The Method Handbook of the funding programme “Biomass energy use” is the result of a joint, intense discussion among the funding programme’s participants who, at the start of their work, were faced with the task of designing, harmonising and creating a transparent methodological approach in order to make not only indicators but also cost calculations and balancing comparable.

The Method Handbook is intentionally aimed at the "simple" user who does not deal with the methods presented day-in and day-out. Selected methods for the material flow-oriented balancing of greenhouse gas effects can be applied with limited expenditure in a simple, transparent and comprehensible manner.

For further use, you will also find the essential working tools used in the Method Handbook on this website.

Here, you find:

• Summary of the general framework conditions
• Most important points regarding the application of the methods
• Lists with the most important parameters
• Documentation lists to download as Excel files

For the time being, the Method Handbook is being applied within the funding programme and is therefore particularly tailored toward questions relating to the corresponding projects, which are assessed based on the climate protection effects achieved.

What can´t the Method Handbook provide?

There is a great need to provide transparency and harmonisation amongst evaluation methods. The only way to achieve this is to provide information and empirical data for as many research projects as possible. This is an arduous task for the researcher involved and normally results with a compromise.

In its present state of revision, the Method Handbook is not a tool for the complete sustainability assessment of bioenergy systems.

To provide simple, harmonized and transparent methods, simplifications (e.g. degree of utilisation, start-up processes, etc.) and a standardised database (e.g. fuel prices)must be provided for various areas. There is no way to ensure that these simplifications and standardisations are appropriate and suitable for all projects and will generate the desired results. Projects should utilise the suggested data and approaches for the calculation and can deviate from them in justified individual cases. When it is not possible to create a consistent database in a standardised fashion (e.g. process-specific indicators for GHG accounting or analysing potential), the harmonisation process focuses on methodological transparency, which is ensured based on documentation lists.

As a general framework, the overriding assumptions and points of view on which the subsequent balancing processes and assessments are based are described.

One crucial factor taken into account was that the central focus of the funding programme is the optimisation of the use of bioenergy production (above all else, the technical elements). Other objectives include Germany contributing as a major role to climate protection and the assessment of energy, economic, and envrionmental factors.

In the Chapter General Framework you find information on:

• Fundamental references and definitions
• Definition of terms relevant to the programme
  
        o    Feedstock and product-specific definitions 
        o    Economic definitions
        o    Definitions related to life-cycle assessment
        o    Definitions related to energy technology
  
  
• System boundaries and system elements: the supply chain for the production and use of bioenergy
• Overriding assessment framework

                o    Geographic reference                 
                o    Temporal reference
                o    Energy technology reference
                o    Sustainability requirements
                o    Presentation of results

BRIEFLY SUMMARIZED 

Residues in the funding programme

For the funding programme, the broadly defined term “(biomass) residues” is utilised, which – in light of the energy / technology / science focus of the programme – is suitable for the relevant disciplines (GHG accounting, analysing potential) and does not exclude any biomass fractions:

Biogenic residues are existing organic material flows that include by-products and /or residues and waste, i.e. all biomass material flows that are not produced as the primary product (c.f. Figure 2).

Figure 2: Definitions of biomass in the programme (Source: DBFZ)

Biomethane is methane that is produced from feedstock (biomass) in technical processes. Biomethane can be produced through biochemical conversion (via anaerobic digestion) or thermochemical conversion (as Bio-SNG). It is upgraded to natural gas quality by processing the gas composition, in particular the methane content, accordingly.

The energy content of the primary energy, input materials and residues, as well as products, is the chemically bound energy of the biomass that is available in the technical conversion process for conversion into other forms of energy. In the funding programme, the energy content of all input materials and residues is stated exclusively as the inferior calorific value H_i. The reference value for the calculation of the chemical power and the efficiency is also the inferior calorific value H_i. The inferior calorific value is also referred to as lower heating value.

Figure 3: System boundaries and elements (Source: DFBZ)

To increase the comparability and accuracy of potential studies in the funding programme "Biomass energy use", a harmonisation of the definitions and documentation is needed. Due to the diversity of biomass categories (biomass fraction under review, definition of potentials, geographic level, temporal reference, type of data collection, methodology), a standardised methodology for all biomass fractions cannot be provided. But some definitions, the type of documentation and the approach can be standardised in the Method Handbook.

The objective of the harmonisation of methods is not only relevant for the funding programme, but is also pursued at the European level (BEE project 2009).

Briefly summarized

In light of the programme's objectives it is therefore recommended to assess and / or list the technical potential in addition to the approach selected in the respective project in order to allow for as much comparability between the projects as possible.

Result presentation

In a documentation lists the biomass fractions and restrictions considered in the determination of the technical potential should be presented. Thus, more transparency should be provided.

Documentation lists I and II show the most important factors that lead to deviations between the results and illustrate which sustainability aspects were taken into consideration in the determination of the potentials.

• Documentation list I/II for important influencing variables for the determination of the (technical) biomass potential – XLSX – 164 KB

Balancing the energy and materials used for the conversion process is a prerequisite for the economic and environmental analysis of the overall chains.Knowing the input and output of the considered bioenergy systems allows calculating indicators with which the conversion process can be characterised and optimized technically and in terms of energy. The indicators used here are based on material and energy balances and are primarily intended for further development of the individual technology groups (combustion, gasification, anaerobic digestion),not for cross comparisons between them.It is the objective of this Method Handbook to harmonise the record of the energy flows entering and exiting the system, or the energy conversion efficiencies among the different projects.

Result presenation

The data is collected in technology-specific projects and the results are presented with the help of a data collection sheet and a documentation list, which differ for combustion, gasification and anaerobic digestion plants. The documentation lists contain entry fields for the necessary material and energy flows and the calculated indicators, but do not make any claim to completeness. In addition to the absolute numeric values, the type of data collection – measured values, derived values, difference values, or assumptions – is also recorded on the data collection sheet and the documentation list. This is intended to document the material and energy flows, as well as the balance indicators transparently and comparably for technologies within one type (e.g. gasification plants) or between different technologies (e.g. gasification and AD plants).Please note the following information for filling in the data collection sheets and documentation lists: The necessary balance indicators must be documented in the first two tables (data collection sheet and a documentation list). To illustrate the certainty of the data, the table consists of two parts. The first part is for entering the balance indicators, and the second part is for the individual material and energy flows with which these were calculated. Through the addition of the material and energy flows for input and output, the plausibility of the data can easily be checked and presented transparently. It is important in this context to specify the boundaries of the balance to which the plausibility check refers. Only the fields shaded in grey have to be filled with the data on the respective system, and the remaining values have to be supplemented via calculation.For the given units, calculation formulas are predefined for the corresponding parameters. If it’s necessary or it is required due to the data situation to use parameters with other units, the predefined calculation formulas have to be adapted accordingly.Examples of filled data collection sheets and documentation lists for each technology field can be downloaded soon here.

Biomass gasification plants:

• Tab. 40 Template for data collection sheet - Energy and material balance for biomass gasification plants – XLXS – 18 KB
• Tab. 41 Filled-in example for the data collection sheet - Energy and material balance for biomass gasification plants - XLXS – 20 KB
• Tab. 42 Template for documentation list - Balance indicators for biomass gasification plants – XLXS – 14 KB
• Tab. 43 Filled-in example for the documentation list - Balance indicators for biomass gasification plants – XLXS – 14 KB

Anaerobic digestion plants (ADs):

• Tab. 44 Template for data collection sheet - Energy and material balance for ADs – XLXS – 16 KB
• Tab. 45 Hypothetical plant example for the data collection sheet - Energy and material balance for ADs - XLXS – 18 KB
• Tab. 46 Template for documentation list - Balance indicators for ADs – XLXS – 14 KB
• Tab. 47 Filled-in example for the documentation list - Balance indicators for ADs – XLXS – 15 KB

Small-scale furnaces

• Tab. 48 Template for data collection sheet - Energy and material balance for small-scale furnaces – XLXS – 14 KB
• Tab. 49 Data collection sheet - Energy and material balance for small-scale furnaces – XLXS – 14 KB
• Tab. 50 Template for documentation list - Balance indicators for small-scale furnaces – XLXS – 12 KB
• Tab. 51 Filled-in example for the documentation list - Balance indicators for small-scale furnaces – XLXS – 14 KB

A look at the balance effects
Assessing complex energy technology systems using different partial balances can lead to confusion and errors if the reference states are not defined consistently. If this occurs, the energy difference between the different reference states used then appears as either lost or generated energy flow. Working with inferior and superior calorific values (also referred to as lower and upper heating value) within the same system is the same as using different reference states. For classic thermochemical processes, which take place at very high temperatures, consistently working with inferior calorific value related energy flows is effective and a rather obvious choice since it is backed by long technical tradition.

But it is not quite as obvious for fuel gases from renewable energy sources. In case of natural gas, for example, it has long been common to work with liquid water as the reference state, in other words using the superior calorific value. It is standard practice to use superior calorific value for this fuel. This lays the groundwork for the trend towards a shift away from the inferior calorific value reference and towards the superior calorific value reference in technology assessment.

In the future, a thorough transition should be made, to a standard practice of calculating energy content for material flows based on the same methodology, thus allowing for comparative assessments across technologies. The increasing interconnections between the technologies, for comparison purposes or for material interconnection, speak for this clear and consistent approach. This is also a plan for the future European standardization.

• Detailed information and sample calculations for an easy comparison of the inferior and superior calorific value (anaerobic digestion of wet biomass / biochemical conversion and biomass gasification / thermochemical conversion) can be found in the Chapter 5.5 of the Method Handbook.

Methodology for calculating the levelied costs of energy

A possibility of determining the cost of GHG mitigation is to calculate the production costs, or levelised costs of energy (LCOE), and carry out an environmental assessment of the different bioenergy production routes. Ultimately, the statements made regarding economic efficiency can help minimise the costs of climate protection and thereby increase societal acceptance of bioenergy, provided the results are implemented politically.

Introducing the production costs (not including delivery to the plant) as a criterion of economic efficiency make it possible to compare the biomass utilisation routes with their different technological approaches, service lives, supply volumes, and separation into the bioenergy forms of fuel, heat and electrical energy. The LCOE are calculated based on the annuity method and are applied uniformly in accordance with the provisions of VDI 6025 (1996).

The micro- and macroeconomic effects are intentionally not presented, since difficult, concept-specific assumptions would need to be made. These have far-reaching consequences, and therefore, cannot be presented in a generalised form.

The system boundaries included in the cost calculation for the projects in the funding programme “Biomass energy use” are the conversion plant, respectively including fuel pretreatment at the plant (chipper, sieve systems, drying, etc.), fuel storage and systems for conditioning the form of energy produced. The upstream chain (biomass supply) is taken into consideration under the costs of fuel procurement. The pure LCOE is calculated, not taking into account potential effects of distribution, to be able to subsequently calculate the GHG mitigation costs.

An expansion of the system boundaries to the distribution is preferable and strived for in order to calculate the positive effects of bioenergy on the provision level. To consider these effects becomes even more relevant considering the transition of the energy production to renewable energy and increasing different supply functions of the different energy fuels.

Result presentation

To calculate the differential cost of providing bioenergy, a fossil reference system should be selected that would be considered as an alternative to bioenergy. The assumptions with respect to the thermal utilisation efficiency have to be the same in the calculations of the material and energy flows, the LCOE and the GHG emissions in order to ensure comparability of the GHG mitigation costs.

The assumptions and system boundaries used to calculate the LCOE for bioenergy and for the fossil reference have to be similar. In addition, sensitivity analyses may help to illustrate the main influencing factors and uncertainties inherent in the LCOE calculation. In this context, an appropriate range of variation for each parameter has to be selected and should be included in the evaluation. For small-scale furnaces, it is necessary to expand the system boundaries to include the useful energy, since there are significant differences in the cost structure of distribution and utilisation in comparison to fossil systems. For all other conversion routes, the bioenergy production is sufficiently exact as a system boundary, with the GHG emissions of the final combustion in the engine being taken into consideration for biofuels and fossil fuels for transport.

In the LCOE calculation it is assumed that a tried-and-tested conversion system which has been introduced to the market is investigated. This offers the advantage of economically comparing technologies in different states of development. Furthermore, it is possible to estimate the future potential of pilot and demo plants, and to make strategic decisions with respect to further funding. However, in order not to consider the results entirely independent of the state of development, it is necessary to document the assumptions or the real data (information regarding the state of development, the market availability and the need for development etc.), in order to render the results more transparent and to point out deviations from commercial plants. The LCOE are therefore to be gathered and published together with the following documentation list.

• Documentation list of important variables influencing the calculation of LCOE – XLSX – 31 KB

Assessing the environmental implications of bioenergy production is crucial in order to support the ongoing climate and environmental policy debates.

The objective of the methodology suggested is to “provide” a simpler and more transparent methodology which allows for the production of comparable balanced results. Therefore, the application of the methodology of the EU Directive on the promotion of the use of energy from renewable sources (EU RED 2009/28/EG) is the most preferable approach for the calculation of greenhouse gas (GHG) emissions, acidification and particle emissions. This methodology limits itself to the calculation of greenhouse gas emissions, as they have been mentioned in the current discussion of the production and use of bioenergy the most. This calculation methodology appears to currently be the only applicable compromise between the necessity for methodical complexity and ensuring the comparability of the results through approaches and methods that are as straightforward and transparent as possible. The methodology does not constitute a substitute for the life-cycle assessment in accordance with ISO 14040 and 14044.

Some essential factors that are important for the sustainability assessment of the projects within the funding programme cannot be taken into consideration in the necessary depth within this part of the Method Handbook. Therefore, their importance of the following aspects is only briefly referenced in the current version: 

• humus effects
• (indirect) land use change
• land use
• P as ressource
• micro- and marcro-economic effects

Briefly summarized

The provision of unallocated data is recommended in order to enhance the transparency and transferability (i.e. to be utilized by others) of the given dataset.

The assumptions with respect to the material and energy flows as well as the thermal utilisation factor for the balancing of GHG emissions and for the calculation of the differential costs of the energy production from biomass have to be the same in order to calculate the GHG mitigation costs. For the balancing of GHG emissions, a fossil reference system should be selected that matches the selected reference system of the calculation of the differential costs of the bioenergy production.

Result presentation

The results of the LCA should be presented in a comprehensive and transparent way and in the form of a bar chart and / or in tabular form. For better comparability between GHG balances, a listing of the emissions in CO₂-equivalents relative to the functional unit is recommended.

The assumptions regarding the balancing of GHG emissions and levelised costs of energy have to be similar in order to calculate the GHG mitigation costs.

Typically, the data collection takes place with the help of data collection sheets. These sheets contain documented lists of all relevant material and energy flows belonging to the processes feedstock production, provision / transport, distribution and use. The corresponding documentation lists for the conversion processes can be found here.

Documentation list of the relevant material and energy flows for the processes of feedstock production, provision / transport, distribution and use – XLS – 164 KB

In order to assess the balance results of bioenergy systems, the comparison to reference systems is necessary. For the production of energy in the Method Handbook, conventional reference systems are to be referenced as standardised basis of comparison by the projects in the funding programme "Biomass energy use". The reference systems for electricity, heat and fuels for transport are presented, each with values for a review of the average and for a marginal analysis, with concrete data with respect to:

• emissions of greenhouse gases (GHG),
• emissions of air pollutants (acidifying emissions and fine dust)
• the cumulative non-renewable primary energy consumption (PEC)

It is recommended to generally use the values of the average systems as reference.

Briefly summarized

To simplify the comparison of project results, it is therefore recommended to always use the average system as a reference system for the electricity production, and - time permitting - to represent the sensitivity of the results by using a marginal analysis. In justified case, another approach may also be selected.

Just like for the electricity systems, it is recommended to always use the average mix as a reference system, and - time permitting - to represent the sensitivity of the results by using a marginal analysis.

For consistency reasons, the values presented here should be used instead of the RED comparators for comparisons with fossil systems since they include life-cycle data regarding air pollutants and primary energy use.

This handbook brings together different methods. The assumptions selected take into account current requirements regarding the sustainable bioenergy use. In its present state of revision, the method handbook is not a tool for the complete sustainability assessment of bioenergy systems. For such a task, it would be necessary to take additional parameters into consideration (e.g. humus effects, iLUC, food security, micro- and macro-economic effects) as well as additional guidance regarding the interpretation of the results.

The further development of this method handbook into an assessment tool for bioenergy systems remains an important topic of discussion accompanying the "Biomass energy use" funding programme, but appears to be useful in the medium term. The aim of simplifying the methodology while avoiding the levelling out of individual technologies’ specific features definitely needs to be fulfilled.

Anyfurther necessary changes to the handbook will only be possible by means of a joint discussion. Adjustments must be carried out by the funding programme’s participants and the handbook’s users. Its further development is a continuous process that requires feedback from both experts and those applying it in practice.

Partners both inside and outside the funding programme are very welcome to provide such feedback.

Do you have questions or comments to the Method Handbook please contact:
E-mail: begleitvorhaben@dbfz.de

DBFZ Deutsches Biomasseforschungszentrum gemeinnützige GmbH / Helmholtz-Zentrum für Umweltforschung GmbH - UFZ
Daniela Thrän

DBFZ Deutsches Biomasseforschungszentrum gemeinnützige GmbH
André Brosowski, Elmar Fischer, André Herrmann, Stefan Majer, Katja Oehmichen, Diana Pfeiffer, Walter Stinner

Former colleauges of the DBFZ: Philipp Adler, Ralf Schmersahl, Torsten Schröder, Kitty Stecher, Vanessa Zeller, Martin Zeymer

GreenDeltaTC GmbH
Andreas Ciroth

University Zittau/Görlitz
Tobias Zschunke

International Institute for Sustainability Analysis and Strategy (IINAS)
Uwe Fritsche

Öko-Institut e.V.
Klaus Hennenberg

Thuringian State Institute for Agriculture (TLL)
Katja Gödeke

This handbook was elaborated also through the joint efforts of the working groups of the programme "Biomass energy use" funded by the German Ministry for Economic Affairs and Energy and supported by the Association for the Promotion of Renewable Energy Sources (FEE – Fördergesellschaft Erneuerbare Energien e.V.) and the Institute for Energy and Environmental Research (ifeu – Institut für Energie- und Umweltforschung Heidelberg GmbH).