Dr Daniel Friedrich leads EPSRC-funded research to decarbonise thermal energy

Figure 1: Schematic of the proposed integrated system that combines renewable electricity, a district energy system and seasonal thermal energy storage
Figure 1: Schematic of the proposed integrated system that combines renewable electricity, a district energy system and seasonal thermal energy storage
The School’s Dr Daniel Friedrich is to lead a new three-year project to investigate what role Seasonal Thermal Energy Storage (STES) systems could play in decarbonising the heating and cooling systems in our businesses, homes and industries, while continuing to meet our fluctuating energy needs.

Last year, the UK government became the first major economy to set a ‘net zero’ target for greenhouse emissions in the fight against climate change. According to the Committee on Climate Change, meeting this target will require the complete decarbonisation of the building, industry and electricity sectors – including the heating and cooling systems on which they rely.

This new project, 'INTEGRATE: Integrating seasoNal Thermal storagE with multiple enerGy souRces to decArbonise Thermal Energy’ aims to address this challenge, and is funded by the Engineering and Physical Sciences Research Council (EPSRC). It brings together researchers from our School’s Institute for Energy Systems, the University of Edinburgh’s School of Social and Political Science, and the engineering departments of the universities of Glasgow and Strathclyde. 

The challenge

It is estimated that around 44% of the total energy demand in the UK is due to heating at present. This demand fluctuates substantially between seasons, and is about six times higher in winter compared to summer. Heating demand also increases significantly in the morning, at a rate around 10 times faster than the demand for electricity. 

Currently, around 80% of the nation’s heat is supplied through the natural gas grid which provides the flexibility and capacity to handle the large-scale, sudden variations, but also causes large greenhouse gas emissions. 

While cooling demand is currently small in the UK, it is expected to increase significantly: the National Grid estimates that the demand for electricity during the summer peak may increase by 100% due to air conditioning by 2050.

Why might STES systems offer a solution?

STES systems could offer a potential solution to these challenges, if they can be integrated within the ‘district’ heating and cooling systems widely used in commercial and educational campuses and proposed for urban districts. 

In simple terms, a seasonal or long-term thermal energy storage system can be imagined as a huge hot water storage tank which is charged during periods of surplus energy supply and discharged during periods of high energy demand. 

Such a system can store the charged energy over several months and is about 100 times cheaper per unit of energy compared to battery storage, due to the large size of the storage system. One challenge is to integrate these systems with low carbon energy sources and district heating and cooling systems, to transfer the stored energy to consumers.

Integrating seasonal thermal energy storage

The research team will consider the interplay and coordination between energy supply and demand, seasonal thermal storage characteristics, and regulation and market frameworks. The insights gained will be used to develop a holistic and integrated whole system model for the design and operation of “smart” district energy systems with STES.  The new model aims to provide sustainable and affordable thermal energy while also enabling the integration of renewable energy. 

The research will be used to develop case studies and guidelines to help urban planners, policymakers, renewable project developers, and others to develop urban and campus thermal energy systems based around the smart integration of STES systems. 

It will also enable the development and deployment of low carbon heating and cooling systems that provide affordable, flexible and reliable thermal energy for customers, improve use of the National Grid infrastructure and the integration of renewable generation assets alongside other heat sources.

Find out more