Gravitational Energy Potential and Multi-Criteria Assessment of Marine Gravitation Energy Sites in Cabo Verde

Abstract

In this study, the Marine Gravitational Energy Storage (MGES) potential was evaluated, and the concept of multi-criteria decision analysis was adopted to classify Cabo Verde’s waters into zones of suitability and quantify the storable energy for two cases of MGES installation. We started by first analyzing the energy state of Cabo Verde with a special attention on wind energy. We combined a variety of datasets including remote sensing, in-situ, model outputs, demography data providers, and research publications. This study highlighted that wind energy consumption is declining over the years while CO2 emission and fossil fuels consumption are increasing due to energy curtailment, intermittency, and grid inefficiency, and consequently resulting in high and unstable electricity prices, energy waste, and negative impacts on the economy. Cabo Verde possesses an enormous renewable capacity for other marine and land-based renewables but many of them are characterized by temporal intermittency. Several locations in the western, central, and southern Cabo Verde are sites that are optimally suitable for the offshore system with a high storage capacity of 6 to 12 kWh per ton of mass. Similarly, most of the islands have portions of their surrounding waters optimally suitable for the onshore-connected system ranging from 3 to 7 kWh and can reach 8 kWh around the South Island chain. Many of the highly populous islands with installed wind turbines also correspond to islands possessing the greatest potential for MGES. Thus, stacking up several masses strategically could meet the current capacity of energy consumption in Cabo Verde, and investment in storage technologies like MGES will improve renewable penetration, reduce CO2 emission and reliance on fossil fuels, improve grid stability, and achieve the goal of Cabo Verdean government of becoming a nation with 100% renewable.