Non-domestic buildings - heating systems: research report

6. Conclusions

In order to investigate the impacts of installing ZDEH we have interviewed stakeholders from 20 non-domestic buildings in Scotland which have installed ZDEH and created case studies. The case studies cover the processes of choosing, installing and operating ZDEH systems, and represent a range of planning classes, newbuild and retrofit, as well as a wide range of technologies, organisations and locations.

Given that this researched focussed on finding examples of ZDEH in buildings, none of the case studies experienced insurmountable barriers to adopting ZDEH. Therefore, the findings inherently miss some of the known barriers that can stop ZDEH from being installed. Additionally, it is not possible to confirm that the 20 case studies within this report form a representative sample of Scotland’s non-domestic buildings. Therefore, the findings outlined throughout this report are specific to this research.

Learnings from identifying case studies

Through the process of identifying potential case studies, we identified over 140 examples of buildings with heat pumps, direct electric heating systems, biomass boilers, and connections to heat networks at a broad range of scales across Scotland. The EPC register, although limited in value to this project, demonstrates that there are thousands more such ZDEH installations throughout the country, on top of the VRF systems that have been commonplace for decades. This indicates that ZDEH installations and compliance with the incoming New Build Heat Standard are both already realised at scale in Scotland.

Through the case studies, there was a conscious aim to represent a range of locations (including rural and urban settlements, on and off the gas network), building tenures, as well as types and sizes of organisations. Over 50 organisations were approached to request case studies. however, many stakeholders were not willing or able to participate within the required timeframes. Additionally, two stakeholders declined to participate due to ongoing maintenance concerns with their GSHP systems, after suppliers in both cases went into administration. Similarly, a restaurant owner who had recently moved into a building with an ASHP had very limited understanding of the system and did not feel able to contribute to the research. Conversely, public organisations and universities were particularly forthcoming in showcasing their buildings. This was expected given that many such organisations have declared climate emergencies and are enthusiastic to be seen as leading the way towards net zero. Seeking case studies from private organisations, such as hotels, businesses and shops was particularly challenging. Secondary research was utilised more for these planning classes, which may have led to a disproportionally high number of buildings which received grant funding being profiled. Although the EPC register was used to identify a shop and a hotel, both had received grant funding. Although conclusions cannot be drawn from this, it is likely that the availability of incentives and grants have been a stimulus and/or enabler for the uptake of ZDEH, due to the cost differential compared to the counterfactual options.

An issue raised during longlisting that was not evident from the case studies was around regulatory compliance. Penalties associated with overestimating emissions during compliance modelling was cited by a city planning officer as a reason that several recent newbuilds were deterred from specifying heat pumps and opted for gas with solar PV instead. However, following the introduction of the NBHS, this will no longer be a barrier to ZDEH uptake.

Experiences of adopting zero direct emissions heating

When planning and installing ZDEH systems, various barriers are experienced, in the form of techno-economic and external constraints (i.e., policy, regulatory and supply chain). Additionally, soft factors such as owner and end-user concerns, and project timing can also make ZDEH deployment challenging. Among the case studies, capital costs, physical site constraints, timing and end-user impacts were most frequently encountered as barriers. It was also found that different technologies, buildings, tenure arrangements, organisations and locations experienced barriers to different degrees. For example, public organisations benefited from inhouse expertise and rural locations experienced more challenges associated with supply chains.

Given the inherent biases of the buildings profiled, in that all successfully installed ZDEH, it was also evident that a similar set of factors posed as drivers for ZDEH. Almost all case studies cited grant funding and/or additional incentives as important drivers to enable their preferred technologies. National, local and internal policy, specifically regarding the climate crisis were other prevalent drivers, along with desires for positive end-user impacts. This highlights that although ZDEH may currently cost a premium to install and operate (as per Appendix D), awareness of the climate crisis has driven the uptake of ZDEH ahead of this being mandated, albeit with external financial support.

Despite the lack of evidence of grid connections affecting ZDEH development from the case studies selected in this project, we would, based on our extensive project development experience, caution against drawing a conclusion that electric heating systems do not impact grid connections. It is evident from industry forums, associations, and contacts that DNOs are concerned and actively working on the impact of electrifying heat on the grid.

Impacts of installing zero direct emissions heating

Through the case study interviews, the impacts of various aspects of operation were explored, including snagging, control and maintenance as well as non-technical factors including running costs and the impacts to end-users. Snagging was a common issue, experienced by half of the case studies, although only four experienced unexpected maintenance requirements. Ongoing dissatisfaction with heat control was noted only for the two case studies with direct electric heating systems. Although most case studies did not report issues or dissatisfaction with running costs, the fact that electrically driven heat demand is not metered in all case studies is likely to have fed into this outcome. This also resulted in a lack of real data being made available to evidence the running costs of these systems.

Impacts to end-users were noted by less than half of case studies, but these were split evenly between positive and negative outcomes. In terms of end-user impacts, is evident from the case studies that considerations and experience of heat within a building are often combined with the end-users’ experience of other building services, and their positive or negative associations with one may affect their experience of all. In addition, users, aside from building and/or energy managers, do not tend to think about heating systems unless they are faulty.

The low volume of maintenance and unresolved end-user issues, although drawn from only a small number of buildings, does bode well for the future rollout of ZDEH systems, provided that these are designed, installed and handed over effectively.