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Funder: UKRI-EPSRC
Duration: 01 September 2018 to 31 August 2023
Staff Involved: Prof N Hewitt, Dr M Huang

Lot-NET considers how waste heat streams from industrial or other sources feeding into low temperature heat networks can combine with optimal heat pump and thermal storage technologies to meet the heating and cooling needs of UK buildings and industrial processes. Heating and cooling produces more than one third of the UK's CO2 emissions and represent about 50% of overall energy demand. BEIS have concluded that heat networks could supply up to 20% of building heat demand by 2050. Heat networks have previously used high temperature hot water to serve buildings and processes but now 4th generation networks seek to use much lower temperatures to make more sources available and reduce losses. Lot-NET will go further by integrating low temperature (LT) networks with heat pump technologies and thermal storage to maximise waste and ambient heat utilisation. There are several advantages of using LT heat networks combined with heat pumps: - They can reuse heat currently wasted from a wide variety of sources in urban environments, e.g. data centres, sewage, substation transformers, low grade industrial reject heat. - Small heat pumps at point of use can upgrade temperature for radiators with minimal electricity use and deleterious effect on the electricity grid. - Industrial high temperature waste can be 'multiplied' by thermal heat pumps increasing the energy into the LT network. - By operating the heat network at lower temperatures, system losses are reduced. Heat source availability is often time dependant. Lot-NET will overcome the challenges of time variation and how to apply smart control and implementation strategies. Thermal storage will be incorporated to reduce the peak loads on electricity networks. The wider use of LT heat networks will require appropriate regulation to support both businesses and customers and Lot-NET will both need to inform and be aware of such regulatory changes. The barrier of initial financial investment is supported by BEIS HNIP but the commercial aspects are still crucial to implementation. Thus, the aim of LoT-NET is to prove a cost-effective near-zero emissions solution for heating and cooling that realises the huge potential of waste heat and renewable energies by utilising a combination of a low-cost low-loss flexible heat distribution network together with novel input, output and storage technologies. Ulster will develop vapour compression booster heat pump technologies