Low Temperature Heat Recovery and Distribution Network Technologies

LoT-NET investigates how waste heat streams from industrial or other sources feeding into low temperature heat networks can combine with renewable energy, thermal storage and optimal heat pump technologies to meet the heating and cooling needs of buildings and industrial processes

LoT-NET will support the development of low cost, low loss, flexible heat distribution networks that integrate intermittent renewable energy supplies, waste heat outputs, low-carbon heat emitters, multi-scale thermal storage and smart thermal energy transformers to provide affordable, secure and sustainable energy to consumers and businesses, whilst ensuring compatibility with future electricity networks. LoT-NET will work with several industrial partners in order to investigate how these technologies can be integrated into smart thermal energy systems that can provide both heating and cooling with maximum efficiency.
Heating and cooling produces more than one third of the UK's Greenhouse Gas (GHG) emissions, and represent approximately 50% of overall energy demand. The UK Government's Department of Business, Energy and Industrial Strategy (BEIS) has concluded that heat networks could supply up to 20% of building heat demand by 2050. Traditionally, heat networks have supplied high temperature hot water to serve buildings and processes, however, more recently 4th and 5th generation networks are seeking to use much lower temperatures to increasing the range of waste heat sources that can be utilised and reducing heat losses. These potential waste heat sources, for example data centres and wastewater i.e. sewage systems, are typically low temperature (e.g. 30-40 °C for data centres, and 18-22 °C for wastewater) and making full use of them often requires the application of appropriate technologies. For example, low temperature heat sources generally require upgrading e.g. using heat pumps, to generate temperatures which are suitable for domestic use.

Also, since electricity input is needed for the heat pump, optimal utilisation of these heat resources can be achieved by the integration of heat and electricity networks. This can be facilitated by the use of thermal storage, as it can reduce peak loads on the electricity grid as well as enhance the efficiency of the distribution network. In addition, waste heat source availability often varies with time,so smart controls may be needed for efficient use of these energy systems. LoT-NET aims to investigate how the integration of these technologies into smart thermal networks will shape the future of heating and cooling, both in the UK and internationally.

Project Outline
During the LoT-NET project, an integrated approach will be adopted to identify minimum Greenhouse Gas (GHG) emissions solutions. The investigators' experience from i-STUTE project has shown the benefits of interdisciplinary research for evaluating the performance of integrated, dynamic multi-vector energy systems. The planned interdisciplinary research will need to combine a range of factors contributing to the performance of energy systems, such as:
  • Advances in technology, e.g. the use of high efficiency heat pumps for boosting the temperature of low grade waste heat, together with the use of novel storage technologies for both intermittent heat and electricity
  • Simulation and demonstration of market situations at a range of scales e.g. from individual dwelling to district
  • Insight into end-user behaviours with respect to heat utilisation and new technology adoption
  • Evaluation of the effects of market incentives and barriers influencing new technology take-up, and evidence-driven proposals for innovation in regulatory frameworks and market structures, e.g. trading options, DSO and aggregator business models, consumer protection for heat

It is notable that to date, smart thermal networks are less well understood than smart power networks, although significantly more energy is used in our homes and businesses as heat rather than electricity. Our programme will address these issues through a focus on how waste heat (and cold) can be recovered and used, for example by incorporating these low carbon energy resources in smart, thermal and electrical energy systems.

Research Challenges
  • Research challenge 1: To develop a spatial and temporal dynamic simulation tool that can be used to simulate a smart thermal network interacting with storage and thermal transformation technologies.
  • Research challenge 2: To advance performance of novel thermal storage, distribution and capture systems. 
  • Research challenge 3: To advance performance of energy transformation technologies, e.g. sorption and vapour compression heat pumps/chillers, ORC, thermal transformers and waste heat recovery.
  • Research challenge 4: To determine key end use and business requirements for timely adoption, i.e. engage with stakeholders, understand their priorities and investigate the potential for low temperature distribution networks.
  • Research challenge 5: To synthesise the results of Research Challenges 1 to 4 in oder to demonstrate and validate the potential of integrated technologies that best satisfy the needs of low GHG emissions, business needs and consumer acceptability.

Page contact: Angeles Rivero Pacho

LoT-NET is funded by EPSRC/UKRI under grant agreement EP/R045496/1
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