FITS-LCD: Fabric Integrated Thermal Storage for Low-Carbon Dwellings

Lead Research Organisation: University of Strathclyde
Department Name: Energy Systems Research Unit

Abstract

The domestic sector faces a range of challenges as the UK attempts to drastically cut its carbon emissions by 2050. A key issue is reducing the overall demand for heat and then decarbonising residual heat loads - which encompasses both demand for space heating and hot water provision. Two non-exclusive means to achieve these goals are: firstly, the diversification of the heat sources serving buildings and communities towards a variety of low-carbon heat sources including solar thermal energy, biomass, waste heat and ground source energy. Secondly, the electrification of space and hot water heating using heat pumps running on decarbonised electricity. Thermal storage would play a key role in facilitating both of these developments, acting as an integrating mechanism for heterogeneous heat sources and decoupling heat supply and demand to mitigate the worst impacts of the electrification of heat. However, there are challenges, one of the most significant is competition for space - as dwelling sizes reduce, the space penalty associated with conventional hot water storage acts as a barrier to uptake. Storage in the future may need to migrate away from the traditional hot water tank at seen at present, towards media such as phase-change materials and storage that makes better use of the existing space and thermal mass in and around buildings, including large scale community storage. An attractive storage option is to integrate future thermal stores into the fabric of the dwelling - fabric integrated thermal stores (FITS).

The aim of this multi-discipline research is to investigate how thermal stores could be integrated into the fabric of future dwellings and communities (both new build and retrofit) and how they would be operated within the local context of accommodating multiple low-carbon thermal energy sources and within the wider context of the decarbonisation of the UK's energy supply. Specific activities include: establishing the operating criteria for fabric-integrated thermal stores (FITS) operating in a future low-carbon energy system; generating prototype FITS concepts, controllers, energy services and heat sensing solutions; performance evaluation of FITS concepts using modelling and simulation leading to selection of best performers for further investigation; construction of scaled FITS prototypes for testing of in-situ performance; gauging user reaction to the concept of using thermal storage for energy services to third parties including demand management; and finally testing of prototype interfaces to FITS with end-users.

The research will generate new knowledge in a number of areas: the architectural integration of thermal storage materials (eliminating the space penalty associated with water tanks); interfacing of thermal stores with heterogeneous heat sources; and information on the acceptability of the participation of domestic heat storage in energy networks. Tangible outputs will include: a range of FITS concept designs - the performance of which will be evaluated using modelling and simulation; two prototypes of promising concepts will be constructed as demonstrators (to test performance in the field); new thermal storage controllers; and energy services will be developed and tested, predicated on the active participation of thermal storage in energy network management.

The work will benefit the construction industry, particularly Architects and Structural Engineers, offering new ideas on the space-efficient integration of thermal storage into buildings. The work will also benefit the building services community and technology developers, providing information on the combination of multiple low-carbon heat sources and the measurement, management and control of stored heat over different timescales. Finally, the work will be of value to utilities and energy service providers, offering insight into the potential of thermal storage to facilitate network support services.

Planned Impact

Fundamentally, this research aims to develop new concepts for the integration and operation of thermal storage in housing in order to support the uptake low-carbon heat sources and promote interaction with low carbon energy networks through demand side response. At a national level, this activity will benefit UK in its efforts towards energy and carbon reductions, contributing to Government targets and energy policy.

More specifically, the work will benefit a wide range of non-academic stakeholders, notably the following.

Building Designers will benefit through the development new storage, balance of plant and control concepts, along with design guidance. This will lead to changes in the way that architects, engineers design and contractors construct buildings and assist the industry in developing future housing (new build and retrofit) that can play a more active role in future energy systems and make use of a wider range of low-carbon heat sources.

Utilities and Energy Service Providers will benefit in that it will generate information on the potential for demand-side participation from heating systems featuring storage, as well as developing concepts for future demand-side energy services and the financial inducements needed to encourage active participation. This could lead to changes in tariff structures, opportunities in wider network control and renewable energy integration and new business opportunities based around storage related energy services.

Building owners, communities and individual homeowners will benefit from the research as it paves the way for the provision of storage-based energy services to netowrk operators, allowing citizens to benefit financially through direct payment or preferential tariffs. The research will also allow end-users to shape the nature and of storage-based energy services through their feedback. Further, end users would benefit from the reduction in need for storage space in housing if fabric integrated storage was to prove viable.

Technology developers will benefit in that the research will develop and test a range of potential new products including fabric integrated store concepts, balance of plant for charging and discharging of heat , control algorithms for heat management and active network participation. Further, concepts for user interfaces to thermal stores will be developed and trialed, again leading to opportunities for new product and service development.

Policy makers will be able to make use of some of the knowledge emerging from the project in the design of future housing policies and standards. Of specific benefit will be the outcomes of research into the fiscal incentives needed to encourage the uptake and operation of thermal stores in dwellings, along with the work gauging end-user's enthusiasm for hosting thermal storage and participating in active demand schemes.

Publications

10 25 50
 
Description 1) Archetype models for common UK dwellings have been developed for the purposes of calculating heating and hot water loads and assessing building thermal storage requirements. 2) A novel, generic sizing method has been developed for thermal stores in buildings that makes use of modelled energy demand and supply profiles application of the sizing method has indicated that a) low temperature domestic thermal stores (<100oC) sized to hold more than 1 week's heating load become infeasibly large b) high temperature storage (~600oC) significantly reduces store sizes, but storing heat for longer than a few days becomes extremely inefficient with the majority of the stored heat being lost, even with very significant levels of insulation. 3) A taxonomy for building integrated thermal stores has been created along with a materials selection guide, allowing practitioners to match storage material, insulation material and working fluid in the design of general and fabric-integrated thermal stores for buildings. 4) A physical fabric integrated store demonstrator has been installed at the University of Bath HIVE facility.
Exploitation Route The findings associated with the outcomes have all already been published in several journal papers and also on the project website. The generic sizing method has already been deployed as part of the H2020 RUGGEDISED project (http://www.ruggedised.eu) to size battery storage for a photovoltaic - electric vehicle charging system. It is envisaged that the taxonomy for storage materials and selection guide will be used by building design practitioners and also heating product designers in the the development of new thermal storage solutions for buildings.
Sectors Construction,Energy,Manufacturing, including Industrial Biotechology

URL http://fits-lcd.org.uk/
 
Title Archetype models of UK houses for use with the ESP-r building simulation tool. 
Description Four archetype building simulation models for use with the ESP-r building simulation tool, which can be used to calculate space heating demands under a variety of operating contexts. 
Type Of Material Computer model/algorithm 
Year Produced 2016 
Provided To Others? Yes  
Impact Results from models provided to: project partners Glasgow School of Art (Prof. Tim Sharpe) and Imperial College (Dr. Adam Hawkes), leading to development of architectural designs for fabric integrated thermal storage and econometric analysis of thermal storage concepts. 
URL http://fits-lcd.org.uk/file_uploads/Other/160547__FITS_Houses_V4.0.zip
 
Title Algorithm for sizing of thermal storage for delivery of heat varying timescales 
Description The algorithm (written in Python) uses supply and demand profile data as input to size a thermal store according the a user-defined period over which heat should be delivered. In the FITS-LCD project to size domestic thermal storage, however the algorithm is generic and can be used to size any other storage technology. 
Type Of Technology Software 
Year Produced 2017 
Open Source License? Yes  
Impact The algorithm has subsequently been used to size battery storage for the H2020 ruggedised project (http://www.ruggedised.eu), the battery store being part of a photovoltaic/electric vehicle charging installation to be installed at the Duke St Car Park in Glasgow. 
URL https://www.sciencedirect.com/science/article/pii/S1359431117370825
 
Description H2020 Project Work Shop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Workshop for the H2020 Ruggedised Project (http://www.ruggedised.eu) 23-24 October, 2017. Results were presented from battery sizing work for a proposed photovoltaic/electric vehicle charging installation in Glasgow. The work reported used the generic storage sizing algorithm developed as part of the FITS-LCD project and described in the paper Allison et al. "Assessing Domestic Heat Storage Requirements for Energy Flexibility Over Varying Timescales", In Press, Applied Thermal Engineering 2018. Attendees at the event included Siemens UK, Transport Scotland, Scottish Power Energy Networks and Glasgow City Council. Glasgow City Council are using the outcomes from this work in the procurement of the battery for the charging installation.
Year(s) Of Engagement Activity 2017
URL http://www.ruggedised.eu
 
Description Participation in Scoland Heat Summit 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact Dr N Kelly participated in the Scotland Heat Summit, presenting on how modelling could be used to inform policy decisions for the Scottish Government's upcoming heat strategy.
Year(s) Of Engagement Activity 2016
URL http://www.climatexchange.org.uk/files/1214/7584/9984/Nick_Kelly_-_Energy_Efficiency_in_Buildings_-_...
 
Description Project web site 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact This was the launch of the project website. This provides information on the project and makes selected outputs publicly available.
Year(s) Of Engagement Activity 2016
URL http://fits-lcd.org.uk
 
Description RCUK Thermal Energy Challenge Network 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Advisory board member
Year(s) Of Engagement Activity 2016,2017
 
Description University of Strathclyde - Engage with Strathclyde - Dissemination Event 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact The seminar will provided an opportunity to see and hear about the latest Strathclyde R,D&D on responsive demand in buildings. The presentations covered recent and ongoing projects (including FITS-LCD), providing information on the potential and limitations of responsive load, highlighting areas where technology development is urgently required and revealing end-users views on automated management of energy systems.

The event attracted ~40 participants including facilities managers, community energy groups, energy services providers, controls and energy technology developers, energy managers and building owners.
Year(s) Of Engagement Activity 2016
URL https://www.engage.strath.ac.uk/event/333