How sustainable are our products?

To achieve a climate-neutral circular economy, we need to know how we generate emissions that harm the climate and where they come from. The key measurement parameter is the product carbon footprint (PCF), which expresses the total greenhouse gas emissions generated by a product. But how do we measure it?

Consider the lifespan of a popular electronic product: a residual-current circuit breaker, millions of which are installed in electrical equipment and are found in nearly every home to protect us from serious electrical accidents. A small circuit breaker weighs about 200 grams. It’s made from a variety of plastics and different iron and copper alloys along with some precious metal. The circuit breaker is expected to last for 20 years of continuous operation with a power loss of approximately 0.4 watts. When it’s disposed of, some of its components may be recycled, or perhaps the entire device ends up in a landfill.

In each phase of its life – from extracting and transporting the raw materials to its production, operation, and recycling or disposal – the circuit breaker usually generates climate-relevant emissions, which together make up the product carbon footprint (PCF). The smaller the PCF, the more climate-friendly the product. On the path toward a climate-neutral circular economy, a product’s PCF becomes an important statistic for suppliers and customers in all industries.

A lifecycle assessment that considers the entire product lifecycle

To obtain reliable PCF values, it’s important to look at the details. “We conduct lifecycle assessments (LCAs) on our products, which systematically determine the environmental footprint: that is, the total impact on the environment,” says Frank Walachowicz, an expert with the? Siemens Sustainability Engineering team in Berlin. “The assessment evaluates the PCF as well as other influences relevant to the environment, including eco-toxicity and water consumption. We begin with a bill of materials that contains all of the product’s individual parts, their materials, and how they’re processed. In the LCA, we look at the product’s entire lifecycle, production, operation, recycling or disposal, and purchased parts and raw materials. So if a product contains copper parts, we also take into account the fact that the copper had to first be extracted, treated, processed, and transported.”

Assessment in product classes

“Such a detailed analysis is, of course, time-consuming. To avoid having to evaluate every single type of electrical product separately – every switch, fuse, and electric motor – we divide the entire product portfolio into suitable classes, if possible. Residual-current circuit breakers is one class: They’re designed for different power levels, but they all have the same basic construction,” says Walachowicz. “Based on the pilot tests for circuit-breaker product assessments, we know that a detailed evaluation of about 20 reference products is sufficient for a portfolio containing approximately 200 different variants. We can use mathematical approximations to accurately calculate the PCF for the other products. This is much faster, and we can still provide our customers with reliable product data.”

The dilemma to get reliable supply chain data

When it comes to the PCF of highly complex products like the control system for an entire factory, it gets more complicated. These products usually contain many different components purchased from a variety of external suppliers. They also contribute their own PCF that directly impacts the climate footprint of the products, often adding up to a considerable sum. In the case of the?SIMATIC?– the Siemens product portfolio for industrial factory automation – for instance, the supply chain accounts for about 90 percent of the of the cradle-to-gate PCF.?

In this case, the LCA is pushed to its limits: the more complex the purchased components, the more difficult it is to estimate their PCF in an assessment. When it comes to a supplied product like a motor, it’s is not possible to determine, for example, where its raw materials originated or the sustainability of the producing factory’s operations. In a case like this, we can only perform a rough and imprecise estimate, or else we need to rely on the manufacturer’s PCF data.

ESTAINIUM and SiGREEN

However, obtaining reliable information from manufacturers is a challenge, because it’s economically beneficial for companies to provide the smallest possible PCF for their products. At the same time, it’s important that they don’t reveal sensitive information about the processes they use to verify their data.

To resolve this conflict of interest and allow customers to rely on the PCF information provided by their suppliers, Siemens initiated a global network of industrial companies –?ESTAINIUM,?whose goal is to exchange reliable PCF data along the supply chain. The Trustworthy Supply Chain Exchange ensures that the PCF data is trustworthy and verifiable, and at the same time it protects the confidentiality of the supplier’s supply chain.?

With?SiGREEN, Siemens’ Web-based application, the company offers a tool on its Siemens Xcelerator business platform? that’s based on the Trustworthy Supply Chain Exchange. The suppliers transmit CO2 values at the customer’s request, i.e., only whatever is truly important, and sensitive data remains protected. Customers can still rely on the data, because every CO2 figure can be verified by independent certification companies. This allows customers to objectively evaluate the climate footprint of their supply chains, compare suppliers, and thereby improve the PCF of their own products.

Author: Aenne Barnard. This article was initially published on Siemens Stories.