Techno-Economic and Life Cycle Assessment of Modular Community Energy Systems for Renewable Energy Valleys

Abstract

The transition to climate-neutral, resilient, and decentralized energy systems is particularly challenging for regions with strong seasonal demand, high renewable potential, and limited grid flexibility. Islands such as Crete exemplify these challenges. This work provides an integrated framework for evaluating both system performance and replication potential of four Modular Renewable Energy Systems (MRES) for Renewable Energy Valleys in Crete under common Renewable Energy Penetration (REP) targets of 90%, 95%, and 99.9%. The framework incorporates output-based levelized cost indicators (LCOE), Net Levelized Electricity Cost (NLEC), Effective Community Electricity Cost (ECEC), capital expenditure (CAPEX), profitability index (PI), payback time (POT), and life-cycle environmental assessment (LCA) relative to the corresponding business-as-usual (BAU) systems. Output-based LCOE ranged from 0.059 to 0.112 €/kWh, NLEC from 0.017 to 0.074 €/kWh, and ECEC from 0.082 to 1.090 €/kWh, highlighting the influence of surplus-electricity revenues on net system economics. The attributional LCA showed substantial global-warming reductions for most configurations, reaching approximately 86% for MRES 3, although trade-offs emerged in mineral resource scarcity and water consumption. Results highlight that replication potential depends on matching each archetype to local resources, demand profiles, infrastructure constraints, and end-use priorities, while 90–95% REP provides a more balanced compromise than 99.9% REP.