Jonathan Whale

Solid Gravity Energy Storage (SGES) Systems are an innovative way to store energy by using the force of gravity. These systems can use the excess energy from solar photovoltaic power systems to lift large blocks of concrete usually around mid-day and later as the sun sets and power demand is high, the blocks are released and generate gravitational energy which is converted to electricity. Colliecrete is a low-carbon, waste-derived, geopolymer concrete developed in 2021, from the Collie power plants' flyash, by the Mudlark geopolymer lab at Murdoch University and geopolymer precursors can come from a number of waste-derived materials. Colliecrete can be used in the blocks for SGES. In Australia, most coal power plants will shut by 2030, while in Indonesia, the expectation is to achieve carbon-neutrality by 2060. There are many methods and pathways to achieve this goal with low-carbon geopolymer concrete one of them. Geopolymer precursor material is abundant with flyash available from 200 coalfired power stations and slag from dozens of steel mills and nickel smelters. Rice husk is disposed of in millions of tonnes by farmers across the archipelago by burning and this ash can be converted to the geopolymer activator. All these make the possibility of an enormous new geopolymer concrete industry to at least partially replace the high-carbon, Portland cement industry. Geopolymer concrete blocks in the SGES system provide long-duration energy storage, assist firming the renewables and reduce carbon emissions while creating a new industry for the energy transition.

Access to affordable electricity supply is crucial to help achieve the seventeen Sustainable Development Goals by 2030. However, there are several unelectrified rural areas in developing countries. These locations are primarily distant from the central grid and best suited for decentralized mini-grids. However, these systems are capital-intensive and require meticulous planning to ensure their sustainability. The situation is exacerbated when they are deployed using intermittent renewable energy resources. Using the Political, Economic, Social, Technical (PESTLE) framework, the authors analyzed the key factors that can drive the sustainable implementation of such systems in developing countries using Ghana as a case study. The results indicated that economic and technical drivers played a significant role in adopting the technology, while social-cultural drivers were the least impactful. The authors made recommendations that can inform policy and decision-makers on the areas that need improvement when planning and implementing future mini-grids in Ghana.