Techno-Economic Optimization Analysis of an Autonomous Photovoltaic Power System for a Shoreline Electrode Station of HVDC Link: Case Study of an Electrode Station on the Small Island of Stachtoroi for the Attica–Crete Interconnection

Panagiota M Deligianni,Panagiotis A Kontaxis,Costas D Tsirekis,Fotis D Kanellos,Vassiliki T Kontargyri,George J Tsekouras

doi:10.3390/en13215550

Panagiota M Deligianni, Panagiotis A Kontaxis + Show 4 more

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https://doi.org/10.3390/en13215550

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Abstract

A lot of autonomous power systems have been designed and operated with different power levels and with special requirements for climatic conditions, availability, operation/maintenance cost, fuel consumption, environmental impacts, etc. In this paper a novel design of an autonomous power system with photovoltaic panels and electrochemical batteries for a shoreline electrode station is analyzed. This station will be constructed on the small island of Stachtoroi for the new high voltage direct current (HVDC) link of Attica–Crete in Greece. The general guidelines of the International Council on Large Electric Systems (CIGRE) and of the International Electrotechnical Committee (IEC) for the power system of lighting and auxiliary loads for these HVDC stations are supplied from the medium voltage or the low voltage distribution network, whereas they do not take into account the criticality of this interconnection, which will practically be the unique power facility of Crete island. The significance of Crete power system interconnection demands an increased reliability level for the power sources, similar to military installations and hospital surgeries. In this research a basic electrical installation design methodology is presented. First, the autonomous photovoltaic power system with the energy storage system (ESS) consisting of electrochemical batteries is preliminary designed according to the relative bibliography. The station power and energy consumption are analytically determined taking into consideration the daily temperature variation annually. Afterwards, a techno-economic optimization process based on a sensitivity analysis is formed modifying the size/power of photovoltaic panels (PVs), the type and the energy capacity of the batteries taking into consideration the operation cycle of PVs—batteries charge and discharge and the battery ageing based on the relationship between battery cycles—the depth of discharge, the daily solar variation per month, the installation cost of PVs and batteries, the respective maintenance cost, etc., while the reliability criteria of expected loss of load power and of load energy are satisfied. Using the proposed methodology the respective results are significantly improved in comparison with the preliminary autonomous power system design or the connection with the distribution power system.

Highlights

During the last three decades many renewable isolated power systems have been installed powering a small electric machine, i.e., air conditioner [1] or a house [2] of a few kilowatts to an autonomous power system for a community [3] or an island [4] of megawatts (MW)
There is a severe lack of meteorological data forcing the authors to use the three hours temperatures for the last 15 years from a near meteorological station in Attica, which were given by H-IPTSO, while the solar radiation are given free of charge as the mean monthly extraterrestrial solar irradiation at the horizontal sea level by [11]
A numerical iterative techno-economic optimization methodology based on a sensitivity analysis is presented for the formation of an autonomous power system with PVs and battery, which is going to supply an isolated shoreline electrode station of the high voltage direct current (HVDC) link

Summary

Introduction

During the last three decades many renewable isolated power systems have been installed powering a small electric machine, i.e., air conditioner [1] or a house [2] of a few kilowatts to an autonomous power system for a community [3] or an island [4] of megawatts (MW). The main research effort focuses on the sizing and efficient operation of the autonomous photovoltaic (PV) system, the principal limitations of high capital investment for PV panels (PVs) and energy storage systems (ESSs) of low reliability and the satisfaction of electrical load requirements [8]. The optimization methods for the sizing of PVs and energy storage items, which can be: â â â â. Additional methods for off-grid hybrid power systems [27,28,29,30] and for energy storage systems [31,32] can be found in the literature

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