Assessing E-Fuel and Electrification Pathways for an Isolated Island Grid with EnergyPLAN: The Case of Tenerife (Canary Islands)

Abstract

Island power systems must decarbonize without the flexibility that an interconnection provides. The Canary Islands have advanced their decarbonization target to 2040, yet Tenerife still generates about 80% of its electricity from oil, and the route to the target remains unresolved. This work addresses a specific technical question: how far can firm synchronous capacity be withdrawn before the ability of the grid to absorb renewable output, rather than the rate of renewable deployment, becomes the binding constraint? Hourly simulations built with the EnergyPLAN energy-balance model, calibrated against the 2023 Tenerife system to within 0.1 percentage points, compare six pathways to 2050: a Business-As-Usual (BAU) baseline, the official Canary Energy Transition Plan (PTECan), and four intermediate scenarios (S01–S04) that retain a synchronous backup plant but convert it to renewable ammonia, while replacing part of the fossil petrol used in road transport with synthetic petrol. Three contributions follow. First, a paired-simulation protocol runs every milestone year twice—once without corrective constraints and once at a technically feasible operating point—so that the renewable energy the system cannot absorb is measured rather than inferred: it reaches 32% of renewable output under BAU by 2050, 42–45% under PTECan and 75–76% in the intermediate scenarios. Second, a sectoral decomposition of emissions exposes a displacement effect: under PTECan, road-transport emissions reach zero by 2040 while total emissions fall only from 4.81 to 4.39 MtCO2, because they migrate to a conventional plant that grows to 7.29 TWh. Third, decarbonizing that plant instead raises renewable penetration above 62% from 2040 and cuts per-vehicle emissions to 0.509 tCO2 (S01). The synthesis of the imported synthetic fuels lies outside the system boundary, so the comparison rests on a tank-to-wheel basis; within that boundary and under the assumptions adopted here, a transport mix that includes synthetic fuels appears technically more feasible for an isolated system than full electrification, provided that renewable expansion is planned jointly with a mechanism to absorb the surplus.