Flexibility Services to Minimize the Electricity Production from Fossil Fuels. A Case Study in a Mediterranean Small Island

Crainz Crainz,Curto Curto,Longo Longo,Franzitta Franzitta,Musca Musca,Riva Sanseverino Riva Sanseverino,Montana Montana,Telaretti Telaretti

doi:10.3390/en12183492

Abstract

The design of multi-carrier energy systems (MESs) has become increasingly important in the last decades, due to the need to move towards more efficient, flexible, and reliable power systems. In a MES, electricity, heating, cooling, water, and other resources interact at various levels, in order to get optimized operation. The aim of this study is to identify the optimal combination of components, their optimal sizes, and operating schedule allowing minimizing the annual cost for meeting the energy demand of Pantelleria, a Mediterranean island. Starting from the existing energy system (comprising diesel generators, desalination plant, freshwater storage, heat pumps, and domestic hot water storages) the installation of solar resources (photovoltaic and solar thermal) and electrical storage were considered. In this way, the optimal scheduling of storage units injections, water desalination operation, and domestic hot water production was deduced. An energy hub model was implemented using MATLAB to represent the problem. All equations in the model are linear functions, and variables are real or integer. Thus, a mixed integer linear programming algorithm was used for the solution of the optimization problem. Results prove that the method allows a strong reduction of operating costs of diesel generators also in the existing configuration.

Highlights

In the last decades, the electricity system underwent large-scale transformation, and the automation degree of power systems has increased significantly
The aim of this study is to identify the optimal combination of components, aim of this(design study isstage) to identify the optimal of components (synthesis theirThe optimal sizes and their optimalcombination operating schedule stage), that allows their optimalthe sizes and theirthe optimalin that allowsof an minimizing annual cost for meeting energyoperating demandschedule in Pantelleria, and more general, minimizing the annual cost forfrom meeting the energy demand in Pantelleria, and more in of an islanded microgrid
It is assumed that the produces the same amount of freshwater that it would have have produced, but the hourly operation schedule is changed, according to the algorithm output is between 60% and 80% of their rated powers, the optimization identifies, hour-by-hour, the produced, butspecifically, theof hourly operation schedule changed, according to the MILPload algorithm results

Summary

Introduction

The electricity system underwent large-scale transformation, and the automation degree of power systems has increased significantly. The effective integration between generation and load requires a real time balancing of demand and supply, that can be achieved using electricity storage systems (ESSs), able to store the excess of energy in periods of high generation for later use during peak demand periods. In this way, the use of ESSs allows a higher integration of renewable energy sources (RESs) in the power system and a reduction of greenhouse gas emissions. The model includes heat exchangers, cogeneration, heat pumps (HP), demand-side measures and dwelling insulation

Methods

Results

Conclusion