According to the United Nations Environment Programme (UNEP), the carbon cost of building is rising.
The UNEP Global Alliance for Buildings and Construction (GlobalABC) global status report highlighted two concerning trends: firstly that, ‘CO2 emissions from the building sector are the highest ever recorded…’ and secondly, ‘new GlobalABC tracker finds sector is losing momentum toward decarbonisation.’
Embodied carbon costs are mainly incurred at the construction stage of any building project. However, these costs can go further than simply the carbon price of materials including concrete and steel, and their use. And while it is true that not all buildings are the same in embodied carbon terms, in almost all cases these emissions created at the beginning of the building lifecycle simply cannot be reduced over time.
Since this is often and, in some cases, especially true in data centres, it is incumbent to consider the best ways for the sector to identify, consider and evaluate the real embodied carbon cost of infrastructure-dense and energy-intensive buildings.
Technical environments and energy intensive buildings such as data centres differ greatly from other forms of commercial real estate, such as offices, warehouses and retail developments. Focusing on the data centre, let’s take for example a new build 50MW facility; it is clear that in order to meet its design objective it’s going to require a great deal more power and cooling infrastructure plant and equipment to function in comparison with other forms of buildings.
Embodied carbon in data centres
Embodied carbon in a data centre comprises all those emissions not attributed to operations as well as the use of energy and water in its day to day running. It’s a long list which includes emissions associated with resource extraction, manufacturing, and transportation, as well as those created during the installation of materials and components used to construct the built environment.
Embodied carbon also includes the lifecycle emissions from ongoing use of all of the above, from maintenance, repair and replacements to end-of-life activities such as deconstruction and demolition, transportation, waste processing and disposal. These lifecycle emissions must be considered when accounting for the total carbon cost.
The complexity of mission critical facilities makes it more important than ever to have a comprehensive process to consider and address all sources of embodied carbon emissions early in design and equipment procurement. Only by early and detailed assessment can operators inform best actions which can contribute to immediate embodied carbon reductions.
Calculating Whole Life Carbon
Boundaries to measure the embodied carbon and emissions of a building at different points in the construction and operating lifecycle are Cradle to Gate; Cradle to Site; Cradle to Use and Cradle to Grave carbon calculations, where ‘Cradle’ is referenced as the earth or ground from which raw materials are extracted.
For data centres, these higher levels of infrastructure are equipment-related, additional, and important considerations because in embodied carbon terms they will be categorised under Scope 3 of the GHG Protocol Standards – also referred to as Value-Chain emissions.
Much of the Scope 3 emissions will be produced by upstream activities that include and cover materials for construction. However, especially important for data centres is that they also include the carbon cost for ongoing maintenance and replacement of the facility plant and equipment.
That brings us to whole of life calculations which will combine embodied and operational carbon.
Combining embodied and operational emissions to analyse the entire lifecycle of a building throughout its useful life and beyond is the Whole Life Carbon approach. It ensures that the embodied carbon (CO2e emissions) together with embodied carbon of materials, components and construction activities are calculated and available to allow comparisons between different design and construction approaches.
Data centre sustainability is more than simply operational efficiency
The great efforts to improve efficiency and reduce energy use – as measured through improvements in PUE – have slowed operational carbon emissions even as demand and the scale of facilities has surged. But reducing operational energy of the facility is measured over time and such reductions are not accounted for until five, 10, 30 years into the future.
However, embodied carbon is mostly spent up-front as the building is constructed; there is, therefore a compelling reason to include embodied carbon within all analyses and data centre design decisions. A ‘Whole Life’ carbon approach that considers the Embodied and the Operational emissions, provides the opportunity to contribute positively to global goals to reduce emissions of greenhouse gases – and will save financial costs.
