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Greenhouse gas emissions, of course, are integral to this. Most of us have heard of scope 1, 2 and 3 emissions, but not everyone fully understands "scope 4" emissions. This unofficial term is used to describe the avoided emissions as the result of good design of the products and services a company produces, rather than its own operational emissions.
EPC companies can generate significant positive environmental impacts through embedding sustainable choices into their entire end-to-end process, from engineering design, to procurement, to construction.
But where to begin to make this a reality? Here are the key questions we all need to be asking to kickstart our project sustainability strategies.
Can I reduce the amount of material in the design?
As a rule of thumb, reducing the amount of construction material used in the design process reduces its carbon footprint. This can also enhance the efficiency of the overall build process. Engineers should, therefore, always consider alternative construction methods to design out material. Using helical piles, for example, rather than concrete foundations, significantly reduces the amount of concrete required for a build.
Components can also be designed out to reduce the embodied carbon. Designing a single step process that takes voltage from a very high to a very low level rather than a more standard two-step process, for example, requires less equipment and enhances value-add. For example, in Birmingham many substations jump straight from 132kV to 11kV, without the intermediate 33kV step.
Spare space on project sites can also be used to develop custom solutions to sustainability problems. When designing a new substation for the HS2 enabling works, Burns & McDonnell included an on-site rainwater harvesting system, avoiding the need for a water supply line to the remote and rural location near Long Itchington. Saving resources in this way can make a project more sustainable, and more cost efficient too!
Could I use a more sustainable material choice?
Engineers should make it a priority to understand ways of using materials with lower environmental impacts or that contain recycled content, within the applicable design standards. Concrete, for example, is a material with a relatively high emissions impact, but there are plenty of low carbon options available today using non-cementitious alternatives. The use of recycled steel is also an effective option and becoming ever-more popular.
In addition, be prepared to challenge clients to think about the impact of the materials they accept. This can only be done successfully through forging strong client partnerships underpinned by consistent and honest engagement. Sustainability is high priority for almost all clients and they will welcome challenges of this kind. Working with clients in this way helps generate innovations for the whole industry.
Don't know what materials have a high or low impact? Check out this database of embodied carbon footprints.
Can I reduce emissions from transport?
We've all got an awful lot better at working remotely during the past year, and consequently have reduced emissions generated by transport. As we return to the "new normal" we need to continue to adapt to enhance and sustain the benefits of this trend on our projects.
Travel to job sites can be reduced effectively and efficiently through the use of technology such as digital site scans that can mean fewer site visits overall, as well as fewer required personnel on any given visit.
Procuring materials and services through local suppliers can additionally minimise transport distances. Clients are, in fact, asking this of their suppliers more and more as standard. Not only is this type of mindset good for sustainability, it’s good for the local economy and community relationships.
Can I make better use of the spaces in and around the project site?
Reducing the spatial footprint of the substation can enable environmental gain, by making extra space available for biodiversity and natural capital schemes. The space surrounding the substation sites can be re-purposed as biodiverse habitats that help reduce the overall net emissions of the site and repopulate the wildlife population. Creating habitats surrounding the substation such as bat boxes, natural animal shelters and bee embankments can be done relatively simply, and provide the opportunity to work with local conservation groups such as the Wildlife Trust for a consistent local approach.
Appropriate landscaping and planting can enhance the overall habitat and value for the local wildlife and human populations. Remember, however, to choose flora and fauna which are consistent with the local area.
Can I make a design choice which would reduce the amount of waste at end-of-life?
Engineers should be asking themselves how and where they can employ circular economy principles, to reduce the consumption of finite resources. Think "cradle to cradle" rather than "cradle to grave". This means choosing components which can be reused or refurbished at end of life, in collaboration with the manufacturers. Making your design modular can also produce value and efficiency in this regard, helping ensure that if there is a faulty component it is the only one that needs to be replaced.
There are a number of innovative levers we as engineers can pull to increase the sustainability of our projects and supply chains. Aside from keeping our own houses in order when it comes to ESG factors, clients expect high environmental standards on the projects we deliver for them and are rightly asking us to deploy sustainable principles right across the board. Embedding sustainability into our work is therefore crucial to the success of our businesses, our sector and our economy. But it’s also the right thing to do, and our industry has to play a central part in in meeting net zero emissions by 2050. Infrastructure is not just a collection of physical assets set across the landscape. It is an ever-changing legacy that continues to evolve with us, and it must be treated as such.
Polly Osborne is an electrical engineer specialising in whole energy system consulting and sustainability at Burns & McDonnell
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Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.