The embedded energy equation

The middle of the production story won’t change; we need chairs, tables and washing machines. But what about the beginning, what about the end? Can those bits of the lifecycle be made more efficient? Polly Theedom finds out about the carbon benefits of reuse and intelligent design

Polly Theedom | 12 May 2010

Every product’s life, be it a sofa or a kettle, comes to fruition with manufacturing. This is the most energy intensive stage of the lifecycle. The sourcing and transportation of materials, factory manufacture and preparation of the product for purchase are just some of the stages in the process, and all use energy.

Let’s take the example of a tub chair (a single-seater sofa – picture a bath tub split in two, with four legs). The British Furniture Manufacturers’ trade association (BFM) estimates that a tub chair starts its useful life with a material carbon footprint of 70 kilogrammes (kg) of CO2 equivalent (CO2e). This initial push of energy is then embedded in the product for the rest of its life. If the chair then goes to landfill, the initial 70kg of CO2e it took to create the product is lost; if a similar chair is manufactured as a replacement, a further 70kg of CO2e is used. By avoiding landfill and reusing the chair the embedded energy would be saved and further production avoided, entailing total CO2 savings of 140kg. Currently, however, the benefits of reuse are seen only in terms of CO2 savings from landfill avoidance and the benefits from preventing production of new furniture or electronic and electrical equipment (EEE) are overlooked.

Acting Chief Executive of the Furniture Reuse Network (FRN), Craig Anderson, says: “The current calculations as they stand are very much about the end of pipe and the impact of the treatment operations for reusers. What they don’t look at is the embedded CO2 within those products.” Indeed, current calculations show carbon savings (based on landfill avoidance) of just 2.7 tonnes per tonne of furniture reused, and 7.6 tonnes per tonne of EEE reused. These are the figures after the carbon expenditure from the reuse facility and transportation have been deducted and do not include the carbon saving benefits from negating production.

Were such calculations included in the equation, the actual savings would be much greater. According to a CRR report on the reuse and remanufacture of refrigerated display cabinets (RDC), for example: “When an RDC is manufactured such that its energy efficiency matches that of the latest designs, the remanufactured RDC saves 2,100 kg of carbon dioxide emissions (CO2e) compared to the manufacture of a new RDC. This is equivalent to the emissions generated from an average car that has been driven for 8,700 miles.” These savings are in addition to CO2 reductions from landfill avoidance.

The report ‘Zero emissions from office, contract and kitchen furniture’, published by the BFM, indicates a rising interest in the environmental cost of production. BFM, which provides information on environmental management to UK furniture manufacturers, states: “Historically, the UK has largely had an ‘open system’ with regard to furniture, where virgin materials are required at the front end of the process and the end-of-life product is sent to landfill.”

This historical trend is in the process of changing, however, and the FRN and the Centre for Remanufacturing and Reuse (CRR) are just two of the organisations working to close the loop for bulky waste. They help other groups take products that may have otherwise been sent to landfill and refurbish them or use the materials in other products.

The Waste Electrical and Electronic Equipment (WEEE) Directive states that priority should be given to the reuse of WEEE and its components, and if we take this statement seriously, we can indeed benefit the environment greatly. At present, FRN members divert 90,000 tonnes of waste from landfill every year, significantly reducing demand for new furniture and electronics. Despite their efforts, 400,000 tonnes of furniture still wind up in the tip.

Anderson comments: “Reuse has always been, let’s say, the poor cousin of recycling, as we can’t hit the tonnage avoidance from landfill that recycling can. But then if you look at the value of keeping those products out of landfill, there’s a much greater value to keeping a tonne of sofas out of landfill compared to a tonne of steel cans.”

There is a further complication when thinking about reuse and WEEE because of additional environmental concern: some of the chemicals and toxic heavy metals used in WEEE are potentially dangerous and can leach into the ground and drinking water. Mercury, for example, often used in flat screen displays, is an easily spread element that is very toxic to plants, animals and humans.

Another concern with the amount of chemicals and different metals present in WEEE is the energy use associated with sourcing the materials and getting them ready for manufacture, which is greater than that used in furniture production. For example, a wooden table made from only one source material uses an estimated 19kg of CO2 in production, whilst a generic washing machine uses an estimated 677kg of CO2. Of course, these are only rough estimates; these figures can differ greatly with the change of different variables, like distances materials travelled and fuel used to create the electricity necessary for manufacture.

Although reuse is nearly always preferable, reduction of the carbon footprint of a product at the manufacturing stage is still important (we are always going to need things after all). The University of Brighton has published a report describing the carbon savings available from conscientious design. The investigation, ‘Cleaner by Design’, conducted by Dr Jeff Readman, describes the importance of designing for ‘longevity and durability’. This objective refers to the versatility, aesthetic appeal and hardiness of a product, attributes that will make it desirable for longer and increase the chance of reuse.

Dr Alistair Bromhead, who has been working with both CRR and BFM, is confident large savings in emissions can be achieved through intelligent design. He says: “We are working on an 80 per cent reduction in CO2 emissions over the whole lifecycle of furniture.”

Indeed, the aforementioned ‘Zero emissions’ report by BFM demonstrates potential benefits to be gained from redesigning a tub chair with carbon in mind. It states: “The LCA with disposal consideration is 46kg CO2e in the original and 8kg of CO2e in the redesign.” This reduction is achieved by reducing the weight of the chair (from 51.6kg to 25.3kg), using fewer highly manufactured materials like plastic in favour of carbon neutral wood, and decreasing the number of different materials used.

When it comes to embedded carbon, most figures come from the business sectors rather than independent observers, though, and more research is needed to understand the true value of reuse. Anderson explains: “Information [about embedded CO2] can only come around from analysis of the full lifecycle of products and that means the involvement of manufacturers.” This is something manufacturers have reservations about, as “it’s not commercially an advantage to put forward figures concerning embedded carbon”.

It has been estimated by the Furniture Industry Research Association, however, that it takes five tonnes of carbon to get a tonne of office desks onto the market, and 15 tonnes of carbon to get a tonne of office chairs onto the market. Anderson comments: “If this is the case, we are completely undervaluing reuse.” To find out if this is indeed the case, WRAP has recently launched an investigation into how to truly value the benefits of reuse. When these missing bits of the equation are filled in, reuse just might get the recognition it deserves.

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