Conclusion
Summary of results from case study
Considering all of the demand reduction and supply decarbonisation options accounted for within this project the project aim of reducing carbon emissions by 50% by the year 2030 has been achieved. Figure a demonstrates this. The remaining emissions are due in approximately equal parts to gas and electricity consumption.
From the chart above it is clear that there are 3 key areas that need to be addressed in order to achieve the bulk of carbon reductions:
1. PC upgrades
2. Lighting upgrades
3. Decarbonisation of supply through the use of a CHP engine in a DEN
Electricity contributes over 70% of carbon emissions to the university’s baseline so electricity reduction and decarbonisation will have the most impact in reducing it. Within electricity demand, PCs and lighting together make up almost 50%. Within the university there is scope for improvement leading to reductions of energy consumption in these areas of approximately 60%, leading to total baseline savings of 23% (as seen above).
Similarly, the decarbonisation of supply through using a DEN and a CHP engine is effective in abating carbon due to the high electricity use on campus. By reducing the carbon intensity of the electricity consumed the CHP engine is responsible for the biggest individual reduction in carbon abatement of any of the technologies considered. However, it is important to note that this changes with grid decarbonisation.
Building upgrades, while having a poor contribution to overall carbon savings, are necessary to meet the carbon reduction target. They also lay the foundation for the targets post 2030 as heat reduction and decarbonisation will play a more important role.
In terms of the overall performance of the projects, it is clear that bundling projects increases the viability of the higher cost upgrades, particularly the building upgrades. Where they had low cost savings resulting in a payback of over 40 years considered in isolation, the high cost savings from the DEN balance this out to a payback of just under 11 years when bundled (still an acceptable return on investment, demonstrated in Table a).
General conclusions
Learning from the case study, the key technologies for demand reduction are as follows:
• PC upgrades
• Lighting upgrades
• Improving data centre energy performance
• Building upgrades from fabric to HVAC
Data centres, despite having a reasonably low contribution to overall emissions, are very energy dense so can have attractive carbon and cost saving potential, especially when considered on an energy use per unit area basis.
Key technologies for supply decarbonisation are:
• District energy networks centralising heat production for greater efficiency
• Combined heat and power engine to decarbonise electricity supply
• Heat pumps to decarbonise heat production
In terms of the overall strategy that should be employed when approaching carbon reduction for university campuses there are three key points to consider:
1. A systemic approach: as demonstrated by the dynamic simulation results, energy upgrades interact with each other in complex ways so are far from additive. If savings are to be assessed effectively, they must be considered as part of a broader system. This is also true for the low carbon supply options as by reducing demand the supply magnitude and fluctuations are affected.
2. Bundle projects: as mentioned above, some projects provide very attractive financial savings while others can never pay themselves off within their lifetimes. By bundling the poor performers with the higher savers the levelised costs will make otherwise unviable individual projects cost effective. In terms of upgrading individual, this could be achieved by grouping lighting, IT, fabric and HVAC systems together into a single project allowing reduced labour costs and better overall financial performance. For supply, savings from CHP engines could be used to pay for expensive heat pumps.
3. Take advantage of new builds: this point cannot be overstated. If new buildings are commissioned it is essential that they are built to be as energy efficient as possible. Higher capital costs will pay off in the long term. In order to have a sustainable campus universities must invest in sustainable buildings.
It is also of utmost importance that universities take the long term view when investing in carbon reduction measures on campuses. It is tempting to leave carbon reduction up to grid decarbonisation but this will do nothing for post 2030 targets. Universities have a legal obligation to meet national carbon reduction targets which include an ambitious 80% reduction by 2050 (see policy page). Even if electricity consumption is reduced to zero carbon emissions on campus there will remain a large portion of emissions from gas. It is the recommendation of this group that financially attractive electricity demand and supply decarbonisation measures (such as lighting, IT and CHPs) are used to subsidise less attractive heating decarbonisation measures (such as fabric upgrades and heat electrification through a DEN). This will lay the crucial foundation required to meet the 2050 target.
Further work
This project represents a snapshot of the state of a case study university campus as it is today and the opportunities for carbon reduction that are available. It is an example of how a general approach to carbon reduction can be implemented: first by reducing energy demand then by decarbonising energy supply.
Opportunities for further work include:
• A more in depth analysis building by building as to the energy saving potentials of the technologies mentioned in this project through the use of more detailed simulation. There was insufficient time to consider every building on campus in this level of detail.
• How the general approach would differ when applied to other campuses throughout the UK and beyond e.g. how would the financial performance of fabric upgrades change if cavity wall insulation was an option?
• Changes in campus makeup and requirements. Although briefly considered in further considerations an in depth analysis of likely changes in campus assets, buildings, student population and energy loads would likely be highly beneficial in order to understand the long term implications of carbon reduction investments.