Forecasting energy use in agriculture

Tim Kränzlein

Working Paper

04-04

Agroscope FAT Tänikon

Annotation:

This Working Paper has been prepared with the support of the

Swiss Federal Office for Education and Science FOES, Berne, Switzerland

Author:

Tim Kränzlein is a research assistant at the Swiss Federal Research Station for Agricultural Economics and Engineering and is focusing on energy input quantification in agricultural production systems.

Address:

Agroscope FAT Tänikon

Swiss Federal Research Station for Agricultural Economics and Engineering

CH-8356 Ettenhausen

Switzerland

Phone: +41-52 368 31 31

Fax: +41-52 365 11 90

Internet:

E-mail:

The series "CAPRI, Working papers" contains preliminary manuscripts which are not (yet) published in professional journals and are prepared in the context of the “Common Agricultural Policy Impact Analysis” and “Common Agricultural Policy Strategy for Regions, Agriculture and Trade” projects, funded by the EU Commission under the 4th and 5th framework programs. Comments and criticisms are welcome and should be sent to the author(s) directly. All citations need to be cleared with the author(s).

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Index

Index

1Introduction

2Literature Review

2.1Energy: definitions and terminology

2.1.1Energy basics

2.1.2Process analysis and Cumulative Energy Demand (KEA)

2.1.3Direct and indirect energy consumption

2.1.4Energy role of machinery and buildings input

2.1.5Energy efficiency measurements

2.2Energy in agricultural modelling

2.2.1Life cycle assessment

2.2.2Level of farm / line of production analysis

3Methodology

3.1CAPRI systematics concerning input in production activities

3.2CAPRI status quo in energy concerns

3.3Basics, system borders, constraints

3.3.1Basics

3.3.2System borders and constraints

3.4Adjusted CAPRI energy methodology referring to input components

3.4.1Component “Energy”

3.4.2Component “Repair”

3.4.3Component “Depreciation”

3.5Methodology of aggregation procedures

4Data Sources

4.1Direct energy

4.2Indirect energy

4.3Possible Cooperation

5Time Schedule

6References

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Forecasting energy use in agriculture

1Introduction

This Working Paper gives information about Work Package No. 6 within the CAPRI DynaSpat Project (Common Agricultural Policy Regionalised Impact – The Dynamic and Spatial Dimension). It contains a description of the given task, a survey of the relevant literature, some methodological approaches and potential data sources. It represents Deliverable No. 17, a public report.

Given Tasks: Work Package and Implementation

The given task is part of the Sixth Framework Programme, Priority 8.1, Task 12: Ex ante policy assessment of CAP. Within the “Agricultural Policy – The Dynamic and Spatial Dimension” project several work packages (WP) have been described. The objective of WP No. 6 is to improve the existing CAPRI model by integrating an indicator of energy use in agriculture. To achieve this aim, the following defaults are given:

  • a description of major production systems with regard to energy usage has to be established
  • a database with energy balance data for each of the regions has to be built up

The work consists of four major steps. Firstly, in order to expand the data set to all Member States, the major prevailing production systems in the EU will be defined for each production activity. Secondly, shares of each production system per activity and NUTS II region have to be defined. Thirdly, the link between the energy use data set and CAPRI needs to be updated and integrated into the modelling system by a module written in GAMS language and the database expanded to cover the new environmental indicator. Fourthly, a projection module needs to be developed which allows forecasting of the activity related coefficients in simulation runs.

2Literature Review

2.1Energy: definitions and terminology

2.1.1Energy basics

For the purpose of methodological traceability it seems useful to offer some definitions in the field of energy analysis. In this context the terms relevant in the course of the project will be outlined.

Definition (1)Force (push or pull)

A vector quantity (a quantity having both magnitude and direction) tending to produce change in the motion of objects. Measured in units such as Newton ()

Definition (2)Energy

Capacity to perform work. Forms of energy include heat or thermal, chemical, electrical and nuclear energy, etc. Measured in such units as Joule (J) and kilowatt-hour (kWh) (); (). “Work” can also be used, in accordance with international SI standards.

Definition (3)Power

Amount of work done per unit of time. This is equivalent to the rate of change of the energy in a system, or the time rate of doing work. The SI unit of power is the Watt (). “Capacity per time unit” can be used as a synonym.

2.1.2Process analysis and Cumulative Energy Demand (KEA)

Process analysis

It seems that methods used for balancing can reasonably be applied to the given task. In energy balancing, process analysis plays an important role in terms of quantifying energy inputs. Fluck (1980) understands methods of “process analysis” as “methods that are used for determining the energy sequestered in goods and services or for performing an energy analysis on a good or service”. Analogously, Moerschner (2000a) states that the basis of an energy balance should be, in every case, the compilation of matter flows, e.g. on the basis of resource input. The relation between matter flows in a process chain and the expended process energy for the relevant chain should be clear at every single step. Thus there is an explicit relationship between matter and energy balancing. Consequently, process analysis can be defined as follows:

Definition (4)Process analysis

The network or processes required to make a final product are identified. Each input is assigned an energy requirement so that the total energy requirement can be summed. (Fluck, 1980)

Using process analysis in terms of energy balancing, the scope of such examination should, according to Moerschner (2000b), contain the following components: basic materials, semi-finished products and finished products produced as well as solid, liquid and gaseous emissions and waste. Beside the agriculturally produced target product, ancillary products, by-products and residual material might appear. Agricultural energy balances usually only represent a part of all the energy flows appearing in a production process. Typically, the effort of fossil energy needs caused by human action (excluding photosynthetic active radiation etc.) is compared with the energy profit resulting from the products used. In process analysis, the life cycle of a product plays an important role. According to Moerschner (2000a), agricultural products can be divided into the following life cycle chapters:

  • extraction of raw materials
  • building and maintenance of infrastructure and factories
  • production of agricultural operating resources
  • further processing
  • usage, consumption
  • disposal, recycling of residues

Referring to durable goods (machinery and buildings), matter flows at production, usage, repair and disposal level have to be allocated to the production process on a pro rata basis. The scope of the examination and assessment has to be set in line with general system borders.

Cumulative Energy Demand

The concept of Cumulative Energy Demand (KEA), described in the “Verein Deutscher Ingenieure (VDI)” guideline No. 4600 (VDI, 1997), follows the principle of process analysis and offers a structured approach to quantifying the energy input into agricultural production systems. The guideline mentioned “shall assist in making energy technological data available and comparable within a uniform framework” (VDI, 1997). The Cumulative Energy Demand (KEA) states the entire demand, valued as primary energy, which arises in connection with the production, use and disposal of an economic good (product or service) or which may be attributed respectively to it in a causal relation. This energy demand represents the sum of the Cumulative Energy Demand for the production (KEAH), use (KEAN) and disposal (KEAE) of the economic good. It has to be indicated for these partial sums which preliminary and parallel stages are included:

In principle, the balancing boundary for the determination of the KEA of an economic good extends from the raw material at its original location to the final storage or deposit of all materials or substances, where diffuse release into air, water and soil also have to be taken into consideration. Unambiguous definition of balancing boundary setting is carried out according to local, temporal and technological criteria and is an important foundation for the KEA. Because of the high complexity and multiplicity of some of the interactions between individual processes, systematic delimitation frequently poses a central problem for energy analysis. A detailed determination of all relevant energy and material flows in the service life of a product requires a separation of the components of the KEA right down to the individual processes. An energy balance in this context registers energy quantities or energy types respectively in J or Wh, crossing the defined balance space boundaries during the period of analysis. The energy balance boundaries are identical with the material balance boundaries (VDI, 1997).

2.1.3Direct and indirect energy consumption

A distinction between direct and indirect energy consumption is a common procedure in literature. For the present purposes, the terms direct and indirect energy will be used as described in Definitions (5) and (6).

Definition (5)Direct energy

Direct energy covers those energy sources that are consumed directly in the production process for the purpose of generation of usable energy. (Werschnitzky et al. 1987)

To assess direct energy input, different methodological approaches are used, e.g. the approach of determining the heating value in the final product or the approach of primary energy. The latter includes energy requirements for allocation of the energy source. All energy sources entering the allocation process are charged in energy equivalents. Following Diepenbrock (1995), the following energy sources are used for direct energy input into agriculture:

  1. mineral oil products
  2. fuels
  3. heating oil
  4. electric energy
  5. biomass (e.g. straw, timber as an energy source)

Definition (6)Indirect energy

Indirect energy use describes external primary energy expenditures linked to materials utilised in production systems, balanced up to a defined system border (Diepenbrock, 1995; Moerschner, 2000a)

The scope of indirect energy consumption covers components such as mineral fertiliser, machinery and buildings, plant protection, pharmaceuticals, imported feedstuffs, seeds etc.

There are several reasons to distinguish between direct and indirect energy consumption. Firstly, direct and indirect energy differ in their usage. Direct energy is consumed in the production process mainly for the generation of usable energy and partly for the functioning of indirect energy components. Indirect energy components do not produce usable energy. Secondly, the methodological approaches to quantifying and determining the scope of such energy differ. Direct energy, according to Diepenbrock (1995), can be quantified by determining the heating value of the energy carrier or the approach of primary energy, where all the energy components consumed in the production process of the direct energy carrier are included in the assessment. Indirect energy quantification methodology is more complex. Apart from the availability of data for the agricultural sector, the lack of a standardized methodology complicates the comparison of results achieved by different authors. A methodological focus is taken within the framework of WP No. 6 on the energy consumption by durable goods. Components such as machinery or buildings represent a large part of energy consumption in animal as well as in plant production processes.

A methodology for quantifying indirect energy consumption by durable goods can be found in the approach of Kalk and Hülsbergen (1996). The usage of fossil energy within durable goods includes input for production of materials and manufacture of machinery and technical equipment as well as energy consumed for building material and construction of buildings and equipment. System borders set exclude an energy assessment of previous steps other than those mentioned above. Farm machinery energy consumption is calculated in a weight-related energy equivalent. Energy input through buildings corresponds to surface area as well as construction materials used.

Due to the lack of a standardized methodology and considering the background of different approaches, the range of energy coefficients is relatively broad. Table (1) shows the range for selected input components according to various authors. This emphasises the clear setting of scope and system borders for the examination ahead.

2.1.4Energy role of machinery and buildings input

Machinery as well as buildings in agricultural production systems play an important role in terms of indirect energy consumption. For Swiss agriculture, a total of 41 % of sectoral energy consumption is linked to machinery and buildings (Fischer, 1999).

It seems useful to present the most important determinants that influence the energy role of machinery and buildings input. For machinery construction, energy sources such as natural gas, light fuel oil and hard coal are needed to transform materials such as metal, glass, plastic, lubricating oil, paper etc. within the manufacturing process. During the physical life period, maintenance and repairs demand similar resources. Disposal of machinery and materials consume energy, too. For actual operation of the machinery, energy sources such as diesel fuels are required.

On the buildings side, construction materials including the transport burden, as well as construction process components such as building machinery and electricity consumption including the transport burden, determine energy use during the construction phase. Similarly to machinery, maintenance requires similar resources. Furthermore, after the usage period, dismantling including transport as well as disposal systems require energy. The functioning of buildings requires energy resources and auxiliary materials (econinvent, 2003).

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Forecasting energy use in agriculture

Table (1)Comparison of different attempts at assessing input components under energy criteria

Variable / AT Bornim/TLL Jena / AT Weihenstephan / IOL Bonn / KTBL / FAT
energy source electricity / 11 MJ kWhel-1 / 10.8 MJ kWhel-1 / 10.75 MJ kWhel-1 / 10.75 MJ kWhel-1 / 15.84 MJ kWhel-1
energy source diesel fuel / 53 MJ kg-1 / 48.2 MJ kg-1 / 47.08 MJ kg-1 / 46.41 MJ kg-1 / 50.5 MJ kg-1
energy source heating oil / 53 MJ kg-1 / 48.2 MJ kg-1 / 47.08 MJ kg-1 / 46.41 MJ kg-1 / -
seeds (cereals) / 5.5 MJ kg-1 / 8.86 MJ kg-1 / following soft wheat
3.49 MJ kg-1 / following soft wheat
3.49 MJ kg-1 (like IOL) / 14.8 MJ kg-1
mineral fertilizer: N-based / 38.9 MJ kg N-1 (as KAS) / 64.99 MJ kg N-1 / 55.5 MJ kg N-1 / 49.1 MJ kg N-1 / following KAS:
48.40 MJ kg N-1
mineral fertilizer: P-based / 9.8 MJ kg P2O5-1 (as TSP) / 21.61 MJ kg P2O5-1 / 17.4 MJ kg P2O5-1 / 17.78 MJ kg P2O5-1 / 19.71 MJ kg P2O5-1
mineral fertilizer: K-based / 3.1 MJ kg K2O-1 (as potash 60) / 13.78 MJ kg K2O-1 / 10.5 MJ kg K2O-1 / 9.14 MJ kg K2O-1 / 11.6 MJ kg K2O-1
lime / 1.8 MJ kg CaO-1 / 0 MJ kg CaO-1 (not considered) / 3.1 MJ kg CaO-1 / 3.47 MJ kg CaO-1 / 2.6 MJ kg CaO-1
plant protection products /  111 MJ kg-1 /  552.05 MJ kg-1 / 114.1 MJ kg-1 / herbicide approach
238.68 MJ kg-1 + 62.1 MJ kg-1 / herbicide approach
258.96 MJ kg-1

Source: Moerschner, 2000a

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Forecasting energy use in agriculture

2.1.5Energy efficiency measurements

Taking energy consumption as a basis, energy efficiency considerations endorse the item of an additional step. Energy efficiency, according to Fluck (1980), can be defined as follows:

Definition (7)Energy efficiency

measures the ratio of output to input and, in doing so, quantifies the amount lost, usually as waste heat (Fluck, 1980).

where:

In the case of CAPRI, other energy parameter such as the “energy conversion coefficient” or the “output/input coefficient” might be more suitable as the amount of “useful work” seems difficult to quantify in the CAPRI approach. The “energy conversion coefficient” is defined (according to Diepenbrock, 1995) as:

Definition (8)Energy conversion coefficient

“Output/input coefficient” is defined (Diepenbrock, 1995) as:

Definition (9)output/input coefficient

2.2Energy in agricultural modelling

Energy input is calculated in a number of simulation models. Depending on the scope of such models, a wide range of possibilities exist for the quantification of such energy input. For purposes of CAPRI WP No. 6, only those models having a certain degree of detail in energy criteria as well as a non-monetary assessment are considered in this context.

2.2.1Life cycle assessment

Life cycle inventories of agricultural production systems are important preconditions for life cycle analysis (LCA). The role of inventories such as ecoinvent (2003) is to provide modules for infrastructure and inputs used in agricultural production necessary for modelling production systems. These modules are intended to be used within life cycle studies of agricultural systems (ecoinvent, 2003). The theoretical background of such analysis is the aim of quantifying negative externalities of agricultural production systems in terms of environmental effects. The strong link between input assessment and energy valuation of the single components as well as solid data on direct energy consumption makes life cycle assessment an important source of energy data for agricultural modelling. Ecoinvent (2003) offers a detailed view of agricultural buildings, machinery and field work processes as well as agricultural input components such as mineral fertilisers, organic fertilisers, pesticides, seed, feedstuffs and drying processes. Output is considered with respect to arable crop production, hay, etc. Clear system boundary information as well as consideration of data quality allows usage of data sets within defined settings.

2.2.2Level of farm / line of production analysis

Energy consumption is of relevance in some farm level / line of production analysis models. The scope of such analysis determines the mode of energy assessment of input components. Monetary approaches extracted from EAA systematics (Economic Accounts for Agriculture) as well as detailed assessment following LCA can be found.

The simulation model “REPRO”, working on the operational level, might be of relevance for the given task. REPRO allows an assessment of the sustainability of agricultural production systems (Hülsbergen, 2003). Analysis and assessment of cultivation as well as environmental impact assessment at farm level can be carried out with the model. A “master file data” module combined with a “location” module, containing soil and climatic conditions for the farm concerned, is endorsed by information about plant and animal production systems. A “material and energy flows” module extracts analyses of economic and ecological aspects at farm level. The detailed level of energy coefficients and the capacity to compile energy flow analyses makes REPRO an important instrument for examination of energy inputs at farm level. Energy efficiency can be studied at farm level.