Westminster City Council King Street Low Carbon Trial - Client Report

CONCLUSION

In conclusion this scheme has demonstrated that significant carbon savings can be made by changing the working method, although at this stage the costs are substantially higher than traditional methods. The operational daily carbon saving of 79% exceeded expectation and the embodied carbon saving of 46% was pleasing for only a simple change in the specification. The additional benefits of clean air, less noise, and legacy of additional EV charging and cycle stands makes it a model that should be expanded and rolled out on more schemes across all contracts. This was the first scheme to record carbon figures and set a benchmark by which to measure carbon reducing methods. It is hoped that this can precipitate change in the industry culture and make carbon saving a focus. By using the carbon calculator designers can offer fully costed, genuine low carbon alternatives compared against standard scheme designs. The scheme’s operational carbon outputs are as efficient as they can be at the current time, however larger public realm schemes are unlikely to perform as well due to the lack of larger equipment on the market. They can only be further improved once the technology also improves to power everything with renewable energy. The outputs are low enough to consider carbon offsetting to make them completely carbon neutral, but at this stage it is important to be transparent and physically reduce the carbon outputs to as low as possible before considering this. With good engagement with committed suppliers this should be ready in time to meet Westminster’s 2030 carbon neutral target. HVO fuel is only an interim solution but there are already 3.5t electric delivery lorries on the market with electric grab lorries in the prototype stage. By working closely with Westminster to show that the demand is there, suppliers will need to start developing electric or hydrogen-based equipment for larger excavators and other plant to start rolling this model out to public realm schemes. The more difficult challenge will be further large reductions in the embodied carbon. At nearly 23t it was the largest area of carbon savings, but it was still less than half than the Marlborough Hill embodied carbon. There are still barriers to short term success in cutting carbon. These fall under five main categories but they are all interlinked:

• Cost

• Demand

• Supply

• Design

• Power

Due to all the unknown factors at the onset of the scheme it was difficult to estimate what the final cost was going to be, and with the extraordinary cost attached, the final bill was far higher than anticipated. If these costs cannot be controlled in future schemes it will result in either a lot less schemes taking place, and therefore a deteriorating network, or the trials will be deferred until there is more cost certainty. However, when the costs are broken down, it is unlikely that the additional costs will be incurred in the future. This means that there should only be a 20% premium to deliver the model, which guarantees that a good programme of works can still be delivered, and will give the teams a chance to improve the working method and start to bring those costs down.

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