The Life Cycle Assessment of a Kettle

 The humble kettle people use for heating water will serve, for the purposes of this essay, as an example in the life cycle assessment (LCA) of a product. Concerns regarding the environmental impact of products from its manufacturing, use, and up to its disposal (“cradle to grave”), have been given close scrutiny by ecologically conscientious groups.

One strategy that has seen wide use in major businesses concerned with sustainability issues is LCA. Briefly, LCA is a methodology for evaluating the environmental impact involved in the manufacture, distribution, use, and disposal of a product of interest in an organized manner. Its importance was recognized by ISO, and standards regarding its implementation have been set.

In drawing up the phases of the kettle’s life cycle, the processes involved in its manufacture can include the molding of the plastic handle (which can be made from polymers like high-density polyethylene, polystyrene, or some other appropriate polymer), the casting of the metal to be used for the kettle body, cover, and spout (which can be any of steel, cast iron, aluminum, and maybe copper, copper being one of the best heat conducting metals with only its cost relative to the other metals mentioned precluding its use), the addition of other functionalities (a whistle that sounds off when the water in the kettle has started boiling is traditional, but fancier additions such as a thermometer have been seen), and the final assembly of all the kettle’s essential parts.

The manufacturing and/or processing of the materials used in making the kettle (e.g. whether the metal used was recycled or mined) and the transport of these to the manufacturing facility can be given less focus on the analysis and thus be relegated to background status and parameters related to such can be set to appropriate values that may already have been cataloged or given reasonable estimates. Distribution-wise, packaging and transportation are main concerns. With packaging, the production of the usual packaging materials such as cardboard or plastic would be of concern.

How the kettle will be transported (truck or van if distribution will be local; international distribution will add some further complications) will also come into play. For the usage phase of the kettle, the primary concern is in how the consumer will use the kettle. A usual concern is that the kettle is left for too long a time on the stove (or whatever other heating utility is in use), more than sufficient to heat the water to a boil, and thus wasting energy that could have been used more productively. Apart from this, heat loss due to possible imperfections or flaws in the kettle may also have to be taken into account. Read about Product Life Cycle of BMW

If the user of the kettle resides in a region where the water is hard (water containing calcium, magnesium, and other ions that form a nonconductive coating on the inside of the kettle and reduce the kettle’s heating efficiency), this can also be an additional factor. With regards to the disposal of the kettle, the kettle may have already been used for many years before it might be considered for disposal due to wear and tear related damage.

Should the kettle have to undergo disposal, however, it can either be sent to a landfill or have its plastic and metal components recycled for other uses. For any other factors where there is uncertainty, one would do well to do an analysis with both the best and worst possible scenarios for the assurance of having been able to cover the entire spectrum.

Having set up the phases and boundaries of the kettle’s life cycle, the needed data can then be gathered from the appropriate sources. Databases might be available that can be used to obtain cost data for materials and/or labor required in manufacture. In the case of the SimaPro 7 software commonly used for LCA by industries, databases such as the ecoinvent database that facilitate the construction of LCA models.

However, if data required is not available in such databases, one must fall back on traditional methods of data gathering such as the use of questionnaires and surveys. Once the data has been gathered, though, it is a simple task to perform the needed analysis. In this respect, if ballpark estimates can be obtained when data is not readily available, it is wise to utilize the estimates to have a feel for what may be involved.

For the scenario of the kettle, data on cost of material production/procurement and processing (dependent on metal and plastic used), the amount and cost of energy required in casting the metal and molding the plastic parts of the kettle, as well as the cost of processing any waste or emissions produced in the manufacture can be taken into consideration.

In distribution, the cost of local or international shipping and handling are for consideration, as well as the production or procurement of packaging material and handling of any waste produced. This sort of data is most probably easily obtained from statistics gathered by manufacturers and distributors, and can be had through surveying if otherwise.

Slightly more complicated is the analysis of how a consumer might use the kettle. The kettle’s capacity for heating is dependent on the material used to make it. Different methods of heating are in use in different parts of the world. The hardness of water in different areas might also have to be considered in evaluating the heating efficiency of a kettle when in use, for lime scale that accumulates after a kettle has long been used to heat hard water impedes efficient heat transfer.

Since the inefficient usage of heat sources is known to be a contributor to waste and pollution, it will be of utility to take these into account when looking into the environmental impact of the kettle during use. Also, it is usually the case that consumers heat far more water in the kettle than what will be used, and that contributes to wastage as well. With this, one can set a period of time for which the kettle will be used (frequency taken into account) and estimate the amount of energy that will be spent for heating in the whole lifetime of the kettle. Typically, kettles are built durably enough to last years. Data on this can be done by an appropriate statistical sampling method. The cost of recycling or disposal in a landfill completes the accounting for data needed.

As a ballpark estimate, a kilogram of the appropriate metal might be needed to construct the metal parts of the kettle, and about 40 grams for the plastic handles. Depending on the temperatures needed and the heat capacity of the metal to be used, around 10-50 kJ/kg of heat might be needed for processing the metal parts, which may take up to an hour. Much less than that can be used to shape the plastic. A typical production of kettles might net around 1000 kettles made per day.

For usage, depending on the capacity of the kettle and the efficiency of the heating, approximately 5 kJ/kg might be needed and about 30 minutes to heat the water to an agreeable temperature. Any of the other needed quantities can be obtained from databases provided on LCA software such as the ecoinvent database built into SimaPro 7 or be obtained from industrial reports or handbooks.

Possible changes in the life cycle may include the use of recycled metal and plastic as raw material, the use of an efficient and nonpolluting heat source for processing the raw materials used in producing the kettle in the manufacturing portion of the life cycle. With regards to consumer usage, the use of softened water and efficient heat sources are possible changes that can be made. Also, modifications that would prevent the consumer from having to use more heat than necessary to heat the water (a whistle, for instance) would also prove useful.

An LCA analysis is only as good as the data put into it, so the gathering of useful data is an absolute must. Uncertainties in data gathering such as how the data was aggregated or whether the data used is applicable to local conditions can affect the analysis considerably. Rigorous bounding of uncertainties involved is of utility in this aspect. The assignment of values to such things as the cost of environmental impact is subjective, and can be considered a both a flaw and a necessary assumption to simplify the analysis.

Of course, automated analyses should also be subjected to human scrutiny to assess whether the results are applicable in an industry’s scenario. An LCA analysis performed at a certain point in time may be either confirmed or refuted by future LCA analyses, and that too is a confounding factor. LCAs may also hinder the adoption of technological innovations that might be even better solutions than that considered in the analysis.

References

AYRES, R.U. and A.V. KNEESE, 1969. Production, consumption and externalities, American Economic Review, 69, p.282.
BRITISH STANDARDS INSTITUTE, n.d. International Standard for ISO 14041 – Environmental Management – Life Cycle Inventory, BSI, Chiswick
CIAMBRONE, D.F., 1997. Environmental Life Cycle Analysis, CRC Press LLC, Boca Raton, Florida

CURRAN, M. A., 1996. Environmental Life Cycle Assessment, McGraw-Hill, London.

DEPARTMENT OF THE ENVIRONMENT, 1990. Protection and Water Statistics no. 13, HMSO, London.
DEFRA, 2005. Securing the Future: Delivering UK Sustainable Development Strategy [online] Available from <http://www.sustainable-development.gov.uk/publications.htm> Accessed November 2005.
DETR, 2000. Waste Strategy 2000, HMSO, London.
DEPARTMENT OF TRADE AND INDUSTRY, 2001. Digest of United Kingdom Statistics, HMSO, London.
ECOBILAN, 1998. Life Cycle Inventory Analysis and Impact Assessment – ‘Disposal’ Options for Used Newspapers and Magazines, Aylesford Newsprint Limited, Aylesford, Kent
GRAEDEL,T.E., B.R. ALLENBY and P. COMRIE, 1995. Matrix approaches to abridged life cycle assessment, Environmental Science and Technology, 29(3), p.134.
HEIJUNGS, R. et al., 1996. Life Cycle Assessment: What It Is and How to Do It, United Nations Environment Programme, Paris, France.
INTERNATIONAL STANDARDS ASSOCIATION, 1995. Life Cycle Assessment Principles and Guidelines, CD 14040. 3

INTERNATIONAL STANDARDS ORGANISATION, 1997. ISOs 14040/1/2/3, Environmental management – Life Cycle Assessment Series.
NISSEN, U., 1995. A methodology for the development of cleaner products: The ideal eco–product approach, Journal of Cleaner Production, 3(1-2), p.83.

PRÉ CONSULTANTS, 2000. Eco-indicator 99: Manual for Designers, Ministry of Housing, Spatial Planning and the Environment Communications Directorate, The Netherlands [online] <http://www.pre.nl/eco-indicator99/ei99-reports.htm> Accessed November 2005.

RUSSELL, A., EKVALL, T. and BAUMANN H., 2005. Editorial: Life cycle assessment – An introduction and overview, Journal of Cleaner Production, 13(13-14), p.1207.
SOCIETY OF ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, 1991. A Technical Framework for Life-Cycle Impact Assessment; Workshop report, SETAC Foundation for Environmental Education, Washington.
SOCIETY OF ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, 1993. Guidelines for Life-Cycle Impact Assessment: A Code of Practice, SETAC Foundation for Environmental Education, Brussels
SOCIETY OF ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, 1993. A Conceptual Framework for Life-Cycle Impact Assessment; Workshop Report, SETAC Foundation for Environmental Education, Washington.
SIMON, M., 1997. The politics of ecodesign, EcoDesign 5(1), p.12.
SWEATMAN, A. AND SIMON, M., 1996. Design for environment tools and product innovation, In CIRP Seminar on Design for Life-Cycle, ETH Zurich, 1996, Zurich. SWEATMAN, A., SIMON, M., AND BLOMBERG, S., 1997. Integrating design for environment within an environmental management system, In International Conference on Engineering Design (ICED’97), WDK.
UNEP, 2004. LCA Tools [online] ;http://www.uneptie.org/pc/pc/tools/lca.htm; Accessed November 2005.

WELFORD, R. AND STARKEY, R. (eds.), 1996. The Earthscan Reader in Business and the Environment, Earthscan. London.