Environmental influences of small-scale use of fuelwood in Finland. Preliminary life cycle observations

Transcription

1 Environmental influences of small-scale use of fuelwood in Finland Preliminary life cycle observations Jukka Torvelainen

2 Contents Preface Introduction Wood-based fuels in Finland Purpose and implementation of this study Greenhouse gas inventory and life cycle assessment Environmental effect during life cycle of fuelwood Fuelwood in greenhouse gas inventory Life cycle observations on small-scale use of fuelwood Discussion...30 References...33 Appendices

3 Preface Bioenergy Promotion -project aims to increase the sustainable use of biomass as an essential means to mitigate harmful, human bases climate change. The work is divided into four Work Packages: WP2 (Communication and information), WP3 (Policy, including, e.g., criteria for sustainable production and the use of bioenergy and recommendation for policy makers), WP4 (Sub Regions) and WP5 (Business). The project work lasts 3 years ( ), and in the accepted, original project there were 33 partners from 10 countries around the Baltic Sea Region. The project is partly funded by the EU from the Baltic Sea Region programme More information is available at This survey is included within the Forestry Development Centre Tapios work plan in the project. The results are connected with Work Package 3 concerning, in particular, the sustainable use of forest bioenergy an essential part of the renewable energy resources in Finland and its National Renewable Energy Action plan (nreap). They provide valuable guidelines in using fuelwood in farms and detached houses, which comprise one-third of all the solid wood-based energy biomass used in Finland. The survey is compiled by researcher Jukka Torvelainen from the Finnish Forest Research Institute, who is also responsible for collecting data from this field of bioenergy use. Forestry Development Centre Tapio thanks researcher Jukka Torvelainen for good work in this highly challenged, difficult and currently still insufficiently researched field in forest bioenergy use. We hope that this survey, though still subject to incomplete results, will provide valuable information for other project partners, forest bioenergy actors and authorities to promote and emphasize forest bioenergy use. In the August issue of the Finnish professional journal, Bioenergy, there will also be a summary regarding the main findings of the survey as guidelines for private bioenergy actors to enhance the more sustainable use of forest bioenergy. We also hope that the survey provides ideas and initiatives for further research on the subject. In the end report in Appendix 3 is summed up the main findings and recommendations of this report to partners and participating countries in Bioenergy Promotion project. Klaus Yrjönen Director, International Affairs in Forestry Development Centre Tapio Timo Weckroth Licentiate Project Leader 3

4 1 Introduction There is quite a large consensus that the growing concentrations of greenhouse gases are exerting an increasing impact on the global mean temperature (IPCC). Global warming has been recognized as one of the most severe environmental problems in human history, and it may have serious and irreversible impacts on our ecosystems and on humankind. The mitigation of climate change requires deep cuts in greenhouse gas emissions in the near future. The use of fossil fuels is the main source of greenhouse gases, as it releases carbon dioxide which has been millions of years outside the carbon cycle. The use of bioenergy and biomass-based products instead of fossil fuels and other emissionintensive products is considered to be one of the most important means to mitigate climate change. The combustion of bioenergy also releases greenhouse gases into the atmosphere: in particular, carbon dioxide. However, this carbon dioxide originates within the modern carbon cycle. In sustainable biomass production, it is also reaccumulated relatively quickly into the growing biomass. The use of biomass plays a vital role towards reaching the 20% renewable energy target on the EU level in In Finland, the national target is as high as 38% and the main solution to decrease greenhouse gas emissions and increase consumption of renewable energy will doubtlessly be the massive use of wood energy. Along with peat, it is Finland s main domestic energy source, which also promotes the rural employment and economy in related production and use. Diminishing oil reserves and rising oil prices are also important factors increasing the need for renewable energy sources, as are the aims to improve energy self-sufficiency and security. There are large forest resources in Finland and Finns have long traditions in using wood in the forest industry and energy generation. Productive forest land covers twothirds of the country's land area, and the area available for wood supply per capita is nearly 4 hectares. The growing stock volume on land available for wood supply amounts to more than million m 3 and the annual increment to almost 100 million m 3 per year (all volumes in this article are cubic meters solid volume over bark). These volumes do not include roots and branches, which are also suitable for energy purposes and raise the figures greatly. In , the average amount of total domestic roundwood removals has been 60 million, and the total use of roundwood 77 million m 3 per year. Corresponding figures per capita are 11 m 3 and 15 m 3 per year. In energy generation, a yearly average of 6 million m 3 of roundwood and 14 million m 3 of forest industry by-products and other wood residues has been used. Two-thirds of these solid wood fuels have been utilized 4

5 in heating and power plants, but fuelwood has been an important source of heating energy also in small-sized residential houses. As described above, the promotion of biomass generates greenhouse gas savings and has other potential environmental benefits. On the other hand, wood combustion is one of the largest causes of local air emissions. Especially in residential heating, particulate matter emissions and emission compounds that may be harmful to human health are at the highest level. Potential ecological and environmental drawbacks of production and transportation of wood energy also have to be taken into consideration. Consumers are increasingly interested in the environmental effects and sustainability of their lives, choices and decision-making. This includes interest in the environmental impacts of wood fuels, too. 2 Wood-based fuels in Finland Finland is currently one of the leading EU countries in terms of energy production from renewable sources. The main source of renewable energy is wood, which in recent years have covered about one-fifth of the total energy consumption. Wood-based fuels have been the second most important source of energy after fossil fuels. Figure 1. Total energy consumption of wood-based fuels in Finland, Wood fuels are used mainly to produce heat and electricity. Heat is needed for industrial processes and the heating of industrial and residential buildings, so wood fuels are utilized by forest industries, the energy industry, district heating plants and households. The major part of wood-based fuels consists of by-products and residues from the forest industry, but roundwood and forest residues also have a significant role. 5

6 In Finnish statistics, wood-based fuels are divided into industrial waste liquors and solid wood fuels. Solid wood fuels are further divided into wood fuels consumed by heating and power plants and fuelwood used in small-sized residential housing (i.e., private houses, farms and recreational houses). Energy Statistics is published annually by Statistics Finland, which is utilizing several different sources in compiling it (Energy Statistics, Yearbook 2008). Data concerning black liquor and other concentrated liquors are acquired from the Confederation of Finnish Industries, and figures for solid wood fuels from the Finnish Forest Research Institute. The Finnish Forest Research Institute collects and compiles annually statistics on solid wood fuels used in heating and power plants (Ylitalo 2009). Statistics on fuelwood used in small-sized residential housing is compiled at 5 10 years' intervals, most recently for the year 2007 or the heating period (Torvelainen 2009). In the next sections, the use of wood-based fuels is described by reference to this classification. More detailed information on fuelwood used in smallsized dwellings is provided in section 5.2. Waste liquors produced and used by forest industries A sulphate pulp mill produces energy from the wood raw material surplus of the bark and wood dissolved in the cooking solution. Usually the energy production exceeds their own consumption considerably. The surplus electricity is sold to the national electrical network, and the excess heat can be utilised by other industry mills or sold as district heat. In pulp production, about half the wood material is turned to pulp fibers and the rest is utilized in energy and heat production. In 2008, the Finnish chemical pulp industry used, in total, 30.3 million m 3 of roundwood and 6.4 million m 3 of sawmill chips and dust originated from the sawmilling and plywood industries. This came to 42% of the total roundwood consumption and 27% of the total secondary use of wood in Finland. Solid wood fuels used in heating and power plants Heating and power plants used a total of 14.3 million m 3 of solid wood fuels in Consumption of forest industry by-products and residues was 9.5 million m 3 and consumption of forest chips 4.0 million m 3. The major part of solid wood fuels comes from sawmills. Large sawmills are usually in the neighborhood of pulp and paper mills, and the majority of sawmill by-products and residues are recycled back to forest industry. Only the bark is available and left for energy production. At small sawmills, residues are not recycled and thus bark, off-cuts, sawdust and wood chips (totaling about 55% of solid stem volume) are directed to energy production. By-products and wood residues of sawmills are already in virtually full use in Finland. The allowable quantity of these as well as the potential of logging residue depend on 6

7 roundwood cuttings and the demand for timber. The most promising bioenergy potential lies in forest chips made of cutting residues (for example, low-quality logs, stumps, crowns and branches) or of small-sized trees from early thinning. In 2008, 72% of the total amount of solid wood fuels used by heating and power plants consisted of sawmill residues, recycled wood and wood pellets. The share of forest chips originating directly from forests was 28%, of which only one quarter was made of roundwood. Solid wood fuels were incinerated in about heating and power plans in The size of these stations varies considerably, as the 30 largest plants use more than 60% and the 100 largest about 90% of the total amount. Among these plants are also more than 400 entrepreneurs producing heat in small units which use, in total, less than 1% of the total quantity of solid wood fuels. The majority of the plants produce heat, but among the biggest units there are more than 50 plants with combined production of heat and power, where bark, sawdust and forest chips are used in co-combustion with peat, recycled waste and fossil fuels. Fuelwood used in small-sized residential housing In Finland, there are about 1.4 million real estate properties in total with at least one small-sized residential house used for permanent or non-permanent living or for holiday purposes. The number of buildings is somewhat larger, as there are, e.g., one-family houses, two-family houses and row or terraced houses. The total amount of small-sized holiday houses or summer cottages is about and that of separate saunas more than Almost all one-family and holiday houses as well as separate saunas have at least one fireplace or stove. In twofamily, row and terraced housing, wood combustion devices are not so common. Fuelwood is currently quite rarely the only source of heating. However, in many cases it can be the primary source of heat. Most typically, fireplaces are sources of reserve or auxiliary heat or are used for entertainment or to create a comfortable atmosphere. Sauna baths have traditionally been heated using wood-burning sauna stoves, this still being very common. In heating period 2007/2008, a total of 6.7 million m 3 of fuelwood was used in smallsized residential housing per year. The major part, 5.4 million m 3, was roundwood, and 1.3 million m 3 consisted of various kinds of residues and by-products. 7

8 Figure 2. Use of fuelwood in small-sized residential housing during the 2007/2008 heating period. Wood energy is important in the space heating of small-sized dwellings. In 2007, it covered 39% of energy sources used in the heating of detached houses, 78% of that used in residential recreational houses and 35% used in agricultural buildings GWh Electric heating District heating Heat pumps etc. Natural gas, LPG Light fuel oil Heavy fuel oil Coal Peat Fuelwood Detached houses Semidetached houses Recreational buildings Agricultural buildings Figure 3. Consumption of energy for space heating in agricultural and small residential buildings in 2007 (Statistics Finland) 8

9 Total amount of wood and energy used as wood-based fuels in Finland In , the average amount of total domestic roundwood removals has been 60 million, and total use of roundwood 77 million m 3 per year. In energy generation, the yearly average of roundwood has been 5.8 million m 3 and forest industry by-products and other wood residues 13.8 million m 3. In 2008, the total amount of roundwood used for energy generation was 6.5 million m 3. More than 80% of that, almost 10% of domestic roundwood removals, were used in small-sized residential housing. For forest industry by-products and various wood residues, the corresponding total amount was more than double, 14.5 million m 3, of which 90% was used in heating and power plants. Figure 4. Wood consumption in Finland,

10 Figure 5. Energy consumption in Finland by source of energy, 2008 In 2008, the total consumption of wood-based fuels was about 300 petajoules (85 MWh). Solid wood fuels were consumed to the total of 153 petajoules (43 MWh) or 21.0 million m 3. Of this, heat and power plants accounted for almost two thirds, with small-sized residential housing accounting for the rest. Potential of wood-biomass In Finland, the potential of wood energy is greater than current use. By-products and wood residues of sawmills are already in almost full utilization, but the cutting possibilities of forests are substantially larger than the present cuttings. The growing stock volume on land available for wood supply amounts to million m 3 and annual increment to 97 million m 3 per year. Both these volumes include roundwood only. Roots and branches raise the figures for wood-biomass remarkably; maybe even as much as 50 percent. In , the average amount of industrial roundwood removals (logs and pulpwood exported or used by domestic forest industries) has been 55 million m 3 per year. In addition to this, the yearly average of 6 million m 3 of fuelwood and 3 million m 3 of forest chips have been cut from forests and used for energy purposes. Almost three quarters of this wood energy have been roundwood, and the rest different kinds of 10

11 forest residues. It has been recently estimated (Salminen 2010) that the maximum sustainable removal of logs and pulpwood for the period of could be 70 million m 3 per year. For the second 10-year period, the corresponding figure is 78 and for the third period 80 million m 3 per year. On top of that, yearly removals of forest chips (mainly stumps, crowns and small-sized roundwood) could reach 13 million m 3. If industrial roundwood removals will stay at the same level as in , the total potential of woodbiomass usable for energy purposes will be almost 30 million m 3. It has been estimated that it could be profitable and technically possible to gather and utilize million m 3 of that. However, the author also points out that more detailed studies are needed. Further, estimates are dependent on assumptions done, and price level and technical development will affect future volumes very strongly. We also have to bear in mind that environmental issues are already highly important and will become extremely important if the use of wood energy is considerably increased. Table 1. Potential and consumption of wood-biomass resources of Finnish forests available for wood supply Roundwood Energy wood Total Forest Fuelwood chips Growing stock, mill. m Increment, mill. m 3 /year Estimates of cutting possibilities ( ), mill. m3/year - Removals maximizing net present value 96 not separated Maximum sustainable removal 70 not separated Removals ( ), mill. m3/year Source: Finnish Forest Research Institute Estimates of cutting possibilities are calculated for the 10-year period starting from the inventory year ( ). Present forestry guidelines and restrictions have been taken into account in the calculations. Estimated removals of energy wood refer to forest chips and assume that cuttings are done according to the recommendations and 70% of cutting residues and 90% of stumps (diameter > 20 cm) are utilized. In this Table, removals of roundwood refer to domestic use and exports of logs and pulpwood. Removals of fuelwood (small-sized residential houses) and forest chips (heating and power plants) include roundwood and forest residues. 11

12 3 Purpose and implementation of this study The aim of this study, firstly, is to provide updated information on the use of woodbased fuels in Finland. The general overview of various fuels and users is in Chapter 2. As the main focus of this study is on fuelwood of small-sized residential housing (i.e., private houses, farms and recreational houses), section 5.2 provides more detailed information on production, transportation and combustion of fuelwood consumed in these buildings. Secondly, the study examines some important environmental effects of solid wood fuels. Greenhouse gas inventory and its results are the main justifications for increasing the use of wood energy. Fuelwood consumed in small-sized residential houses is included in the national inventory report (NIR) for greenhouse gas emissions of Finland. In this study, an effort is made to analyze the impacts of fuelwood consumption specified in reporting system for the energy sector and for the sector of land use, land use change and forestry. The internationally agreed framework and related principles should also provide adequate information for comparing greenhouse gas emissions of alternative sources of energy used in space heating in small-sized residential houses. A life-cycle assessment procedure is usually used to estimate the sustainability of production and the use of the chosen product or system. It would also be a useful framework to evaluate environmental impacts of fuelwood. However, the most recent survey data on fuelwood consumption in Finnish small-sized housing was collected in the summer of This was before the approval of Bioenergy-promotion project funding and the start of this research study, so the data is not sufficient for a proper life cycle assessment. Even so, it can be used to make preliminary observations on the life cycle impacts of fuelwood as well as on the data requirements of detailed life cycle assessment. These findings can be utilized in the next data collection. 12

13 4 Greenhouse gas inventory and life cycle assessment Greenhouse Gas Inventory Finland is a Party to the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol. Under these international agreements, Finland is committed to provide information annually on its national anthropogenic greenhouse gas emissions by sources and removals by sinks. As a member of the European Union, Finland has reporting obligations also under the mechanism for monitoring European Community greenhouse gas emissions and for implementing the Kyoto Protocol. Obligations for reducing the greenhouse gas emissions and for increasing the use of renewable energies are binding, so all participants must calculate and report the relevant figures (most of all greenhouse gas emissions and removals), according to the same principles. Greenhouse gas inventory is an internationally agreed system to monitor some selected environmental influences of various energy sources, including fuelwood. It also provides a framework to compare various energy sources with the same measuring instruments. Life Cycle Assessment Life Cycle Assessment (LCA) is a widely accepted approach to evaluate environmental impacts of products, systems and processes. It considers material and energy flows throughout the life cycle, from cradle to grave. The general principles of the methodology were standardized by the International Organization for Standardization (ISO) in four steps in the latter half of the 1990s (ISO 14040:1997, ISO 14041:1999, ISO 14042:2000 and ISO 14043:2000). There are several life cycle-based approaches, such as attributional (ALCA) and consequential (CLCA) life cycle assessment, process LCA, Environmental Input/Output LCA and other hybrid methods. However, only traditional/attributional LCA is described in the following text, as it is the method applied in reference articles used as a backbone of investigation later in this study. The overview presented here is based on Finnish articles dealing with environmental benefits/drawbacks and greenhouse gas emissions of, e.g., different types of solid wood fuels and other forest products (Mälkki et al 2001, Mälkki & Virtanen 2001, Kujanpää et al 2009, Nors et al 2009, Sokka & Soimakallio 2009, Soimakallio et al 2009). Life cycle assessment (LCA) is a methodological framework for estimating and assessing the ecological aspects and environmental impacts related to the life cycle of a product. LCA consists of four iterative steps: goal and scope definition, life cycle inventory, life cycle impact assessment and interpretation. The general categories of environmental impacts in LCA are resource use, human health and ecological 13

14 consequences. Environmental impacts are considered from the acquisition of raw material to manufacturing, use and consumption, and end use and recycling. LCA is becoming increasingly important, especially in view of the challenge of climate change and the related global policy activities. It is used, for example, at policy level, in product, process and sustainability comparisons and in the development of environmental indicators and the assessment of life cycle costs. Environmentally relevant physical flows (for example causing greenhouse gas emissions) directly related to the life cycle of the product are included in the assessment. For example, the setting of the spatial and dynamic system boundary may affect results significantly. In case of several products, the main challenge is how to carry out the allocation of environmental impacts between products, as no single objective allocation method exists. Emissions are allocated between co-products using, for example, mass or economic value as a basis of the allocation. Detailed LCA is very demanding and challenging to carry out. As generally accepted methodology is not yet available, several varying approaches are applied, depending on who is performing the calculations and what their goal and scope are. In practice, the system always needs to be limited. It is typical, for instance, that capital goods (e.g., renewal of facilities, immaterial services), general infrastructures (e.g. roads), and human labor are excluded from the system. The task is sometimes simplified also by concentrating on phases with the most important environmental impacts. This can mean, e.g., calculating only the greenhouse gas emissions or emission of carbon dioxide. 14

15 OTHER SYSTEMS SYSTEM ENVIRONMENT Setting of system boundary & allocation methods INPUTS: OUTPUTS: Product flows Production of fuelwood Ecological impacts I - soil, water, biodiversity Material flows Felling of fuelwood - fuels I Emissions: Forest haulage - greenhouse gases I - other pollutants Cutting and splitting - particle emissions Not included: I - human labor Transportation - capital goods I - infrastructures Use / combustion of fuel wood Energy / Heat I Use of waste / ash Figure 6. System flowchart for (chopped) fuelwood Carbon footprint Climate change impacts represent one of the major concerns associated with sustainable production and consumption. Due to this, controlling and reducing greenhouse gas (GHG) emissions has become an important issue. Life cycle assessment provides an existing and internationally agreed basis for calculating the 'carbon footprints' of goods and services. A carbon footprint is an assessment limited to emissions that have an impact on climate change. It can be seen as a subset for life cycle-based information being used for knowledge-based decision-making within the context of sustainable consumption and production. The carbon footprint is the overall amount of carbon dioxide (CO 2 ) and other greenhouse gas (GHG) emissions generated during the life cycle of a commodity or service along its supply-chain and sometimes including use and end-of-life recovery and disposal. Causes of these emissions are, for example, fossil fuels and transport operations. The carbon footprint is quantified using indicators such as the Global Warming Potential (GWP) in a manner in which the indicators for various emissions can be added together. The global warming potentials of some greenhouse gases are (IPCC 2007): 15

16 Species Chemical formula GWP Carbon dioxide CO 2 1 Methane CH 4 25 Nitrous oxide N 2 O 298 HFCs PFCs The carbon footprints of various goods can be compared if they have been analyzed with the same framework and assumptions. Previously, carbon footprint calculations have included only the GHG emissions originating from fossil sources. However, arguments have been advanced that biogenic carbon should also be incorporated in the carbon footprint concept. How to deal with carbon dioxide? The treatment of carbon dioxide represents one of the most important decisions in the calculations. Kujanpää et al (2009) points out that there are at least three different approaches to handle carbon dioxide in calculations, leading to totally opposite conclusions. In the first approach, it is claimed that sustainable forest management ensures that the carbon taken out from the forest is absorbed again by forest growth. Wood growth and bio-based CO 2 emissions are therefore ignored in the calculations. This approach is explained by the fact that in Northern Europe wood is generally harvested from sustainably managed forest. Forest growth exceeds harvesting and thus net carbon sequestration takes place. The long-term carbon balance is positive carbon that is released in the burning or decaying of bio-based products is captured again during biomass growth. This principle is valid when an equivalent amount of growing and burning takes place on the area studied during the observed time period. The opposite way is to calculate the lost carbon stock and allocate it to products. This approach calculates the loss of carbon sequestration potential when wood is harvested and allocates it as an emission to a product in relation to the amounts of wood raw material used. The third approach takes annual forest net growth into account and allocates it to the forest products. Net carbon sequestration is allocated to products to the ratio virgin fiber is used in the manufacturing process. A common way to think is that when biomass is used in a renewable way, the carbon released during biomass combustion or decay is accumulating back into the growing biomass. That is why biomass combustion is very often considered as carbon neutral in LCA and in the interpretation of greenhouse gas inventories of countries with sustainable forestry. The EU emission trading scheme also regards biomass combustion as carbon neutral. 16

17 5 Environmental effect during life cycle of fuelwood 5.1 Fuelwood in greenhouse gas inventory Emissions of greenhouse gases are one of the biggest interests when investigating the environmental impacts related to wood energy. This makes it relevant to study basis and findings of greenhouse gas inventory from the point of view of fuel wood. Greenhouse gas inventory has its root in life cycle assessment and can be seen as one simplified and reduced form of LCA. However, it is necessary to point out that the framework and contents of the analyses are quite different and the inventory consists of annual balance calculations of rather broad sectors. The greenhouse gas emissions and removals are usually divided into the reporting categories in accordance with the reporting guidelines. Here we are interested in results connected with fuelwood used in small-sized residential housing, so we concentrate on the reporting sectors: Energy (CRF 1.A) and Land Use, Land Use Change and Forestry (LULUCF) (CRF 5). In 2007, Finland's greenhouse gas emissions totaled (without LULUCF) 78.3 million tonnes of carbon dioxide equivalent (Mt CO 2 eq.). The LULUCF sector in Finland has been a net sink during the whole reporting period in as the CO 2 removals in the sector exceed clearly the emissions. Most of the removals in the LULUCF sector are based on forest growth; the tree volume increment exceeds annual harvesting and natural mortality. In 2007, the sink totaled Mt CO 2 eq. (Greenhouse gas emissions in Finland , 2009). In 2008 emissions amounted to 70.1 million, and the net sink of the LULUCF sector to 35.4 Mt CO 2 eq. Emissions were 10 percent less and net removals of the LULUCF sector approximately 15 percent more than in the previous year. The decrease of emissions was due to diminishing use of energy and the increase of removals was mainly due to reduced volumes of fellings. The most important greenhouse gas in Finland is carbon dioxide. The share of CO 2 emissions from the total greenhouse gas emissions has varied from 80% to 85%. Nitrous oxide (N 2 O) accounts for about three-fifths and methane (CH 4 ) about two-fifths of the remaining amount of CO 2 eq. emissions. Energy The energy sector is the main source of greenhouse gas emissions in Finland. In 2007, the sector contributed 81% to total national emissions, totaling 63.6 Mt CO 2 eq. Most of these emissions originate from fuel combustion. The substantial amount of energyrelated emissions reflect the high energy intensity of Finnish industry, the extensive consumption of fuels during the long heating period, as well as the energy consumed for transport in this relatively large and sparsely inhabited country. 17

18 CO 2 emissions from fossil fuel combustion (61.7 Mt) accounted for 97% of the energy sector's total emissions and 79% of total greenhouse gas emissions in The portion of N 2 O emissions from fuel combustion in 2007 was about 2%. N 2 O emissions come mainly from fluidized bed combustion and transportation. CH 4 emissions from fuel combustion are relatively small and are mainly due to the incomplete combustion of wood fuels (especially in small-scale combustion). Emissions from fuel combustion (CRF 1.A 1-1.A 5) are in general calculated by multiplying fuel consumption with either a fuel type-specific emission factor or a technology-specific emission factor. Uncertainties in emission factors for CH 4 and N 2 O are high, because these emissions vary greatly between different boilers and furnaces, etc. Especially in biomass combustion in small-scale applications, CH 4 emissions depend considerably on the fuel and furnace used. There is also very little information available about the emissions from these sources. International data cannot be applied directly in greenhouse gas reporting, because the design of furnaces, fuel used and the means of combustion vary. International climate change negotiations are ongoing to decide accounting methods for LULUCF under a new international agreement. Further, The European Commission published in February 2010 a report on sustainability requirements for the use of solid and gaseous biomass sources in electricity, heating and cooling. Among recommendations is e.g. suggestion to extent the calculation method for greenhouse gas emissions to include conversion efficiency. Heating The table in Appendix 2 includes emission factors of wood used in the heating of residential and agricultural buildings as calculated in the GHG Inventory of Finland for Comparable emissions of electric heating and heating with light fuel oil (heating gasiol) are also presented as reference material. The three main greenhouse gases carbon dioxide (CO 2 ), methane (CH 4 ) and nitrous oxide (N 2 O) are usually summarized in equivalent carbon dioxide equivalents (CO 2 eq.). In wood combustion, biogenic CO 2 emissions are excluded from total GHG emissions, but CH 4 and N 2 O emissions are included. As wood energy is treated as CO 2 neutral in Finland, the GHG unit emission factors of wood combusted in agricultural buildings are only 2 3%, and in residential buildings only 6 7% of the emissions that are caused by light fuel oil or electricity. When comparing net effective heating energy in different types of heating systems, the fuel economy (efficiency in energy conversion) must also be taken into account. The default efficiency of small-scale combustion of wood is quite low (55%). If losses for energy conversion are included, greenhouse gas emissions of wood heating in agricultural buildings are 3 5%, and in residential buildings 10 14% of the emissions in light fuel oil or electricity heating. 18

19 250,00 200,00 t CO2 eq / TJ 150,00 100,00 N2O CH4 CO2 50,00 0,00 Wood fuel (CO2 excluded) Wood fuel (CO2 included) Light fuel oil Electric heating (average mix) Figure 7. Greenhouse gas emissions of net effective heating energy of selected energy sources in space heating of small residential buildings in 2008 If biogenic CO 2 and losses for energy conversion are both taken into account, the gross GHG emissions of wood heating are more than 3.1 times those of electric heating (default efficiency 100%) and 2.2 times that of light fuel oil-heating (default efficiency 83%). Transportation sector Fuel used in transportation and working machines is included in the greenhouse gas inventory. However, emissions from, e.g., production and transportation of alternative energy sources are not specified in calculations. The Land Use, Land-Use Change and Forestry (LULUCF) In boreal forests the largest carbon stock is in the soils, in Finland particularly in the peat reserves. Changes in the soil carbon stock, especially peatland, will thus be very important. As the rotation period of pine and spruce may exceed years, standing stock also acts for a relatively long time as growing storage of organic carbon. Thinning as a forestry option provides raw materials and accelerates the growth of trees left in the forests. The harvested wood is compensated by re-growth of new biomass, which binds new carbon. In Finland, annual growth exceeds total harvest and natural mortality clearly. Emissions related to land use, land-use change and forestry (LULUCF) are reported as a part of greenhouse gas reporting. LULUCF as a whole sector is a net sink in Finland, as the sector binds more greenhouse gases than are released, e.g., in fellings and other relevant processes. The magnitude of the net sink has varied from approximately 20% to 50% of the annual emissions from other sectors during the reporting period. In 2007, the sink was approximately 25 million tonnes CO 2 equivalent, 32% of the total national emissions without the LULUCF sector. CO 2 emissions and removals of the 19

20 LULUCF sector are reported in full scale. However, the sink is not included in its full extent in the commitments under the Kyoto Protocol. It can be used to compensate for the emissions of the LULUCF sector and above that the maximum sink allowed for Finland is 0.58 Mt CO 2 eq per year. The main elements of LULUCF calculations are: land areas and changes, carbon stock changes in living biomass, dead organic matter and soils, greenhouse gas emissions from peat extraction areas and biomass burning, direct N 2 O emissions from forest fertilization and harvested wood products. The forests are the biggest sink in Finland, as most of the CO 2 removals in the LULUCF sector come from forest growth. The annual increment of trees has increased almost steadily, for which reason the CO 2 uptake has also grown. Drain is the decrease in the growing stock due to fellings and natural losses. Fellings consist of commercial and non-commercial roundwood removals and harvesting losses. The non-commercial roundwood removals refer to logs for contract sawing and fuelwood used in residential housing. The total drain of trees is very much affected by commercial fellings and the global market situation. Figure 8. Annual increment of growing stock and growing stock drain in Finland The net sink was 25 million tonnes CO 2 equivalent in If it is allocated in accordance with the domestic roundwood consumption figures, the share of roundwood used in heating of small-sized residential buildings is 3.3 million tonnes CO 2 equivalent. The interpretation of this could be that the LULUCF sector was binding almost 60% more of greenhouse gases than were released in combustion with biogenic carbon of fuelwood included. A net sink of this magnitude is most apparently big enough to compensate also for other emissions caused by, e.g. production and transportation of fuelwood. 20

21 5.2 Life cycle observations on small-scale use of fuelwood Bioenergy Promotion -project is aiming at e.g. assessing sustainable biomass potentials, promoting sustainable bioenergy use at sub-regional levels, comparing existing sustainability certification systems and developing recommendations for their optimization or for their development and also translating criteria into policy instruments. In summer 2010 published report defines sustainable bioenergy production and suggests principles, criteria and indicators to be used on the Baltic Sea Region (Niemi Hjulfors & Hjerpe 2010). The report also represents relevant EUregulations, which are not repeated in this work focusing on country level. This section presents the life cycle of fuelwood used in Finnish small-sized residential buildings. The description is based mainly on studies and expert estimates by the Finnish Forest Research Institute, which collects and compiles statistics of fuelwood used in small-sized residential housing in Finland. The most recent survey was carried out in 2008, collecting basic information on real estate and main building, as well as fuelwood consumption by assortment, type of building and type of burning device from more than real estate properties. Data was gathered with stratified mail-enquiry to residents or owners of real estate properties. Stratification was based on the type of the main residential building, which generated five stratums (farms, one-family houses, two-family houses, terraced/row houses and summer cottages). Farms are real estate properties with one- or two-family houses and at least one agricultural building. In other categories, real estate properties have at least one small-sized residential building mentioned in the name of stratum. This section also includes some observations on environmental influences of e.g., production, transportation and combustion of fuelwood. These observations are based mainly on reference studies and expert estimations, as available data and resources are insufficient for a detailed life cycle assessment. The next paragraphs deal first with the quantity and allocation of total emissions and the energy efficiency of the fuelwood systems. This is followed by consecutive phases of the life cycle of fuelwood. Amount and allocation of total emissions Mälkki and Virtanen (2003) studied the life cycle of logging residue-based energy. In the case of energy use of logging and sawmill residues, almost all (98%) gross carbon dioxide emissions (biogenic carbon included) were generated in the energy production phase. The sulphur dioxide emissions come mostly from energy production and forest machines. The nitrogen oxides and carbon monoxide derive mostly from energy production. 21

22 Net CO 2 emissions were low (7 9 kg/mwh) and less than 2% of the gross CO 2 emissions. The authors reported some other logging residue studies where the net CO 2 emissions were between 5.6 and 7.8 kg/mwh in Finland (Korpilahti 1998) and 17 kg/mwh in Sweden (Forsberg 1999). Wihersaari (2005) reported greenhouse gas emissions from final harvest fuel chip production in Finland. The emissions from collecting, chipping and transporting the residues were evaluated to be about 4 7 CO 2 eq./mwh depending on harvesting and chipping methods and transportation distances. In favorable situation as much as 97 98% of the greenhouse gas emissions could be avoided by substituting a fossil fuel with wood fuel, but even in an unfavorable situation the amount avoided should be higher than 75%. Energy efficiency The energy efficiencies of the fuelwood systems using logging and sawmill residues were quite high, as the proportion of the external primary energy input to the useful energy produced was low (Mälkki & Virtanen 2003). This indicator varied from 2.8% to 3.7% of the total useful energy produced. The external primary energy input included mainly fuels used by the forest machinery and transport vehicles. Utilization of stumps as well as small-sized trees from early thinnings requires more energy than utilizing residues consisting mainly of crowns and branches. Life cycle of fuelwood Production of fuelwood The consumption of fuelwood is highest on farms, where yearly average consumption of the whole real estate (20 m 3 /year) is almost four times larger than in one- or twofamily houses. In summer cottages, the consumption is about two cubic meters, and in terraced/row houses less than one-half cubic meters per year. The average consumption of all these real estate properties is slightly less than four cubic meters. 22

23 25,0 Other residues and by-products Forest residues Roundwood m3 / year / real estate 20,0 15,0 10,0 5,0 0,0 Farm One-family house Two-family house Terraced/row house Summer cottage Total Figure 9. Average fuelwood consumption in small-sized residential houses, heating period 2007/2008 Altogether 5.4 million m 3 of roundwood and 0.6 million m 3 of forest residues is used in small-sized residential houses. The remaining part of fuelwood (0.7 million m 3 ) consists mainly of industrial residues and by-products as well as recovered wood and wood pellets. 8,0 Other residues and by-products Forest residues Roundwood 7,0 6,0 mill m3 / year 5,0 4,0 3,0 2,0 1,0 0,0 Farm One-family house Two-family house Terraced/row house Summer cottage Total Figure 10. Total fuelwood consumption in small-sized residential houses, heating period 2007/2008 Forests are the main source of fuelwood, as almost all fuelwood assortments and 90% of fuelwood amount are products or residues of forestry. Roundwood used for energy generation purposes is usually acquired by picking up dead or living trees from 23

24 standing forests or from cutting areas. This roundwood consists mainly of separate individual trees or trees cut as done in thinnings, but it also includes stems or logs with low quality found on cutting areas. This means that some forest residues are gathered for fuelwood, but the major part of utilized residues is used in heating and power plants. Bioenergy production can be seen as one part of forestry. Finnish forestry is quite generally approved and about 95 percent of Finland s commercial forest area is certified according to the PEFC Finland forest certification system. For a long time, forest management and measures have been regulated and guided also with a versatile set of other instructions, regulations and legislation. There are also several parallel processes on the development of principles and criteria for sustainable production of bioenergy (Niemi Hjulfors & Hjerpe 2010). Environmental risks of wood fuel production systems are discussed in detail by, e.g., Lattimore et al (2009). In Finland, the most common conflicts and environmental drawbacks of forestry have been related to clear fellings and roundwood removals in old stands. Lately, recovery of forest residues and stumps after final fellings have aroused doubts, as there is insufficient information on impacts to, e.g., productivity, biodiversity and the carbon balance. The Finnish Forest Research Institute and Forestry Development Centre Tapio published a research report on the environmental impact of the harvesting of wood energy (Kuusinen & Ilvesniemi 2008). The articles concentrated on forest chips harvested with efficient machinery (e.g., harvesters and forwarders) and used in heating and power plants in Finland. Disagreements and uncertainties related to forestry or the possible drawbacks of the production of forest chips are clearly smaller or are irrelevant in fuelwood production. Even small clear cuttings are extremely rare for fuelwood purposes, and stumps are not used for fuelwood in small-sized residential houses. Needles and leafs are also left in the forest, which reduces the risk of nutrient losses. Terrain damage remains low, as machines are usually lightweight and poor harvesting conditions can be avoided. However, there is an obvious risk in collecting also those dead or living retention trees, which are meant to remain in the forest to increase biodiversity. Industrial residues and by-products burned in residential houses are usually acquired from local sawmills. In some cases, these fuelwood assortments are produced by entrepreneurs with portable sawing machinery contracting in a rural area. Recovered wood is usually waste wood from local building constructions or recycled wood from, e.g., loading pallets. Felling, forest haulage, cutting and splitting of fuelwood The chain of production is very much affected by the origin and raw material of fuelwood. In Finland, users self-produce 60% of fuelwood using their own roundwood 24

25 or waste wood. A total of 17% of raw material is acquired without a fee and 23% of fuelwood is purchased from fuelwood entrepreneurs or local forest owners. The share of various production methods has not been surveyed, but choices are clearly influenced by e.g. size of production, available machines, age and background of persons involved. In some cases, production methods are relatively labor-intensive; including, e.g., felling with manual equipment or motor saw, forest haulage by man-power, cutting with manual or motor saw and splitting with an axe. However, methods can also be quite intensive and effective if the machines and sufficient skills are available or the quantities are large. In practice, this can mean use of the most modern technology such as harvesters and forwarders in harvesting and firewood processors respective to cutting and splitting fuelwood. Actually, different types of firewood processors (e.g., Kärhä & Jouhiaho 2009) are quite common, as firewood merchants and forest owners in rural areas produce chopped firewood. As proper investigations have not been done, even fossil fuel inputs in harvesting, processing and transportation of fuelwood are difficult to calculate. It can be estimated that they are bigger than in reforestation and other silvicultural measures. However, the emissions from all these working phases remain relatively small compared to combustion. Fuelwood transportation A large share of fuelwood originates from users' own forests. This is probably the main reason why the transportation distance is less than 1 kilometer on many real estate properties and why it also can be as high as 500 or 600 kilometers. The average transportation distance of all fuelwood used in small-sized residential houses is relatively short: only 14 kilometers. The mean distance is shortest, 5 kilometers with summer cottages and other recreational residential houses. On farms, the average is 8 kilometers and in one- or two-family houses about twice that total. 25

26 30,0 25,0 20,0 Kilometres 15,0 10,0 5,0 0,0 Farm One-family house Two-family house Terraced/row house Summer cottage Total Figure 11. Average transportation distance of fuelwood Three-quarters of fuelwood are produced using timber and residues from own forests or raw material acquired free-of-charge. One-quarter is purchased from a fuelwood producer. This means that users know the transportation distance quite well even if, in the case of purchased fuelwood, the transportation of raw material may not be included in the figures. So far no statistics are available on transportation vehicles, capacities and loads used with fuelwood. Quite frequently, short distances and large quantities are handled by tractor and longer distances by delivery lorry, van or passenger car equipped with a trailer. Three-fifths of fuelwood are produced using own roundwood or waste wood as raw material. In many cases, several trips are required between the source and use locality in the production and transportation of fuelwood. According to reference studies, transportation can play an important role with greenhouse gases produced along the life cycle of fuelwood. If the assessment could be implemented further, transport energy consumption and emissions in Finland can be obtained from the LIPASTO calculation system (Mäkelä & Auvinen 2009). This database contains energy consumption and emission figures for passenger and freight transport. It also includes emission factors for hundreds of vehicles and working machines, including harvesters, forwarders (forest tractors), farm tractors and chain saws. The results consist of data for energy consumption and emissions of the following compounds: CO, HC, NOX, CH 4, PM, N 2 O, SO 2 and CO 2. In addition, a value for carbon dioxide equivalent is calculated, combining the warming effects of carbon dioxide, methane and nitrous oxide. The vehicle types and their performance reflect the situation in Finland. The results and figures are published in Finnish and English on a free website: 26