HOT|COOL NO. 4/2017 "Technical Innovation and Optimization"


AFFORDABILITY Given the lack of available data to perform a robust financial analysis, the study looked to use the quantitative data available alongside qualitative evidence from SHP employees and residents to assess affordability of the schemes. In addition to this some modelling was carried out using Standard Assessment Procedure (SAP) software to estimate fuel costs for the case study schemes. Five out of eight of the case studies involved in the research were able to provide actual fuel bill data, but in some cases, this was only available for a small number of dwellings. From this data, it was apparent that residents were on average paying a lot less than the costs calculated through SAP which is possibly a result of under-heating or the limitations of SAP. Results of the survey showed that 16 out of 24 SHPs felt that their schemes were either ‘effective’ or ‘very effective’ at meeting their aim of providing affordable warmth to residents. However, 11 out of 38 SHPs, less than a third, had carried out an evaluation with the residents. So what do the residents really think? Amongst the case study schemes most residents felt that their heating was affordable. The only schemes where this was not the case was where a standing charge had been introduced and/ or where the heat being provided was not felt to be sufficient. Despite being unable to switch energy supplier, residents were generally comfortable having their landlord as their provider, with some stating that they do not want the task of shopping around and trusted their landlord to get a good price. However, most of the residents were not aware of what district heating was prior to an explanation in the focus group, meaning that a lack of awareness and/or understanding could be a factor in this. SUSTAINABILITY Modelled SAP results from the case studies indicate that DCCH can provide a significant reduction in CO2 emissions particularly when compared to incumbent electric heating systems. However, SAP has the potential to significantly overstate these reductions by assuming much lower distribution heat losses than those typically achieved in practice. In reality, the sustainability of the DCCH system is at risk of being compromised by issues during the design and development phase. In particular, overheating caused by poor design, commissioning and operation of schemes, has both a direct and indirect negative impact on sustainability. Energy is wasted through more heat being produced than is required and is exacerbated further by residents in some schemes using electric cooling systems to maintain a comfortable temperature. Unsurprisingly, SAP modelling shows that DCCH schemes are more likely to reduce carbon emissions where they include low carbon technology, e.g. gas combined heat and power. As existing communal and community schemes are connected to form district schemes the opportunity to include low carbon heat sources grows as they can be supported by other heat sources.


Monitoring and analysis A significant finding is that SHP owned schemes in the UK are not currently undertaking sufficient data collection and analysis. Without the option to review this data, it is impossible to definitively say whether or not schemes are delivering affordable and/or sustainable heat, and if anything can be done to improve them. In light of this, it is recommended that SHPs set up detailed monitoring systems that include collecting heat metering data from the heat generator, building and/or dwelling level meters to robustly assess system performance in real time. To support SHPs in the delivery of this, the UK Government should look to develop standard and robust methods of monitoring and reporting on heat production and consumption. Design and development In a number of cases, a lack of internal knowledge and experience in designing and developing a scheme proved a barrier or affected the operational efficiency of a scheme. This ultimately influences its affordability and sustainability. SHPs should look to embed best practice in the design, delivery, construction and operational phases through ensuring: • Design engineers have appropriate professional accreditations and experience for this type of work • Existing best practice guidance and standards are used, such as the CIBSE/ADE Heat Networks Code of Practice • A single main contractor is employed for design and build • The principal contractor has a technical lead on site, and a Clerk of Works or Quantity Surveyor is employed to oversee the installation and put in place a quality management system • Realistic operational and maintenance costs are factored in at the feasibility stage • The needs of the tenants are considered before, during and after installation

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