Stephanie Parker, Senior Advisor – Decarbonisation of Complex Sites at Energy Systems Catapult, and Nick Solman, Research Fellow at University of Warwick – Warwick Business School
Universities account for 27% of public sector emissions. The University of Warwick has been leading the way in tackling its emissions with its Reduce, Decarbonise, Smart strategy.
Since the early 2000’s the University of Warwick has been increasing the energy efficiency of its buildings beyond building regulations. In 2019, the University set out its goal to make the campus Net Zero for scope 1 and 2 emissions by 2030. This article shares some of the University’s experiences in rolling out its Net Zero strategy, and highlights what has been identified to be the most cost-effective measures.
Strategy
The University’s buildings were responsible for 95% of scope 1 and 2 emissions in 2019. A strategy of Reduce, Decarbonise, Smart was adopted. Starting with incremental low-regret investments – implementing the measures that have the highest paybacks first. The below sets out more detail under the different pillars.
Reduce
New build standards: From 2005, the University began building to a level of energy efficiency above the building standards. The financial sweet-spot has been to construct buildings to a near-Passivhaus standard. This has seen the energy consumption per square metre of the campus decrease by 45% from 2005 to 2023 at minimal additional capital expenditure.
Retrofit standards: Much of the University’s building stock was constructed between 1970 and 2010 and needs to be retrofitted to achieve Net Zero. Fabric upgrades are undertaken as part of the regular maintenance cycle to minimise costs. Any building that will not be able to meet these standards has been earmarked for demolition.
Net Zero operating procedures: This involves outlining what Net Zero compliant schedules and set points are for each building and ensuring they are not changed. The cost of implementing this paid for itself in a matter of weeks.
Lower flow temperatures: This will increase the efficiency of both the district heating network and heating circuits within the buildings. Some buildings will struggle to meet contracted temperatures (e.g. in student halls) and others will need the heat exchangers to be upgraded. These constraints are delaying the immediate implementation.
Decarbonise
Solar PV: It is cheaper for the University to meet its baseload using solar PV than purchase electricity from the grid. If we produce above baseload and start selling electricity back to the grid, the business case becomes less appealing.
Heat pump solutions: Finding a solution that will be able to meet the University’s peak heat demand will be difficult and expensive. Starting the project early, gathering detailed data on heat consumption and how its profile can be changed will be vital to our success.
Electrical storage: Until ‘Time-of-Use-Tariffs’ are introduced for businesses no commercial reason to install electrical storage has been identified.
Thermal Storage: The University has used thermal storage for several years to help it meet peak heat demand. Work by colleagues at Loughborough University shows this is a cost-effective way to reduce expenditure on new heating solutions. As heating is electrified, it will help to shift demand away from peak periods when grid electricity to be more expensive.
Smart
Energy management systems: The University needs to move to a system where each building has its own Building Energy Management System (BEMS) that runs on non-proprietary software. These can be linked to a Campus Energy Management System (CEMS) that makes 117 buildings cooperate to minimise peak demand. This will allow the University to reduce capital expenditure on both the heating system and the electricity grid.
Monitoring and control: Research found that a sample of buildings are running 1-2oC hotter than the BEMSs think they are. This is because the thermostats do not provide a representative sample. By increasing the number of thermostats, 15% could be cut from the energy bill of each building.
On-demand heating: For small rooms in occasional use, on-demand heating can deliver large savings. In several seminar rooms, electric radiators with push-button activation were installed. They originally kept the rooms at 21oC. They were set to 16oC, increasing to 21oC when the boost function was activated. This reduced energy consumption in these rooms by 75% and halved peak consumption.
Recoverable heat: Colleagues at London South Bank University showed that if heat that is being wasted near to a heat network, it can be highly cost-effective to recover this, rather than pay to heat rooms and cool equipment simultaneously. Electrical transformers, industrial equipment and server rooms can be very cheap heat sources.
By starting with incremental low-regret investments it is possible to reduce total and peak demand. This lowers energy expenditure now and reduces capital expenditure on new infrastructure.
In future, the ability to load-shift to times when grid electricity is cheaper, and lower carbon will allow further savings to be made. Some technologies – such as solar PV – are cheaper than the legacy solution and should be adopted where possible. We have found that the push for Net Zero can be not just greener and cheaper but also make our buildings more enjoyable places to be.
For more information about how to decarbonise universities and other public sector buildings, please check out the Public Sector Decarbonisation Guidance.
This article appeared in the Jan/Feb 2025 issue of Energy Manager magazine. Subscribe here.