A Life Cycle Assessment of the PureCell Stationary Fuel Cell System ...

Chapter 2 - Procedures
LCA Software
The software that was used to model the PureCell system LCA is SimaPro 6.0. This
LCA tool was developed by PRe Consultants, an independent private company in the
Netherlands. SimaPro (System for Integrated environMental Assessment of PROducts) is
currently the most widely used software for LCA studies worldwide [5].
Data Collection
Collection of data is an important part of LCA. One could say that the scientific quality
of the final LCA results can only be as high as the quality of the data that are used. The
objective must therefore be to work with data as specific as possible. Since this LCA
represents a UTC Power product, primary data were collected from UTC Power wherever
possible. However, many of the components in the PureCell system are not
manufactured by UTC Power but by supplying companies, which made the data
collection more difficult and time-consuming. Therefore, in many cases data from
generic Life Cycle Inventory (LCI) databases have been used. In general, a strategy of
hierarchical preference regarding data collection has been used:
1. Data obtained from UTC Power.
2. Data from LCI databases especially derived with the geographical location of
UTC Power in mind. This means: applying the hierarchy described in point 3 up
to and including 7, and incorporating UTC-specific data in case they can be made
more relevant to the PureCell system.
3. Data from the Franklin database in SimaPro. This database contains late 1990’s
inventory data for North American materials, energy and transport.
4. Data from the online National Renewable Energy Laboratory (NREL) Life Cycle
Inventory Database [6]. This is a publicly available database developed in close
cooperation with the U.S. government and industry. It includes data from the
Franklin database.
5. Data from other databases in SimaPro, determined on a case-by-case basis to
provide the most relevant information.
6. Data from other non-SimaPro databases.
7. Data obtained by internet research.
Even though this strategy for data collection was systematically applied, some of the data
used in the LCA are still incomplete or have been subject to sometimes major
assumptions. In the inventory analysis for each PureCell system component these data
gaps and assumptions are described as transparently and precisely as possible.
Allocation Procedures
Data on overhead energy use (electricity and natural gas) could only be provided by UTC
Power in aggregate for the entire plant, which precluded a bottom-up allocation. A topdown
approach was used, allocating overhead energy to the PureCell system by
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