**1. Introduction**

There is a global challenge to reduce the greenhouse gas (GHG) emission to the environment by 2050. For this reason, the UK has committed to decrease GHG emissions by 80% compared to 1990 levels [1] and to achieve net zero carbon emissions by 2050. Two main trends to reduce emissions are to either reduce the carbon intensity of electricity generation by introducing more renewable or low-carbon generation systems, and the other is to reduce average and peak consumption, usually achieved by enhancing the efficiency of the overall distribution system and by influencing consumption patterns.

Due to this challenge, there has been an accelerated increase of renewable energy installation in the past 10 years, boosted by a variety of factors like governmental incentives, a drastic drop in manufacturing prices, and technological maturity that helps drive the price of projects lower. With all these advantages, the cost of renewable energies can help reduce overall generating cost.

The growth of renewable energy generation needs to be monitored because a high penetration of renewable energy sources into the grid can create instability resulting in issues with the frequency control and response issues. Furthermore, the intermittent nature of renewables like solar and wind directly affects the grid stability. This effect is even more severe on small islanded systems without interconnection to other generation or loads that can absorb the energy generation surplus.

Energy storage helps to balance the grid by reshaping supply and demand patterns by storing the energy and enabling its use at a later time. There are many di fferent types of energy storage methods, such as mechanical (hydroelectric, pumped-storage, compressed air, etc.), thermal (sensible heat, latent heat, etc.), and electrochemical.

The scope of this study is to validate the feasibility of introducing renewable energy penetration to cover the island's current and near future energy needs, comparing a variety of parameters concerning the installation and sizing. The outcomes of the followed methodology are validated by evaluating key control parameters for each individual scenario considered. Those control values are the installation cost, CO2 emissions, levelized cost of energy, and the return of investment [2].

This article is focused on finding the best renewable energy system with the lowest LCOE in comparison to the current energy cost of 66 p/kWh [3]. Based on educated assumptions in addition to data analysis and manipulation, we estimate an optimal integration of wind and solar as primary renewable energies with an energy storage system (if required) to stabilize the grid.

Furthermore, besides a high level of performance, the study compares the financial viability of the generation system to obtain a LCOE lower than the actual cost the energy of 66 p/kWh. This article also relates to the goal of the Sark Island energy commissioner on the price control order aiming to achieve an energy cost reduction to 56 p/kWh for the island.

The scope for this article is limited to


The main advances of this research, related to di fferent studies conducted in this area, were


(7) The sensitivity analysis in this article evaluates more than 40 di fferent scenarios to compare and validate the best energy mix for the island. Moreover, the way that it is implemented enables the coding to be used to calculate the same output for any other new set of data.
