a) Defining the project – Input Project sheet
In the first step of the assessment process, the entire life cycle of the bio-energy system has to be defined with all the inputs and outputs. In the upper part of the sheet, feedstock(s), final conversion technology, final energy and functional unit must be selected from the lists with available options.
The calculation structure in this tool offers the possibility to feed up to two different feedstocks (with exception for waste streams as they can also be added in secondary steps) into the bioenergy system. The life cycle of one feedstock consequently consists of a biomass production phase, a first transportation/storage phase, a first conversion phase, a second transportation/storage phase, a second conversion phase and a third transportation/storage phase. This life cycle then results in a secondary energy carrier which is used, together with the secondary energy carrier of a possible second feedstock, for the final conversion process into electricity and/or heat. The use of a second feedstock is optional.
An example with two feedstocks is the production of palm oil from fresh palm fruit bunches (feedstock 1: production " transport 3) and the production of biogas from the fermentation of maize and organic waste (feedstock 2: production " transport 3), both fed into a dual fuel engine for production of electricity and heat (final conversion). In the second part of the sheet, all data are listed that are needed to calculate the mass balance of the system.
A schematical reproduction of the calculation structure is given below:
Input numbers and default values
The input project sheet contains two kind of input values: “user input” and “default values”.
For every feedstock option, default data are available in the tool. These are the same data that are used within the calculations of the BioGrace tool and additional input from peer-reviewed literature and VITO’s knowledge on the bioenergy pathways. The user is therefore not obliged to fill in data and can directly proceed to the next step if desired.
Personal data can be inserted in the user input area. In that case the personal data will be used for any further calculation. User input numbers are for instance the amount of fertiliser to grow rape or the amount of electricity and natural gas to convert rapeseed into biodiesel that users fill in based on a specific case.
b) Global warming – Input GW sheet
The global warming potential (GWP) of a bioenergy system is the sum of greenhouse gas emissions into the atmosphere throughout the whole production chain. Greenhouse gases are gases that contribute to global warming including carbon dioxide (CO2), methane (CH4) and nitrogen oxides (N2O). The GWP is expressed in CO2 equivalents which means that all gases are expressed against the mass of carbon dioxide. Carbon stock changes due to direct land use change are taken into account.
In this input sheet the user can further define the location and situation of its feedstock production, by indicating the soil and climate type using GIS data and maps and specifying current and previous land use.
c) Evaluating biodiversity and high carbon debt – Input BIO sheet
Biodiversity and high carbon stocks (above and below ground) can be endangered as well as enhanced due to bioenergy production. Risks mainly exist in loss of lands with high biodiversity value (e.g. primary forests, nature protection areas, highly biodiverse grasslands) or lands with high carbon stocks (e.g. wetlands, continuously forested areas, peatland) due to land conversion for biomass cultivation. Both biodiversity and carbon stocks can be enhanced in case degraded land is restored and brought back under cultivation.
In this input sheet the user can indicate what kind of land is used for the production of the feedstock by using GIS data and maps based on location of the biomass cultivation sites.
d) Evaluating social aspects – Input LW sheet
The impact of a bio-energy system on local well-being is approached in a twofold way in the B-SAT tool. It considers on the one hand the risk of violation of human and property rights, and on the other hand the working conditions including health and safety at work, fair wages, legal contracts and workers rights.
Although various attempts have been made to integrate social aspects into sustainability assessment, a generally accepted methodology to assess the impact of a product or a process on local well-being is not yet existing. Furthermore, most of the social parameters that are used today are qualitative and therefore difficult to integrate in the B-SAT tool.
It was chosen to create a socio-economic risk factor which takes into account the impacts of the bio-energy project on local well-being. The risk factor is not based on quantitative assessment, but rather on qualitative assessment.
The user can either choose to use the default values, or indicate in this sheet specific information about the project and the origin of its biomass resources with respect to human and property rights, also including child labour, and working conditions, amongst which health and safety at work, fair wages, legal contracts and workers rights.