MSc Thesis Title: Electric energy storage assessment in Crete

Wednesday 17 April 2019, at:12:00, Venue: Hall K2.A3

Examination Committee

• Professor Theocharis Tsoutsos (advisor)
• Professor Ioannis Yentekakis
• Assistant Professor Paraskevi Panagiotopoulou

Abstract:

Crete is the largest isolated electrical system in Greece. The island is powered by steam units, diesel units, gas turbines and one combined Cycle, which burn fuel oil and diesel oil, contributing to high-cost energy production. At the same time, the wind and solar potential in Crete are among the largest in Europe. With a view to low cost energy production and environmental protection, integrating variable renewable energy in the energy system could help to this direction. The integration of variable energy requires flexibility, which energy storage can provide with a high-degree of energy self-sufficiency, while enhancing the national security of energy supply.

The objective of this thesis is to identify the best-fit energy storage technologies in Crete, until 2032, in terms of their ability to satisfy the energy system needs at the best financial return. Therefore, 2 decision-support models, Energy Storage Computational tool (ESCT) and ES Select tool, support the assessment of appropriate for Crete storage options. More specifically, many different storage technologies serving different sets of storage applications are evaluated and ranked at different grid locations (residential, commercial, transmission, distribution and generation).

ESCT identifies 18 applications and their benefits, categorized as Economic, Reliability, or Environmental. The ESCT helps the user analyse the costs and benefits to determine the storage system’s overall value (payback). The user can use the ESCT to analyse costs and benefits of storage deployments under different scenarios and assumptions. The monetary value of the benefits calculated by the ESCT could be attributed to ratepayers/utilities, non-utility merchants, end-users, society, or a combination of these parties, depending on the nature of the deployment and the applications pursued.

Regarding ES Select, the assessment which ranks the technologies is derived on 2 criteria: a total feasibility score and probability of having a payback. The total feasibility score is calculated by aggregating relative feasibility scores of 4 sub-criteria, as maturity or readiness for commercial deployment, appropriateness for the selected grid location, meeting application requirements, and installed cost on the specific grid location. The probability of having a payback and the total feasibility score are estimated through Monte Carlo Simulation, which is a computational algorithm integrated in the ES-Select™ model handling uncertainties of input parameters, including operational characteristics as deliverable power, energy efficiency, discharge duration and lifecycle, and business factors as costs, possible storage applications and financial benefits . Values for application-specific benefits and market potentials are estimated based on recommendations developed by Sandia National Laboratories in the US.

Initially, given the fact that ESCT combines up to 3 applications, 2 different sets of 3 applications are evaluated from both tools concluding that there is no beneficial energy storage technology for the island of Crete. Afterward, cases with sets of 6 applications are ranked at 4 different grid locations using the ES Select tool resulting that the best-fit technologies are NaNiCl for technology options over 1 MW and NaS for technology options up to 1 MW.