The main aim of this background part is to give an overview and to compare available data on wood energy in Europe/OECD countries. Data have been collected by literature searches, but mainly by means of personal visits to all statistical institutes involved, which are FAO, UNECE, Eurostat, IEA and the Lawrence Berkeley Laboratory. Each of the 5 databases has been put into a common format which consists of a set of 8 tables in order to facilitate mutual comparison.

An overview of the main characteristics of the various databases is presented in Table S.1. The FAO database only concentrates on fuelwood, which is wood that is directly removed from the forest for the purpose of energy generation. Data collection is integrated with the annual forestry questionnaire. All countries in the world are included. The UNECE sends out questionnaires focused on wood energy, each 5 years. The rate of reply is relatively low but the level of detail of replying countries high. All European countries are included. Eurostat constructs their renewable energy database on the basis of a standard questionnaire. Each member state gets a contract to write a detailed background report. They cover the whole EU, although the present data quality for the three new member states is relatively low. Beside wood and wood-waste also agricultural residues are included in one aggregated category. The International Energy Agency has increased their efforts to estimate wood energy consumption in both OECD and non-OECD countries. However, their present database consists of data collected in the past, which are believed to be not very reliable. The Lawrence Berkeley Laboratory constructs their energy database, which also includes data on wood, directly on individual national statistics. They include 10 OECD countries. Appendix 4 presents all databases in the common format.

One has to be very careful with comparing the figures of the different databases. There are large differences in both the amount of countries covered and the types of woodfuels included.

However, it is possible to learn from such a comparison. One clear trend is that (especially in the EU where the data quality is the largest) the FAO figures are much lower (about a factor 5 as compared with UNECE and Eurostat for the EU) than the figures in the other databases. The reason for this is that the FAO only includes direct removals (probably only from inventoried sources) used for fuelwood. This appears to be only a small part of the total picture. Data quality for non EU countries appears to be much lower. Much more figures here are based on estimations of the database organiser instead of questionnaire results.

This background part of the report "Wood energy today for tomorrow: a regional study for Europe/OECD" presents the methodology and results of a comparison of statistical databases on wood energy. On the basis of these results a best estimate will be made for the use of wood energy. This serves as an input for the analytical Part A of this report.

Only international statistical databases were covered in this study. Individual country databases were therefore not considered.

• Presenting an overview on total wood energy use in European/OECD countries based on literature searches and on personal communication with the respective authors and institutes.
• Presenting various data sources in a comparable format, including:

• Time series of total wood energy consumption
• Disaggregation into different types of wood that are used for energy
• Disaggregation into the main sectors which consume the wood energy.

• Comparing the main characteristics of the databases
• Construction of a best estimate for wood energy.
• Making recommendations for future improvement of wood energy databases at FAO and other institutes.

Part B starts with an overview of the methodology used. Both the steps undertaken in the project and the format in which all databases are presented is discussed here. Thereafter, a description is given of the 5 databases which were studied. For all databases the method of data collection and the structure of the database is discussed. An overview of the databases in the common format is given in Appendix 4. In this background part they are presented in an aggregated way and the most important differences are explained. On the basis of these data a best estimate is made for the consumption of wood energy in European and OECD countries.

In order to meet the objectives as stated above the following steps were undertaken:

• Literature study on the available database sources on wood energy production and consumption in Europe/OECD;
• Writing of preparatory document to give an overview of the literature search [Broek, 1996]
• Visits to responsible persons of the 5 most important institutes on the field of databases of wood energy in Europe/OECD;
• Analysis of available databases and converting them all into the same format in order to facilitate comparison.

All data sources are presented by means of 8 tables each. All tables have a list of all European and OECD countries on the y-axis. The countries are grouped into three groups, namely: EU-15, OECD-non-Europe and Europe-non-EU.

Basically, in these 8 tables 5 different aspects of the databases are shown on the x-axes:¹²

1. Timeseries of the total use of wood for energy between 1980-1994. Table A.z.1. presents the timeseries in volume terms with 1000m³ as unit and Table A.z.3 presents the same timeseries translated into primary energy with PJ (peta-Joule = 10¹⁵ Joule) as the unit.^1,13
2. The ratio between the amount of wood energy consumed and the total removals (within the country under consideration). This is presented in Table A.z.2. with % as the unit.¹⁴ Total removals are represented by the figures on total roundwood production from the FAO forest product yearbook [FAO, 1996].
3. The ratio between the amount of wood energy consumed and the total primary energy supply in the country under consideration. This is presented in Table A.z.4.; again with % as the unit.² Figures on total primary energy supply are based on the IEA database [Denman, 1996].
4. The different types of wood that are used for energy. The basis distinction that has been made here is between woodfuel and wood-derived fuels.¹⁵ Woodfuels are further divided into direct forest woodfuels (from inventoried and non-inventoried sources) and indirect forest woodfuels (industrial residues and recovered products). The only wood-derived fuel that was included in the various databases was black liquor. Exact definitions on all these items are given in Appendix 1. The main aim of this division was to make results of different databases comparable. Only UNECE and IEA have presented disaggregated figures on these items. The division made here has largely been based on the UNECE division, but included the idea of making the highest level division only on the basis of the inherent quality of the wood. This item is presented in Table A.z.5. and Table A.z.6., respectively in the units 1000m³ and PJ.
5. The various sectors in which the wood energy is consumed. The sectors that are considered are: households, industry, transformation and others. Again, definitions have been given in Appendix 1.

Different fonts and shading have been used to indicate the main characteristics for each figure in the databases. This mainly refers to whether a figure comes directly from the questionnaires, whether it has been estimated by the database organiser and whether it is an original figure or the result of a calculation in order to be put in the common format. An overview of the symbols that have been used is presented in Appendix 2.¹⁶

In this study, 5 databases on wood energy use in Europe/OECD have been analysed, namely:

1. FAO forest product yearbook [FAO, 1996];
2. UNECE/FAO European Timber Trend Study V [UNECE, 1996];
3. Eurostat Renewable Energy Resources Statistics [Eurostat, 1996];
4. IEA Energy Balances [IEA, 1996a];
5. Lawrence Berkeley Laboratory Energy Statistics [Schipper, 1996].

All five databases are briefly described on the basis of the method of data collection and the structure of the database.

For the purpose in this study we analysed the fuelwood and charcoal production data of the FAO forest product yearbook [FAO, 1996]. These figures are part of an extensive overview of production figures on various types of forest products.

Data are collected by means of annual questionnaires send to basically all countries in the world [UNECE, 1996]. This questionnaire is joint by FAO and UNECE and since one year also Eurostat uses the same questionnaire in order to have equal databases, save money and to avoid that the same information is asked twice to countries.

As part of total removals, data on fuelwood (including wood used for charcoal) are asked, disaggregated into coniferous and non-coniferous wood. Further, in the production section, production on charcoal is asked for.

Neither in the questionnaire nor in the yearbook, an explicit definition has been given for "fuelwood". The FAO Internet site where all statistical data can be accessed, defines fuelwood as "Wood in the rough (from trunks, and branches of trees) to be used as fuel for purposes such as cooking, heating or power production. The commodities included are fuelwood, coniferous and non-coniferous and the roundwood equivalent of charcoal" .¹⁷ Charcoal is defined there as "Wood carbonized by partial combustion or application of heat from an external source. It is used as a fuel or for other uses".

Chipeta defines fuelwood as "wood harvested specifically for the purpose of energy production" [Chipeta, 1996]. So it includes the fuelwood that comes directly from the forest, thus excluding residues from industries, recycled products, etc..

Further, figures on import and export of fuelwood is asked for. This figures have not been included in this study for it is believed that in practice they represent other types of wood than fuelwood [Prins, 1996].

Basically, an annual overview is given for all countries in the world. Roughly one third of the figures for Europe/OECD are estimated by the FAO. This is in first instance done by repeating the figures of the years in which data were given. If no data are available at all, estimations are made on the basis of assumed average per capita consumption figures of fuelwood which are multiplied with the number of inhabitants of the country under consideration [Padovani, 1996].

The Timber Section of the UNECE Trade Division and the forestry staff attached to the FAO Liaison Office at Geneva, have recently produced the European Timber Trend Study V (ETTS V). Within the framework of this outlook study, one chapter is devoted on energy from wood.

For the energy chapter of ETTS V, questionnaires have been made by a "team of specialists on energy from wood" and were sent out to specialised institutes regarding the use of wood for energy of all ECE member countries. Similar questionnaires have already been analysed in 1980, 1985 and 1990. According to Prins [Prins, 1996] it is not useful to have annual questionnaires on wood energy, for the information at national levels is not available in sufficient detail for this purpose. About 10 useful replies to the 1995 questionnaire were received.

In these questionnaires (related to the ETTS V study) detailed information is asked on the use of wood for energy, disaggregated into different types of wood and the various sectors within which the wood is consumed.

The disaggregation into the various wood types has been done according to the following definitions:

Fuelwood

Wood from the forest used for energy. This may come from inventoried sources (stemwood in forest formations) or from non-inventoried sources, such as tops and branches, trees outside the forest, etc. It may be harvested commercially and marketed, enter "informal" circuits or be consumed by the forest owner himself.

Industry residues

Residues of all sorts, including solid wood chips and offcuts, bark, sawdust, etc., whether clean or contaminated by paint and lacquer. This is further divided into:

Primary residues	:	residues from sawmilling and panel-producers
Secondary residues	:	residues from joinery, furniture, wooden elements, etc
Pulp and paper residues	:	bark and chips residues of the pulp- and paper industry

Recovered wood

Wood which is used for energy after it has carried out its initial function, which includes short-lived products, especially pallets and other packaging as well as demolition waste.

Black liquors

The lignin naturally occurring in wood, dissolved out with the hemi-cellulose during sulphate pulping. They are normally burnt in recovery boilers to provide process heat and to recover the chemicals.

The main categorisation is not done on the basis of the inherent quality of the wood, but on the location where the wood comes from (an implicit inherent quality criterion used is: black liquor or no-black liquor). This may have advantages in relation to policies that try to maximise the use of residues during the different stages of wood through society.

The disaggregation into the consuming sectors is as follows [according to questionnaire]:

• households:
• forest industry
• intermediate users, including: district heating plants, non-forest industry, and consumers like schools and hospitals.
• manufacture of charcoal
• manufacture of wood-derived solid fuels (such as pellets and briquettes)
• manufacture of synthetic fuels

Here, the third category is a bit problematic from the viewpoint of comparison with official energy statistics, for it includes a mixture of ISIC categories (transformation, industries and service sectors in one category). Moreover, the second category includes more than one basic ISIC category, that is used in the official UNECE, Eurostat and IEA energy statistics.

The replies from the ETTS V questionnaires were analysed by Morin [Morin, 1995]. On the basis of his background report the results were presented in the final ETTS V study [UNECE, 1996]. The main differences between those two publications were that the database of the second one included all UNECE countries, while the first one not includes a number of Eastern European countries. The main results of the study of Morin in terms of the share of wood energy in total removals and total primary energy supply, however, were used in both studies.

The countries are grouped into the regions: Central-Europe, East-Europe, South-east-Europe, the Baltic States, the Nordic countries and EU-12. The database in Geneva comprises the years 1980 and 1990¹⁸ and has 1000m³ as unit.

The figures for the non-replying countries for fuelwood and primary residues were estimated. In the report of Morin the method of estimation has been described. For fuelwood, Morin uses the FAO forest products yearbook for estimations for the year 1990. For primary residues the figure for a non-replying country was linked to the average value for replying countries within the same country region. This was done by multiplying this value with the ratio of the veneer- and sawnwood production of the country under consideration and the average value of (veneer and sawnwood-production of the) the replying countries.¹⁹

Wood equivalents of black liquor for 1990 were calculated on the basis of the volume of wood (lignin) that was needed to "produce" the black liquor. This was not done on the basis of the questionnaire results, but on the basis of the amounts of chemical pulp produced from the FAO forest product yearbook [Morin, 1995]. The questionnaire results were used in the sense that on the basis on their 1980/1990 ratio the 1980 black liquor wood equivalents data were calculated.²⁰

For the other fuel types only questionnaire replies were used and no additional estimations were made.

The secretariat in Geneva made some additional estimations. The 1980 figures for fuelwood and primary residues were estimated by repeating the 1990 figures estimated by Morin²¹. Additional estimates were made for fuelwood and primary residues of the countries that were added. Regional estimations for regions with non-replying countries were made for secondary residues and recovered wood products.²² The methodology for these estimates has not been described in the ETTS V report. The black liquor wood equivalents are presented in the UNECE database as regional totals.

In order to be able to evaluate the extend in which the EU quantitative objectives for renewable energy sources are achieved, Eurostat in 1991 started with the establishment of a methodology for collecting and presenting renewable energy sources statistics for their member countries. One major demand was that it had to fit in the annual energy balances as published by Eurostat.

The main part of the data are collected by getting out contracts with centres of expertise of each member state. In this way country-reports have been established for all EU countries. On the basis of this information a synthesis report was made [Eurostat, 1995] which presented the renewable energy data for 1989-1991. Recently an updated version of this report has been published for the period of 1989 - 1994 [Eurostat, 1996].

Additional input to these synthesis reports on the field of wood consumption in households came from a household energy consumption survey study [Eurostat, 1993] of which an updated version is upcoming. Household wood consumption in Belgium and Germany was considered as being weak areas of information. Therefore, additional surveys have been undertaken on this.

The questionnaire that was sent out to the centres of expertise and which formed the core of the country reports, included basically the following four items concerning wood energy:

• heat production by burning firewood in households;
• heat production in district heating plants burning wood/wood waste/other solid waste;
• heat production (exclusively) for on-site use in industry burning wood/wood waste/other solid waste; and
• electricity generation by the public supply and autoproducers.

Thus, for the first sector, wood has been aggregated into one item, while in the other 3 the level of aggregation in somewhat higher, since the data also include other solid waste.

This aggregated category of "wood/wood waste/other solid waste" includes firewood and wood waste (wood chips, bark, etc.) while there is a minor contribution from black liquor, straw and other agricultural waste [Eurostat, 1995]. It is estimated that the first three categories consist for about 100% of "pure wood" and the fourth for about 20%, the remainder being black liquor and bark. [Roubanis, 1996].

The database has exactly been organised according to these categories in the questionnaire. It presently contains information of the period 1989-1994 for the EU-12 and Finland. Figures for Austria and Sweden are not available yet on the categories presented above. Estimation have been made for total biomass/waste use in these countries (also including MSW, anaerobic fermentation and biofuel production).

The data on wood energy of the IEA ultimately have to fit in the structure of their energy balances. These energy balances are the main basis for modelling and forecasting work that is undertaken within IEA. Therefore it is essential that data are available in the form of timeseries, that a clear definition of the various types of wood is available (based on their inherent quality and that information on sectoral consumption is according to the (ISIC based) system which is already developed for all conventional fuels.

Information on wood energy is included in the IEA coal questionnaire, which is a joint questionnaire together with the UNECE. Since 1995 this questionnaire has also been joint by Eurostat [Roubanis, 1996]. Before 1995, all biomass was included in the category "other solid waste", which also included peat, municipal solid waste and industrial waste. In the new questionnaire, production, transformation and final consumption data are asked for "solid biomass and animal products". Production figures only are asked for a higher level of disaggregation. Here "wood" and "wood waste" are included [IEA, 1995].

Questionnaires are sent to official national administrations which have some kind of government connection, for IEA members are obliged to answer the questionnaire. These institutes, however, are often not very familiar with wood or biomass in general so responses on these items are relatively poor [Denman, 1996]. Since last year the IEA increased efforts to improve the quality of the biomass data by discussing them intensively with the various countries. One way to improve reliability will be to send the results of the statistical project on renewable energy of Eurostat to the IEA respondents. Since the Eurostat data are official country data they have to be accepted by all member states [Savage, 1996].

Deliberately, no exact definitions "wood" and "wood-waste" have been given in the questionnaire. After the answers have been received from the respondents, IEA is now trying to understand how countries interpret these categories [Savage, 1996].

In general IEA has two types of published statistical outputs for OECD countries. The "energy balances" are the most aggregated as regards types of energy sources, but presents all data in energy units so that the whole system of production, transformation and supply is in balance [IEA, 1996a]. Wood is included here in the aggregated item of "combustible renewables and waste". The other one is the "basic energy statistics". This gives a higher level of disaggregation and presents the data in their original units (e.g. tones, m3, litres, etc.) [IEA, 1996b]. It does include the production, transformation and sectoral consumption. The main item "combustible renewables and waste" is split up into "solid biomass and animal products", "gas/liquids from biomass", "municipal solid waste" and "industrial waste".²³

The item "solid biomass and animal products" is further disaggregated in the database itself into "wood", "vegetal waste (including the share of "wood waste"), "black liquors" and "other solid biomass". Only production figures are included.²⁴

The energy statistics of the Lawrence Berkeley Laboratory are used for many analytical purposes, like international comparison of energy efficiency in different sectors and looking for improvement potentials for energy efficiency.

Their database is directly based on country statistics. It comprises 10 OECD countries and includes information on wood for the following sectors: households, manufacturing and services/commercial sector. Wood as energy source is not further disaggregated. For some countries it may even also include non-woody biomass, for the main aim was to get those fuels in one category which is CO₂ neutral [Schipper, 1996]. The timeseries are for the period 1970-1992. In the household sector disaggregation is available for the purpose for which the energy source is used (e.g. space heating, cooking, etc.).