Pumped Thermal Energy Storage for Sector-Coupling in Multi-Energy Systems

The shift towards a carbon-neutral future is driving the integration of Renewable Energy Sources (RES) into electricity grids, but their intermittent nature poses some challenges. Modern energy systems must address not just electricity but also heating, cooling, and industrial demands, forming Multi-Energy Systems. Sector coupling, which links electricity, thermal, and transport sectors, enhances flexibility is then crucial to optimizes RES integration. A key enabler of this transition is the Multi-energy Storage (MEST) concept, traditionally formed by technologies like electrochemical batteries, heat pumps, and thermal storage to decouple energy production from consumption. However, MEST can also be realized by using Pumped Thermal Energy Storage (PTES), which stands out for its ability to store electricity as heat and later convert it back to electricity or use it directly for heating/cooling. This dissertation explores PTES as a multi-energy storage solution in urban MES, focusing on its cost-effectiveness, flexibility, and competitiveness with benchmark MEST technologies. PTES performance is evaluated by comparing different PTES systems with market-ready technologies, by simulating the optimal management and computing associated costs and carbon emissions. The thesis findings highlight PTES's potential to enhance MES flexibility and reduce investments costs.