This paper aims at examining and reviewing currently used terminology and definitions for woodfuels and other biofuels used in FAO and other major databases on wood-based energy sources, and at proposing ways to improve the methodology for the definition, classification compilation and presentation of woodfuel data and information using the Unified Wood Energy Terminology (UWET).
UWET is compared with current terminology and classification systems, notably the FAO system for gathering woodfuel statistics for its FAOSTAT database and later reproduction in the FAO Forest Products Yearbook, the International Energy Agency (IEA), EUROSTAT, and the United Nations Standard International Trade Classification (SITC). The main departure with these systems is that UWET stresses the supply and demand aspects of wood energy products and commodities and the flow of wood energy from the source to satisfy end user requirements.
Woodfuels are classified as direct, indirect or recovered woodfuels, according to their "journey" from supply to the end user; the inclusion of agrofuels, such as bagasse, straw, stalks, etc. and the use of municipal by-products (sludge, municipal wastes, sludge gas, etc.) represent further innovations in the UWET classification proposal. The document offers basic working definitions and outlines the measurement parameters and units taken into account. Biofuel conversion and accounting factors are provided in order to obtain the energy worth of a mass or volume flow of a particular biofuel.
UWET was prepared jointly and discussed with many institutions, with the common objective of assessing properly the amount of energy produced from biofuels and of facilitating the exchange of bioenergy databases among national and international organizations. Certainly this new terminology and set of definitions are not the panacea to solving the many problems associated with wood energy data, but intend to be a first and essential step towards their improvement.
In the future, also more attention will be given to the definition of different types of agrofuels which so far have received marginal attention; not only regarding the terminology used but also for the development of improved data bases.
National and international energy statistics seldom include the same level of detailed information on biofuel and woodfuel consumption as other conventional energy sources and forest products. Moreover, existing information on woodfuel in most forestry data banks at both national and international levels is rather limited and very aggregated for the comprehensive analysis of how much woodfuel is being used where and by whom. Moreover, the scarce information available is collected, compiled and presented using different terminology without clear definitions and the units and conversion factors used for the figures make comparison, aggregation and exchange extremely difficult and tedious.
In addition, most existing information on biofuel and woodfuels is focused on biomass consumption without paying due attention to other related aspects such as production and supply sources. In addition, the data on biofuels, and woodfuels in particular, have also to fit into the structure of the energy and forestry statistics which are the main basis for modelling and forecasting work that is undertaken in the respective technical organizations involved.
Thus, there has been a growing awareness and interest in improved and more detailed bioenergy data in order to gain a proper understanding of bioenergy systems and to plan the sustainable production and utilization of biomass by both traditional and modern uses. Up to now, FAO data are considered a reference for many institutions, but there is an increasing necessity to improve the method by which FAO collects, organizes and presents wood energy data.
In response to the need to refine and restructure the way in which wood energy data are presented in FAO statistics, and taking also into account other bioenergy database methodology, this document put forward a new framework for wood energy classification and accounting. The basic aspects of such an approach include the following:
1. creation of woodfuel category to encompass all kinds of energy material from wood;
2. inclusion of new types of bioenergy products, including agrofuels and municipal by-products;
3. improved disaggregation on both the supply and demand sides.
It is important to mention that UWET has been prepared jointly and discussed with many institutions, with the common objective of assessing properly the amount of energy produced from biofuels and of facilitating the exchange of bioenergy databases among national and international organizations.
Certainly this new terminology and set of definitions are not the panacea to solving the many problems associated with bioenergy data, but intend to be a first and essential step towards their improvement.