King’s Cross - A Net Zero Carbon Future?
Exploring the urban planning & sustainability credentials of Kings Cross, London.
A dynamic social space.
Once a derelict part of London, King’s Cross Central now is a vibrant and artistic part of the city, comfortably hosting a wide spectrum of professionals you’d expect from modern society; artists and fashion designers of Central St. Martins Arts school, the best minds in Artificial Intelligence in Google’s DeepMind, to the central hub of Shi‘a Ismaili Muslims in the Aga Khan Centre.
This diversity is why I find this area of King’s Cross really interesting and this has come about through well thought out design, coupled with with demanding planning policies set by the London Boroughs of Camden and Islington.
It’s natural then, for me at least, to see the objectives Sustainable Development entrenched in the development; ranging from community consultation, cycle networks and ample cycle parking, urban greening, sensitively refurbishing historic buildings and a community heating network seeking to deliver low carbon heat to much of the development.
Via the naked eye, the redevelopment of King’s Cross seems to have met its objectives, however it’s only by closer inspection of the engineering design, can you glean a flaw within it’s overarching environmental sustainability plan.
The Gasholders - First constructed in the 1850’s to store natural gas to supply London, now eye wateringly expensive (but very nice) residential apartments.
The Granary Building designed by Lewis Cubitt and completed in 1852. Usage rights courtesy of National Railway Museum/SSPL.
An alleyway in St Pancras Square, looking onto St Pancras Station and adjacent to the King’s Cross Brompton Bicycle Dock.
District Heating and CHP.
I know what you are thinking; “this article started with some gorgeous images and now I’m looking at a black and white annotated diagram of an engine thing”.
I’ll keep it brief so please bear with me, it’s pretty crucial to the story.
Most of the King’s Cross development is connected to a district heating network, which is fundamentally a lot of underground pipes connecting all buildings to a single heat generator (like a gas boiler). A key part of this heat delivery strategy incorporates a Combined Heat and Power Engine (CHP), which is just a large car engine running on natural gas, spinning an electricity generator rather than wheels and captures waste heat from this process to feed the heating network.
Sounds great right? We are generating electricity from natural gas which is considered a lower carbon fuel compared to coal AND we are capturing waste heat so we don’t need to run the gas boiler as long.
Unfortunately, this process is horribly inefficient and with the recent surge in renewable energy projects coming online in the UK, it now means that on average, electricity sourced from a CHP engine results in more carbon emissions than the electricity generated by the national grid.
Diagram of a CHP engine taken from the CIBSE TM12.
UK Grid Decarbonisation.
The carbon intensity of the electricity delivered by the UK’s National grid has reduced significantly between 2010 and 2020, mostly driven by shutting down coal power stations and boosting solar and wind renewable energy projects.
Both the UK Government and the National Grid are projecting that by 2030, on average; 0.1 kilograms (kg) of carbon dioxide will be emitted per kilowatt-hour (kWh) of energy consumed.This is approximatley half of the carbon intensity of natural gas (0.2 kgCO2/kWh) and therefore over the coming years, developments which are fuelled by natural gas for heating and hot water will likely be higher in carbon than developments which use grid electricity.
This means that once the King's Cross development is fully complete (~2026) it could be operating with higher carbon emissions than a development which uses electric resistance heating and hot water.
For more information on the projects which have facilitated grid decarbonisation, please see this fantastic interactive article published on carbonbrief.org.
The Net Zero Carbon Future.
We now understand that despite the superb implementation of social sustainability, King’s Cross may be higher in carbon than one which has been designed to account for decarbonisation of the national grid.
Hope is not lost however.
The central ‘Energy Centre’ which houses the CHP and the gas boilers could likely accommodate heat generating plant which is powered by electricity (and therefore taking advantage of a low carbon grid). A heat pump system (a heat engine utilising the Carnot Cycle) could also be installed to lower the carbon intensity of the heat generated.
It will be interesting how the carbon story pans out for Kings Cross; Argent - the landlords for much of the commercial areas - are cognisant of the challenges of CHP and are looking for solutions to manage their carbon emissions, however, I feel that so much financial investment has gone into the CHP solution that it may be 5-10 years before a the neat network truly delivers low carbon heat.
King Cross
1 Granary Square,
England, N1C 4AB
United Kingdom