the procurement of timber and timber products, forest certification schemes and other forms of evidences of sustainability (Category B evidence).
Testing moisture content (simple method) Testing moisture content (simple method)
A simple guide to testing moisture content of woodfuel without using expensive specialist equipment (PDF - 1.0 MB)
Wood as fuelWood as fuel
Information about using conventional firewood logs for domestic heating in both traditional log stoves and boilers, and modern, high efficiency batch type log boilers which offer a highly sophisticated central heating system. Updated 2010. (PDF - 1.7 MB)
Wood as fuel - Technical supplement for fuel suppliersWood as fuel - Technical supplement for fuel suppliers
This document is a technical supplement to Wood as Fuel, A Guide to Choosing and Drying Logs. It is aimed at log suppliers and individuals processing logs for their own use. Updated 2011. (PDF - 1.0 MB)
A guide to biomass heating standards
A guide to the relevant standards for biomass heating from the FOREST Project.