Utility Management: Counting Carbon -- A Utility's Perspective

The UK is legally committed to achieve an 80% carbon emissions reduction by 2050. One water utility leading the way is Anglian Water. Here they share their approach to carbon reduction measures and how it might be used as a blueprint by others moving forward.

By Mark Enzer. and David Riley

When the purse-strings are tight, low carbon infrastructure solutions can seem like a luxury, adding an extra layer of complexity to projects and requiring expensive new products and materials.

Yet to think this way is a mistake. Reduced carbon actually correlates with reduced cost, because carbon emissions act as a proxy for consumption of energy and other resources.

An emphasis on lowering carbon emissions fosters innovation. Engineers, contractors and asset managers are called to exercise creativity and develop fresh solutions, rather than re-treading old roads such as squeezing margins in the supply chain.

These truths were formally recognised in 2013 when HM Treasury, the Department for Business, Innovation & Skills and the Green Construction Board (GCB) published the Infrastructure Carbon Review, authored by management, engineering and development consultancy Mott MacDonald.

The UK's most progressive infrastructure clients and their supply chains have tackled carbon emissions at both a project and a programme level, driving down capital carbon by 39% and operational carbon by 34% compared to ‘business as usual', reducing average capital costs of assets by 22% in the process.

The Infrastructure Carbon Review reported that the efficiency gained by pursuing low carbon solutions across the UK's infrastructure sector would yield a £1.5 billion annual economic benefit by 2050.

The sustainability advantage would also be considerable: Infrastructure accounts for 53% of total current UK carbon emissions, and the emissions directly controlled by the infrastructure industry as opposed to end users are 16% of the total. With the UK legally committed to achieve an 80% carbon emissions reduction by 2050, against the 1990 baseline, that 16% could be a make-or-break issue.

Anglian Water was profiled in the Infrastructure Carbon Review as an industry leader in carbon reduction. The company's approach to carbon reduction provides a replicable blueprint which infrastructure organisations of all types can follow to drive carbon reduction into their DNA in a similar way to ethics and health and safety. Various strategies can be implemented to cut carbon, but setting baselines and targets is one of the most important.

Anglian Water's approach to carbon modelling, by David Riley
In 2010 the utility launched a set of 10 ambitious targets to transform the business into a water company for the 21st century, standing up to climate change and population growth. Two of these targets related directly to carbon: to reduce operational carbon emissions by 10% in real terms by 2015, and a 50% reduction in embodied carbon in new assets we build by 2015 (later revised to 60% by 2020) from a 2010 baseline.

Carbon modelling is a practical tool that allows for real achievement of low carbon infrastructure solutions.

Modelling has been invaluable for informing our carbon reduction plans and tracking our progress. Operational carbon modelling is common, but leading organisations also measure embodied (also known as capital) carbon. This can be more complex, but the additional value gained makes it well worth pursuing.

Our carbon models revealed that only up to 11% of embodied carbon was in a pipe itself, while 89% was associated with the excavation, laying and backfill activities during that pipe's installation.

Carbon modelling is not fundamentally complex – at its simplest a carbon model is simply a model of the quantity of each material used, which is multiplied by its emission factor to calculate a carbon footprint.

The model should include quantities of energy consumed by each activity, such as material extraction, manufacturing, transport, installation, removal and recycling. The model may also include aspects of operational carbon.

Specifying these boundaries before modelling begins is essential to ensure consistency across all data sets within individual projects, and across projects at a programme level. The other critical question to answer at an early stage is how the model will be used to drive business outcomes, in order to ensure the model being built will serve those requirements. Measuring and modelling alone won't reduce carbon; it's what the business does with that data that matters.

Likewise, an individual calculation will have limited value – real advantages come from repeated modelling (optioneering) as the project evolves, and assessment of the differences each time. Models can also be combined on a programme scale to identify carbon ‘hotspots' across the programme.

Anglian Water policy requires that carbon is measured three times on every scheme before site work begins. By making carbon measurement a condition for passing through project gateways, we embed into the design process repeated challenges to the solutions being proposed, driving engineers to find ever greater reductions.

We do this because of the carbon reduction curve, which shows the potential to reduce carbon is inversely proportional with the progression of a project.

The greatest opportunity lies at the investment appraisal and early design stages, because the optimal way to minimise embodied carbon is to minimise new construction. This can be achieved by, for example, duplicating the function of a component or making better use of underused assets – strategies which our engineers consider further when challenged on carbon. Following definition of activity boundaries, selection of materials and products and calculation of quantities, the next step is to obtain data for the emissions factors associated with those choices. This data is often available at no cost.

A carbon model must be a basis for confident business decisions, so it should be as accurate as is reasonably practicable. But the pursuit of perfection can paralyse. It is better to use a less-than-100% accurate model – which can still provide valuable insight and reliable guidance – than to wait years before taking any decisions.

Looking at data out of context can lead to false conclusions. Consider comparisons between different materials or products: the design may require a smaller quantity of one option than the other, so carbon calculations must be adjusted to reflect this.

Design life must also be accounted for. A component with higher embodied carbon may be preferable to one with lower embodied carbon, if the former can be used for significantly longer or will result in lower operational carbon. In addition, waste must be taken into account. Any excess materials ordered for wastage also contribute to a project's carbon footprint, even if they are not used.

Indicative calculations can facilitate more informed decisions at an early stage, as long as the approach to measurement is consistent.

At Anglian Water we developed a Carbon Modeller tool containing over 1300 carbon models with raw carbon data on materials used by our suppliers, typical site activities, construction methods and transport options, for use in-house and by our value chain suppliers. Engineers draw from this tool at the design stage to experiment in search of the best low carbon solution.

Anglian Water's work is far from finished, but with modelling tools in place we will continue to further reduce the carbon associated with our services.

David Riley is the Anglian Water carbon manager and Mark Enzer is the Mott MacDonald group practice manager for water and environment and Green Construction Board Infrastructure Working Group member.