Carbon and energy

To help achieve Imperial’s net-zero target by 2040 for Scopes 1 and 2, Arup, a London-based engineering consultancy, have been helping us in identifying the necessary investments to achieve this goal. Their study focuses on attaining net zero for power and heating emissions in more than 130 buildings across all campuses including the hospital sites, White City North, South Kensington and Silwood Park. The programme has been modelled within three five-year financial cycles to allow the programme to evolve and include new technology over time.

The challenge lies in the age and diversity of the central London campus buildings, which currently have limited incoming electrical power to run low carbon heat solutions. Despite these constraints, progress has been made by installing LED lighting and automatic control upgrades for heating, ventilation, and air conditioning systems.

The study shows just how complex our journey is towards net zero. Highlighting the challenge are our energy-intensive laboratories and the difficulties in relocating occupants during necessary renovations. Unlike typical net zero projects in the property sector, which usually prioritise fabric improvements, Imperial’s journey takes on specific constraints. Many of our historic buildings hold listed status, limiting the ease of retrofitting, and the dense nature of our site presents further challenges.

However, where challenges arise, so too do innovative solutions. Our investigations suggest that a hybrid approach may be the quickest route to achieving net zero – combining air source heat pumps for baseload heating with gas boilers as backup during colder periods and peak demand. This solution will bridge the gap until we are able to configure a fully heat-pump solution within our constraints.

Removing the steam network at South Kensington to reduce energy use

Current works:

• Installation of three new Cochran 10-megawatt water boilers with integrated heat recovery units (from the CHP engine exhaust) replacing end-of-life steam boilers.
• Tunnels and heat network: larger, higher capacity heated water network pipes are being installed to improve efficiency.
• Plant rooms: new systems to provide services from the district heat network to replace steam heat interface units.
• Buildings: modifying units to receive heated water instead of steam (such as air handling units).

Results in:

• Increase efficiency to 87%, from 79%, through extracting more waste heat from CHP engines.
• Significant reduction in NOx emissions, associated with poor air quality and respiratory conditions.
• Savings over 2,400 tonnes of CO₂ per annum.

Next phase:

• Installation of all the pipework, heat exchangers and heating coils.
• In early 2024, the temporary boilers will be removed.

Long-term ambition:

• All South Kensington Campus to be on a low temperature, hot water system running at 80℃ in preparation for further heat decarbonisation.

With the cost of technology reducing, we are investigating where solar power can help achieve our net zero ambitions through a whole-site solar study.  

Up until now, our South Kensington Campus focus has been on the use of combined heat and power which generates 80–90% of the electrical power needs alongside its heat output. We have also been investing in methods that give greater fuel or carbon reductions than solar, as it has been estimated that solar could potentially meet only 0.6% of our campus needs.  

Unfortunately, many of our roofs are not suitable locations for solar, because of roof designs, construction, and access requirements to other plant equipment housed on them. At our Silwood Park campus there is greater potential for solar solutions, and we are developing options for this site. The site has large number of suitable roofs and there is the potential to generate up to 11.3% of the site’s needs from solar.

Reduce total Scope 1 and 2 carbon emissions from energy consumption by 15% by 2025–26 (against the baseline year 2018–19).

Currently on target as a result of the ongoing works to remove steam from the South Kensington Campus, energy efficiency works including LED installation and solar PV at Silwood. Read our full carbon footprint in the accompanying annex.