LUSTER - London Urban Sub-Terrain Energy Recovery

London Urban Sub-Terrain Energy Recovery - LUSTER - proposes a collaborative research project to identify and quantify the potential for inclusive heat energy recovery from urban subterranean structures (e.g. sewers, railway tunnels), using London as a case study.

The UK is committed to a reduction in greenhouse gas emissions of 80% by 2050. Our vision, through LUSTER, is to scope the feasibility of technically and economically viable systems for recovering heat from subterranean sources, so as to enable this 2050 target to be met in a resource efficient manner. Subterranean infrastructure systems, such as sewers, electricity and data cable tunnels, water mains, railway tunnels etc., are potent and untapped energy sources. They are normally in close proximity to areas of high heat demand and could potentially provide a year-round heat supply. The majority of these structures can be found in big cities, such as in London, but are also prevalent in most urban areas in the UK and elsewhere.

The project will be carried out by two teams with complementary expertise in energy research, heat transfer and systems simulation. The lead team will be based at London South Bank University (LSBU), with University College London (UCL) as the principal research partner. A key outcome of the investigation will be a map which will identify urban subterranean structures and applications with the greatest energy recovery potential. A successful feasibility study will yield many opportunities for urban subterranean energy recovery, not only across the capital, but also in other cities and urban areas with underground infrastructure systems.

LUSTER will investigate the heat energy recovery potential from different types of urban sub-terrain structures in London. The outcomes of this feasibility study will also be applicable in other cities and urban areas with underground infrastructure systems. Success will bring wide societal and environmental benefits as follows:

- Government, policy makers and regulators who are seeking economically and technically viable solutions to the long term challenges of heating and cooling faced by society; this research would make a major contribution towards meeting CO2 reduction targets. Decentralised energy is a UK Government and a Mayoral Priority in London and the use of waste heat will have a big impact on reducing the environmental impact of buildings. In urban settings, there is substantial waste heat available from subterranean infrastructures to meet heat demand and this heat could be utilised in the large number of district heating schemes proposed. It has been shown that 71 TWh/yr of heat could be recovered from secondary sources in London leading to 48% carbon saving. There is significant interest in the use of waste heat, if feasible. For example, Islington Council in London alone have identified 13 potential locations for energy centres for using waste heat from Underground Railway tunnels which, if implemented, would save 30,000 tCO2/yr.

- The outcomes of LUSTER will provide rules of thumb guidance for engineers working on the field of energy distribution. For example, the geo-spatial heat maps developed by LUSTER could be utilised when district heating networks are designed. The knowledge gained from LUSTER will allow prospective engineers and technicians to be better qualified to tackle CO2 emissions and to receive the necessary training for the job market, where the demand for their skills is considerable.

- The outcomes of LUSTER will deliver reduced energy costs for building operators and owners and contribute to meeting their emission targets, and in particular planning regulations in the use of renewable energy technologies. Furthermore, the heat recovered will be eligible for the Renewable Heat Incentive (RHI). Also, recovering heat from subterranean infrastructure will potentially reduce the building services plant space required and noise associated with heat rejection to the external environment.

- LUSTER will benefit UK energy, refrigeration air conditioning heat pump (RACHP) and manufacturing industry. New business opportunities will arise from the development and implementation of the technology solutions devised through this project. LUSTER will drive the development of bespoke design and manufacturing capability of UK manufacturing companies, through the better understanding of existing processes and the use of advanced design and manufacturing methods, leading to a wide range of opportunities.

- Other researchers in academia, industry and government, both in the UK and abroad, will gain from the breakthroughs we make through our multi-disciplinary approach to sustainable energy systems. This includes researchers both in the immediately related areas of heating and cooling, but also those engaged in the wider energy research field.

- LUSTER will result in additional benefits for companies and organisations with waste heat. For instance, London Underground will result in additional free cooling which is now required throughout the year due to line upgrades. Cable tunnel operators will benefit from lower cable temperatures and no requirement for mechanical cooling and dehumidification. Thames Water will result in lower fluctuations in mains water temperatures, which will result in a significant reduction in water leakage through expansion and contraction of water pipe couplings.